Dimension changes with Fusion 360 post processing

Hi

I’m a newbie to CNC and am starting to get the grips with Fusion 360, Easel and my new X- Carve. I have an issue I’m struggling to resolve - I post process my designs in Fusion using the Easel post process via the Fusion 360 cloud library and then import the gcode. However, the object is 10% larger in all dimensions when I mill it. I’ve checked and confirmed the dimension in Fusion 360 and am sure I have selected the right bit. Any help will be appreciated!

Ian

Welcome to the Forum.

How well has your X-Carve been calibrated?
Steps per mm is a crucial factor in making sure your machine moves 1 inch when you tell it to move 1 inch.

That being said.
I do not use Fusion360 an am not familiar with it’s Post processing. There may be something there, but I’d look at machine calibration first.

Check this, find a ruler and measure the actual travel when jogging say 10".
If you in Easel only, draw a 10x2" retangle, set carve to Outline, what are the measured dimensions?

What size are your obejcts BTW?

The symptom you experience most likely do not stem from F360/PP, its likely a step/mm issue, as Robert suggest.

Hi

Thanks for the response. I spent quite some time on it and get 0.08mm - 0.10mm over a 100mm distance and also checked the square on the X/Y by cutting large rectangles and get a 0.05mm - 0.08mm difference on the diagonal measurement of a 100mm x 100mm square.

I’m not sure, but I think that’s reasonable.

I tried the test cuts from Fusion with 2 different design - one a more complicated design, and the other a simple cube, but got the same results from both files.

Object sizes are 50mm x 80mm and the test cube was 40mm x 40mm

Just to add - I will check steps/mm again

Can you share the Fusion file along with the expected and actual dimensions?

If a shape designed in Easel come out carved samze size as design, then steps/mm is not the issue.

Hi All

thanks for the advise. after resetting GRBL settings and re-calibration the issue is now resolved.

Ian