But your patience will give the greatest satisfaction when you receive it and can start printing all the ideas you've gathered in time!

 

They have various 'blends' of the stuff, not to forget a few others produce similar products under different names. In the case of Alumilite, there is a ... going from memory here. a ... VAC-25 and VAC-50 version. The latter mostly for people making molds to thermoform. It's suppose to have upwards of 50% aluminum particles in it to help with heat dissipation (or whatever). I wasn't looking closely enough to say more then that's the one I would probably go for, if I did go for this approach, not knowing much.

We'll see the results soon enough from RogueGeek's trials. He also seems to have some experience with the stuff. I suspect he's experienced with the leaking and such issues. Having some gear to test and compare deflection with and without, maybe he can enlighten a few of us as well.

What would be real interesting is for him to get a hold of a few of those 3D printed connectors to run measurements using them. Especially considering they are 'removeable'. He could test with the exact same lengths of extrusions :

• just the extrusions
• extrusions with 3 connectors (either ends and centre)
• extrusions with 5 connectors (add first and last third to above)
• extrusions with just the 'joints' made of Aluminite (specifing which mix)
• extrusions with all cavities filled with the Aluminite (heavier and 'stiffer')

If using release agent is 'wise', he should be able to slide the aluminite 'connector' right out and start from square one with other alternatives, like :

• extrusions with 3 bolts
• extrusions with 5 bolts
• then adding the Alumilite (which, with the bolts in the way, would become quite permanent UNLESS the bolts could somehow unscrew ...)

We would then have actual data to use in our discussions.

If he's willing to do those tests, anyone able to send him at least 5 3D printed connectors ?

Just a thought ...

 

The list is already growing quite fast. I better order extra rolls of the various types of raw material, eh ?

 

That's a great idea !

Could maybe add a hole to screw into a t-nut so any vibration does not cause the holder to travel ... unless there is a tight fit already designed in ...

Yet an other project for the awaited Micro3D printer.

Can anyone already see an automated tool change area for their OX ? I noticed myOX actually can get the tool end of the router to reach past the front ... enough to maybe reach for the next tool Of course, the electronics would have to change in consequence.

 

I would be happy to do some testing but in the interest of getting my OX running and usable I will probably order a couple of pieces of 20x60 and dedicate them to testing.
This will also allow me to build a proper test rig and not have to keep removing my X axis from my machine

 

I've never actually calculated the chip loads. I've simply tried a number of router speeds and feeds and settled on 12,000 RPM @100 IMP as a good speed for my machine for cutting MDF with 1/4" bits. My machine is made using makerslide by the way. I hope to have my new one ready by mid to late December.

BTW Paul, do not use an up spiral bit cutting MDF. It will leave a very poor finish.

 

Thanks for the info Paul... maybe I can start cutting these plates a little faster.

 

Can anybody point me to where I can get a problem with my order resolved? My openbuilds order is missing the GT3 belt and one of the Xtreme wheels is poorly machined. I have yet to get a reply for my About Us e-mail. Looking forward to showing you guys my build once its finished.

 

You can send a message through the Parts Store, go to "view messages" in the "My account" section. You should be able to send a message there, the guys running the store have always resolved my concerns professionally and quickly.

 

Thanks for the tip Steve. Mmm, at the moment I have only up cutters reasoning that it removes the chips better, hence removing heat. For cutting through I could place the work upside down to avoid the poor finish. But for the carving that won't do. Maybe it is possible to do the carving with climb cutting to get a better result?

BTW, your Maya calendar looks beautiful! Very nice job and inspiring to get it going.

 

Hi Chris, you're welcome. But be aware that this is information from Onsrud, and will probably only apply to their bits. Maybe other brands have other characteristics for their bits. I've seen some impressive aluminum cutting (really very fast!) on youtube, maybe you can get some ideas from there? I'm a real newbie in this, so don't go on my information only.

 

That would be great. Any test results would be quite valuable for at least some ... and it won't hurt the curious, like me. Inquisitive minds want to know.

