X-Axis is Jittery/Skipping

[MitchTalmadge]

Mayo, thanks for the awesome suggestions! I'm not sure of the exact software version, I will get back to you on that.

We did mess with the turnbuckles and pinions. I didn't think too much about getting the pinions squared up, so that along with the turnbuckles probably being at different tensions might be what is causing the issues.

The CNC does have hard stops installed on both x rails. I'll try on Monday and see if I can square up the pinions, thanks so much for the tips!

[MitchTalmadge]

So today I tried realigning the pinions, and that didn't do anything. I was pretty surprised, I definitely thought that would fix it. So I did something suggested to me by a couple of you guys and someone on my YouTube video and lowered the pinions from the rack and jogged the x-axis. I noticed that X-2 ran perfectly smooth, but X-1 was really having a hard time, it was doing exactly what the jittery movement looked like, except it was not attached to anything. I swapped the X-1 and X-2 ports on the driver board to see if it would do anything, and then X-2 made the same bad movements that X-1 was making, and X-1 was running smooth again. This told me that the motor was good, as was the cable, and that the driver board must have a "tired" port as Brady told me in the very first post.

When I tried moving X-1 to A earlier, X-1 wouldn't move at all, so I figured that port A was dead. I guess I jumped to conclusions, because this time changing A to X-1 DID work, and the machine is smooth and fast again. I also reset the ramp settings to default, and now it cuts great, it sounds great, and I'm happy knowing what the issue is. I feel like even though I lead everyone on a wild goose chase, I learned a lot from messing with the ShopBot and reading manuals, a lot more than I did before I started this topic. Thanks for all the awesome support you all gave me, I am happy to have a working machine again! I love ShopBots!

(P.S. Is there a known way of fixing "tired" driver boards? I am not sure my school has another $1500 to spend on one driver board, so I'd like to get as much life out of this one as I can until we can raise the money to get the upgrade. It sounds like if another port goes "tired," we will be out of luck)

[scottp55]

Congrats Mitch! Way to go.

[Brady Watson]

You'd have to pull the board and visually inspect it - looking for burnt traces or fried components. Often they can be repaired, but you might want to call SB and see if they still repair them. Otherwise, you can look for a used 3G board someone might have for sale.

-B

[MitchTalmadge]

Thanks for the info Brady