I was milling some aluminium today - and was getting allot of chatter - after a minute it got so bad the machine spun out. Luckily nothing was damaged other than a clamp.
I went on to inspect and found my X axis carriage was loose - usually I would just rotate up the eccentric nuts - however after 360 degrees the V wheels were barely gripping.
I then took the whole carriage off - and tried to lower the top V wheels a fraction lower - with no luck.
I went on to replace the V wheels, eccentric nuts to no avail - whilst the carriage is on the tracks and wheels spin when you move the carriage, a finger gently on the wheel will stop it. Even on it’s tightest setting.
I’m at a bit of a loss as to what it could be - I’ve always struggled to tighten the x carriage wheels to a suitable tension. There is no obvious damage to the screw holes or the plate.
Any ideas?
I was wondering if I should fit eccentric nuts to the top of the carriage, but not sure if it’s a suitable/good idea.
I’ve emails C3D, but I figured I’d also ask you guys.
I had the EXACT problem, and did exactly what you did and got the SAME results…upon further inspection, I found that the belt guide bearings were rubbing against the aluminum extrusion. I removed the two bearings and OD ground them smaller (until they cleared the extrusion. The details are somewhere here in this forum. I’ll look for it and link it. Once I stopped the rubbing, the wheels got tighter and the carriage was tight.
I had enough up/down in the bolt holes to get the wheels off my extrusion. I am now able to slip two playing cards between the wheels and the extrusion.
I would have thought that having the wheels ON the extrusion would have tightened things, not loosened, though. Thus my comment above.
Ok, there is (was) too much variation in the V-Wheels back then, so next, I’d try swapping them out for wheels in other (Y axis) location. It’s called tolerance stack-up.
FYI: Before MY fix, I even entailed the thought of making some eccentric nuts with 0.036" offset (from annealed Allen wrenches). I even wrote the program, but never needed it. (I think the factory nuts are 0.028 to 0.031 offset)
Morning guys - I wanted to post a successful resolution and thank @WillAdams and support and the rest of the guys at C3D.
As everyone says support is first class. 8 days after posting this a new X/Z carriage has travels 3000 odd miles to me in England.
Whilst I had to dismantle and re-build my X/Z carriage, I can confirm this has resolved my issue. Interestingly my original one is of a different spec and I measured between the holes and found I had a slight difference - 0.9mm on the right and 0.7 on the left - compared to the new one sent to me.
It appears the original was slightly out of tolerance - that said it has been usable till late.
However what I’d like to highlight is the constant improvement I see from C3D. Whilst I do have an early revision of the Shapeoko 3, many companies would say this is good enough. Wait a year then knock out a new version. Not these guys! They improve and re-build their contents feeding improvements in from all sorts of places.
The original X carriage does the job very well, but the new version has multiple enhancements, such as fixed motors and tension bolt for the Z axis belt.
Now these enhancements might help with assembly but they also help give us a more rigid assembly that is easier to maintain.
So hats off you you! Thank you and I will post some pics when I have some time