The unusual direct drive design meant I couldn't just bolt on a new motor and adjust the drive belt length to suit. The drive pulley is like a set of those Russian dolls that open up in layers revealing smaller and smaller sizes. This only has two sizes, (one for metal, one for wood) but you get the idea:
(the rubber coating on the big one was a strip of bicycle inner-tube I glued on in an attempt to stop the belt from slipping when struggling with cuts in thick wood)
It couldn't be transferred to a bigger motor as it is sized for a 1/2" shaft and bigger motors come with bigger shafts. So I always made do with what I had. But wait! Since then I bought a metal lathe! I can make new parts now! Maybe it's time to revisit this issue. Off to Princess Auto to source a nice 1hp ball-bearing motor:
The new motor has a 5/8" keyed shaft. My broach set doesn't go that big, and I didn't feel like laying out a couple of hundred bucks for the set that does, so I picked up a suitable shaft collar and welded an extension to it. This was then turned to form the new hub/low speed drive pulley. I used a slice from a piece of 6" diameter aluminium 6061 round bar to form the outer pulley.
The old pulley was 5" in diameter. I went a bit bigger, 5-1/2", which should increase the blade speed from 2,200 feet per minute to 2,500 fpm and at the same time, have more surface area in contact with the belt to prevent slipping.
I made sure I mimicked the crown of the original pulleys. The crown serves to self-centre the belt just like a belt sander.
Wondering why my hub/inner pulley is so much larger in diameter? The old set-up relied on a single centre bolt and washer to keep the outer pulley rotating with the inner. I opted for a more robust connection, with 3 cap screws securing the two, so I needed more meat. However, the actual inner pulley is only slightly larger than the original: 1" vs 0.850"
The existing motor mount was also too small:
That was a simple fabrication:
I never clued in that the capacitors might interfere with the table. Fortuately there is just enough clearance. Barely!
With a heavier motor extending further from the frame, I thought it wise to add some additional support, in the form of a bolt to the stand.
Was it all worth it? Here I am slicing 5-1/2" deep red oak like it was Bologna. Oh Yeah! Bring it on!
