09-02-2019, 03:00 PM
As to the type of collet held by the spindle as long as you have it torn down for new bearings this would be an opportune time to set it up in your lathe and bore it for R8 collets. There are plenty of drawings on line of the R8 collets dimensions so you don't have to reinvent the wheel. Wait until you have the new bearings and set up the spindle with the bearing held in a steady rest. That will keep you from scoring the spindle OD.
You have a similar situation to my Fray mill. I converted it to a reversible 240V single phase spindle motor from the Surplus Center and the feed motor was also 3 phase. In my case Fray used the Bridgeport feed unit from the 1950's and I found prints for them available on line for free. I happened to have a 110V single phase face mount motor and just made an adapter to marry it to the feed unit. BTW, I also needed several gears for the feed unit and found spur gear blanks from Boston Gear that just needed some simple mods to fit. A whole lot cheaper than buying the necessary gear cutters.
Among my many to do lists I plan to add two more pulleys to the spindle drive so I can slow down the spindle to some RPMs that will allow me to use larger HSS end mills. My slowest RPM is around 500 and I want to get it down to about 200 so I can use the 4" carbide face mill. I already have a ER32 collet adapter so I may or may not bore the spindle to accept R8 collets.
You have a similar situation to my Fray mill. I converted it to a reversible 240V single phase spindle motor from the Surplus Center and the feed motor was also 3 phase. In my case Fray used the Bridgeport feed unit from the 1950's and I found prints for them available on line for free. I happened to have a 110V single phase face mount motor and just made an adapter to marry it to the feed unit. BTW, I also needed several gears for the feed unit and found spur gear blanks from Boston Gear that just needed some simple mods to fit. A whole lot cheaper than buying the necessary gear cutters.
Among my many to do lists I plan to add two more pulleys to the spindle drive so I can slow down the spindle to some RPMs that will allow me to use larger HSS end mills. My slowest RPM is around 500 and I want to get it down to about 200 so I can use the 4" carbide face mill. I already have a ER32 collet adapter so I may or may not bore the spindle to accept R8 collets.