Back before Christmas, I came across a decent quality 3 phase motor (Asea ) and decided to upgrade my Chester RF45 Mill, which I've owned and used for the last 5 years (https://www.hobby-machinist.com/threads/new-toy-s-h-rf45-mill.76666/). The original Chinese single phase motor (750W 1400rpm) motor was still working, but I was frustrated by the limited range and power through the gear box.
I took this motor off when I originally stripped the mill, but it was jammed on solidly when I came to remove it and I destroyed it in the process. Not quite sure how it had got stuck so fast, but there was some rust in the keyed input shaft union and I had to jack it off in stages..
The mill is shaft driven by a 3/4" shaft c/w 15/16" key. The motor mounts by a four hole bolt circle at 90 degrees, with 4 5/8" between centres and the motor has a 5 1/8" alignment ring.
This photo shows the different motor shafts and keys side by side, old motor armature to right
My new motor is an Asea MT90L24F165-4, which is a 1420RPM 1.5KW, which appears to have had a very light previous life in HVAC.
This motor has an identical bolt circle and alignment ring, but has a 15/16" shaft and was keyed to 5/16". This required a strip down, turning down and cutting a new keyway to match the input shaft on the mill. The turning was quick and easy on my Colchester lathe, but with no working mill I had to resort to using the lathe carriage as a manual shaper to cut the new keyway.
It took a little patience, but got there in the end:
All now ready to reassemble and mount - tbc in next post!
I took this motor off when I originally stripped the mill, but it was jammed on solidly when I came to remove it and I destroyed it in the process. Not quite sure how it had got stuck so fast, but there was some rust in the keyed input shaft union and I had to jack it off in stages..
The mill is shaft driven by a 3/4" shaft c/w 15/16" key. The motor mounts by a four hole bolt circle at 90 degrees, with 4 5/8" between centres and the motor has a 5 1/8" alignment ring.
This photo shows the different motor shafts and keys side by side, old motor armature to right
My new motor is an Asea MT90L24F165-4, which is a 1420RPM 1.5KW, which appears to have had a very light previous life in HVAC.
This motor has an identical bolt circle and alignment ring, but has a 15/16" shaft and was keyed to 5/16". This required a strip down, turning down and cutting a new keyway to match the input shaft on the mill. The turning was quick and easy on my Colchester lathe, but with no working mill I had to resort to using the lathe carriage as a manual shaper to cut the new keyway.
It took a little patience, but got there in the end:
All now ready to reassemble and mount - tbc in next post!