Point of origin/WCS issue

[Steve H]

I’m using Fusion360 for the modelling and cam but it seems that regardless of where I set the Point of origin (top or bottom) the CNC software always assumes it’s on the bottom. I’ve been through the Gcode and that seems right. Is this something anyone else has come across?

[Aze]

I'm using a R-CNC (not a RS-CNC) and it's working for me (Fusion360 CAM).
Sorry, I can't help you more than that

[Steve H]

Hi Aze
I’d be really grateful if you can give me any steers as to why, despite setting the origin and wcs in Fusion360 at the top corner of the model the RS CNC goes off and tries to cut above the surface of the job. The G code is showing -z numbers so it should be cutting down from the zero point. The only way I can get it to work is to zero the bit on the bottom...despite Fusion being set to the top. I’m sure it’s something stupid I’m doing but I really can’t see what. Any ideas really greatfully received!

[Aze]

To be sure, can you try to make a gcode with Estlcam and see what happens?

[Patient0x00]

Hi,

Let me try to rephrase your problem. Are you saying that the cutter is never going below the starting point on the Z axis?

If this is the case try to add G1 S1 at the beginning of the Gcode. This will allow negative Zs.

Once I get back to my computer I will post a modified post for F360 that set this parameter properly and also turn the spindle on and off and lift the spindle on the z axis at the end of the cut...




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[Patient0x00]

Attached is a modified post for Fusion 360. You can see the areas that I have changed by looking in the code and look for the comments // P0x00:.
The base post is from MPCNC_Mill_Laser ...

Let me know if you have any issue with it or if this is working better for you with it.

Frederik

[Steve H]

Hi Frederik,
Thats it! as soon as I put in the G1 S1 into the code it worked!

Thank you so much. I will download and run your new file as well and confirm that.

Thanks again

Steve

[Patient0x00]

Credits for the solution go to @kachidoki . Is the one who gave me the solution when I had exactly the same issue.




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[Steve H]

The new post file works great!

Thanks again for your help

Steve

[Steve H]

Just a slightly different issue, Ive noticed that at the end of the job ,with "Go to origin on finish", set, the z position is set to zero first and then X and Y are set to zero. The effect seems that the tool loweras to zero then just skims across, (if Im lucky) the surface before getting to X0, Y0.

Is that correct or am I setting something wrong.

Many thanks