I was not trying to put you, or anyone for that matter, in any particular situation, much less obligation. I was trying to underline that until someone - anyone, does actual comparative tests, at least somewhat controlled tests as you are more than willing to do, it will be difficult for anyone to talk with any level of certitude. Until actual numbers surface, we are talking based on our individual experience and knowledge, including theories since, as shown by our discussion so far, no one has actually tried the idea and talked to us about it.

Most often, as confident as we can each be, it is rarely all encompassing experience and at least partly theoretical knowledge. I realize we, especially me, do not know exactly how much each of us have for actual experience. I can only say many of you have more than me especially at this stage. However, this doesn't make any of us automatically right. Theories, even for what seems impossible otherwise by whatever reasoning, usually ends up proven incorrect or even pure nonsense. For as long as we breath, we never stop learning.

At one time, most truly thought our planet was flat and going too far would have us fall right off the edge. It took some risk takers to prove us wrong, before anyone hung or burned them. It's somewhat the same situation here. Until someone actually tries, we won't really know, will we ? don't pay attention to those of us holding a rope, matches or logs ...

Human nature wants us to believe, which is stronger than just trust and at times even what we perceive as reality, that those with more experience know better. At the very same time, the same human nature has at least some of us willing to explore and go beyond current knowledge and experience. Man, the species, still can not truly fly, yet here we are with millions of people zooming through the air every year, faster than any bird can imagine... A very select few of us actually go into space and, even more amazing, returning to tell us "all" about it. Not forgetting some want us to believe it is all 'movie making'. Why would it be or, for what it might be worth, not be ?

Not only does the word 'impossible' has two too many letters, but it can also be read as "I'm possible" just by adding a bit of 'ink' at the right places. Only months ago I would not of believed anyone if they told me I would be building any kind of machine, much less CNC machine in my garage !

Inquisitive minds want to know. Prove us wrong ... or right. Sail that ship. But, please, come back to let us know what you have found at the edge or actually beyond the edge of our current knowledge and experience. I don't have the inclination needed to be part of that adventure. As much as I love water, I still can't get myself to learn swimming - my old mind as put up one heck of a barrier. I can only convince myself to cogitate about how I would do it if I had the guts to actually try it.

Oh, and as a thinker, I give myself the rights to criticize... but just so you or anyone else can go the extra step, not to burn anyone at the stake.

...Do you think that's enough wood ?

Who has the matches ?

Eh, wait ! Come back ... I brought the marshmallows.

Where has everyone gone ?

Did you just fart ? Really !?

 

Hey guys, I hate to bring up a topic that has already been beat to death but can somebody point me to the TinyG/TGFX tuning parameters for the OX that I'm sure I've seen here someplace on Openbuilds? I've tried a search and I've gone through a bunch of these 60 some odd pages but I can't find the parameters listed anywhere. If I'm not loosing my marbles and have actually seen them here someplace, it would be nice to have them placed on a sticky in the Resources section as the TinyG seems to be a pretty popular controller.

I have my OX cutting based on some playing around with the obvious tuning parameters in TGFX but would like to have some idea what I'm doing before I start tweaking things like jerk and junction deviation. The router is moving fairly well but does some weird pausing on some of the shorter cuts (longer ones are great). I have very good cooling on the chips and on the back of the board so don't think its a thermal problem.

Thanks for your help.

Doug M

 

Doug Nash how's that Zenith Stol shaking out for you I assume it's a Zenith sure looks like one I use to fly.

 

Absolutely is a Zenith CH-701. The OX is going to help with my present build, a scratch built Zenith Cruzer

 

Kool deal Doug I wish I would of had a cnc when I built our RV7 I ended up making the panel the hard way. Good luck and happy rivet driving.

 

I'm glad I could make someone laugh as laughter is the best remedy around.

 

Swoooooooossssshhhhhhhhh

 

Just for the heck of it I've asked a "local" aluminium extrusion company (yay, Google) what it would cost to create a bigger profile like a 40x60. Making the tool for the extrusion would be about 2400 € ($ 3000) and I'd have to order at least 500 kg of Aluminium for the smallest batch.

