Shapeoko Pro 5 Stepper Stutter

[markpjacobs (Mark)]

While working on an end grain board, the steppers began to chatter rapidly, and then the machine unexpectedly moved up the Y axis, ruining the board. Any idea why this might have happened?

1. I made sure there were no obstructions.
2. I’m running it again to ensure it’s not a G code issue.
3. I have successfully made around 20 of these with no issues.
4. My feeds and speeds are slow
   
   
   
   .

[WillAdams (William Adams (Carbide 3D))]

Are you cutting a slot as narrow as the tool?

Where possible avoid slotting and add geometry and cut as a pocket

Making vacuum hose adapters

While cutting up vacuum extension wands for this is expedient, it’s a bit problematic given that Shop Vac recently filed for bankruptcy, was bought at the last minute, and production hasn’t caught up. I need a receptacle for the Sweepy 2.0 dust fitting — one option would be to purchase one from Woodcraft, but Carbide 3D sells blocks of HDPE: which looks to be just barely big enough for things to fit. Measuring the hose fitting I get a diameter of ~63.5mm — offsetting that twice we arrive at…

and/or

Adding geometry to cut as a pocket with a finishing pass

One technique which is often suggested to avoid slotting is to add geometry around a part which one wishes to cut out and cut as a pocket down to tab depth — here’s one technique for that. In this case, the project is a bevel gauge which will be cut out of 0.0625" (~1.5mm) thick aluminum: [bevelgauge] Due to the narrowness of the angles, an 0.03125" endmill has to be used, so after importing and scaling the file (we will be cutting out one which is 3") we select the perimeter and offset it tw…

and consider leaving a roughing clearance and taking a finishing pass.

Best Bit for full cut through

One which has a cutting flute length equal to or greater than the thickness of the stock — pretty much any tool should work. Big thing is the toolpaths — if cutting out, rather than just cutting a slot: [image] Offset to the outside by endmill diameter plus 10% or so: [image] [image] [image] Then cut as a pocket: [image] down to tab height or the penultimate pass: [image] then move the contour down to below the pocket and start cutting at the bottom of the pocket: [image] and…

[markpjacobs (Mark)]

@WillAdams

Are you cutting a slot as narrow as the tool?

Where possible avoid slotting and add geometry and cut as a pocket

Thanks for the response. Unfortunately I don’t believe this is my issue.

I’m using a 0.5mm ball nose with a 12.4-degree taper for deep inlays, approximately 0.25 inches. I’ve never encountered any issues with it before today. When I reran the program, the problem didn’t recur. I would really like to understand what went wrong, as it ruined a commissioned project. All ideas are welcome. Also I use Vcarve Pro, carbide motion 622, so maybe just a little out of date.

[Chaotica (Joel McKenzie)]

The stepper motor wiring connectors are likely suspects. If you jog your machine while gently flexing/straining the connectors/wiring by hand & the axis grinds/stutters/stops, that’s your issue. The connectors are notorious for giving intermittent issues - seemingly fine for a bunch of runs & then screwing up for no apparent reason. One thing to do is to secure/tie them to prevent strain on them. If that’s not enough, you can look at getting a new wiring harness. Or you can cut off the connectors & put new ones on or even hardwire the motors - Carbide3D will obviously not support this last option but it is the most dead certain way to make a secure connection that will hold up under machine vibrations.

If it’s not the wiring connectors, then the next thing to replace would be the controller board.