Circles not consistent

Hi all,
I have carved about 180 holes (10mm) into piece of plywood. Some of them are circular but some of them are definitely more oval. Why is this? I checked the machine before starting and it was all square - plus surely if the machine was off all of the circles would be. Instead they are just randomly inconsistent.
Any advice much welcome!
Dave

Play (lack of rigitidy) in your system.

When carving the sideway force on the bit will vary based on tightness of wood etc and have different magnitude. Also if X is more rigid that Y then the deflection will be less on the stronger axis, causing a “loopsided” circle.

Any play/axis deflection on Z will also impact the results here.

Tighten up you machine and also try going slower/less aggressively for small circle holes.

2 Likes

Great - thank you!

Are there any ‘how to’ tutorials for tightening up to reduce deflection?

I am not much help in that department as I don’t own an Xcarve.
But that topic is covered quite extensively here on this forum so you might find some good tips by searching for “upgrade”, X & Y modification etc. The stock Z-assembly is also a weak link in the “non-rigid chain”.

A few things…

with the Xcarve having dual Y steppers, vs a single X stepper, the machine is stronger moving North/south than east/west.

Typically, things oval in the y+/- direction. but before i would be able to really help, i would need to know more.

how fast are you running the machine? Ply isnt the best test material, because if you aren’t using nice Baltic Birch, there is just no consistency in strength, density, etc over the average piece of ply.

do a grid of 15 0r so 10mm holes in MDF and note the speed. if you are using a 1/8" bit, its easy to push it faster than it can clear.

if you can give me more info, i might be able to help further

Hi there - many thanks for getting back to me. Attached are the cut settings - just went with what Easel recommended for birch plywood. It is proper baltic birch ply that I am using by the way …