 

I think this would be a good idea for openbuilds to pursue

 

One nearly in my backward would do orders as small as 250 kg. It's still quite a bit of extrusion, even at 40x60. They are also confident in doing longer length than 1500 mm. There are two others I would deal with, but a bit further away with similar requirements. It's all a matter of not cutting into OBPS sales (as in riding their coat tails)... I would rather add to it. The open hardware concept is enhancing a product, not just copying or, worse, making low cost copies ... OBPS must be thinking about producing 40x60 as we (I) mentioned it a few times already. The work and cost is with receiving and reshipping the stuff. They already have a handle on that.

 

Im thinking 4060 would be nice, but 4080 would be cooler

 

Certainly would be ... But does it need to be that hefty ? Or would 60x60 be better overall ? Wouldn't even need to change existing gantry plates if we went with 60x60, just a few more wheels and longer screws for the X assembly. Many of us could upgrade easily, cost would be minimal (no new/custom plates).

Of course, keeping in mind some of the ideas mentioned earlier for the X plates (ex: allowing for wider spread wheels to guide the Z length of V-slot) and enhancing original design to take advantage of the beefier (or is it OXier ?) extrusion, going to 40x80 could be thrown in the redesign mix. They could also be used for heftier (and longer) Y beams ...

Seems like there is a growing number of larger OX builds as well, so these larger/wider extrusions would be nice to have around ...

It's at least a 10k$ investment to get a first small production (250 kg) run done. If all goes well, it can be had in about 4 weeks time, including design/consulting to optimize profile (ex: core structure). It just needs to be sold and shipped out ... Time for pre-orders (KickStarter or otherwise) ?

 

I'm sure Mark is lurking in the depths of the openbuilds OX cnc discussion forum and is pondering this route with great tenderness... lol. I think 4080 would be a nice addition for people who would like to do larger builds. Not really necessary for the OX.

 

New guy here with a completed design in Sketchup for a "beefier" OX. My spin on Marks design uses dual 20x80 (40x80) V-slot for the Y-axis, and triple 20x60 V-Slot (60x60) for the X-axis. This design uses the existing gantry plates but unfortunately requires me to "sister" two or more rails together to achieve the desired effect. I would love to see Openbuilds expand on their linear rail offerings. So how 'bout it Mark? Where's the beef?

 

Well, threw a plate of 19mm plywood on the spoiler board today in an attempt to cut out parts for a Buffalo Table. At a feed rate of 900mm/min (35IPM) and spindle speed of 12,000 RPM it all seemed to go very well. 2 flute up spiral bit, 1/4" diameter, 3mm passes. But then…. the nice sound of the bit cutting into the plywood started to change gradually and it looked like we were starting to skip some steps until the Buffalo decided to follow a complete other trail. Hooray for the e-stop!

So, tried it again from the start and this time the second square to be cut went wrong. The Buffalo wanted to take a short cut through the square at 15mm deep and smoke and even a small fire started in the cutting groove! E-STOP!! again. And some water over it to stop the small fire. I'm puzzled, dazed and confused! Was the feed rate too slow? The bit already too dull? The spindle speed to high? This Makita C0701 can't go any slower than 10,000 RPM and with higher feed speeds I'm not sure if the steppers can handle that (@12V). Maybe less deeper passes (1.5 or 2mm per pass) and faster feeding?

I would appreciate it if anybody with experience could give some good advice in this matter? Thanks a lot, in advance.

 

Hi Paul,

It sounds like a software/communication issue... like some of the G codes are not getting to the controller as it is cutting.
Try doing a dry run .5" above the part first.

Is compacted dust building up in the flutes? Maybe you need air flowing around the bit as it is cutting.

The feed (35ipm) sounds perfect to me.
Also, is the router moving a bit in the mount? I do make a very rigid mounting kit for the 701. (I thought you were using a 1617).

chris