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I see a lack of CNC engine lathes? Is there a reason?

Discussion in 'CNC Lathes' started by Pyrex, Nov 7, 2018.

  1. Pyrex

    Pyrex New
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    Feel free to correct me on this, as my experience lies primarily with cartesian CNC routers. I recently upgraded my CNC and have a bunch of leftover NEMA 23 steppers, and I was trying to find a project to start on. I was curious if it is even possible to create a 3"x22" lathe (or somewhere around those dimensions) for use as a gunsmithing tool. It would primarily be used for threading and reprofiling barrels. I honestly do not know where to start on something like this, as I have very limited CNC lathe experience. I browsed some of the projects, and most of them appeared to either be wood lathes, or soft metal applications like aluminum. Any insight would be great where to start, just so I can see a basic layout of a lathe capable of mild/stainless steel work. My main questions are what kind of spindle motor would be necessary, and the general costs involved. Lastly, is the best approach to just retrofit an existing lathe or can you design one from the ground up affordable.. Thanks!
     
  2. Rick 2.0

    Rick 2.0 OpenBuilds Team
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    What your seeking is a bit more hardcore than what goes on around here. I would suggest checking CNCZone. Aluminum framed systems are pretty much limited to cutting soft materials and as the common thread of this forum is aluminum framed systems, you're probably not going to find much to work with.
     
  3. Pyrex

    Pyrex New
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    Thanks Rick, that's great info. I did not know the nuances of the different forums.
     
  4. Rob Taylor

    Rob Taylor Master
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    I think I'm one of maybe only 2-3 people around here who are particularly interested in and/or work with "real" machines, it's definitely an aluminum-extrusion-heavy environment (as you'd expect, since that's what they sell- the store came first, back in the day). But Mark was super helpful to me back in mid-2013 around the V-Slot Kickstarter which ended up kicking me fully into making/machining and my journey of learning machine-building, so this is basically where I've made my home! I occasionally have ideas for extrusion machines too, as a lightweight, rigid material it's great.

    CNCZone is a great repository of information, though I think it's a slightly less friendly environment overall than here, but maybe that's just my perception. That, Practical Machinist and IndustryArena are where I get the majority of my information from, but I like bringing it back here because there's so much that can be learned and applied to hobbyist machines.

    I'm getting ready to convert my mini mill here- Grizzly G0758 Benchtop Mill Conversion - and I'm seriously thinking about doing the lathe as well once that's finished. I have a good idea of what I'd need to do in order to convert it, and it's a lot, which is what's giving me pause, but the result would be fantastic.

    So basically you want a machine that'll cut steel. So you need a big, heavy, rigid machine made from either cast iron, bolted hot-rolled steel, or mineral epoxy (or some combination thereof). If it's really just for simple reprofiling, maybe some fluting, and threading each end, you don't really have a ton of requirements, but it'll still get expensive fast, so I hope you have a way to monetise it (or a really huge rifle barrel collection...). There are two main options to start off with:

    1) Buy an off-the-shelf manual lathe. Probably a Grizzly, maybe a Precision Matthews. For 22" of useable space, make sure it's at least 30-36" long, because you need to factor in the chuck, tailstock, and width of the carriage. Might be worth trying to play with one locally to get a feel for the travel if this is a really hard limit. "Just buy one" is going to be fairly expensive- probably in the region of $3-4000 for a new one- and for CNC conversion, you probably need a new one- but you won't need to do very much precision work on it; the spindle, ways and cross slide are all set up for you. That's a pretty big deal. A 36" lathe is gonna take up a big chunk of floor space and might need a dedicated concrete pad for some machines, perhaps even a new power line run. Real machines aren't just more expensive for the unit itself, but everything that goes with it.

    2) Build something perfectly suited to your needs. I'd consider building it all on top of a granite surface plate with linear rails if you need real precision- and I imagine the threads have to be pretty concentric on a gun barrel.You couldn't get away with an 18x24" plate for 22" of travel, and going above that gets super expensive- not to mention, all that wasted width, because they're all a similar aspect ratio and straight-edges have the wrong sides flat. But it's doable. Alternatively, a steel bolt-up chassis with epoxy (or surface-ground steel, if you have a grinding company nearby) for precision surfaces and setting mating planes. This would require the most experience, but probably be the cheapest, especially if you have a local steel supplier. You're also gonna need to run linear rails for either option, which are super not-cheap, though you can almost always get away with one or two sizes down from what most people do, they have crazy load ratings. Basically, this option requires you to go in with a fair bit of fundamental knowledge pre-baked, because there's a TON to learn about how and why machines are built as they are. Done right, you should still be able to dial in tenths and actually run at faster speeds because you're on rails, not ways. It also has the possibility of running substantially over the budget of the off-the-shelf unit, though you have the possibility of buying parts a bit at a time.

    The screws will be ballscrews, there's just no question there. Much cheaper than they used to be though, so probably not that big a deal. At this point I'd put ballscrews on literally any machine, they're so inexpensive.

    If you buy a lathe (and I'd strongly recommend it if you don't already have at least a couple years' experience doing traditional "proper" machining, because it's a whole different world), then you can either a) replace the compound slide with a solid block toolholder, and then run a QCTP or some kind of built-in toolholding, b) figure out a way to do gang tooling, but this probably isn't the ideal solution on this type of work (better for short, small parts), or c) make some kind of turret, like the real CNC turning centers have. Obviously A will get you running the fastest and require the least time, knowledge and effort. You would also be able to turn and drill the cube to pretty high tolerances right on the machine itself in a 4-jaw.

    Then you're 1) ripping out the leadscrews and replacing them with a pair of ballscrews (don't need a separate threading screw or power cross-slide transmission), 2) adding an encoder to the spindle so that you have positional feedback for threading, and 3) dumping all the extraneous gearbox bits, pulleys, etc. The actual machine conversion isn't super difficult, it's the workholding and potential automation that makes lathes so tricky.

    Basically for 22" of travel, I'd make sure to budget around $5000. This lathe is under three grand and looks like a solid potential base for conversion: 12" x 36" Gear-Head, Cam Lock Spindle, Gap Bed Lathe | Grizzly Industrial - with a 12" swing, you could easily even throw linear rails screwed right into the ground ways on there and keep your 3" of swing with high travel speeds, if production speed was ever a concern. 1.5" thru-bore is pretty nice too.

    Add in tooling, electronics, screws, coolant and oil systems, whatever else, you're probably looking at $4500. A fairly reasonable price for the capabilities.

    Alternatively, start looking up particle packing in epoxy, torsional and flexural rigidity of steels in various sections, heat treatment and aging, tool pressure, spindle grinding, bearing preload, vibratory damping, etc etc etc... It's a deep dive.
     
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  5. stephen cia

    stephen cia Veteran
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    Good read. Been chasing the rabit lathe for a while now. I'm thinking of just get the package Taig and be done. But then I remember opebuilds! And thought hmm maybe I can start another project... At the moment still undecided like you said the dinn is deep on this one... But it's going to be a heck of a dive for sure :)
     
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  6. Batcrave

    Batcrave Veteran
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    My first thought on reading this (after a bit of incoherent sputtering) was "My... this man has a remarkable gift for understatement!"

    Then I re-read the paragraph (actually paying attention, this time!) and realized that was a 36" long lathe, and not a 36" swing lathe.

