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Herbert 4 Senior Pre-Optive Lathe Problem.

After being in storage for about 10 years I have relocated an old Herbert 4 Senior Lathe to a new workshop. It was working previously via a 3 phase converter but it did work OK. It was sprayed with oil prior to storage and it all looks in quite good knick.

When I powered it all up I could not get the pre-optive motor to operate for a while. I found 3 small 5 amp fuses, some of which had blown, - not violently, just not connected and a few other problems. The pre-op motor would turn, using a small socket and extension but only about 20 turns from one jammed position to the other. Also the main speed knob was jammed. I also turned the main motor which was free

and which turned the chuck - so it was all free and in gear, highest speed was selected. I finally got the pre-op. motor driving and going the right way but it still jammed after about 20 revs from the fully anti clockwise jammed position. After messing about for about an hour, running from fully anti-clock to fully clock, it suddenly overcame the jam and the speed knob freed up.

Aha! I thought, now it will be OK. But no, even with the pre-op. motor running and the speed selector apparently free, the main motor would not come on. Previously there was a big click of the power relay(s) when you pushed the forward, reverse or inch buttons. Then the pre-op.

trip tripped again (as it always used to if left running for a while due to the converter not giving true 3 phase), when I reset it the jamming was there again.

Does anyone know enough about this old Lathe to suggest what may be wrong and does anyone have either a circuit diagram or handbook (or both) that I could beg borrow or buy. I am sure there is not much wrong with it and I really don't like to attempt the dismantling of it to get into the pre-optive gearbox assembly.

Any comments or suggestions would be welcome. It is a fine machine and I am sure I can put it to good use again.

Thanks a lot, George Bell.

Reply to
George
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highest

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pre-op.

George,

I don't know the lathe, but the motor symptoms sound like 'rusticles' between the stator and rotor

AWEM

Reply to
Andrew Mawson

twenty turns to lock.... check the gearbox to see if there is a rusted up tooth or a tooth with other**** on it. If the pre op was not running when the main motor was energised it could have been " single phased " this can easily burn out a motor. I suggest you check the main motor windings.

Reply to
Jonathan Barnes

George,somewhere I have electrical drwgs for a No4,will have a look for them at the weekend.BSA might have manual/drwgs as they took over a lot of the Herbert range.Herbert & Cridan in Coventry will have them and so will Tony Griffith,but his will be expensive.There won`t be a lot wrong with it,I`ve rewired the control panel on a couple of them.Check the voltage in and out of the control transformer and through the overloads and stop buttons.With the power off check the contactors are free to move and with the power on try pushing them in manually,don`t hold them in too long if the motor buzzes or fails to start cleanly.Some motors had a sensor on the NDE of the motor,check that out as well. As for the selector motor jamming,a very common problem on these machines.It`s normally caused by a bent pin on the selector shaft but in your case if it was not a problem before you stored the machine it will be rust caused by condensation and you will have to lift the headstock cover to check.I would also megger the windings of the selector motor as I would expect them to be low due to their position in the headstock. Hope this helps and I will look for the drwgs when I get time.Where are you based? regards,Mark.

Reply to
mark

Hi Mark, I got a very good reply from rec.crafts.metalworking. I am in Norfolk on the Wroxham Road out of Norwich.

If the advice I received previously does not work I shall try yours. It would be very nice to get some sort of description or cct. diagrams though.

Thanks and regards, George.

Reply to
George

George,BSA,Kitts Green,Birmingham have all the original Herbert spares,drwgs etc.Tel 0121 783 4071 go to spares and ask for Andy. regards,Mark.

Reply to
mark

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