Swapping Bantam Lathe Motor

[WarwickWoodshop]

Hi all, my long-running Bantam 1600 cleanup/project is hopefully nearing the point I can actually start using the thing.

I recently made the decision to swap out the original motor and electrics for a modern 2hp one and VFD. Was in two minds about this, as the lathe actually came with an old Transwave static converter and being a 1600 is fitted with the dual-voltage and speed motor.

However neither are in particularly great shape and the Transwave had been poorly wired up by a previous owner, along with probably being due some new capacitors - and my knowledge of 3 phase electrics is sufficiently lacking that going through and checking wires/contactors and all the associated 60 year old wiring and switches would still leave me a little uncomfortable on a 415v machine.

By contrast the new motor and VFD are wired up and working (on a bench) within a couple of hours work. I intend to eventually connect the original lathe controls up to the low voltage signalling circuit.

It also gives me the benefits of soft start, braking and all that jazz, and as a 1440rpm motor I can presumably wind the frequency up to approximate the 1600 speeds with the gearbox if needed.

So on to the actual question - if anyone has done this in the past what is the best way to deal with the change of pulley? I've seen a few people remove the original one and adjust to fit the new shaft, but they generally have a spare lathe to fix the main lathe

Is it just a case of measuring the old one and new motor spindle and ponying up for a new pulley and belt to suit?

Finally, I've added a couple of photos just to sense check the wiring as it's my first venture into VFDs. I saw in another thread that the thin blue wires are for temperature sensing, presumably it's ok to just leave this as it came capped off in the connector block? Don't think my cheapo VFD has an input for monitoring it.

And at the VFD end, I've tied the two earths together as shown - and checked for continuity from various points on the motor housing through to the earth pin of the plug I've wired to the VFD input.

Thanks in advance for any comments/suggestions!

 

[RobCox]

Is it just a case of measuring the old one and new motor spindle and ponying up for a new pulley and belt to suit?

Certainly an option. I recently replaced the motor pulley on my M300 as I was refurbishing it. New taperlock pulley, new taperlock bushing to suit the motor spindle and jobsagoodun. Far easier than old pulleys to mount and dismount. I think mine came from simplybearings.

 

[WarwickWoodshop]

Ok great thanks, that's definitely sounding like the path of least resistance at the moment. I'll measure it up tomorrow and check out simplybearings.

 

[Mark Davison]

I have done something similar. I fitted a 3hp 3 phase 3000rpm 2 pole motor with VFD. I'd need to check the motor pulley size, but from memory I selected a size that gave me approx 1600rpm at 65hz in the highest gear. I can't say I've run it at that sort of speed very often. It spends most of its time running in the middle 30s (rpm). No issues with lack of torque and rarely have to change down gear from the 2nd highest gear it seems to live in. I almost exclusively us the VFD for speed control. I'd change down gear for single point threading and using large dia drills.