    Sputtering at substantial sizes aside, another option also occurred to me, that could come out significantly cheaper than #1 and might require less raw engineering than #2. I'm not at all sure it's a good option, or one I'd ever recommend (like Dave Gingery's "build a whole **** machine shop from nothing but scrap aluminum castings and bubble gum" series of books, it's one of the ideas I looked at and discarded before finally buying an old South Bend light 10), but your reference to mineral epoxy put me in mind of Pat Delany's concrete Yeoman Lathe, which would offer an extremely heavy and rigid starting point, and both dimensions and adaptations for CNC could be designed in from the ground up, rather than trying to figure out how to bolt stuff on to an existing model. Of course, I didn't follow the development closely enough to know whether anyone's actually ironed out the bugs & developed a step-by-step modern process for building them, or, if like Delany's "Multimachine", it's still struggling somewhere between design and reality.

    Yeoman’s Lathe: Background and FAQ | flowXRG
    http://web.archive.org/web/20180216151805/http://concretelathe.wikispaces.com:80/
    (the latter is via the wayback machine, since the wiki's hosting service appears to be shutting down)

    Manual lathes are also great to have because it becomes a whole lot easier to make the rest of the parts you need to build your CNC lathe. Of course, then you get to the point where you realize you need a mill to make the tooling for your manual lathe to make the... er... sorry, am I projecting here?

    Funny you should mention that. I've actually got some ballscrew actuators that were given to me with the suggestion that I drive the carriage & cross slide on my South Bend, but I never wanted to give up the feedback of the manual cranks. Of course, I also don't do much that could ever be mistaken for production.


    -Bats
     
  7. Batcrave

    Batcrave Veteran
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    I just placed my first Openbuilds order so I can't speak to that end of things, but a year or so into my previous CNC router build I did eventually find myself in need of a lathe, so I'll pass along a piece of advice I was repeatedly given, but that I didn't properly understand until later:

    If you're planning to turn steel, buy the biggest lathe you can find space for, because, unless you're strictly making miniatures, it's still going to be too small.

    To explain what I didn't appreciate at the time, this isn't really a matter of project size inevitably outgrowing tool size (after all, that aspect goes without saying - there are never enough tools, and they're never big enough). As long as you can fit your work on it, length isn't a big deal (and on lathes with a hole through the spindle, you often you need even less length than you might think). Similarly, unless it's a wood lathe you shouldn't be looking at swing as a question of "will I ever really need to turn a steel cylinder x inches in diameter?", because no, you likely won't, and an x inch swing lathe very likely wouldn't be very happy with the job if you did. Weight, on the other hand, is immensely important. The less likely you are to survive (or remain recognizable) after having it dropped on you, the better it'll behave.

    I started out trying to decide between a Taig and a Harbor Freight mini lathe, and somehow I eventually ended up dragging home a well-used 600lb South Bend Light 10 (10" swing, 3ft bed, and, yes, that's the lighter of their two 10" designs by a fair margin). Once I got over the fear of turning on this big hulking iron behemoth, and then moving from aluminum to real metals, it quickly started feeling awfully light, flexible, and prone to chattering, even on pieces that would've fit the swing of a Taig. Every time I use it, I end up kicking myself for not figuring out some way to move the ~2000lb vintage gearhead (also with a 10" swing and 3ft bed) that I'd written off as "too big".

    Not everyone has space for a gigantic industrial lathe (hell, I wish I did), or even one like I ended up with (actually, I'm pretty sure I don't have room for this one, either), and not everyone really needs a huge machine (for all I know, your primary application is just turning brass parts for small model engines), but the size of the machine makes a difference in a lot more than just the size of workpiece and depth of cut, so if you have any way of getting something much bigger than you think you need, do it.

    Personally, I'm fond of old machines to begin with, which has the side benefit of making it possible to get a lot more machine for the money (being younger than I am, the one I ended up doesn't quite count as 'old', but I only paid half as much as the little 7x10 Harbor Freight mini lathe I started out looking at). Rob may well be right in his comment that newer machines are more suitable for CNC conversions, though (and I get the impression he's got an awful lot more experience there than I do) - if nothing else, I'd rather mount hardware on something with a lot of flat, square faces than one covered in curves.

    The dive is the fun part. Once everything's purchased, assembled, tested, and stable, there's nothing left to do but actually use the thing. :p


    -Bats
     
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  8. stephen cia

    stephen cia Veteran
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    I'm pretty sure I'm getting a Taig... although I just checked craiglist there's used southbend not far from me for $950 hmmm.....
     
  9. Batcrave

    Batcrave Veteran
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    Assuming it's a Model A (you can identify one by the incredibly useful quick-change gearbox at the left end of the leadscrew - they've also got power crossfeed, which I use far less), then that sounds like around the same price they usually list for around here. It's probably not a great deal for the bare lathe (although I could be wrong - there's a lot of geographic variation in prices, and I'm not sure what counts as "normal" down in your area) but it could be well worth it if it's in nice condition and comes with a good load of tooling & accessories.

    That's the one big advantage (err, other than floorspace and pulled muscles while hauling) to the little lathes - getting tooled up is a lot cheaper, and if you're buying new, they'll often come with a full set of gear. I still find myself trying to make do without handy things like the steady rest that didn't come with mine, just because of the cost of picking them up later. With the little lathes, you can usually get what you need relatively cheap at somewhere like littlemachineshop.

    Either way you decide to go, I wish you the best - lathes are all sorts of fun (occasionally they're even useful!). While I may have occasional regrets about the size, I've never once regretted putting the money (and effort. and floorspace) into getting one.


    -Bats
    (ok, fine, getting two. well, maybe three if you count that cute little homebrew thing... but the others are pretty much limited to turning wood, so that doesn't really count, right? although I keep meaning to try spinning metal on the Delta)
     
  10. Rob Taylor

    Rob Taylor Master
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    I actually looked at the concrete lathe first, before anything else- even long before OpenBuilds and my return to making. It's a great idea in theory, concrete is super damping and heavy like cast iron, but unlike cast iron, concrete as a material isn't all that dimensionally consistent and stable. If you use more expensive cements- self-levelling coatings and precision grouts- you could possibly get a fairly decent machine, but 1) you're still going to have issues with tensile strength, 2) concrete secretly hates reinforcement to overcome that, 3) you still really need precision metal surfaces placed precisely to get optimal functioning, and 4) the overall workflow of skeleton-surfaces-molds-concrete is going to be identical and performance concretes are also very expensive.

    As an option to simply add vibratory damping mass to an epoxy granite build with designated cavities, I'm not wildly opposed to it, but all my research suggested that if you're going to go to all the trouble of making a concrete machine, you should just make the binder epoxy instead of Portland cement and get a significantly higher performance machine out at the end. As an option just to go SUPER cheap (standard concrete, SBR rails, etc) it has some potential merit, as long as you design in adjustability over time to allow the concrete to move around.

    Generally I'm of the opinion that those types of experimental machines are nice and fun projects, but if you go in expecting to get a functional, consistent machine out at the end you're probably in it for the wrong reasons.

    Yeah, if all else fails you can square up stock, bore holes, all that good stuff, in a 4-jaw. With some workholding you can also use it as a 2-axis mill for slotting (I would strongly recommend against attempting to use a milling attachment... Been there, done that).

    And mill, pshh. Surface grinders, that's where it's at!

