So, when EstlCAM uses the default pocketing (linear), it doesn’t respect the plunge angle, so it just drives straight down. With my downcut bit, and the 2.5mm cut depth, I think that’s causing a lot of stress. I’m changing it to parallel, and I can see in the preview that it uses a spiral cutting pattern to drive down, which I think will work better. I’m guessing this will also fix the wavy pattern, but I haven’t figured out why yet 
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Huh, this is making even less sense.
I switched to parallel pocketing, and I accidentally did 1mm/step, and it still is skipping steps on the right side…
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Something fishy going on. Is the driver power low for that axis?
Just trying to push the head around, it’s really not giving up easily, I don’t think it’s the stepper giving up.
I’m going to try to cut in foam next, but I have two new theories. Just theories, but if there’s a good way someone can think of to test them, I’m all ears.
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As the Z is moving down/up, maybe it’s also moving left/right. I think the bit is perpendicular to the spoil board, but if both the left and right sides were skewed to one side, then each layer in Z would be offset in X.
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Maybe the wheels have some hysteresis. Possibly moving more left after a clockwise rotation. Something like that. The right side is flush against the table now, and I’ve seen that a couple of times, but it just now clicked that it might be the issue.
I’m going to test this same thing in foam, to eliminate all my speeds and strain. If it still has the steps then it’s something like one of these, or it’s maybe something in grbl, but I haven’t had issues before with it.
The slope of that pipe on the right doesn’t match the slope of the steps at all, so I’m thinking it’s not likely #1.
Those z rails really need to be perpendicular to your work surface. That could cause your steps.
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I think it’s #2, and I think it’s some goofiness in the carriages.
I measured the squareness of the pipes to the z carriage part, and they are very square, but the carriages themselves aren’t doing so well. All these pictures were taken without rotating the camera.
You can see that the back wheel mounts are to the right, and the front ones are to the left.
I am also sure the table (under the spoil board) is square, and before turning on the motors, I’m making sure that each carriage is flush to the front of that table.
I think I just need to nudge them a little in the right direction. I’m not sure why they are tracking differently front to back, but my guess is that this is just happening over a lot of movements (and probably exaggerated with some missed steps, or mistakes I made earlier). Maybe I should make some kind of bracket to adjust the square before I start the machine…
It looks like I’m arguing, because of the order of the posts, but I saw this after I responded. I agree with you. I think the goofy tracking is what caused them to me misaligned.
I was able to nudge them back to aligned. The bottom wheels touch the bottom of the table, but I can still turn them. I’m not sure if that’s a good or a bad thing. Maybe they should be tighter?
I also have been driving “off” the front, where the thing is only supported by the top wheels. That might be a problem. I can fill that area out with more material, but I was hoping it wasn’t necessary.
Yeah the rest looks good, really good. Hang that square off the table and see how the z rails are, I bet you have a parallelogram.
(Finished my quad, gunna go maiden crash it…Be back in a bit. With pics!)
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As soon as it moved, it tracked back to offset (in the same direction).
Don’t really understand it, but I think it’s the pipe joint. When I move the carts back to straight, the pipes are no longer square… Makes some sense, sort of… I can’t think of square in 3D…
I’ll see if I can force the carts to be square, then adjust the pipes until they are also square. Didn’t you suggest it was // or \ like a week ago ?
Pfft. California… 10in of snow today, and counting. Which is the main reason I’m in the garage with the LR, and not in the shed with my table saw.
Crashed it…never even left the ground had to remap the motors, gunna try again.
Cali is great, but we pay for it in rent (cuz we can’t afford houses here), and it isn’t perfect there was a mud puddle and I’m wearing flip flops, could have been horrible. 
Well, I am circling the drain, and I have a workaround that is working for my simple test.
The Z rails (the 11" pipes) are square to the table top as long as the wheels are in line. After moving forward and backward, it gets misaligned. I thought I could fix that by loosening the connection on the long pipes, but duh, I can only make them shorter, longer, or trapezoidal by moving those. But they are a parallelogram. I think I need to reprint the little pieces in the middle of that joint, at least, maybe those entire joints.
But, I do have a neat workaround. Like I said, the root problem (I think) is that as the wheels turn, it’s getting off track. So I ripped some 3/4" plywood into some strips, and installed them 1" from the edge of the table. Then I loosened the long pipes, and pulled it together so the wheels were touching those strips. I could do it on the bottom too, but since there aren’t pipes pulling the bottom together, I’m not sure how much it will help.
Photo of the hack/track:
Before:
After:
( It’s the middle one, it’s a little blurry, but it’s smooth IRL )
Something is not square. I have a suspicion that it’s either the printed joint, or one of the screws that holds the wheels on is bent.
I can tell from where the hack/track is touching the wheels that the front left and rear right want to move past the track. There is a small gap in the other two wheels. The original cut edge was pretty sharp, so I rounded it over with some sand paper before installing it to try to reduce the wear on the wheels.
I don’t think the hack/track is the right final solution, but I have something I want to cut today and I think this will get me moving until those parts are reprinted.
Whatever works!
:sad trombone:
Once you get it working, make sure your plywood you are cutting is flat! So far I’ve been able to make big pieces of plywood into smaller pieces of scrap plywood. Haven’t cut a good part yet… I have it set to cut 20mm deep to cut 3/4" plywood, but it’s going almost 30mm, not sure what’s happening there, then I have it set to have a 10mm clearance for rapid moves, but it’s dragging the bit. Buying flat plywood at Lowe’s is impossible, all they have is boat plywood. I tried to use a screw in the middle of the plywood to hold it flat, but after 10 minutes of cutting it pulled out of the hardboard I have my table made out of. Because of the height difference, my holding tabs aren’t being cut, so I just had a part pop up and the router bound up on it pulling everything out of zero.
@Barry, OUCH. You think it’s just due to the incoming plywood? Is your table flat enough? You could take the plywood off, and manually move around to see what Z value it is at a few locations. I have a 3/4" Red Oak spoil board, so the screws are holding well for me, but I haven’t cut anything huge yet.
The hack/tracks are working well. I’m working on a new fence based on John Heisz’s plans (ibuildit.ca).
I cut a the CAM handle, but didn’t take a pic before I glued it together. Then I cut the words “HEISZMEYER” into the top piece (Biesemeyer is a popular aftermarket fence).
I also recut the table saw zero clearance insert in foam, but I haven’t tried it again in plywood yet:
I don’t know why I don’t use foam more often, especially for prototypes. It’s cheap, fast, and you can just push it into place to see where it’s failing.
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The thing that seems very strange to me is that my vertical pipes seem to be very similar to yours, but mine seems to pocket just fine using 3mm steps. Granted I’ve only cut about 7mm deep so far and all in mdf.
But multiple parts from different areas of the table all line up perfectly when I stack them. Turns out yesterday’s cut didn’t even have the bottom wheels on the near side touching the rail.
very very strange.