- Joined
- Jul 16, 2007
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Gentlemen, I am taking a small break from the V-twin project to finish up a few unfinished jobs. One of them was this high speed spindle attachment for my mill. I have a first generation Enco mill and the most I can get out of it is 2130 rpm so for small mills I needed something like this.
The drawings along with the bearings came from Jerry Howell. I purchased the 24 volt power supply and motor from Ebay. The motor runs at 4000 rpm so I sized the pulleys to get 1-1/2 times that speed, around 6000 rpm. I also bought a 7/8 R-8 collet to mount it in.
The machining was straightforward but with close fits for the bearings and shaft. The spindle is reamed for .187 diameter as most of the small high speed end mills come with that sized shank.
I have a stash of 'O' rings and found one that was actually for the oil filter cover on my old motorcycle.
Not knowing how much torque this motor has I started out with a .062 end and took a cut at .04 deep, it cut fine. Next I put a .125 end mill in and went .05 deep. This time I could hear the motor change sound but it still cut through the brass with no trouble. I think this attachment will work out great for all the small pieces I make.
Jerry included a caution when using this tool, unplug your mill!! If you inadvertently reach for the on off switch as you are so accustomed to doing you might have parts and pieces flying everywhere.
George
The drawings along with the bearings came from Jerry Howell. I purchased the 24 volt power supply and motor from Ebay. The motor runs at 4000 rpm so I sized the pulleys to get 1-1/2 times that speed, around 6000 rpm. I also bought a 7/8 R-8 collet to mount it in.
The machining was straightforward but with close fits for the bearings and shaft. The spindle is reamed for .187 diameter as most of the small high speed end mills come with that sized shank.
I have a stash of 'O' rings and found one that was actually for the oil filter cover on my old motorcycle.
Not knowing how much torque this motor has I started out with a .062 end and took a cut at .04 deep, it cut fine. Next I put a .125 end mill in and went .05 deep. This time I could hear the motor change sound but it still cut through the brass with no trouble. I think this attachment will work out great for all the small pieces I make.
Jerry included a caution when using this tool, unplug your mill!! If you inadvertently reach for the on off switch as you are so accustomed to doing you might have parts and pieces flying everywhere.
George
I was thinking of doing something similar I have a question about spindle speed though :-\ my router spins at 28,000rpm, commercial high speed mills run at over twice that, for my project, do you think 6,000 rpm is fast enough for 1/8 or less dia mills when machining ali or delrin?
