Colchester bantam mk1 single phase

hi

I have just purchase a Colchester bantam to get me back into machining. Its been 25yrs since I last used one so a bit rusty. The machine I have bought seems in very good condition. It’s a 1969 I think with very little wear. It’s single phase from original but 8 have a few questions if anyone can help.

1. It has the plate to suggest it is a twin speed but how do you select between the red and blue speeds? I have read that there is a switch but I can’t see one, is 8t possible that single phase doesnt have it?

2. The joystick lever at the bottom only seems to go into gear in two positions but it looks like it should have 6 places is this correct?

I will try and post some pics tonight.

Cheers jon

jon

With the red/blue speed indicator range it seems your lathe was originally factory fitted with the 3 phase 2 speed motor.

I have no doubt you will be advised by many to purchase a 220v 3 phase motor and a VFD to obtain the desired speed range from 240v supply.

The gear select lever as you say should move to any of the 6 positions for traverse speed selection, movement up or down is made with the lever in the centre position, if it won't engage try turning the chuck by hand to position the gears to a point where they can engage.

Emgee

Edited By Emgee on 09/02/2018 10:41:44

Jon, I have a similar Bantam, in original condition, but mine is 3 phase. On the front of the lathe below the suds tray there is an electrical enclosure with a red emergency stop and to the right of that is a 2 position switch one position points to a red square and the other to a blue square corresponding to the 2 blue and red speed ranges shown on the plate. Mine still has an original 2 speed motor and is connected to a Transwave phase converter so I can use both speed ranges. Once the main motor is running I can also use the suds pump.

If yours really is an original single phase machine it will have a single speed motor, and the 2 speed ranges will not be available to you, and I imagine it should have a different speed range plate fitted so you know what the speeds are. They may not be either the blue or red range.

The Bantam manual clearly states, 1ph single speed motor or 3ph 2 speed motor.

As far as the joystick goes, it does have 6 positions, I rarely move mine as it is set to the finest feed rate, and they can stiffen up, try some maintenance spray around the lever and also try moving it when the main spindle is gently rotated back and forth by hand to help the gears mesh.

Chris Gunn

Chris Gunn

You can operate the various feed selectors with the machine running on one of the slow speeds. Certainly I find I often have to turn the spindle to get any of the gears to engage (including the spindle gearbox), as they they are all dog clutches.

Do you have the manuals and parts lists? Here's a link to most of them on my Google Drive.

IIRC, mine's a '69 too.

Murray

It is definitely single phase from original as it states on the brass id plate. I have got the original manual with it but it is a bit vague on some details. I will try and get some pics up. I am not to sure what is original and what’s not. It hasn’t got a foot break but it has got a bracket keeping the start lever engaged which I don’t think is original. Apart from that it seem to run nice and smooth with little backlash.

Allen

Does it have a push button starter with stop and start buttons ?

If the motor is 1450rpm you will have the lower 36-800rpm spindle speed range, if 2800 then the high 72-1600rpm speed range.

Depending which gears are fitted will determine feed speeds from the gearbox, if you have the manual details of gears required for particular threads you will see which power feed speeds are available for traversing and facing cuts.

Emgee

It’s got 1425rpm motor on it so looks like it’s 800rpm max. The motor is a“brook crompton Parkinson motors”, it doesn’t look original so suspect it has been changed at some point.