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Discussion in '3D printers' started by evilc66, Jul 27, 2016.
Larger format FDM printer using C-Beam linear stages
evilc66 published a new build:
Read more about this build...
All Openbuilds parts showed up yesterday, so hopefully I can get a start on the mechanical build this weekend. Everything else will be trickling in over the next two weeks.
This bad boy showed up today, which is about a week and a half faster than anticipated. I don't think I'll have temperature issues with this guy
So, here's the CAD model in it's current state. There is still some more to add, like all the corner brackets, all the hardware, extruder. hot end, etc... At the very least, I have verified that I can get greater than 300mm travel in all directions. Pretty happy with that. Still patiently awaiting the updated belt reduction plates for the X and Y-axis.
Awesome you know I am always game for a good lead screw based printer lol Even without the belt drive the OB tr8x8 leadscrews have no problem getting the job done "video link". I wish I had taken more video of Adamantine up and running but it got partially incorporated into another build and now a neighbor is rebuilding it with the metal plates I made.
Nice! That certainly seems to be workable. The 1:2 ratio though would make it fly.
I put the heater mat up against my Two-Up earlier today, and it just as big as it's footprint. This sucker is huge!
Managed to get the X and Y axis rails assembled on Sunday. I would have got further with the assembly if I didn't find my order short 4 of the 8mm locking collars for the lead screws The team at the OB store have me taken care of though, and the missing parts will be here tomorrow. With the Misumi order that showed up today, I will be able to have it mechanically assembled this week! I do have to trim the 20x60 extrusions though, as they were all cut 10mm too long for some reason.
I think I have everything but the controller now on hand. I have an extra Ramps 1.4 board and drivers that I can use in the mean time, but I'm thinking of going to a Smoothieboard for the smoother operation. The Azteeg X5 Mini was on the list too, but I'm not thrilled about it only having 4 stepper drivers. Other suggestions are welcome.
Progress, and pictures!
That's the base and Y-axis done for now. 8mm lock collars should be arriving today, so that will allow me to get some more done tonight. You can see the Misumi t-brackets and the 45 degree support extrusions that came in yesterday. Everything fit together as expected.
As you would imagine, even this part of the printer is not light. I don't think I'll have much in the way of vibration issues with this beastie!
All mechanical parts now assembled!
This thing is stiff and heavy, both of which I find to be good things. I'll have to get it on a scale once it's all said and done, but I'm estimating this thing is currently tipping the scales at about 40lbs. Certainly overkill for a 3D printer, but anything worth doing is worth overdoing
Next thing on the list will be the heated bed. I have to get the mounting plate sorted out first (the part that mounts to the Y-axis carriage), which I'm still trying to decide on the material for. I had initially ordered two 1/4" thick MIC-6 cast tool plates (one for the mount, one for the build plate), but that's an awful lot of weight to throw around at high rates of speed. Then I thought about 1/8" aluminum plate. Much less weight, but I worry about it flexing under the weight of the build platform, which will be the 1/4" tool plate. I also thought about 1/4" MDF, as it's pretty rigid all by itself, not too heavy, and shouldn't have the same resonance issues the thinner aluminum would. I dunno...
G10/Garolite might be a good choice for the bed mount. It's lighter than aluminum and much stiffer. I'm pretty sure I have a decent sized sheet of carbon fiber kicking around the house too. I've had it for years, so I might as well put it to good use.
your build is looking great ! G10 should be a excellent material to use for that purpose.
I literally just found my sheet of carbon fiber seconds ago. I think I'll be using that, even if it's only for the bling factor
I have looked everywhere but where would I find a large Y plate at? I can find the Prusa I3 Y plate size all over the place but what about ~300mm size? Taz has theirs but it uses a 4 point leveling and I refuse to do that ever again as it is a nightmare and too constrained.
Just make one. Lots of places will cut material to size if you don't have the tools to do it yourself. I use Online Metals a lot, and they will cut to any size you want. My build plate is 1/4" thick 12"x12" cast tooling plate and was cut to size by the vendor I bought from on ebay. The bottom plate was just a 12"x9" sheet of 1/8" carbon fiber that I had laying around. I used a C-Beam gantry plate as a template for the mounting holes, then laid out the mounts for the build plate adjusters by hand. Took about half an hour to do and all I needed was a ruler, a pencil, some masking tape (to mark on so you don't mark up the plates permanently), a drill, a few bits, and an M5 tap (and handle).
Speaking of, I did get the build platform done over the weekend. I just haven't posted pictures yet (I will tonight). I'm going with a 3-point mount, but rigid (no springs). 5mm shims of varying thicknesses are readily available in the R/C car world, so I picked up a set of 0.5mm, 0.35mm, 0.20mm, and 0.10mm shims. with how rigid this machine is, I think I will only ever need to level the bed once, until I take it apart
I had to do a little surgery on the heater mat. Turns out I wasn't paying attention to the dimensions when converting from metric to imperial, and didn't realize that there would only be about 2mm clearance around the heater to the edge of the build plate. That's not really enough room to get a standoff and screw in there, so out came the xacto and the soldering iron. The heater mat I bought is made with nichrome wire (versus a kapton heater), and the wires do end up coming quite close to the edge of the mat. As a result, the wires were exposed when I cut into the mat to allow clearance for the three standoffs. I cut the nichrome wire and crimped a section of regular wire (you can't solder nichrome wire) to the ends to re-route everything around the standoffs. Everything was then sealed back up with high temperature red RTV silicone. Looks a little ugly, but gets the job done.
The PEI sheet came the other day (took forever to ship due to an issue with the vendor's ordering system supposedly), so that's going to get mounted to the build plate here shortly. Once that's done, the Y-axis will be complete. Next up will be the extruder mounting plate.
