SO3 XXL: Slop in X axis in Z plate,chatter etc

CNC Machines Shapeoko
1

Hi!

I just bought my second SO, this time the XXL, this one has been running for about 4 hours in total.

I am having a problem with some play on the X axis in the Z axis plate/assembly.
I think this is the reason I get chatter almost at any feed/speed when cutting… (Wood…)

I have tried reducing feeds and speeds with both 2 flute and 4 flute bits in oak, but still get a bad chatter in slots and also often just when the bit is cutting in general…

I have tried to locate the problem and thought I would start with stiffness.

The first problem I found was this:


I just press with on finger on the Z-plate.

I have alot of play in one of the V-wheels (Top left on Z plate).
I first thought it was just the eccentric nut not making enough pressure on the wheel against the rail.
Tried tightening this, but it was tight! Also check that the bolt/nut was tight!

It seems to be play in the bearing maby?

I also have ALOT (In my opinion) play in the X axis/Z plate in general… Is this the case for other owners of this model?

The movement is made by me just just on hand on the router and pushing/pulling on it.

Video:

All the V-wheels are tightened according to the guides regarding tightening of the eccentric nuts.
Have also tried “overtightening” just to see if this reduced the play in general.

Any improvements I can make or is this because of the V-wheel/rail design?

Hope to hear from you guys!

Morten

2

After looking on my own video, the last one, I think I see the bolt head moving in the closest wheel also, like in the first video…?

3

I have the same play, can minimize it a bit by tightening the eccentric but it still seems like a lot.

4

According to the guides, the nuts are not supposed to tighten the v-wheels against the rails with more pressure than that they just stops free-running.

This must be a production problem i would assume? My old SO2 has less movment in the z plate than this one :slight_smile:

5

I believe that we need to view the assembly as a convenience, but one which does not relieve one of the necessities of calibration and fine tuning, which may require some dis-assembly and verification of fasteners and alignments.

1 Like
6

I agree with you @WillAdams, but I am just checking to see if this was a common problem / design problem, or just something that happens when some of the fasteners/wheels are out of spec.

But I wonder if this V-wheel configuration is better or worse than the 4 V-wheels used on the SO2?
I would assume the stiffness in the Z-plate assembly would be better if they has a support to the back of the X rail as with SO2?

If I have understood correctly, the biggest problem with the V-wheels is in the axial direction, not in the radial because of slop in bearings or incorrect shimming of the spacer between them?