Super excited to finish the program up for the skateboard trucks today, and I had some new insights on machining techniques for simultaneous machining.
The changes I made to this new program was adding the swarf toolpath to both sides of the lower half of the trucks, I was able to leave approximately ten thou total as a web between the part and the stock, and it had quite a bit of rigidity. I switched up my final cut from being at the bottom half of the truck to the upper half where there was a flat, and I could take a few small 2D passes to cut away all but a thou or two, making it easy to break off.
I noticed pretty quickly that the swarf toolpaths were leaving some pretty bad marks on the surface of the part, and that made the cleanup quite painful. It looks as if the tool is deflecting pretty bad and jumping around as its cutting. The odd thing is that there is almost no sound when it's milling, and the stepdowns are pretty small at five thou per. I talked to my boss, and he suggested to rough it out first, leaving one or two thou on the walls and then taking a single finishing pass at full depth, which I will try out tomorrow.
I'm also getting some weird results with the ball endmill when cleaning up the slight radius' on the top and sides of the part. I'm climb milling with a 0.09" ball endmill and only cutting three thou in height, but it's leaving a rough finish sort of like light sandpaper. It's not that big of a deal, and I'm able to clean it up with a few passes of scotch bright but still is concerning me why it's happening at all.