    Yeah, I wouldn't buy an old lathe as a CNC conversion unit. Too many variables and inconsistencies for effective machine control- plus, if you irreversibly mess something up, you've basically ruined a piece of history.

    Check any used bench lathes carefully for spindle runout and way dip- nothing like getting your new piece of history home to find out you're gonna be turning beads or cones instead of cylinders because the previous owner ran it too hard for too long, and getting ways (or spindles, for that matter, but they're a little easier to DIY) rebuilt and/or reground costs serious money.
     
  11. Batcrave

    Batcrave Veteran
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    I think the concrete lathe was the second DIY solution I considered - the first being, as I mentioned before, Dave Gingery's (admittedly awesome) series of books that starts with green sand casting scrap aluminum in a charcoal foundry to build a lathe, and then uses that to build a drill press, shaper, mill, and, eventually, a manned mission to Mars (the last couple steps of the process may have been in one of the unpublished volumes). I only reluctantly rejected the idea, partially due to that whole "water+aluminum=BOOM" thing combined with my usual carelessness, partly due to the fact that scrap aluminum doesn't seem to be nearly so freely available as in Dave's time, but mostly due to the fact that I figured I'd get altogether too distracted by the variety of things I could cast, and three years later would realize I'd completely forgotten to start on the lathe.

    I still haven't let go of the idea of playing with casting, but it's far down behind a list of projects that I'm already at least partially equipped for.

    Now you tell me this? What am I supposed to do with the half ton of portland cement Amazon just unloaded in my driver's seat?

    *sigh*

    I should've known signing up for that new "in-car delivery" program would be a mistake.

    I think I'd seen some comments to similar effect in the past, but designing adjustability into a poured concrete machine tool (especially with absolutely no instinctive feel for how concrete moves over time) sounded even harder for me to wrap my head around than coming up with an adjustable steel structure.

    My previous CNC build was very much that sort of project... Based off an instructable (this one, in fact), for a combination CNC/3D printer designed around off-the-rack hardware & plumbing supplies, and starting out (as I described in another thread) with little more than a cordless drill and some screwdrivers in my toolbox. If I'd followed it through to the designer's apparent end goal & used it for 3D printing, it might've been adequate (if slow)... but I went the other way, trying to turn it into a viable CNC router, and along the way slowly learning what was important in the design of a good CNC router, and, eventually, why this never would be one.

    It's been an absolutely fantastic journey that's cost me the past three years of my life, drained almost the entirety of my disposable income over that time, and has taken me from being baffled by anything more mechanically complex than a circuit with two toggle switches (the circuits were never a problem, but those toggle switches? at least they didn't have gears *shudder*) to very nearly picking up a Bridgeport as the starting point for my next CNC build. It's an experience I'd recommend to absolutely anyone who wants a CNC machine but has absolutely no idea what one is, how one works, or what they'd make with one if they had it.

    There's a I may still end up going there (since my new Openbuilds purchase means I've pretty much given up on getting a proper mill before spring), but, having made some T-nuts using a QCTP, I have an extremely dim view of how the experience is likely to go on my lathe. Dim enough that, while I've spent the past week or two watching a local listing for a South Bend milling adapter at the far-less-absurd-than-ebay price of only $250, I've felt very little motivation to actually buy the ****... (err... darn? dang?) thing.

    I've wanted a surface grinder on more than one occasion too, but if I have to throw out the bed to make space for yet another machine tool, I'm pretty sure it's going to be a mill... although I'm open to being convinced otherwise. The surface grinder would certainly be easier to move in.

    I'd be more sentimental about historical value (and I do get awfully sentimental about old machinery - I just recently spent most of a week making reproduction typewriter keys to inlay on a knife for my brother, simply because I couldn't bring myself to buy the real deal off some butcher on ebay who'd murdered a vintage typewriter to get them) if mine weren't a mid-80s model. That's not even a proper piece of 80s history, like a Nintendo Robotic Operating Buddy, or an Iron Maiden "Somewhere On Tour" t-shirt... although it did mean that the public school it came from didn't get too many years to beat on it before trade classes were finally crushed out of existence.

    Still, it's been enough to keep me from ever figuring out how to rig up an indexing plate, for fear of having to drill a hole in any of the castings.


    Also: If the levers on the gear box won't move & the guy tells you it's just because they're stiff, gummed up, and haven't been used in years, he's lying through his teeth, and the gears have half of theirs sheered off and embedded in the other half. Just speaking hypothetically, of course - not from experience or anything.

    Mind you, even after replacing the entire gearbox, and allowing for the fact that the guy claimed there were a few drawers full of tooling (it originally came fully loaded), only to realize when I got there that he'd forgotten to pick up it all up when he bought the lathe :banghead:, I still got a pretty decent price (it probably helped that said owned absolutely refused to believe he was selling a 10" rather than a 9")... but the lesson to be learned at the expense of someone hypothetical who totally isn't me is that, if it's at all possible, have someone with a clue show you around a machine & how to use/evaluate it before you head out to get a used one.


    -Bats
     
  12. Rob Taylor

    Rob Taylor Master
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    I think Elon must've found those last couple of volumes. Actually, building a small lathe from scratch is one of my bucket list projects- literally from scratch, including mining (or otherwise acquiring) and refining the ore, then casting plates, three-plate method, etc etc. Try to get a feel for how they might have done it in the late 1700s.

    I definitely do have some forge'n'foundry ambitions, but slowly building up the equipment over time. Though it's amazing what you can do with a few house bricks on the basement floor.

    Building a tabletop for your new OB machine sounds like a good idea! Or perhaps take up sculpture.

    I would assume it would be the same way adjustability is always built in- start low to allow shimming for up/down, and oversized mounting holes with bolts for side-to-side.

    How concrete moves, I'm not entirely sure, though. Definitely seems easier to stick to steel.

    Ah, yes. The mythical mill/printer combination. DMG Mori has a rather nice one. Other than that, I've never seen it succeed or really serve any purpose whatsoever.

    At this point I don't think I'd do a Bridgeport conversion. I know they're popular, but I think BPs are more useful as standalone manual units, available for slotting and punching holes in whatever random stuff you need to do off in one corner, while more suitable machines do all the real work. I'd get a very large bench-style mill (moving head) and use the ground ways as mounting points for linear rails. The large machines, like the Precision Matthews 940M, have all the work volume you need to be able to slip in some rails and still have plenty of space. That's my plan for my next machine- essentially resulting in a Haas-like machine for the price of a midrange Tormach. After that, the next upgrade will most likely be an actual Haas machine like the VF2SS (Or a Brother Speedio, maybe, they look rather fancy). Not that I like to get ahead of myself or anything.

    I spent a year milling on my lathe. Never again... Remember, every time you put it on, you have to tram it in in the B axis, and just hope you don't have to shim it in the A or C axes. Then when you need to turn something, it all has to come off again. Leaving a vice on it is easier said than done, so you're gonna be tramming that in every time too. An hour of setup, even if it's a three second cut. And then you get maybe 3" of usable Y travel, if you're lucky. At this point, I think I'd rather just block something up on on the cross slide on 123 blocks, gauge blocks and shims. At least after a few tries, you'd be very familiar with the table-to-spindle-axis distance.

    Yeah, no, given the choice it has to be a mill, but in terms of making tooling, man, what I'd give for a grinder some days...

    As a propmaker (and as a photographer, for that matter), I had a hard time cutting into a client's vintage Strobonar flashtube for one of his lightsabers. Like... But do I HAVE to? Could I not just find some other piece of stainless tubing...?

