On to the Z-axis. I had a hard time fastening the timing pulley to the lead screw. In the end I managed to strip the threads of the lock screw... ;-( If anyone is listening. There is some slack between the lead screw and the bearings. Have you done anything about this?
That is to make assembly go smoother. With full/true size rods it extremely difficult to fit the bearings on the screws and then slide them back into the pockets. If the gap is bothersome try wrapping the screw with teflon tape prior to installing the bearing.
Some electronics. Lets just call the case a, hrmmm, prototype... Raspberry with Protoneer-hat and DRV8825 drivers. We'll see how long these will take me. I have a feeling I'll need to spring for some proper drivers before everything is said and done.
Did as much assembly as possible on X. It seems like when using Chris plates you can't use a 1mm shim on the outside. Otherwise the lock nuts won't reach the nylon properly. I simply skipped them. Also mounted my router. Not sure where I saw the design but it's definitely stolen.
Began assembly. Attached all the axes and started working on the frame. At this point I have an 1-axis CNC.
More work with the assembly. Spent quite some time shimming in order to get proper angles. It's time to start thinking about wiring. I'm to lazy to move the gantry all the way to the other side and want to check movement before tightening everything down.
Build has been slow since I blew my back and have to take it easy for a while. I removed the Lead screws from Y in order to check for any pinching. Movement was good but some of the wheels (on the excenters) didn't have proper contact.. It's a hassle to adjust when the gantry is assembled.
When I pull my gantry all the way back to the plates I get a gap of about 3mm on one side. You can look at the pictures.. Any suggestions? I'm guessing that my X axis C beam isn't 100% square or if I possibly mounted the Y axis C-beams to close to each other... Any suggestions on fixes? I would really like to avoid disassembling the gantry...
Added 0.2mm shims (from an old soda can) to X beam, a lot squarer now but then the next problem surfaced... I originally squared the base with the gantry in place. But the gantry wasn't square which pulled the beams... I had to resquare the base again..
Finished the base frame. Originally I was planning to follow @Kyo's original design but with 80x20 as a frame and 60x20 as supports. Then I hade a change of heart after seeing one of @Savvas videos and decided to use the base simliar to his. I simply spaced out the 80x20 and 60x20 evenly and fastened with 90deg blocks. This way I didn't need to cut any aluminum and squareness wasn't as critical. Once a wasteboard is attached I think it will be plenty rigid.
It's alive! I wired up X/Y and that found one of the DRV8825 was broken. One of the Y-screews simply didn't travel the same distance as it's cloned buddy... I created a dead simple pen holder from a piece of wood, a nylon spacer and some rubber bands. Works fairly well...
So far so good. I seems to draw pretty accurately. I'm not having that much much with Chilipeppr at the moment. It seems like half the widgets on the page are broken. Got the final piece of cable for Z and soldered a connector to it. (Why is it only once you get to the last soldering it starts to look halfway decent?) I'll hopefully be able to wire up Z later tonight or tomorrow...
Got Z up and running and made a few cuts. Since the waste board isn't attached Z is all over the place but otherwise it looks pretty good. Also carved my first part. (a holder for limit switches). This made me realize that this thing generates a lot of dust.. A dust shoe moved up the priority list.
Did some more tuning and found weird slack in my Y's. So I ran the gantry back and forth and one of the lead screws is bent. :-( Just ordered a new one and be done with it...
I've done a bunch tightening. The new lead screw has arrived and I ordered a set of DM542 drivers. To be honest, the DRV8825 are doing a pretty good job so far and I'm not really sure I need the beefier drivers... But since I got them I might as well wire them in. If you're considering repeating a build like this you could very well try with the DRV8825 first and see if they serve you well... I've managed to do some pretty good cuts as well. Check out this knob. (Planning to use it for hold downs)
Started working on the wasteboard. Routed out some countersink for M5 heads on the top. Then flipped it around and routed out holes for 80 T-nuts... Now comes the fun part of drilling 320 tiny holes for the t-nut teeth. ;-) '
Congrats on a great build @Andreas Bockert p.s. that wood T-nut knob would make a great helpful post for the new Project share section! Thanks for the share and keep up the good work. Mark
Finished my 320 holes and hammered in 80 t-nuts (with a dab of hot-glue, not sure if it will help but it couldn't hurt). Also cut some threaded rod and created a prototype hold-down system. Not pretty but the stock doesn't move... Obviously, I need to fabricate some prettier hold-downs... I'm thinking plywood...
Lots of bits and pieces. I’ve been working on a dust boot with heavy inspiration from Suckit (Suckit Dust Boot) and other derived works found on the internet. What I liked about the design is that it I attaches to the Z C-beam. That way you get very secure mounting and can mount it very close to the surface. First prototype is using 3/4" mdf and 5mm plywood. The bottom part works pretty well. I'm going to change some minor things to make it easier to machine. The hose holder on top works well with just friction fit. The next version I'll try something that mounts on top of the Z beam. That way it will be out of the way and there is no chance that the router will hit it. I also want to replace the plywood with Lexan or Acrylic but I still need to figure out how to route those properly.
Long time no update. Been working on smaller things and designing parts for the machine. The other day the fan I was using to cool the drivers (still running on the DRV8825) died on me. I was a bit too lazy to fix it immediately. Today I was cutting some parts and all of a sudden Z got way off. Like it missed a whole bunch of steps... At first I didn't connect the dots but once I fixed the fan it started working again. I havet to say that I'm pretty happy with the DRVs performance but I'll upgrade at some point...
Hi @Andreas Bockert. Nice Build. i'm planning to build something similar. What is the size of your CBEAM extrusion for each axis ?
I got 1000mm for X & Y. Then I shaved a few mm off to square them up. So in the end Y is probably about 997mm or so. For Z I used 250mm and the regular plates (not the tall ones).
Mounting them was a chore and they tend to fall out. Next version I might simply route slots in the wasteboard and use them like a poor mans t-track. I’ve been tossing around some design ideas but nothing concrete yet.
I know what you're talking about. There are ways of using two layers of material to accomplish a t-slot structure.
You can mill slots then glue strips over the top, surface mill then you're done. A consumable t-slot table.
I was thinking of routing them through the waste board and then add some larger holes where I could fit through screw heads or head+washer. It's not possible to have slots where there extrusions are but it should work for most of the area. Alternatively if it's possible to make something that can fit through the slot instead of a washer. Here is a very quick sketch of the idea.