Blidgeport motor modification finished

Spent much of yesterday (Saturday) lifting 3 layers of floor tiles in the kitchen. Top layer was an off white 9" ceramic thing , then a layer of PVC things, glued to the previous layer of small red tiles (3"?) which were probably the original 1930s floor. Luckily I had Ewan and Tom in to help and together we saw them off and into the skip out front. SWMBO even joined in! There are probably about 50% of the bottom layer left but the skip is now full to the brim and I'm shafted anyway.

In between lifting tiles and emptying the wheelbarrow, I nipped out to the workshop periodically to apply another bead with the MIG welder. By the end of the afternoon I seemed to have built up sufficient metal to prepare for machining it down to 22mm. It's not pretty - looks like a tramp's knob - but seems to have achieved the required result. I made a slight cockup at one point by leaving the mega fan running when welding. It's great for cooling down the rotor after applying a bead but also pretty effective at blowing away the argon shielding gas, resulting in a crap, porous weld if you forget to turn it off. I attempted to run 2 beads in one go at one point and almost melted off the entire end of the shaft (top pic)...

Now over to the lathe. Luckily I acquired a  fixed (and travelling) steady for the bantam last year. This is one job that definitely requires a fixed steady and I'm glad I didn't have to waste a day or two bodging one myself. 

As mentioned, the welding was somewhat less than ideal and I had a few occlusions in there but it's only holding a pulley, so not massively critical to get a dead smooth surface. I managed to avoid turning it down below 22mm which would have been a bummer.

 I had to extend the machined part further towards the rotor. This is the final result:

Next, make a 7mm keyway. Obviously I couldn't use the Blidgeport for this without having to reassemble the old pancake motor and connect it up again. So I machined it in the Shiz, using the MPG pendant to control the movement manually. Ideally I would used a 7mm end mill but the closest I have is a 6mm. So, 2 passes 1mm apart to create the correct width.

Used the edge finder to set the shaft up centrally below the spindle, then set Z zero on the surface of the shaft (carefully!). Using the Martest probe would have required me to lower the knee which sounded like excessive effort and was dismissed obviously.

Job went ahead reasonably straightforwardly. Bit slower than the manual mill but perfectly manageable. Yes, I thought the pervy gloves were justified. Besides, my hands were a bit raw after unaccustomed effort today. I'd even managed to wear my fingerprints off, rendering the iPhone Touch ID ineffective.

Finished result after deburring with a needle file:

That left the pulley. Rather than recentring the shaft and tapping a new M8 hole, I opted to drill and tap an M8 thread radially into the pulley, with a lock screw acting on the key. Used the Blidgeport for this although obviously I had to turn the spindle by hand, just enough to get it started. Then cordless drill, then M8 tap held in the Blidgeport to ensure it went in straight. I set it up carefully with the edge finder:

Then banged it all back together, ready for slapping back on the machine:

Job done!