    Yeah, mid-80s is a little hard to get too excited about. It was the doldrums of machine tools. 4kB Fanuc controllers and all that...
     
  13. Batcrave

    Batcrave Veteran
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    Well, it's some consolation that at least they went to someone crazy enough to use them.


    That sounds like a fantastic project, although I suspect I'd get in some trouble if I started mining in the back yard. There could be some entertainment value in leaking word of a "local refining operation" to some of the area conservation groups, though...

    As for the three-plate method, one of these days I'd really like to take a shot at learning hand scraping. I doubt I'd ever trust myself to scrape in the ways on an existing tool, but even for purely decorative flaking, it's a skill I'd love to pick up.

    I'm barely even into the 'bricks on the basement floor with a propane torch' stage. I do have a little vacuum furnace - currently shoved under the ill-fated CNC Contraption - that I semi-inherited, but it hasn't seen much use beyond annealing & heat treating some tiny wood lathe tools (a set I made from allen wrenches for hollowing out ornaments last year).

    Better make that stone carving. It was raining, and they left the window open.


    I spotted a nice little Mori Seiki VMC when I was shopping for my lathe - cheap, too. I just couldn't sell anyone on the idea that kicking all the cars out of the garage to make room for it was "helping them get back to nature".

    In this case, though, it was a passable enough CNC router for low-precision flat cutouts in soft materials (plastics & moderately-hard woods) - allowing it to be used to make its own upgrade parts - and it wasn't bad at decorative carving either, and (at least when I could get the spindle to cooperate) I could even manage matching (at least in the XY plane) pieces for inlayish designs. The problem arose whenever thickness came into play, as the X/Y table had a terribly squishy design. The X-axis used horizonal patio door wheels alternating along round stock (which, surprisingly, ended up pretty solid after bolting the rod to some 1" square steel tubing in a ghetto "supported rail" setup). The table, though, was all cut from 1/4" acrylic (covered with a scrap oak spoilboard), and the Y-axis used those same wheels running along the edges of 1" square aluminum tubing. Between the flex of the acrylic ribs supporting the "rails" and the flex of the upper table that needed to hold the wheels tight against them, it would offer less and less resistance to the spindle (or even droop outright) the farther it traveled from the center.

    I've got some square linear rails & bearings that I'd considered using to rebuild the Y portion of the table, and figured I'd need to buy a new spindle for any machine I built, but a few crashes rather pointedly reminded me that the only way of correcting the angle of the Z axis when it (frequently) got out of whack involved pipe wrenches in one dimension and bashing it repeatedly with a dead blow hammer in the other. Adjustability and standardized components made an OB replacement really really attractive.

    I suspect it could have made a functional 3D printer - at least for materials that don't mind speeds under 70IPM - since the fundamental flaws were mostly related to pressure/torque/cutting stresses... but I ended up far more interested in CNC than I'd ever been in FDM, and just can't afford a 3x3ft footprint for a 3D printer, so I backed one on Kickstarter that someone else gets to design and test for me. And it's much smaller. And I'm sure this year will be the year it finally delivers. Or maybe next. I can wait.

    Heh... I'd love to have the sort of space where I could just stick a Bridgeport in the corner, then turn around and bring in the real machines... unfortunately my "shop" is a residential furnace room (inconveniently occupied by all the usual big awkward furnacey stuff that can't be used for melting metal) and I'm chronically short on both floorspace and headroom (the Bridgeport lost out largely due to overhead pipes & ductwork), so I was hoping to find a solution that would solve the CNC problem and give me proper milling capabilities for steel within the same (or similar) footprint.


    Oops. Just had to recalibrate my sense of size, there. Following up "Bridgeports" with "very large" and I started picturing something large like a Cincinnati knee mill, then scaled up to a very large gantry mill that'd cut a car frame out of a single billet.

    The 940M is probably a little large, but still possibly in the same class I'd like to try picking up as a dedicated manual machine, now that smashing it together with the CNC into something bigger is off the table. I'd been eyeing similar sized older hardware, like the Rockwell 21-122 and Clausing 8520, but was constantly frustrated by the fact that despite (or because of) being much smaller machines, the prices started significantly higher than the Bports. (also, the fact that they were inevitably a three hour drive away, and I was having trouble convincing anyone to dedicate an entire day to helping me collect one).

    I love getting ahead of myself. My first and second choices for the lathe were a Monarch 10EE and an old Hendey gearhead. :p


    ...and then you discover your machine just plain isn't rigid enough, and chatters and bucks like some sort of machine tool rodeo as soon as you bring the workpiece within eyeshot of the tool.

    I'll have to keep that in mind, although I'm not entirely sure how I'd fasten it all down. Maybe turning a round dovetailed disc like the base of the compound with a few tapped holes for holddowns? The top of the compound gives less to work with, since it's only flat for about an inch on either side of the toolpost's T-slot, unlike the boxy modern import designs.


    I'd be happy with even a little tool & cutter grinder, to save me from my inarticulate freehand fumbling at the bench grinder.


    Many Graflex died to bring you this lightsaber!

    I absolutely understand the desire for authenticity - feeling the need for the realness of the materials beyond just their apparent accuracy, for top-grade ebony inlays rather than substituting utterly indistinguishable black plastic just because knowing what's in there is even more important than how it looks... but when you have to cannibalize something you know will never be made again to get the components for something else? That's always a hard one.

    In the case of the knife, his hobby is repairing old typewriters, so he appreciated the fact that I'd avoided destroying any to make the inlay... but when you've got a client who wants the real thing?

    I guess there's no alternative but to own all the tools, and manufacture replicas from the molecular level up!


    -Bats
    (but I think I'm going to need a bigger shop for that...)
     
  14. Rob Taylor

    Rob Taylor Master
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    Given that mining is a lot harder than it is in Skyrim, I may try and settle for just acquiring a ton of iron ore in some fashion, and starting from the smelting point. I suspect that months of pickaxing may not quite be the educational experience I'm anticipating.

    I was actually pleasantly surprised at how well it went, running a TS8000 torch off a 20lb BBQ tank through one of the three-hole type bricks. Holds enough heat to easily discolour and crack the bottom brick.

    Oh, me too. I'm in a basement at the minute- the garage is uninsulated and without power. Anything I buy has to be physically carriable up and down stairs. One of the reasonas I ended up going for the G0758 mill over the G0704- at only 160lb (vs 300 or so?) I can just pick it up and carry it around as need be. I'm not anticipating being in this same place for tooooo much longer, so I don't want to get into bigger stuff yet. The downside is, there's not enough Z travel to be able to put square rails on and still have usable tooling options.

    Well, very large for a bench-style machine that's publicly available. Obviously VMCs all use the same design, but I don't think you can pop down to the Haas factory and ask for a casting.

    I think that size is perfect for a lot of normal-size shops, but buying used without a friendly freight truck driver with a pallet jack and a liftgate to help you is always going to be tough. Down here, good machines are hard to come by on the used market. The occasional BP or 80s CNC, but that's about it. I just stopped looking. It's like anvils, too. If you're not in the area where they happened to congregate 100 years ago, you have no chance.

    Always an issue, yeah, especially on stainless. Discovering the relative rigidity of even the much smaller mill was extremely pleasant (also, getting away from my 3x5" work envelope...).

