Jones & Shipman Surface grinder

[Keith 66]

I acquired one of these a while ago & am just getting round to sorting it out.
Its a lateish one probably built in the 1980's.
Its a non runner the main 3 phase motor having gone pop, looks like there are two motors one for the hydraulics & another for the Grinder
Question has anyone converted one of these to single phase? Is it doable?

 

[ronan]

Again you swap out switches and the other electrical components, it would probably be easier to just fit an inverter. What size motor does the J&S grinder use ?

 

[Keith 66]

Its one hp 3 phase, im pretty sure the main motor is cooked so im going to have to replace it anyway, seems logical to convert it if i can find two motors the right size!

 

[ronan]

Its one hp 3 phase, im pretty sure the main motor is cooked so im going to have to replace it anyway, seems logical to convert it if i can find two motors the right size!

Just remember three phase motors are smoother (supposidely) than single phase, which may be an issue with the finish you get while grinding. Why not take the motor out and test it before you do anything else.

 

[awemawson]

The hydraulic motor would be no problem, however there are well documented cases of the spindle drive motor being exchanged for a single phase one, and not being able to get a decent finish on the work. The original motors are very carefully dynamically balanced as an assembly with the pulley, and of course inherantly single phase motors don't give as smooth a rotation as three phase ones.

If you go this route do so with open eyes. Personally I'd try to get the motor rewound, and failing that fit a decent three phase one that I carefully balance and run it off an inverter at a fixed speed - never leave an inverter drive to a grinding wheel able to be 'speed tweaked' without tools - safety issue to avoid some twit over speeding the wheel and causing mayhem.

 

[Keith 66]

Never thought of that, its going to be a lot of work so a rewind might be easier!

 

[penfold]

Very much in favour of a rewind in this case; as said by others on precision grinders the spindle motor(and all the other rotating bits) is carefully dynamically balanced to avoid the finished grind looking like mackerel skin.

 

[Pete.]

I also have a 540 and I also have fitted a single phase motor to the hydraulic feed pump. I have kept the 3 phase spindle motor and fitted it with a VFD. The later ones are dual voltage (in fact all but the very early ones are) so check the wiring in the connection box first to see if you have and loose link bars. Also there's a lot of stuff to chafe and rub in the belly of the machine, that might be what's ailing yours.

 

[Keith 66]

Top plan, to be honest though it is a fairly late machine the bloke who i got it from was a messy so & so & it is very filthy, big clean up & then start having a go to see what it needs.