I'm stumped on this and just need help thinking this through. I'm essentially milling a cylinder from 1" square stock. I have 1 setup to mill one side using a parallel tool path, then I flip the stock 180 degrees and run basically the same tool path to make a cylinder. My issue is the top half is about 10 thousands off of the bottom. I have calibrated the mill till i'm blue in the face and normally I would say it's the backlash however it had been calibrated out and, after I run the first setup and flip the stock over, I hit "return to zero" and the mill will return to the same starting point within a thousands of an inch,. I'm thinking if my mill was off, it would not return to the exact spot to start the second setup?
Which leaves me with the way the CAM is set up. Any Ideas? I can reset my zero on the second set up and just move the Y-axis out 10 thousandths but I would like to have it run from the zero point I programed.
Hi, I see your 0 in X Y and Z is set on the edge of your stock, my guess would be that your stock is off .005 or so from what you have your stock set. When you flip the part over it doubles any amount that is off....I could be wrong though.
Thank you for your replies, I measured the stock that I am using and it does vary from 0" to .003". I should have perhaps faced all sides to get that more consistent though I dismissed this as an issue after the position was within .001" after flipping the stock. Could this be it I'm wondering?
Forgive my ignorance but can you elaborate on "Fusion Model" you would like to see? Do you mean the CAD drawing?
I measured how far I was off and it looks like I'm off .025" ???? I guess I was being optimistic. Again, this was with perfect zero settings On both sides. I've attached a pic with a crudely drawn arrow. Note I stopped the finish strategy half way throu to safe my tooling.
If you go into the File menu at the top and choose "export", a window should open that gives you some options.
On my Mac, there is a checkbox near the bottom of that window that says: "save to my computer", and that will allow you to save a local copy (.f3d file) that contains everything, your CAD work, CAM, all of it).
fwiw: it's rare that you can flip a piece of "rough stock" and run the exact same program. A "common" approach might be to machine your features (in this case your cylindrical part), and also skim the top of your stock. At that point, when you CAM the other side, you can use the same tools, strategies, etc,, however it's often best to move the "origin" (for the CAM) to the bottom of the part (the surface you "skimmed" when you had the part right side up). That means probing either the bottom of the vise, the step in a jaw, a parallel, or something that the flipped part will rest on.
Once I can see your model, this should not be a problem to resolve.
Thank you so much for your assistance, after redrawing the model and starting over on the CAM I had the same misalignment. I decided to check the calibration and found that my Y axis is not holding the backlash numbers I am entering. I think I may have a bad ball nut on that axis. I'll have to tear it all apart and see what I can find, but I'm pretty sure it's not a software issue.