    Something along those lines, yeah. I'm running a G4000 lathe, so I could use the T-slots, but old machines do tend to focus more on the aesthetics than the adaptability. Without the specific attachments, they can be hard to repurpose.

    I'd just settle for a bench grinder that doesn't double as a vibratory casting table at this point.

    Yep, I'm definitely a replica fan over original parts. I think trying to replicate the manufacturing process so you get the same surface marks is also fun. Pulling and poring over reference to try and reverse-engineer the way they made it, bearing in mind the various machines available at different times. Like shapers!

    A molecular 3D printer would be fascinating. It wouldn't even need to stick anything together, just push it close enough that the right forces take over. One day!
     
  15. Batcrave

    Batcrave Veteran
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    Most things are harder than they are in Skyrim. Have you ever tried yelling at a real dragon hard enough to get it to flinch? That's an educational experience right there.

    Tangentially, an old project of mine involved hooking up pin tumbler locks using an arduino as a USB interface. The plan was to require picking a real lock unlock doors in Skyrim. Unfortunately it eventually fell through because, after getting the physical side & electronics working, it turned out I couldn't find any info or any modders who'd sorted out a way to modify the lockpicking minigame or programmatically trigger a success.

    Since you mention the TS8000 and we've drifted entirely off topic anyhow, maybe you can tell me... aside from the price tag and the odd bells & whistles, what's the difference between the torches labeled as being for propane vs those labeled as being for MAPP (or MAP Pro, or whatever the junk in the yellow tanks is these days)? Is there a good reason not to just stick whatever dusty old torch heads I have lying around on a yellow bottle & let 'er rip?

    That's the main reason I finally broke down and ordered the Lead Machine instead of getting a mill. I've got a back door into the basement, so stairs aren't an issue, but getting there involves going down a hill (with a 90° twist in the angle midway down) on soft, mole-riddled lawn. I have no idea how to ever get the 600lb South Bend back out again, never mind something as heavy as a Bridgeport.

    No? Great. There go my plans for the weekend.

    I've actually seen cheap (~$1-3k) VMCs turn up on craigslist around here every few months... unfortunately there's that whole "space" problem again.

    I was starting to look at U-haul rentals, which seemed surprisingly reasonable... right up until I figured in the 300 mile round trip.

    As far as historical congregation of tools, I'm theoretically in something of a sweet spot - being less than 100 miles from scenic Bridgeport, Connecticut, historical seat of Bridgeport Machines and their famous machine, the Bridgeport! - which might explain why they regularly pop up on craigslist as low as $750 around here (often, of course, with caveats like "as-is" and "you figure out how to get the #$%^ing thing out of my basement"). Go down to a mill half that size, though, and prices seem to hover around $2k.

    Given the headaches I had with mild steel T-nuts (one for mounting the QCTP on the lathe, then another four for mounting a cheap "milling" table on my drill press), I don't even want to think about trying it with stainless.

    Then again, I found myself turning 303 stainless for the first time not long ago, and it turned out to be infinitely more pleasant than, say, hardware store CRS round stock (which has given me more headaches than the worst mystery metal I've ever stuck in a chuck).


    You use a bench grinder? I use an old Craftsman scrollsaw for my casting & degassing. At least some good comes of all that awful vibration.

    I recently upgraded from a nigh-useless little little no-brand 5" grinder to a trash-tier 6" Ryobi "thin line" (that still has wheels twice as fat as the skinny little things on the 5"). It actually runs smoothly, though (and for about five minutes after cutting the power), meaning I may have to find something new to blame for my inability to grind decent cutters.


    Shapers are nifty little machines... I'm always surprised I don't see more (or any) of them turning up on the used market around here (probably for the best - I don't have the space or budget for the tools I need, never mind the ones that I just think would be neat to have).

    On the typewriter keys, I ended up with a process I think was almost completely and utterly unrelated to the original, beyond the fact that both were made out of metal and had little paper inserts. I didn't have the real thing on hand to check (the recipient of the gift having absconded with my vintage typewriter some years ago), but I suspect they were made by flaring or swaging & then rolling over thin-walled tubing, with tabs then cut on the back & folded over to hold the glass, letter insert, and a rigid backing (or possibly a metal backing to get welded to the levers). Lacking the right tooling (and not having any stainless tubing on hand), I ended up turning a similar shape (but with a solid back) from stainless, then dropping in a printed insert and flooding it with resin. Not nearly as elegant as the original or likely to fool anyone on close inspection, but I suspect it's far better suited to being carried in a pocket.

    One of these days I need to look into tooling for more of that sort of thing - and maybe a press & dies for small sheet metal work. I've been trying for some time to come up with a way to make my own clips for turned pens, but the standard designs use an awful lot of small-scale folding, and I have yet to come up with anything better suited to my current hardware that'll stand up to use.

    Why push it? Just print the next molecule within range!

    I'm still expecting to see one of Neal Stephenson's all-purpose recycling 3D printers - print all your clothing, furniture, electronics, and other day to day needs with the house's printer, then, when they get old, toss them back in to be recycled and print a new batch. Of course, it'll probably make us long for the days of those high quality goods that were hand assembled by artisans in China back at the dawn of the 21st century.

    For the moment, though, I'll settle for a high-rez laser sintering printer on my desk. And maybe a bioprinter, too. That way I can print replacement skin & organs for the ones I inevitably destroy by inhaling and spontaneously combusting powdered metals, and print the scalpels I need to install them!


    -Bats
    (I can install new components in my PC - installing new organs is basically the same thing, right?)
     
  16. Rob Taylor

    Rob Taylor Master
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    That's amazing, I'd play the hell out of that! Sadly, my modding experience is entirely limited to ripping game models so I can build them, at least in anything this side of Unreal Tournament.

    I've wondered this myself as well, actually, but judging by the differences between similarly featured torches, I believe the primary difference is the stainless vs brass nozzle tubes. Since the MAP-Pro (some kind of propylene blend, or something) burns significantly hotter than the propane (though still less than MAPP, may it RIP), the brass nozzle would probably melt or droop or oxidize too quickly or whatever.

    It's times like this I wish I were more of a woodworker- Simple, lightweight, inexpensive (ish) machines can do everything you ever need! Alas, my brain seems hell bent on convincing me that if it's not made from steel, it's cheating.

    That said, I really do have a hankering to build a moderately large-scale (1200x800x300, perhaps?) high-speed 5-axis machine exclusively for plastics and MDF. The components have come down far enough that it's actually a possibility, and they're tempting me from my Amazon Saved For Later (where all temporarily fascinating products go to die).

    I know that feeling. Even though my lathe is only 250lb, I haven't yet devised a system to extract it again. I'm guessing some kind of wooden boards on the stairs and a winch sort of trapped by a door frame, perhaps.

    That's a fairly glorious place to be. Here in Roanoke VA, Greensboro NC seems to be the nearest reasonable concentration of machine tools, but that's really not saying much.

    I'm just working on the assumption that wherever I end up, a decent manual mill will be at least $2500 and a decent manual lathe will be at least $4000, assuming I don't just save the headaches and unknowns and just buy new, of course.

    I'm lucky, my lathe has a permanent stud rather than a T-slot, so it was just a case of turning an adaptor (Adding a QCTP to a 9×20 Lathe)

    I think, in that situation, I'd have turned them down (mounted on the stud, turning in reverse, tool mounted either upside down or coming in from the back) to almost size and then ground in the two flats on the sides. I know milling in the QCTP is theoretically possible, but it does seem miserable.

