This is a tough one for a rigid coupler because of the high chance of one side lowering before the other. Damage is sure to happen. This needs some ability to bend, so either a flex/hinge mount at the nut or trap the spring coupler a little better with two bearings. I am not sure.
Or the new anti backlash nuts for these rods might add enough friction to help hold it up by itself then we can switch to rigid couplers.
As soon as I start my machine, the motors are powered, so as long as they start at the same height, and they never skip steps, they will stay ālevelā. I am nervous to give it a big piece of plywood to see if itās an issue. Maybe thereās something I can do to force them to me right when I start it. Like twist the screws up to remove any slack before powering up.
I got much better results with the mpcnc (pre 525) when I pulled the x/y tight to square it up while plugging it in.
I should also test drilling to 3mm or so in several places in the spoil board and see what the variance is. This table is much flatter than my mpcnc was.
I see what you are saying, like a preload from the start. I have never looked at that, but makes sense. The stuff I have done was a cut all the way through so if the edges were at a half a degree angle it would not have mattered either. That could be checked before you start with a jog to the other side and see if it is still at the surface (or whatever your zero point is). Check the z zero nearest you, jog to the furthest side of your material check for the z zero, adjust by turning the leadscrew if necessary.
Interesting, I have not looked at this, but it could be a bit of an issue.
So, Iām having a problem. Sorry for the crummy picture.
I was skipping steps the first time I tried this gcode, and I upped the stepper output and tried again in roughly the same place. The first cut only made it 2.5mm deep, so thatās why there are all those mess ups on the top.
The really issue that I canāt figure out, is the leftmost side in this image. It has those wavy cuts. It was cutting a pocket, then going around the outside, then cutting the next depth pocket. So on that left side, it had already done the pocket and it was moving from close to far every pass. Itās hard to tell from the perspective, but the waves were getting bigger not smaller.
Any ideas on whatās causing it? The other side (counter clockwise) was perfect. The left side of the right side of the pocket also had the waves, but to a smaller amount.
Bit was 1/8" downcut, 2x. Not brand new.
Linear speed was 15mm/s. Depth of cut was 2.5mm/pass. Material is plywood.
You can see the cart in the image, but in case itās not obvious, toward and away from the camera (I call that y) is on the roller wheels. Left and right (I call that x) is on the long rails.
This is a plate for my table saw, and itās possible it wouldnāt have fit with a perfect cut, but it seems like itās not removing enough material, not that itās removing too much.
I measured the period, and itās the same as the period from the pocketing. I think the pocket made the pattern and the clean up passes were either in the wrong place, or the machine was flexing and not cutting smoothly on that part.
So that explains the pattern.
Hmmm. I could do smaller depth cuts. I could replace the bit. I could change the pocketing scheme in EstlCAM. I could just recut it without the initial screw up. Lots of variables.
Here is the .e10 and .gcode, if anyone is interested. I think Iāll peek at the gcode a little, to see if itās somehow a CAM issue not lining up the pocketing with the trimming. Then Iāll probably just cut it again and see if itās reproducible.
Huh. I made a 10mmx100mm box, pocket, linear 15mm/s, 2.5mm/pass. I was expecting to see the same waves. I didnāt, but I thought it was ok when I noticed the right side wasnāt lined up later to layerā¦ So I put in a new bit. Similar, but it was the same behavior, but a little less.
The Gap is wider than 10mm, so I think itās skipping steps at some point. Weird that itās skipping a small amount, exactly the same on each layer. I am guessing itās during the plungeā¦
I am thinking both these problems fall into āJeff needs to learn to CAMā.
Your gcode looks okay, I usually tell it to put a speed on every line but I donāt think that is an issue.
I am pretty confident you have an angle on your machine somewhere. From your camera angle something looks to be angled high on the left. If you cross section it is the bottom of the cut flat, or angled?
Coloradoās just a 20 hour drive. You could be here by breakfast. Err. Dinner.
Thanks for looking at the gcode. Here is the box cutout code. Dead simple though.
The big cam mistake Iām making I think is plunging. I wasnāt cutting 2.5mm/pass before, and I donāt think I have that plunge angle right. Plus Iām using a downcut bit. So if it skips a step after plunging every time, then that would explain the stairs. Skipped steps have to be whole steps, right? You canāt skip a 1/32 step, so that might explain the consistency.
Looking forward to seeing the pics. So far no two have been the same.
