I am putting a VFD on my 8x12 lathe. This means a 3 phase motor needed to be mounted. After removing the old motor, I marked holes to be drilled and tapped into the cast iron for the new motor mount. I was playing with the position of the new motor to get the belts right, so that involved tightening and loosening the 1/4 - 20 bolts a few times. In no time two of the 3 bolts were stuck in thier tapped holes. One bolt I got out but the threads were stripped, the other bolt eventually broke off. Pissed me off.
My question is why did the bolts gall up in the cast iron? I thought cast was pretty forgiving that way. Yes, I drilled and tapped plenty deep. I can only think I didn't blow the crap out of the blind holes causing the cast dust to get trapped in there, siezing it all up. Thing is all was well until I tried to remove the bolts. They went in all the way with no effort.
I ended up drilling and tapping all new holes and greased up the 1/4 - 20 socket cap screws (ofter making sure all the cast dust was removed) and now all is well.
I'll put some photos in the machine modifications section once I am done this mod.
E
My question is why did the bolts gall up in the cast iron? I thought cast was pretty forgiving that way. Yes, I drilled and tapped plenty deep. I can only think I didn't blow the crap out of the blind holes causing the cast dust to get trapped in there, siezing it all up. Thing is all was well until I tried to remove the bolts. They went in all the way with no effort.
I ended up drilling and tapping all new holes and greased up the 1/4 - 20 socket cap screws (ofter making sure all the cast dust was removed) and now all is well.
I'll put some photos in the machine modifications section once I am done this mod.
E