I think I am going to go Ghetto on mine but will only require cuts. Now the tooling plate that is another story as I will have to buy a Drill Press for it since I cannot make straight holes by hand BUT I can buy a drill press, and the plate, for far less than having the 3 holes drilled and counter sunk. Prices I was given by 3 places was around 250-400 dollars and locally it was around 700 dollars for a 12x12 tooling plate plus the 3 holes and the 3 counter sinks. I refuse to pay those sorts of prices.
That's madness! I paid $25 plus shipping for the 1/4" tooling plate! Try these guys. This is where I got my plate
diamond plate aluminum tread 3003 6061 7075 2024 7050 5052 items in Metal store on eBay!
The other alternative is Online Metal. More expensive than the ebay option, but they will cut to size (1/8" increments) if you have an oddball size that you need.
See if you have any places locally that deals with used tools. I have a place down the street from me where I picked up my drill press (the recondition them before sale). It's a 3ft bench top unit (variable speed, 1/2" chuck), but it's built like a floor standing unit (much thicker column) and weighs over 150lbs. Looking around, I'd have to pay close to $400 for an equivalent, and picked it up with a vice for $150
It isn't the plate that is costing it is the 3 holes having to be drilled and countersunk.
Either way, it's insane.
LOL, I 100% agree. Plate will run me around 20 dollars and the rest is their labor costs, etc... They will say it is because this is a one off and they have to break it all down to do just this one piece plus they charge for labor etc... I just say they are all thieves at those prices.
It's almost like they are planning to CNC machine it for those prices. How much do they think it costs to operate a drill press for crying out loud!
Out of curiosity, where are you located?
I am in Memphis, TN.
I priced a single 1/4in (no shop does metric here and if you mention metric they get very hostile) aluminum Prusa I3 frame locally 3 years ago and just last year and the price done around here would have been around 800 dollars. Everything around here is expensive if you need work done. For instance a roof on my house here is around 50-60k and if a complete teardown and redo is around 80-100k while in Pensacola, FL (for instance) the same house would run 5-6k or at the absolute worst 8-9k for a teardown and redo.
Heck, even a HF 50 dollar "special" would be enough to do this job since CL is dead here for machines as people run them until too far gone and/or ask far too much. Might find a rare case but most times I have never been able to get anything off of CL. I almost purchased a Sears 12in earlier this year when it was on sale but my cat had to go to the vet and 500 dollars went to the vet instead. I still have my eye on that press but I really would like more than 5 speeds since I need slow for metal and fast for wood. Sears 12 in does 355rpm to 3065rpm.
Some pictures. They aren't very exciting, but pictures none the less.
That last picture isn't the clearest, but it's one of the spots where I had to tweak the heater mat. Having the mat come that close to the edge will be good though, as it should offer pretty even heat across the whole build surface, especially once that big slab of aluminum reaches equilibrium.
I am scared of CF or I should say I am scared to drill it or cut it. Bad <stuff>.
I am jealous as that is what I want is that plate.
btw, should a 250x250 250 watts silicone heater pad be enough for a 300mmx300mm plate to get to 120c?
Carbon is pretty easy to cut and drill. The only thing you need to be worried about is the dust, as it's not really that nice to breathe. As long as you wear a dust mask or respirator and wet the cut a little to keep the dust at bay, you shouldn't have anything to worry about. For saw cuts, just use the same blades as you would for non-ferrous metal. Good sharp drills cut through it like butter.
As for the heater, 250W can work, but it will just take longer to get up to temperature. The heated bed on my Two-Up is a pcb based 6" heater (about 150W IIRC) and that would get up to 120C, but it took an age, and certainly wouldn't have gone much higher. If you are going to use an aluminum build plate, a little more wattage wouldn't hurt.
That is what I meant about the CF is the dust.
What controller will allow more wattage as I don't want to SSR it and for a Ramps 1.4 at 24v 250watts is already pushing it (though I did change out the MOSFETS to much better ones)?
I know I want a 250x250 heater to give me some elbow room as my M5 holes will be 10mm from each corner.
Why don't you want to use an SSR? That gives you so much more flexibility than relying on keeping the MOSFET cool enough to conduct enough current.
I haven't run across many boards that have MOSFET outputs that can handle more than 12-15A, but then again, I haven't been keeping track of all the different offerings and current limits due to deciding to use an SSR right out of the gate. Keeping your current MOSFET cooler with a beefy heatsink and a fan will help you eek out a little more current. You could even try running MOSFETs in parallel for greater current capacity.
The MOSFET I went to on the Ramps is rated @60A as the ones that was originally on the one that died was so hot with a MK2B that it melted the plastic on the header it bent over and touched and would blister you if you touched it. With the new board I replaced the MOSFETs with an IRF version and it isn't even lukewarm (actually it is at room temp without a fan). I figure it could do 15-16A without a need of any cooling but I have no way to push it to test that.
The issue with a SSR is I don't want to do an AC heated bed and a true DC SSR is not cheap.
Fair. While the MOSFET can handle a healthy amount of current, the board may not. 15A requires some pretty thick traces, even though they are very short. If you really want to beef up that portion of the board, you can scrape off the solder mask that lead to the drain and source (incoming power and outgoing power) and add a healthy bead of solder to them. That will help carry more current. Heatsinking the MOSFET is still a good idea, but with the tight packaging of the Ramps board, that's not so easy. Mounting the MOSFET remotely will allow you to cool it better with a beefy heatsink and a little airflow. If you decide to try this, just make sure you use appropriately sized wire.
Not even going to try it as too much work for too little gain. This 250watt will have to suffice I think.