    Actually, that said, I have seen people put little bars on the bottom of small vises to mount them in QCTP holders... Potentially an option for desperate steel work.

    I haven't tried 303, though it's supposed to be quite well behaved. I've only done 304, which is supposed to be terrible but didn't give me too much grief, and also welds quite smoothly (or, as smoothly as I can weld anything at this point). I'm sure 316 will come along sooner or later for whatever reason, which should be interesting.

    And you think hardware store CRS is bad, try hardware store aluminum! No idea what grade it is, but I know it just bends and tears instead of cutting.

    The one with the flexshaft takeoff on the side? I actually have one of those, which I tend to avoid using unless absolutely unavoidable.

    I had a Harbor Freight 8" grinder, which was awful and I still haven't reassembled- or, in fact, checked the shaft for runout/bending/misbalancing, so it may be some time. Now I have a Ryobi 8" grinder, which is not enormously pleasant to use. I have a second one still in the box over a year later, which I really ought to get out and see if it's better behaved. Hard to grind accurate angles with the thing vibrating things off the other end of the workbench.

    I found that my HSS grinding (as little as I do... Carbide inserts for this guy) got lightyears better when I sat down and obsessively watched every grinding video I could get my eyeballs on, and of course Abom's multiple times. Once I really grokked what all the facets were doing, I didn't really need to pay attention to exact sizes or angles any more, form just followed function naturally.

    Sounds distinctly plausible. I like the replication though, I bet it looks great.

    Dies for my hydraulic press (and possibly pneumatic press... A 4-ton Multi-Power cylinder lying around suspiciously doing nothing is a dangerous thing) is one of the main jobs I hope for the mill to do. D2/D3 steel, machined, heat treated, maybe a skim pass of hardmilling, and bolted to some kind of somewhat-standardised bearing plate assembly with pressed bushings and chrome shafts. Maybe even give the press an air-over-hydraulic cylinder while I'm on. Should result in some nice repeatable pressed parts for... Something. That's the bit I'm not 100% sure about yet.

    Meanwhile, I'm kind of in love with hammer sheet work, so anything in the short term would probably be hammerformed.

    For some of the more ubiquitous, easy-to-reuse plastics, we're just about at that point. HDPE is possible to shred, re-extrude, and re-print, and probably a handful of other plastics too (ABS? PETG?)

    And yeah, DMLS is something I'd love to build at some point. I suspect it's more feasible than most people think, seems like it's mostly just acquiring the right laser and figuring out gas containment.
     
  17. Batcrave

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    I occasionally went in the opposite direction, ripping textures from games to use when I was playing with building/modeling in Second Life.... but that's sort of the direction I ended up approaching all of this from. Until it took this abrupt lurch into the physical a couple years back, my background was pretty much entirely in the virtual. Way back in the foggy mists of time (in the far away and probably mythical land of Hyze K'oul) I was trying to decide whether to go into programming or electronics... Being frustrated - like many a poor Hyze K'oul youth before the growing May'kur religion brought partial enlightenment to the education system - by never having access to the supplies or tools to do much of anything, I came to the conclusion that by diving into programming I'd only ever need one tool.

    Surprisingly enough, it largely worked, too... but *mumble*ty years later I suddenly woke up horrified by the fact - not new, but newly horrifying - that I was completely and utterly incapable of creating anything that could be appreciated without staring at it through a monitor, and it was all downhill from there.

    Well, anything except cakes - I was ok with creating those.


    Ahh... that could be it. It wouldn't account for the price difference, but it would at least account for there being a functional difference.

    I'd gotten the impression that, unlike MAPP, though, MAP-Pro was really pretty close to propane in temperature, and only significantly higher in "heat content" or something (no, I don't pretend to understand how that's supposed to work - my eyes sort of glazed over and I went back to burning stuff with the blue bottle). In either case, would there really be enough heat at the torch (as opposed to at the focus of the flame) to cause a problem?

    Not that I'm in a huge hurry to start melting torches to find out. I can usually just drag out the furnace and crank the dial when I need something hotter than propane, since I have yet to play with brazing or anything else where mobility matters.

    It's usually at times when I'm working with wood that I wish I were more of a woodworker.:( And that I had a whole lot more space for tools.

    You start out with a large-swing lathe - leaving substantial clear space around it, both for your excessively long-handled chisels and for outboard turning those large bowls. You'll probably just decide to grab an old metal lathe since they're sturdier anyhow, and set up a bench nearby with low-speed water-cooled grinder for those chisels. You get a decent sized bandsaw for cutting those blanks (better go for a Laguna), but you decide you want to do segmented bowls (since it's expensive to find solid chunks big enough for your bowls, and because just using one wood is so boring), so you really need a tablesaw - heck, you need a tablesaw just because you're a woodworker - so that takes up another huge chunk of floorspace, and you really need a jointer/planer for keeping all those little bits of stock squared up. Naturally you'll need at least one big, nice quality workbench to assemble everything on (and maybe a couple extras that can go along the two walls that're covered in your plane-and-chisel collection), but that's ok, because underneath it'll give you space for an assortment of smaller power sanders - to supplement your stationary belt & disc sanders - and saws. You probably don't need a router table just for those segmented bowls, but, face it, you're going to discover you need one for something so you might as well go all the way and get a shaper - you can stick it next to that radial arm saw that you found a really great deal on. And don't forget about dust collection...

    Machine tools are definitely heavier and harder to bring home (except maybe the lathes, since half the serious wood turners seem to go for metal lathes anyhow - there's a guy up the road here with three or four in his basement, and one's a multi-ton monster that has to have at least a 16" swing), but I don't know that they offer particularly stiff competition on floorspace to an enthusiast's wood shop.

    Of course, you also find those rare artists who can do absolutely anything with a box of hand tools and some space to set up (look up the Studley Tool Chest, ye mighty, and despair)... but everyone knows a real machinist can build a jet engine with nothing but a hand file and calipers.

    I do wish I was better at woodworking, though - and that I had either more power tools, or more talent with hand tools. One advantage to my poor failing CNC Contraption, though, is that it's been forcing me to do a lot more manual work that I never even would've attempted before. Or, well, forcing me to try a lot more manual work - some turns out better than others. And it's helped to fill the emptiness when I've wanted to make something out of metal and didn't have the tools for that.

    That sounds like an awesome project, but I think I'd be short on applications for it. MDF is generally something I use when I'm expecting an experiment to fail horribly & don't want to destroy real materials, or when I need to stick together slabs of something that's stable, flat, functional, and will never be seen, and plastic... well, I guess I've just never really gotten back into plastic, after spending much of the 80s making a sloppy, sticky, glue-melted mess out countless model kits. For a prop maker, though, I can see how that could be invaluable. In the early aughts (the aughties? the zeroes?) I spent a while working in the crafts shop of a theater's costume department, and having a toy like that would've been amazing for some of the strange things they'd come and ask us to make.

    Two words: Sikorsky. Skycrane.

    Like Bridgeports, Connecticut has made lots of helicopters (although generally not named after their towns) - we've got Kaman Aerospace here, too (purveyors of fine guitars and guide dogs!). I bet if we look on Craigslist we can find a clapped out one o' them for under a grand, too!

    ...

