Toolpath Starting Point

[mattclara]

I'm coming from Aspire, where when you set up the material it would ask, where do you want your start point, in the corner, or in the center. For the life of me, I can't figure out how to tell Fusion 360 to cut my part from the center. I've got a symmetrical 3D model made in Rhino and exported as an stl file imported in to Fusion 360, and I've gotten so far to get a roughing pass and a finishing pass that I think will work, but then I notice it's starting in the corner, which I suppose I could work with, I just never have, I always cut from the center, so I've spent probably an hour googling to figure this out and I'll be danged if there's a simple solution that I can find. Any help you can give would be greatly appreciated. Thanks.

[hamid.sh.]

You can set Entry Position in the Linking tab of most operations (the last tab).

 

Also, in case you need a point not represented by a geometry (e.g. center) go to design space and add a sketch that contains your desired point. 

[jhackney1972]

Please Attach your model.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section of a forum post to attach it.

[djlunty · Accepted solution]

@mattclara 

I think what you are asking is how to set the machining origin to the center of your stock.  If so, it is in the Setup "Work Coordinate System" - "Stock Point".  Select "Stock Point" and you will be provided with 4 options.  Select the one you want  - in your case likely "Stock Box Point" and a bunch of white dots appear.  Select the one you want to be your machining origin.  You can also change your xyz axis in the "Orientation" dialogue

Doug

[djlunty]

@mattclara 

See my above post  - missed you in the reply.

Doug

[mattclara]

I think you're right, Doug, that's what I'm looking for.  It's because of my experience with Aspire, where I don't worry about a home position.  I tell the software that I'll touch off the center of my stock, and then generate my g code, then I mount my stock, position the bit so it's top/center of the stock, zero the machine, load the code and tell it to start the cycle (Mach3), and it's always worked great.  Before I saw your post I went back to Rhino, moved my parts so that the origin was at the center, bottom of the part, exported again, and when I reimported, they were at the origin in 360, so that made things easier.  I still wasn't certain it was going to let me touch off the middle, but I found this app called openSCAM that reads your g code and tells you what it's going to do, and sure enough, the tool rested in the center at the beginning, so I went ahead and cut it, and success!  Except the bit didn't retract before it moved to position for the first cut, and not only did it not retract, it plunged to the depth of the first cut and then moved to into position to make the first cut.  Fortunately it did execute M3 before moving, so it just cut a quarter inch gouge across the top of the stock, ruining two of my parts, and then at the end, it didn't retract to full height before going back to the center, so it ruined a third part.  Out of eight.  Since I'm just getting going and these are only a couple of inches each part, that's not a huge loss, I just need to figure out what to do next to fix the problem.  I found this, which seems to point to the problem also being my lack of a home position/ home switches. https://forums.autodesk.com/t5/fusion-360-manufacture/cutting-tool-doesn-t-retract/td-p/7766741

The good news is, Fusion did a much nicer job cutting the parts than Aspire did, which is why I wanted to try it in the first place.  The finished parts looked better, particularly on the steep slopes, and the cutting time was less, too.

With regards to your suggestion, when I went in there with my newly imported part, the stock box point was already where I wanted it, so I didn't mess with it, but that's good to know for future reference, pun intended.  Thanks, and thanks to everyone else who answered, this is a very helpful forum.