This is my second build on here and I'm really excited to share it! I think I'll eventually delete the previous build unless people have an interest in the old files (let me know in the comments). The previous files were able to be 100% 3d printed, which was a great way to get into the game of CNC for me seems how I own a Prusa I3 mk2.5. Once the CNC router was built, it's then been slowly upgrading itself into what it is today, which is different in every way.
I'll be updating this with progress photos as I go. The ultimate goal will be to document the CNC electronics enclosure as I haven't finished that yet. The custom Raspberry Pi based pendant that is also in the works as well as the entire machine itself. I haven't seen too many rack and pinion systems out there for home brew builds, and I know people are going to ask "why not ball or lead screw" but I promise I have my reasons! Speed, price, agility, adjustability, and again price, brought me to this conclusion. Also, in terms of going from the previous belt drive system to a rack and pinion, the upgrade wasn't incredibly painful to think about in terms of necessary modifications. A belt drive is essentially a crappy rack and pinion, in my opinion.
The first step was acquiring 1/4" aluminum plate, which the current CNC will mill out to upgrade the gantry plates. Next will be 3d printing the mount to hold the rack in place and actually acquiring the gear racks.
Attached are some existing photos of the mill and you'll see pretty quickly how it changes. The rack I'm thinking about buying is from Mcmaster Carr. I know McMaster has some huge mark ups on their pricing so if someone knows of a better place for a consumer to order industrial parts let me know! I'm going to get the 14.5 degree 24 pitch rack they offer as it's one of the few that offers a matching pinion with a 1/4" inner diameter which is perfect for the NEMA 23 steppers Open Builds offers..
This is the first piece off the mill that's made out of aluminum. It's for the z Axis and it's only temporary. There was a lot of slop in the Z axis when milling aluminum so this was milled super slowly so that I could at least beef it up temporarily while I finish the rest of the parts.
Test cut out of foam for the pendant. It will feature a key switch, E stop, touch screen, and custom mapped jogging controls. That's the goal at least. There's also switches that have been wired up to run lights, a vacuum, and an air blaster.
The plexi backing was milled just because I've never found touching 120VAC to be particularly fun (or safe). Once I finish the final design I might do something differently, but honestly if I threw some lights in there and worked on my cable management it might be really cool.
Custom fan case milled for the enclosure. It looks a little crappy because for some reason the stepper drivers on the Panucatt Azteeg x5 gt are super finicky.. In my case my steppers get bricked if I plug it in ABAB instead of AABB. Well, I didn't know I had done that before I powered it up so turns out my poor Y axis was limping along with just one driver going. If someone knows how to fix this please let me know... It seems like something that shouldn't brick the driver but its happened twice now (and funny enough the only two times I've plugged them in like that) and then I have to buy new ones. I've done this on other projects with arduinos and pololu stepper drivers and nothing goes wrong. I've held on to the bricked drivers for now because I feel like there must be some way to get them going again. They just make a horrible noise now and vibrate the stepper motor back and forth a couple degrees.
In this image are the rough locations for the PSU's and the smoothieboard. There actually needs to be one more power supply (12v) mounted in here for the laser. I left a lot of room for when I decided a 500 watt spindle just doesn't cut it anymore and I'll buy a proper VFD.
Another shot of milling out part of the electronics encloser. If you look and are horrified of the fact that I have the laser mounted to the spindle while it's running, fear not, I printed dust covers that protect the lens and other open areas, just pop them off and the laser is good to go. I also haven't been able to get the laser properly working on that, but more on that later... Probably not until I graduate from college next spring, I just don't have time to think about it and it's not super important to my work.
These are test parts milled out of acrylic for now. For the moment, I'm going to leave the X axis as belt driven and only upgrade the Y axis to have a rack and pinion system. I'm hitting numbers within 2 thou in the x axis (short axis) which is fine for the time being, but the extra length of the belts in the Y axis is leading to some pretty unacceptable slop and is as much as 1mm off at times.. Fine for woodworking projects in my opinion but unacceptable for when I need to make functional parts.
This is a pretty rough image of tramming in the spindle. Most importantly in the shot is the dust extraction that's temporarily been used as a blower as well for aluminum (just swapping the input on shop vac to the exhaust)... I know it's not the most efficient way of sucking chips up and maybe some day I'll have a dust shoe. But it does a pretty decent job at keeping things clean and it also allows for easy video as well by just having two hoses come in from the side and meet back up up top.
Rack and Pinion Cartesian Mill
This is a rework of a previous build I did on here, a mostly printed cartesian CNC. Initially intended to just be an update to that, but so many things changed including the linear motion and every single part has been modified significantly that I felt as though it deserved a whole new build.
- Build License:
- CC - Attribution NonCommercial - CC BY NC
Reason for this BuildCutting Aluminum was a must. My previous build could cut aluminum, but only at about 4 IPM before the belts started stretching or my DOC was just too pathetic.