    Here's one! RESCUE HEROES HELICOPTER AND WATERCRAFT

    It's a great place to shop for Bridgeports, but glorious it most certainly is not. My biggest regret about getting into all of this is that the more big tools I get, the less likely I ever am I escape again. It's going to be tough to try hauling a ton or two of old iron into a single bedroom third floor walkup back in Boston or NYC.

    Then again, I can't say a whole lot for NC, either - about the only things I remember were the run down old Dillon Fence factory (apparently no relation to the NC band called 'Dillon Fence'), finding a Cure t-shirt in a thrift store for $.50, buying cigarettes for about the same, and a whole lot of tears (those were more expensive)... but I think that was Greenville, not Greensboro. VA I've never even been in for that long.

    Even around here, the mill prices I've been seeing are running $1500-2500 if you don't have room for a big honkin' BP & try looking for old iron in half scale or benchtop sizes. Modern stuff seems even rarer, unless you're looking to buy a beat up Harbor Freight import that someone still wants 90% of the new price for.

    I'm curious what you're looking for in a manual lathe at that price point, though. Even with the historical tool drought there, that sounds like it should buy a couple times the machine - new or used - that I'm running on (and, I suppose, unsatisfied by) right now.

    It was both desperate and miserable, and I don't even remember what I did for the QCTP's T-nut (did I hold it in the 4-way? *shudder*), but it's close to two inches long. Some long-ago student managed to take a big chunk out of the inside of the toolpost's T-slot (the top face is just fine), so I wanted something that would bridge it. It did work, but both the method and the result were hideously ugly, and something I hope never to repeat.

    I've read a lot about people turning in reverse & from the back for various situations, but it just doesn't seem to be something the Light 10 is cut out for. There's no lock on the chuck to keep it from unscrewing, which requires a little extra care, but even then, the cross slide doesn't really go back far enough for it - with the possible exception of small diameter work and a lantern toolpost.

    I've always meant to take another crack at making a ball-turning replacement for the compound, though (my first try involved some of the first pieces of metal I ever turned, and... worked about as well as you might expect), and a similar base could probably also be used to offset a toolpost farther back.


    I'd gotten a few lengths of surplus 1/2" 303 offcuts cheap on ebay at some point, so which just happened to be the only appropriately sized stainless on hand (I think the next size up was a massive 2" round of unidentified stainless I'd found in a parking lot), and I was expecting hell. I think the worst of the problems I had with it were because I was trying to turn a recessed center with a 1/16" thick, 1/8" tall straight wall with a radiused edge on top, which tool a few different custom tools ground from HSS blanks (have I mentioned my amazing tool grinding skills? no? because I have none). The radiused cutter for the lip gave me particular problems getting it sharp, and the dull tool rubbing (obviously) would cause it to harden. Thankfully not enough to keep me from finishing with a file, though.


    Really? I've usually had pretty good luck with it. It costs far too much and I ran into endless frustration trying to anodize it, but it cut far more smoothly than the steel. The CRS always cut like it had begun life as a rod of steel swiss cheese before having the holes filled alternately with aluminum and rocks.


    Nope, no flex shaft (actually, I don't think I'd ever seen the flexshaft-enhanced scrollsaws before tonight - at first I thought you were talking about the Harbor Freight grinders with attached rotary tools)... It's one of these (give or take about three years):

    Sawdust, Rust & Blood.: Craftsman 16" Scroll Saw - Model No. 113.236110


    That's what clamps are for. Just clamp everything to the workbench. Everything. Then clamp the clamps to the workbench, in case they try to vibrate off. You might also want to get a few more to clamp the clamps to the clamps, in case they turn into an outdated meme.

    I don't think I've watched any of Abom's before. I'll have to add him to the increasingly long backlog. Lately I find myself always running late with a project & never doing more than frantically fastforwarding videos in hopes of finding an answer to the one specific problem I'm stuck on at the moment. Maybe once the holidays are out of the way, I'll be able to start sitting down and digesting basic concepts again.

    I always have much better luck and usually a lot more fun when I'm using carbide (and to hell with anyone who says it's not appropriate to use with aluminum on anything as slow as an old South Bend), but there are some things I'm just not imaginative enough to figure out with inserts, or just aren't compatible with the size carbide tooling I have around (the rounded lip on the typewriter keys and small-scale boring, respectively). It's also one of those things I just feel like I should be able to do.

    Of course, I've found that I'm lousy with sharpening of just about any variety, so it's probably not surprising I have trouble doing it with lathe tools too. Some day I'm going to have to just dedicate a solid month (and a stack of disposable tools) to sharpening techniques, and see if I can overcome it. I was recently given a Wolverine sharpening jig for the grinder (probably worth several times more than the grinder itself), so that may save the life of a few chisels for the wood lathe, and finally give me a solid surface to rest the HSS blanks on while I mutilate them.

    I thought so too, but every time I look at pictures I spot new flaws. Probably good that I can't stare at the real thing anymore.

    This is how it came out (just the scales, mind you - the knife hardware was obviously a kit. I'm still a ways from pulling off that sort of work in aluminum, never mind 303C) :
    upload_2018-11-30_0-57-57.png

    (his typewriter, not mine... the fact that the inserts on my keys perfectly matched the model was pure dumb luck)

    Oddly enough, the single most challenging part - and the one time I really missed CNC - turned out to be cutting the slot for that inlaid brass strip.

    I'm curious, though, if you can think of an easier way I could've gotten the straight inner edges & rounded lip. As it is I ended up with three that looked the same, but never would've stood up to even cursory measurements - the problems I ran into grinding the form tools, the resulting work hardening of the stainless, and finishing with files meant that repeatability was pretty much non-existent.

    Personally I'd be more worried if a 4-ton multi-power cylinder suspiciously started to do something.

    I've never looked into hammerforming in much depth, but that's probably something I should consider. I've mostly seen it applied to much larger pieces, though. Do you think it would be practical to scale the techniques down to, say, folding .05" edges down the long sides of a .125" x 1-2" strip? Although there's a chance something like a single 45° crease down the center might also provide enough stiffness to get by, and could be an easier operation.

    True. I can't count the number of videos & instructables I've seen turning bottles into blanks for turning or machining - there was a gorgeous pseudo-damascus effect I saw used on an HDPE mallet and wanted to try replicating, but it seemed to be a result of some sort of two-layer milk bottle that doesn't grow wild in the US. Setups for recycling failed ABS & PLA prints back into filament are becoming more common too. Recycling the morning's raincoat and umbrella into a (probably pretty tacky, admittedly) synthetic leisure suit for a formal affair in the evening might not be so far off either - although 3D printed textiles still seem to be struggling to make the leap from runways and clubwear to casual practicality - but getting that same box to print something like a new phone for you (even *shudder* last year's model) is another matter entirely.

    Then again, it's likely to surprise me. Despite at least vaguely following 3D printing since the announcements of the first generation of RepRaps, it's something I feel like I'm way behind the curve on. Somehow, in some dark alley in the city of manufacturing techniques, I got jumped by CNC and never made it to my first date with FDM.

    DIY laser sintering, though - whether DMLS or SLS - is so far beyond my current skill set, I wouldn't even know where to start. Maybe if I could hack together a working SLS unit out of the incomplete and ill-documented wreckage of the Peachy Printer, I'd be heading in the right direction.


    -Bats
     
  18. Batcrave

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    Umm... this doesn't really have much to do with CNC engine lathes anymore, does it?

