Hi,

I don't have a Bantam but a Harrsion the operation of all geared head lathes is bascally the same.

Lets see if we can break this down into chunks

1. The "apron lever " usually called the third rod switch only lets you run in forward ?

2. The high/low switch now controls spindle direction. ?

3. The leadscrew lever does nothing ?

Issues 1 & 2 are electrical and are related.

Now onto issue 3.

I think 1 & 2 stem from the fact that the lathe was originally 3 phase and has been converted (arguably not that well) to single phase. Reversing 3 phase motors is easy and required less switching than single phase ones.

When you switch your high / low switch does the third rod switch then allow you to run in the opposite direction ?

If so apart from the slightly unconventional set-up you can achieve both direction or rotation.

Originall your lathe had a two speed 3 phase motor – the high & low switch controlled which of the motor speeds was being used. This is was made redundant when they fitted the single speed motor so they used it to change spindle direction.

Your third rod issue can be fixed but it sounds like you don't have much electrical experience and need an electrician – be warned your standard domestic sparky may not be able to help you. You really need someone familliar with motor switching controls, its not difficult but someone doing this all the time will have it sorted out quickly.

The lathe has two gearboxes – one to control spindle speed the upper one, and anothet – the lower one to control the leadscrew speed and therfore feeds for surfacing and screw cutting. As you are getting nothing it sounds like there is no input power to the lower box. If you take the end cover off you will see a gear train and I suspect that the input shaft to the screwcutting box is not connected to the rest.

If you can post some images of your machine that will give everyone a better idea of the model – and take one of the geartrain inside the end cover.

Don't despair nothing sounds too serious to me

Tony

3 is mechanical

Hi glimmer 81,
When you say "when i set the leadscrew lever to either forward, reverse or neutral it makes no difference." do you mean that the leadscrew does not rotate in any of the three positions or do you mean that the saddle does not move ? If the leadscrew is rotating then are you sure the half nut is engaged ? Sorry for such an obvious question but as this is your first post I have now way of knowing how familiar you are with lathes.

Les.

Both the leadscrew and the slotted feed shaft are driven by the (threading) gearbox. The slotted feed shaft is what provides the power feed to the cross slide and carriage. The leadscrew is for screwcutting and has a manual dog clutch to disengage it and reduce wear when not in use.

Take the gear cover off and check whether there are any gears between the shaft directly under the spindle and the input to the gearbox (mounted on the banjo). I suspect you'll find the problem there. I assume you have drive to the spindle itself.

Sounds as if the high / low speed switch was rewired when the single phase motor was fitted. Quite what the “apron control lever” does now is for you to figure out, but it may not be capable of reversing the motor in this arrangement. No loss – my Bantam no longer has this lever – I simply control the motor from a pendant switch that controls a VFD.

It's a nice "little" lathe, so once you figure out how to use it, I suspect you'll be very happy with it

Murray

Check your inbox – I have PM'd you a link to some manuals.

Edited By Muzzer on 13/02/2015 21:47:46

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Looking at the change wheel photograph it is very similar to my Boxford STS (as many, many other lathes) When I first got mine one of the first things I did was crash it in a right royal fashion.

I thought I had goosed it in an equally royal way. – The change wheels were turning but no drive was coming out of the gearbox. I went to bed convinced I had rendered the gearbox 'fubar' !!!

The morning brought a clear mind and I discovered that part of the splines that the gears sit on was a brass 4mm sheer pin. This had done it's job and sheered. So it gave the impression it was turning the gearbox when in reality it had protected it's self from a clumbsey twonk ………………. i.e. me.!!

I am wondering if your Bantam has a similar arrangement of sheer pins somewhere as mentioned by others. Mine are behind the splines so you cannot actually see them until you take it apart.

Nick

Edited By Nick_G on 14/02/2015 21:42:05

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Think positive.

Here is a **LINK** to the Boxford arrangement. I know yours is a Bantam but the principle 'should' be similar.

On this drawing there are 2.

Regards, Nick

Breva, PM sent.

If you turn the chuck by hand the shaft should turn ( the part with the thread on) when the lever at the front is set to forwards or reverse there is a neutral position in between

If the shaft turns but the spline doesnt the the shear pin is broken

If the shaft doesnt turn then its inside the gearbox or the selecter mechanism thats failing to engage

But the splined sleeve should pull off but no need to unless the shaft is turning but the sleeve isnt

As Ian says, without the shear pin the splined carrier should spin freely on the shaft and pull off easily. If the threaded shaft doesn't turn with the main spindle, there's no drive getting there through the gearbox.

First of all – is the forward / reverse selector properly and fully engaged in one direction of the other? This whole thing could simply be due to you not having engaged it fully. If that isn't the problem, it sounds as if your gearbox is bu99ered. The US Clausing manual mentioned by Breva in the thread above may help you to investigate further within the gearbox. It's not something I've needed to delve in to myself.

Murray