Z-axis zero Error

[Anonymous]

hey guys

so im new to fusion and the cam side of things 

2.0.10440
Active Plan: Fusion 360, Personal
Windows 10 (19042)

my issue is when i setup the tool paths in Fusion and set the Bottom, Top, retract heights etc.

i set the zero at the top of the part (its a 6mm pocket cut in 12mm material i want ) and set the retract heights etc as low as possible ~5 mm from the top of the part, run the simulation etc and tool path looks good, but when i go and run it through UGS suddenly the overall tool path from top of retract to bottom of cut is around 23mm and it bottoms my endmill out on the alloy bed, i set and home the x/y/z axis and zero on the top of the part as per Fusion but then it retracts more than i specified and plunges into the material before the lead in toolpath kicks in (desktop cnc el cheapo to practice before buying something more substantial)

i have attached a copy of the g-code i used if someone can point out what ive done wrong 

hopefully its something stupid i have done and and easy fix but if not i can provide screen shots etc of what im having issues with.

[seth.madore · Accepted solution]

Your NC code is going to a max depth of -8mm and your retracts are 5mm above the part. If you are getting something different at the machine, it's likely that you've not properly established the length of the tool in your controller, or you've not defined the work offset properly (again, at the controller)

[Anonymous]

Hey Seth

thanks for that, so just so i understand this correctly, if i zero the tool at the top of the part it should retract 5mm as i wanted then begin the plunge helix, however at the machine its trying to retract the entire depth (14mm) then plunging striaght down into the material to about the -8mm before starting the helix plunge and then trying to go deeper again, im not sure if im using the right Post Process for my machine if that makes a difference, as its one of the little chinese 3018 machines(but with a 500w spindle) 

[johnswetz1982 · Accepted solution]

There are 2 different offsets, one for your tool, and and one for your work coordinate system. What post are you using/attach if you could.

[Anonymous]

Hey Guys

thanks for the ideas, so i tried using a couple of different post processes after i went through and re-checked tool length and co-ordinate system points etc, my tool length was right but my stickout below the holder was incorrect, after fixing that and reducing the retract heights (my setup only has about 40mm of z-travel atm) i got it to cut as it should, admitedly only a 5mm deep circular pocket but its a start and points me in the right direction for future projects. so thanks again