    -Bats
    (oops)
     
  19. GrayUK

    GrayUK Openbuilds Team Elder
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    "Once I really grokked what all the facets were doing"
    That didn't get by me! I remember it was a good book, what was it called?:D
    Was it by Robert A. Heinlein?
     
  20. Batcrave

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    A strange word in a stranger novel?

    -Bats
    (...but no stranger than TANSTAAFL)
     
  21. GrayUK

    GrayUK Openbuilds Team Elder
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    In A Strange Land. Indeed. :thumbsup::thumbsup:
     
  22. Rob Taylor

    Rob Taylor Master
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    This was me with photography. While I haven't really fully left it behind- the props, ultimately, are an extension of it- the realization that digital media is a very tenuous place to hang your hat really pushed me over. That and remembering how much I like working with my hands.

    Yeah. The extra features like piezo ignition, locking on/off, turbo swirly flame tube thingy (technical term), all that good stuff are really nice. And of course, a MAPP torch gives you the option of going hotter when necessary, but will still happily run propane all day.

    I read into it once, got the gist, and never really thought about it again. I assume heat content, as in actual calories, relates to the number of molecular bonds being broken and reformed and the net exothermic energy output compared to the actual size of the molecule and how many moles of it you can squeeze into a given volume. Since propylene is, I'm assuming, a molecule somewhat more complex than propane (by at least two extra letters!) yet perhaps compact or geometrically pleasant enough to pack appropriately, it magically contains more heat in a given volume. Something along those lines, anyway, I was never an enormous fan of chemistry.

    Ah yes. That feeling. The one right before I once again look up the two-speed DeWalt planer, only to disappointedly close the tab when I realise it's still unjustifiable.

    I have a Harbor freight 10x18 wood lathe, grinder, Ryobi 9" bandsaw, and an ancient Ryobi "portable" table saw that I got for $15 at a yard sale (it's terrible). I finally got a Ryobi plunge router on clearance relatively recently that I don't have any bits for, but am yet to build a table for it- I have an old Porter-Cable or Craftsman mini router table, but I don't think it fits. I do have the HF 6"/4x36" disc/belt sander that's not too awful on wood, and a nice Milwaukee random orbital sander I've never used and have no sheets for, as well as our collection of quarter and third sheet sanders, which seem to keep multiplying when I'm not looking. Close enough, right?! Hahaha

    I do want a low-speed grinder, though. Seems like a Tormech can be had for about $200 or so, which doesn't sound that bad.

    I cringe any time anyone cuts wood on a machine tool... I just can't do it. Like, how do they keep it oiled?! DO they keep it oiled? Wouldn't that stain the wood? It's bad on multiple levels.

    That's always fascinated me, and I love the idea of it, but I also rather like the idea of actually producing more than two things in my lifetime and possibly making some money, so it's always been less-than-ideal.

    Ditto. It always seems like wood should be easier than metal, but I'm really not convinced it is. At least, not with the tools I have.

    If it can directly machine solid urethane, Delrin, stuff like that, maybe some wood carving for "detail" set pieces, and MDF for components to be separately finished and/or moulded and cast, then that would be a prop shop monster.

    Perfect! Helicopters! Always the solution!

    (...I wonder if shop drone-cranes would find a market?)

    That's the exact reason I'm sticking with lightweight machines, and just the two of them for the foreseeable future. In an ideal world, I'd be in WA inside of 18 months.

    Either way, not missing much in that state. VA's a weird one. VERY different depending on where you are.

    Good condition BPs, Acras, Monarchs, Americans, Schaublins, Clausings, anything that's a good machine in useable condition. Full size, too- minimum of 16x30 on the lathe, for example. That's for when I've found at least a state to settle in, if not a town/mountain/cave/forest (you can run Robodrills on an off-grid solar setup, right?!)

    Yeah, the inability to come in from the back has always been a failing of the older machines, I think. Those beautiful sculpted castings are only really intended to be used in a very conservative, 50s, whisky-swilling, tie-and-spectacled fashion.

    I need to make a ballturner! In fact, I think I have a suitable tapered roller bearing in my eBay saved for later (there's a theme happening here, I know) but just haven't pulled the trigger yet. Maybe it'll be a CNC project, that would be fun and I could make it really nice.

    I was making this:

    16228711_1260953580650156_777398782907121664_n.jpg

    And wanted actual heat-bluing on the barrel, instead of airbrushing an aluminum barrel. (Not steel... Cheating. Check. :rolleyes:) That entire project was done on the lathe milling attachment. Miserable.

    Those are blind-tapped M2 screws connecting the barrel and tip, too. Talk about pucker-factor:

    20161219_204439160_iOS_2.jpg

    Solid 304 round bar, barrel is turned-town-and-bored-out seamless 304.

    Huh. The exact opposite problem here. Steel seems largely ok, some kind of A36-like blend, probably. The aluminum machines and welds like it's pot metal scrapings.

    Ah, yes. That one. No, I'm talking about the much inferior, and possibly actually older (or at least worse-designed) Model 572.247202. Now there's a saw that'll degas some castings! I've never needed to buy a superior one though, I do almost everything curved with the bandsaws and my recently-acquired fancy new Milwaukee M18 jigsaw that I love.

    I've always wanted to clamp while I clamp. You must've heard I love clamps?!

    The Abom one is required viewing. It should change the way you understand grinding HSS. I think this is it, but this may have been a later one he did bouncing back and forth with Tom Lipton: - The ThisOldTony one is probably worth watching too, he usually illustrates things helpfully, but I don't remember it.

    I've never had an issue with going slow on aluminum. I mainly just like the fact that "too fast" simply isn't an available setting. What's the machine set at? Doesn't matter, let it rip!

    Jigs are great. I bought a little wheeled-wedge type to use on flat stones with chisels and planer blades, should be good. I deliberately freehand HSS though, because I feel like it's a skill I should gradually acquire.

    Looks great! Simple slab-scaled gentleman folder, nothing wrong with that. Clean.

    Diagonal lines really are tricky! I suppose that's what rotary vise bases are for, but I can't fit them in my tiny z-travel. :p

    I mean, the only way you could realistically do it would be with form tools.

    For me, I'd have made a soft jaw or mandrel- or used a collet- that could hold it right, and then done all three back to back with that straight inner edge with the compound slide only and carbide, carriage and cross slide locked. Perfect repeatability- tap in, slide, back out, loosen, next part, tap in, repeat. Then do the same thing with all three with a simple radius form tool from the outside with a locked down carriage and compound. Separating it into multiple processes allows repeatability and consistency because you're only moving a single axis to a dial indicator stop point.

    I really want to make some kind of high-speed setup, where it's magazine-fed by another cylinder, so there's a sort of bam-BAM-bam-BAM cadence and finished die-pressed parts fly out at great speed, but I'm not sure just what those would be off-hand yet.

    I think you could do that, yeah. The workholding could be tricky, but it would be possible. Probably easier than trying to press it in a vise, too.

    Ditto, actually. I fell way too hard into the CNC well and ended up at machine tools, with no printers. I may acquire a couple of printers next year, but we'll see. If I build a big 5-axis, it probably wouldn't be necessary. Cutting is way faster than printing plus sanding.

    LCD SLS seems fairly straightforward, but with decent $500 machines available, it seems hard to justify the project. DMLS seems super exciting, though. Aerospace!
     

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