X/Y Drifting ...And QUESTIONS

After I purchased, and assembled my X-Carve, it broke a couple bits during cuts, and I immediately had to replace the 300W/24V spindle, due to the common noise issue. After replacing the spindle, the Y-axis would stutter and drag when attempting a rapid movement. I browsed the forum, and learned about the pots on the gShield. All the pots were set at 25%, so I adjusted all of them to approx. 50%.
Now, I notice X and Y are slowly drifting to the right, and to the back, during cuts. (This may also be happening to the Z-axis, but I have only focused on X and Y) The drifting becomes noticeable within the first minute, or so, and then progressively becomes much worse. When I turn off the spindle, and do an “air” cut, it does not drift, and always returns to home properly. When I turn on the spindle, and do an “air” cut, it always drifts, and will not return to home properly.
These issues have broken several bits, ruined a lot of material, burned a ton of my time due to repetitive troubleshooting, and basically render the machine useless. I really need to get the X-Carve working properly.

If the spindle is the problem, is there a better spindle upgrade for the X-Carve? I noticed others on the forum like the Dewalt 611, but I thought the 300W/24V spindle was the best, so I’m a bit uninformed, I guess.
Please, help me get my X-Carve running.

What’s the difference between the 300W/24V spindle, and the Dewalt 611?
Which is better?
What is the proper setting for the gShield X/Y/Z pots?
Is there a maximum setting of the pots?
Shouldn’t the gShield X/Y/Z pot adjustments be part of the assembly instructions?

Thanks, in advance!

The Dewalt DWP611 is 1.25 hp which is equal to about 930 watts. So in rough terms the Dewalt is about 3 times as powerful as the 300W spindle. The reason the extra power is good is because problems occur when the spindle speed slows down due to a lack of torque when cutting. The 611 has a feedback controller that works to keep the spindle speed constant no matter what you are cutting (up to the limit of the available torque)

In practical terms the more powerful 611 will allow you to increase your feed rates and DOC to the optimal amounts needed to minimize bit deflection (chatter)

If you are up to the challenge, the best spindle option is probably an air or water cooled 800W AC induction spindle driven by a VFD. It is a harder to set up, and the mount (the same mount as the 611) requires some shimming material to get a good fit. But it is dead silent, much quieter than the stock spindle.

The 611 is probably a bit more powerful, but it is a noisy as hell, and it doesn’t have the accurate speed control you get with the VFD.


What is the proper setting for the gShield X/Y/Z pots?
Is there a maximum setting of the pots?
Shouldn’t the gShield X/Y/Z pot adjustments be part of the assembly instructions?

No easy answers here. Depends on the stepper motors you have installed.

When my X-carve came the pots were set to limit the current to the stepper motors to 0.9 amps per phase. The maximum current per phase the gShield can deliver is theoretically 2.5 amps with “appropriate cooling”. You may be able to get “appropriate cooling” in the lab, but in the real world you’re not likely to get it. Certainly with the fan that comes with the X-carve you are not going to be able to get that much current.

The NEMA 17 (part #25253-01) can handle 1.68 amps per phase.

The NEMA 23 (part #25311-05) can handle 2.8 amps per phase.

Check this thread for information on setting the pots to a specific value.

Allen, Chris, Larry…Thank you! Great info!
It seems to be the spindle, again, so I’m going to try the 611 this time. Can’t take a chance with another 300W going bad.
Thanks, again!

I saw this new 611 on Ebay for $100 with free shipping


Thanks, Allen.
I noticed the 611 has a 1/4" collet. My bits are all 1/8". Is there a 1/8" collet for the 611?

Yes there is, I bought a 4mm and 6mm collet here, but they have 1/8 inch also.

Or you can purchase a 1/8 inch adapter here


And, another big THANK YOU to you, Sir! :smiley: