Middle assembly tension bolt "C" bearings not touching conduit

Mostly Printed CNC - MPCNC Troubleshooting
1

Title says it all, I’m trouble shooting some chatter during curved cuts (think rounded rectangle corners).

I re-read over the assembly guide about the middle assembly. The guide mentions several times about the various tension bolts, but I want to make sure I’m barking up the right tree. Link to photo below. All parts were purchased from Ryan’s shop.

https://gyazo.com/8627023801993a48b50f96c5b7928203

The yellow circles are bearings that are not touching the z-axis, or are hardly touching the z-axis. Will tightening the green arrows help correct this? If not, any other advice?

I’ve been pretty happy with the quality of my cuts up until this point, but now I’ve started cutting white oak which is much harder than the pine plywood I’ve been working with previously, so I believe now I’m pushing the limits of my current mis-configuration.

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2

Yes, the bolts with the green arrows will tighten the bearings around the Z axis rails. Tighten each one until the bearings are just touching the Z axis rails and that should be enough. No need to go tighter.

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Beautiful, thanks for the clarification, I’ll give that a shot.

4

A common mistake lately has been two missing bearings it the very center on the 5" bolt.

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Yeah i definitely had to go out and check to make sure those are there, I wasn’t sure what you are talking about. They’re definitely there.

I also tightened up tension bolts C so that all 4 bearings are now touching+rolling on the Z-axis.

I think I can still hear some chatter though, especially when doing trochoidal cuts in white oak. I can’t say I noticed it in my plywood prototypes.

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6

Give it a little time, use it. Then at some point take the center apart swap the XYZ parts and put it back together. That usually solves it.

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