1" Thick 6061 Al on ShapeOko
I've built a slightly upgraded ShapeOko 2 machine and am just starting to work with aluminum. I should have started with something thinner than 1" but I've already got most of it machined and have broken 3 bits so I'm on a mission to tackle this!
I've got a Bosch Colt router and the bit that seemed to give me the best results is a Titan 2FL 1/8" shank, 1/8" diameter, 1" LOC, and 3" OAL.
I tried different feeds and speeds keeping the feed rate below 40ipm in some cases but mostly under 20ipm. I was using 0.010" DOC and performing a contour on my part so the bit was making a slot (see pictures for details).
I made a roughing pass and I'm now trying to do the finishing pass which has ~0.005" of material left. I use approximately because during one of the bit breaks I must have lost some steps and lost my 0,0 which I tried to adjust for but was still a little off.
The last bit broke when I was 0.610" deep into the material. It actually broke in the position you see in the photo which I would assume to be the lowest torque since it was barely taking anything off of the wall and only has material on 1 side. It broke when my vacuum hose touched the bit (the hose is plastic so I was surprised that it broke the bit).
I thinking perhaps I wasn't paying close enough attention to tool deflection? Since the machine isn't the most rigid and I'm working with a bit that sticks out probably 2" a little deflection could be very bad?
I was using a vacuum to clear out chips and also spraying occasionally with WD40.
In this case do I ignore chip load and pay more attention to defection? I was trying to hit a chip load of 0.001" before but if I use a deflection of 0.0007" it tells me to use the following:
What would you do if you didn't want to break anymore bits??!!