Base plate bolted up using socket button head screws. I made sure that they missed the original bolt holes and that they would be away from bolts for the bearing assembly.
Bearing assembly clamped up again for double checking and rough marking where the slots will be milled.
Marking out for the slots on the back surface making sure the slots will be square to the shaft and aligned properly in all respects.
A little while later, all bolted up and working, a "rough as guts" quick set up and an old vee belt dug from my pile of, you guessed it, old vee belts. Wow , great, this is actually working :-))
With the "rough as guts" set up I actually machined 4 thick washers for the 4 bolts in the slots. There is a bit of vibration but that's because the belt is pretty stiff, somewhat twisted and running wonky and the big chunk of timber isn't supported very well out from the lathe.
Close up of the VFD unit, I have already set the parameters for "remote" control of speed and Forward, Stop, Reverse. You can see the potentiometer and the SPDT centre off switch there beside the unit. Basically the VFD is 240 volt single phase in and 240 volt three phase out.
All wired up and operational. There is enough room on the left side of the control box for the "clutch lever".
The motor mount fairly well sorted out. It is bolted to both the bench and to two mild steel angle brackets underneath the timber, the brackets are welded to the bench frame. I do want to bolt a piece of aluminium on the board with two adjustment screws bearing against the base of the motor so I can easily adjust the belt tension. I bought a new Gates "Green Stripe" vee belt that has the notches on the inside edge so as to improve flexibility, this belt runs nice and smooth. The motor is a second-hand, three phase, connectable in Star or Delta, 0.75Kw (1HP) Aussie made light industrial motor. The motor is connected in Delta for 240 volt three phase. It has sealed ball race bearings and is fan cooled. It's a British standard specs, foot mount with 5/8" shaft, 4 pole, got it cheap, so that's good and it's in very good nic. The pulleys give 2 to 1 speed ratio, motor to jack shaft. Wow I can take some good cuts now with the small vee belt squeaky clean and dry. Of course at high frequency and the highest belt speed setting there is not a lot of torque at the chuck but generally one would be doing small diameter work anyway so it doesn't matter that much. I have the VFD set for operation from 20Hz to 130 Hz. For the different belt positions the spindle speeds I get are, BC1- 23 to 152RPM ; BC2- 55 to 358RPM ; AC1- 65 to 421RPM ; BC3- 107 to 690RPM ; AC2 181 to1155RPM ; and AC3- 362 to 2219RPM. The two belt positionsI like are BC2 and AC3 as both those seem to be a good "sweet spot" for a variety of different diameter work.My original top speed was about 1800 so 2219 is a bit of an increase, I don't think I really need any higher than this BUT I have allowed enough room at the back for a two speed belt set up, would just have to whip up new pulleys and an over centre locking mount for the motor for quick belt position changes. That belt change would only be needed when I wanted to go up to higher speeds. A fair bit of risk enters here though if too high a speed was used with the larger chucks, one would have to make sure that the chuck was certified for the high speeds. Hey, minimal belt changes,, GREAT STUFF !!!!! It's icing on the cake but it sure spoils a person.
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