Wobbly Y Axis

Hey everyone! I’ve been having some issue with my Gantry as seen in the video. The belts are tight, all screws seem tight, the wheels are taught and everything seems otherwise fine but theres this play between the 2 sides of the gantry which isnt much but enough to throw off carves requiring more accurate cuts. Any idea what could be causing it? Its at the point where i have to actually measure the 2 sides to make sure they are equally distant from the front frame before i start the carve and even then it would walk slightly out of alignment during a carve.

Is there any fix or mod i could use to square the 2 gantries? Any help and advice is greatly appreciated!


Cool good to know! I just realized im still able to manipulate them easily even after turning on the machine though so im not sure if there could be a problem with my steppers

Is the controller powered up when you are causing this movement in the video? The reason I ask is the pulley is still rotating as you introduce the twist.

The xcarve design isn’t robust enough to keep that twist from happening with the frame itself. It relies on the belts and steppers to hold each side in place. That twist can happen during operation but it should only happen if you are losing steps on one side of the gantry. This can happen from low driver amperage, lose pulleys or driving a cut harder than the machine can handle which could cause the belt to slip or skipped steps with the stepper motor.

In this case, it seems your power is off and the motors aren’t holding the gantry stationary. When powered up, however, the belts can and do stretch when you attempt the same movement. Some stretch is totally normal and one of the limitations of the design. More robust belts improve the belt flex dramatically, and lead screws eliminate this movement completely.

If your machine is powered up in the video, it seems there is an issue of some kind as it should not be that easy to turn the right side Y motor.

Hey Jeremy actually the Xcarve is on while im doing it which is why I’m surprised. I only noticed recently that i can turn the gear even when its on. Not sure if it means i have to adjust the Amp settings on. My Y axes have independent driver boards (instead of both servos going to a single one) not sure if that affects anything…

I would suggest 3 things.

First, make sure your grbl settings for $1 show $1=255. That will make sure the motors stay locked up.

Second, check to make sure you aren’t cutting your current at idle

Third, check and see and possible up your holding current.

You’re also sure The Set screws are tight to keep the pulley from just turning on the shaft? Does the movement happen the same on the left side of the gantry?

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Interesting. Im sure the set screws are tight i already checked them.

How do i check the 2nd and 3rd suggestions?

Assuming you have the Xcontroller, Open the Xcontroller and turn off DIP switch #4 on all axis. Then try it again.

Are you using easel or something like ugcs?

If you are using easel someone else will have to coach you on accessing your grbl settings. If you are in ugcs, you can simply type $$ in the command line and it will give you an output of grbl settings. You can also skip this step and just type in $1=255 to modify the setting without seeing what it is first.

If this setting is anything but 255, the stepper drivers will disable after a certain amount of time.

Just turned off all DIP#4 switches. It sounds a lot stronger when engaged in motion but it still doesnt lock the steppers at rest =/ i’m wondering if it could be a code issue

Try this thread - https://discuss.inventables.com/t/stepper-motors-dont-lock/35251

Don’t assume it is anything else until you check/modify the grbl setting.

@HishamT_Bary, did you make any headway on this?

Hey JeremyHanks! Thabks for checking up on me! I’ll be modifying the settings tomorrow and trying again! Will let you know!