Hi
I have a piece that I would like to mill two sided. I 'm not clear how to setup Fusion 360 to do this. I read something about adding dowels for alignment and that makes sense. What is not clear is how I setup Fusion to make this work.
Thanks
Top
Bottom
The easiest way is to create a sketch on the top surface of the part and create at least two sketch points where you will drill dowel holes in the stock (not the part). In your top setup do all your tool paths and then add a drill tool path at the sketch points. Be sure and use tabs so the remaining stock is attached to the part. Now you need to add a spoil board setup to receive dowel holes from the sketch points. Use the stock from the previous setup. The part is flipped 180 along an axis so the stock and sketch points are flipped too. Keep the XY origin at the same place on the stock but z starts at the bottom of the stock next to the spoil board. So if your XY origin was on the bottom left corner in the top setup and you flip along the X axis the XY origin will be at the top left corner in the spoil board setup. Create the drill tool path from the sketch points. These will drill down into the spoil board. Now dowels in the spoil board connected to the top of the stock will position the part for the bottom operations. For the bottom set up again use the stock from previous setup and same XY origin.
You need to create two configurations, each milling from a different direction (I use French words: dessus = above; dessous = below but you name them however you like):
On the “above” configuration, you set your work coordination system (WCS) to a point on the top part of the model. In the “below” configuration system, you set the WCS on the bottom part of the model and you flip the Z axis (again my screen is in French but I hope you recognise the controls, note that I checked the option to invert the Z axis):
I like to place the point in the center of the block (for reasons I explain below) but it only depends on how you will align the block in the machine.
Then you create your paths, as usual, post-process, etc. as usual. That’s for the software aspect.
Physically you need to make sure that you flip the part reliably. There are many techniques (I’m particularly impressed by this one), including dowels. Because I only ever milled small parts from 2 sides, I have set a FoxAlien vice. I very, very carefully aligned its jaw with X axis of the 1F using a test indicator so I know that the X axis of the part is stable when flipping.
I set the origin (0, 0) on the 1F in the center of the block because I can easily and reliably find the center from both sides.
