After all this the machine was still occasionally hesitating (losing steps?) during the X-Y movements for several seconds, but I did not notice anything on the Z axis. Maybe it was but I did not notice. But now the Z seems to be diving during the cut?
It could be a USB issue (bad cable or not enough current from your USP port) or overheat of the driver chips?
It looks like it may have missed some steps going around the main curve?
Also it looks like some of the smaller circle cutouts are a bit oblong? Or are they ellipses? That “tilted circle” effect is usually happens when a belt it loose.
When my aluminum cuts went bad it was in in the deep cuts about 80% down. I think it was runout in my 1/8" bit adaptor. The bit would hit against the cuts sides, deflect into the material taking a more aggressive cut. (It would always do this in the same spot, something about the motion and geometry) This would cause it to flex and deflect even more. In some cases binding and breaking the bit. I switched from a profile cut with 100% of the bit, to a pocket cut.
I made an outline of the object 40% of the bit width larger and cut the outline as a pocket with a 40% step over so it was done in 2 passes. I did this for all but the last 1.3mm. Then I did a normal profile cut with tabs on the remainder.
The extra bit of clearance in the cut made the difference.
Hi Aaron, thanks, and sorry my file is not available, maybe the problem is on their server.
I am wondering now that you mention it if it might be the USB as well. I as wondering if it might be the Arduino but if it is just the USB I would be thrilled.
Yes I agree with your assessment of the bit hitting the walls. I have seen that as it gets toward the bottom, sometimes it will start to bounce. I put in the stiffener mod this week so keeping an eye on that. As a note I cut through quite a few aluminum parts prior to this in the last few days with little problem. The only persistent problem has been the hesitating on axis movement. It sits still for several seconds then begin moving again. This has been going on both prior to and after I did my voltage tuning. Do you think this is caused by a loose connection in the USB port?
I am wondering as I was out of the room at the time but in the pics above when it went crazy I swear it stopped and lifted up on the Z axis and set down again like it was starting the part all over. This was just before I intervened to stop the part. USB?
Yes you are right on the belt tightening I saw the ellipse as well and need to do that again.
One way the Z axis gets off is a loose connection or missed steps keeps it from rising up when it should so it just keeps going deeper.
But the Z axis moving when it shouldn’t is bad. That could be a bad controller.
My XC started to get a lot more “sloppy” suddenly, it turned out it was one of my Z axis wheels. The bolt was slightly bent and the eccentric nut hole was stretched out just a bit. So it would not tighten up properly.
It probably happened when I had things crash and the force bent it.
The major USB issues seem to be:
The supplied cable goes bad. A few people had this happen, swapping cables fixed it.
The Adriano is actual powered off the USB connection so if your ports can’t supply enough current strange things can happen. Adding a powered USB hub will fix this by providing stable current to the Adriano.
I would double check that you don’t have any aluminum filings in your controller housing, just to be safe.
Yes you really got me thinking as I know the USB connections are very sloppy on my laptop, so I need to address that first. I had a couple good slams also, 1. when I thought I had it set on MM and it was on inches during the set home process, and 2. you can see from the pic some real grinding halts. Not sure how these dramatic halts effect or can overload the Arduino board.
My unit is not where any filings can get at it but yes always good to check that.
Have you calibrated your machine; NOT the same as adjusting the voltage.
How much wood have you cut on your machine?
Have you performed any X or Y rigidity mods?
Aluminum on a non rigid machine is pretty tough. Especially as a first project.
I hate to say it, but Easel’s CAM is not the always the best. Using Fusion 360 or a different CAM package may be better. Their cutting strategies are much smarter such as adaptive cutting, chip relief, helix and ramping during cutting, etc etc…
Good software can workaround hardware issues that the X-Carve has (I.E. a weak Z axis).
If you are sticking with Easel, at least lower the Plunge speed. A lower plunge speed will give the bit more time to cut the material before the X-Y operations begin.
The stock unit is going to have some issue with cutting aluminum and when the bit is forcing along a cut for a while the resistance can cause the code to get a little warped in the translation… also determining on the bit you are using. Lots of these guys do aluminum fairly regular so someone should see what is going on!