Carvey X and Y axis drift during plunge

Hey guys!
I’m having an issue where both X and Y axis of the Carvey drift up to +1mm when plunging into material.
I guess the force from the bit makes part of the construction flex… There’s definitely some give in the spindle mount itself, as well as in the belts/stepper motors, but I’m not sure if you can really improve that?

The deeper it plunges, the more it drifts, as can be seen in the two images for both X and Y axis - this gets even worse when carving tougher materials like hard wood and aluminium.

Any idea how to improve this?


Has anyone else experienced this problem?

Any help is greatly appreciated!

Hey @RasmusHauschild,
Good to “see” you again!
Are you generating toolpaths with easel?
Can you give any more details on your settings or share your project?
In general, slotting is always the hardest on the machine. How long is your endmill?

In general, I think we should see better results than that on the Carvey. I definitely try to keep my depth of cut shallower, but in that material I wouldn’t expect that much deviation. Really looks like mechanical slop somewhere.
:frowning:

Hey @NeilFerreri1 !
You too! Thanks for reaching out to help! :blush:
The paths are generated in Easel, but I also see the issue when using Fusion360.
Here’s a link to the Easel file: Easel - Carvey drift test
And I’m using this bit from Inventables: Solid Carbide - Fishtail Spiral, Upcut Bits- 1/8 in D | Inventables

I have tightened the belt on the y-axis, but that didn’t help much, and the x-axis seems to be tightened all the way already.

Perhaps there could be an issue with the stepper drivers that causes the motors to not have sufficient power?

Thanks for helping out!

Probably not…motor drivers typically work or they fry.
Is the issue only on the plunge and retract? It’s hard to tell from the pics if the lines are parallel to the axis of motion.
Can you try a simple square, maybe a bit smaller than your other tests? If you can get a video, that’d be helpful.
Workholding good?
Endmill tight and straight?
Collet secure?
Is the slot width exactly 3.175mm wide?

Hi Neil,
So sorry about my late reply! Work has been crazy over the summer, and this completely fled my mind.

The drifting seems to only occur when plunging and retracting - this then offsets the rest of the line.
I have carved two squares (35x35mm) with 0.8mm and 2mm stepdown - with plunge and retraction taking place in the bottom right corner of the squares.

I have also recorded a video of the 2mm cut here.

Workholding is solid.
Endmill is tight and straight.
Collet is secure.
Slot measures between 3.15mm - 3.20mm

I have also noticed that when tugging (even gently) on the bed or router, I can see/feel the wheel of the stepper motors turn slightly, so that seems to be where the give is.

Is this normal, or could something be wrong with either steppers, driver board, or powersupply, etc.?

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Hey Rasmus,
When you say you can feel the stepper wheel move, dudes it just move a little bit then hold pretty well? Or does gentle pressure cause it to continue to move.
If it just move a little, you might just need to tighten your belts.
I can get pics tomorrow showing you how.

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Right, so when I tug at the bed or the router while looking at the shaft of the stepper motor, I can see that the shaft itself is rotating slightly when it should be held in place firmly - if I add a bit more force it starts skipping, and the bed or router slides.

The stepper motors seem pretty weak, but I’m not sure if that’s just how it’s built?

I did actually tighten both belts, but it didn’t seem to make a difference, so I think the problem is with the steppers themselves.

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Any chance you have a slipping pulley?
Can you get a video to show what you’re seeing when you see the shaft move?
Are you generating the guide in easel? Can you share your project? I can try running it on my machine.

2 Likes

Here is a video of the pulley on the bed with a hex key in the screw hole to make it easier to see how much it turns: Video1
And here is a video demonstrating the amount of force that makes the steppers skip (it’s actually less than it looks like): Video2

I don’t think the pulley itself i lose, as you can hear the motor changing pitch when tugged at.

EDIT: here is the Easel file: Easel

And thanks again for taking the time to troubleshoot this with me! I appreciate it!

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