laser cut CNC linear axis
Description
The innovations in this system are its extremely minimal vitamin count -- only a handful of bolts, washers, and nuts are required. It also uses several long pieces of kapton tape as a linear slide bushing, to dramatically reduce friction and drag (though regular old scotch tape may work just as well ;) ).
Instructions
( the design was prototyped with 3mm material, but the material thickness isn't critical to the design ).
The bolt holes should snugly fit 6-32 bolts.
Update (from some questions recieved from folks who have made it: )
The width of the top plate (the one with 13 screw holes + 1 shaft hole, and the big curvy notch at the bottom) is 95mm wide by 102mm high, to help get your scale right.
The steppers that I’m using are KP35FM2-035, which I get at Sayal Electronics ( sayal.com/ActionIndexP.asp?ID=162138 ), which has a bunch of stores in and around toronto, ontario, canada (and also an online presence, I think). These typically go for about $5, and I think they have a NEMA-14 footprint, with a 5mm shaft diameter.
All the bolt holes are sized to snuggly fit 6-32 bolts, and you will likely have to tap these if you're using a material like acrylic (you can typically self-tap them with the bolt itself through a softer material like hardboard). The bolt holes are 3.4mm dia, while the gear hub holes are 4mm in diameter, making the gears loosely fit (and have a bit of play to find their place -- but you could certainly try cutting the gears with smaller holes to see if that works better). I used 3/4 inch length bolts, but some (for the gears) protrude out, so 1/2 inch would probably be more appropriate for these.
I put a small washer on the underside (but not the top) of each gear to dramatically reduce the friction -- without the washers, the hardboard version doesn't work very well at all, but with them it works quite well. In addition, between each of the structural plates, I placed washers to give a little extra travel height for the gears.
I have added two SVG files with the parts already layed out, that I used for laser cutting. There are some extra gears in there, just to fill out the space. I just put them in a ziplock bag full of gears for later tinkering, or give them away to friends who think they're the coolest thing ever :)
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This is great! There is some info on gear calculations that might be useful at this link: http://www.reprap.org/wiki/Gea...
this is fantastic, thanks for your work! :) (i like your solution -- i was trying to simultaneously solve for all unknowns given tooth pitch ;). what does alpha represent?)
the machine you designed looks really neat, what is it for?
i propose that if no one has before used the 6-gear (+2 linear gear) configuration, that it be named the jansen-moses configuration ;)
Wow cool gear generator!
Perhaps it might be worth mentioning how Vitaly (of contraptor.org) does Linear slides. He uses PTFE. Check it out:
http://www.contraptor.org/make...
FYI.
Also, you might want to get some lexan for the Gears. (even plexi would be better). However, I assume you are just prototyping still. As I do the same thing. Use the cheap MDF / Masonite then go to the more expensive stuff.
Ril3y
blog.synthetos.com
thanks :). yup, i just use hardboard for prototyping because it's silly inexpensive -- about $6 for 16 sq feet at home depot for the 3mm material. Something rigid and slippery like PTFE or block HDPE would probably be ideal for cutting the gears and things, but I'd first have to source them then give them a try in the laser cutter. Acrylic (plexiglass) is what I normally use, once the design works. ABS would also be a neat thing to try, too.
Bloody awesome design here Peter.
What's so nifty is that it's completely extensible. There's no limit to how long you could make that track, provided you can get a large enough extension cable.
I'm imagining all the things you could do with this. From automatic focal length measurement to all sorts of laborotory automation. How about a stop motion rig? :D
This is exactly what I was hoping people would see and say! "Imagine all the things you could do with this!". While I'm trying to design an extremely low cost 3D printer to make it 3D printing more accessible, a set of CNC axis are so very generally useful.
You're definitely pegged a pretty fantastic design element -- you can make the axis pretty long, and only have to worry about sagging or a little support if you're using thin material. Conceivably you could cut (or print) the track out in sections, then just tack on as many sections as you need l
ength in the axis. Completely modular, and /so/ inexpensive.
This has about $7 of components in it -- $1 for the hardboard, $1 for the screws, and $5 for the stepper! :)
Why have the motor move at all. If you fixed the motor you could have rollers for the track to slide on so it was supported. very very cool. 8-)
How are you designing the gears? Or should I say in what software rather?
Very good work bud. Wish this was around before I need my xy plotter for stepper code testing.
Ril3y
Thanks! I really hope people find it useful. I should have a new x/y version out soon, just wanted to hear people's comments before I did another iteration :).
I use a simple online generator to make the gears, and save them to a PDF when I print them. Then I import the PDF, copy out the gear, and there you go :).
License
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I'm in Europe, so I can only get metric bolts. 6-32 in metric is M3.5.. which obviously isn't sold anywhere. So I got M4, which fits surprisingly well =)
glad to hear it! i think the bigger sizes tend to thread the hardboard a little better, which is kind of nice. how's it working?