@pawel.piela1
Depends on what you have set for a finish pass and how you worked out the DOC for the amount you need to rough out.
An example would be a 50mm bar to turn down to 35mm, that is 7.5mm on the Radius so a reasonable DOC would be around your 2mm value. So, say we divide the 7.5mm x 4 which gives us a DOC of 1.875mm which is fine if you are not wanting a finish pass.
However if we put in a finish pass that alters the last 2 roughing passes so if you want a decent DOC at this point then set a decent amount for the finishing pass, in our example above if we input a finish pass of say 1mm then the last 2 roughing passes will be reduced by half the finish pass amount so the 1.875mm DOC will become 1.375mm on the last 2 rough passes to leave you the 1mm for a finish pass.
Some folks will just use the diameter with a finish allowance and divide that equally for example instead of setting a finish pass we could just divide the 7mm x 4 which now gives us a DOC of 1.75mm and there will still be 1mm left for a finish pass.
There are many ways to adress this, just need to do a little math to get the desired DOC instead of just going for an arbitrary DOC that is good for the tool and chipping and ending up with a small last pass as you have.
Sort of adresses what your issue is, hope it is of some help, I am not the worlds best with the Turning side of Fusion as most of the time I am just changing numbers in Fanuc Canned Cycles that I have in the Lathe memory, old school, way faster and easier than using Cad-CAM software for a lot of jobs 🙂 🙂
@VicKosta will probably give you a much better answer on this!!
Regards
Rob
Fusion
