topic CNC Z axis higher than expected in Fusion Support Forum

CNC Z axis higher than expected

Djrose093 — Sun, 11 Oct 2020 19:23:34 GMT

I'm brand new to CNC and Fusion 360 but I've done a lot of searching and tinkering trying to find a solution before posting here. No matter what settings I change the Z axis is about 2mm higher than desired. To get anywhere near the level I need I either have to set negative offsets for the top and bottom heights or zero the machine below the surface of the material I'm cutting. I don't know what else the issue could be and its getting quite discouraging having every cut be the wrong depth. Any suggestions and advice are welcome. Thanks for any help you can offer!

Re: CNC Z axis higher than expected

Richard.stubley — Mon, 12 Oct 2020 08:06:17 GMT

Hi, What machine do you have?

What controller or software are you using to drive it?

Are the co-ordinates as expected for example if you are expecting the cut to be at Z-1 is that where the machine is telling you it is?

Top tip: You can right click on a toolpath and view the moves in the WCS co-ordinate system so you can see the co-ordinates that should be output.

Re: CNC Z axis higher than expected

Djrose093 — Mon, 12 Oct 2020 22:16:46 GMT

I'm using Candle, the user guide that came with the CNC machine suggested it. Although if there are any better suggestions I'll try them. Candle doesn't behave on my computer.

After viewing the toolpath as you suggested the Z is at 2.5 when cutting starts and never even gets to 0 to make contact. So that confirms it is an issue with my Fusion 360 settings at least. I just have no idea what.

Edit: When I do Simulate in Fusion 360 everything looks correct there. It makes contact quickly and goes the correct depth.