I have a small 1 rpm motor with a shaft that mikes out as 0.240" diameter that I need to couple to a shaft on a larger component that is pretty much exactly 0.500" diameter. I looked around for ready-to-use 1/4" to 1/2" couplings but wasn't able to find much.
So I thought it wouldn't be too involved to fabricate one on the mill. I was thinking of taking a 3D rectangle of aluminum, drilling and/or milling a 1/4" hole all the way through it, then enlarging that on one end using a 1/2" end mill as far as about halfway through the piece, then drilling a couple of holes on the sides and tapping them for setscrews.
I'm a little concerned about the clearance. If I drill/mill a 1/4" hole, the diameter of the small motor's shaft will be 10 thou's smaller. Does that sound like a problem? I want these shafts to line up pretty exactly and not cause any side torques as they rotate.
On the other hand, a 1/2" hole for the larger shaft sounds like it's not going to provide any wiggle room at all.
So, any suggestions about the best way to work this? What's an appropriate amount of clearance to allow the shafts to slide in without appreciable sideways movement? I'd like to avoid having to buy reamers for exact sizes unless that's really the only way to do this right.
So I thought it wouldn't be too involved to fabricate one on the mill. I was thinking of taking a 3D rectangle of aluminum, drilling and/or milling a 1/4" hole all the way through it, then enlarging that on one end using a 1/2" end mill as far as about halfway through the piece, then drilling a couple of holes on the sides and tapping them for setscrews.
I'm a little concerned about the clearance. If I drill/mill a 1/4" hole, the diameter of the small motor's shaft will be 10 thou's smaller. Does that sound like a problem? I want these shafts to line up pretty exactly and not cause any side torques as they rotate.
On the other hand, a 1/2" hole for the larger shaft sounds like it's not going to provide any wiggle room at all.
So, any suggestions about the best way to work this? What's an appropriate amount of clearance to allow the shafts to slide in without appreciable sideways movement? I'd like to avoid having to buy reamers for exact sizes unless that's really the only way to do this right.
