04-06-2014, 05:56 PM
Well, tired of walking around with a fiberglass splint and my left arm in a sling, I shed it today and headed for the shop.
With the help of my younger son Brian, I mounted the 12" Pratt Burnerd 4-jaw independent chuck that's been on the machine perhaps ONCE and clearly never made chips. I had to clean off old Cosmoline that was in all the jaws, too bad my dad had already wiped it off the larger surfaces because it was coated with a layer of rust that took a lot of work to get (most of it) off.
I then put the long 1-1/4"-5 Acme screw I'd made weeks ago for Darren into it, gripping with copper between the jaws and the Acme threads. To make sure it was running true to the threads, I engaged the lead screw, set to 5TPI and put the spindle in it's highest speed gear to make it easy to turn by hand. With the half nut engaged and an indicator running on the crest of the threads, I dialed it in quickly and brought in the live center.
With the workpiece trued up, I finish turned the 20mm diameter for the bevel gear, and threaded the M12x1.75 for the nut that keeps the thrust bearing and bevel gear in place. It's now ready for the milling of a keyway and a couple of small holes. I ran out of time, so it'll have to wait (probably) until next weekend for that. I don't have a 5mm end mill so I'll be profile milling it with a 3/16" or smaller end mill, using the 2 axis Prototrak control.
Not the best finish, but the 20mm size was verified with the 20mm bores on the spurs gears I had to make to enable metric threading.
With the help of my younger son Brian, I mounted the 12" Pratt Burnerd 4-jaw independent chuck that's been on the machine perhaps ONCE and clearly never made chips. I had to clean off old Cosmoline that was in all the jaws, too bad my dad had already wiped it off the larger surfaces because it was coated with a layer of rust that took a lot of work to get (most of it) off.
I then put the long 1-1/4"-5 Acme screw I'd made weeks ago for Darren into it, gripping with copper between the jaws and the Acme threads. To make sure it was running true to the threads, I engaged the lead screw, set to 5TPI and put the spindle in it's highest speed gear to make it easy to turn by hand. With the half nut engaged and an indicator running on the crest of the threads, I dialed it in quickly and brought in the live center.
With the workpiece trued up, I finish turned the 20mm diameter for the bevel gear, and threaded the M12x1.75 for the nut that keeps the thrust bearing and bevel gear in place. It's now ready for the milling of a keyway and a couple of small holes. I ran out of time, so it'll have to wait (probably) until next weekend for that. I don't have a 5mm end mill so I'll be profile milling it with a 3/16" or smaller end mill, using the 2 axis Prototrak control.
Not the best finish, but the 20mm size was verified with the 20mm bores on the spurs gears I had to make to enable metric threading.