Boxford Model A back gear

[jilly5599Participant @jilly5599]

Hello,

 

I have recently got a boxford model A, when I try and put it into back gear with the back gear lever fully to the left and I power on the lathe the chuck doesnt turn and the lever gets thrown back to the right. Can anyone help me on this? If I move the motor by hand it seems to turn the chuck in reverse ok but not forward.

 

Thanks

[Gerard O’TooleParticipant @gerardotoole60348]

I am no expert, but on my model A, in order to engage the back gear TWO separate levers need to be moved, what Boxford call the back gear to the rear left and the ‘sliding gear lever’ on the front of the headstock to the right.

Which lever did you move . The controls also seem to have changed over the years and so more details might help with a more appropriate answer.

Here is a photograph of the plate on my lathe. A/B is the sliding gear lever and C/D is the back gear lever

 

[Clive Brown 1Participant @clivebrown1]

Underdrive machines have back-gear operated by a single lever, of which I have no experience. Is that the OP’s machine?

The handbook says:-

“The back gear on underdrive machines is operated by a single lever mounted on top of the headstock.Two movements of the lever are necessary. The lever is normally locked in position by one or other of the socket-head cap screws fixed in the lever. These screws engage contacts of a microswitch in the headstock casting and prevent the lever being depressed etc etc”

HTH

[BazyleParticipant @bazyle]

Is this an old lathe with the motor behind the headstock and visible which is known as the ‘model A’? If it has the motor in the cabinet underneath it is an AUD.

If you have the lever on the front style then with the other lever in the ‘normal’ running position the pulley is released from the big gear (bullwheel). Then you can freely rotate the chuck as it is completely disconnected from the drive. Useful for setting up. However in old lathes sometimes the brass dog inside the headstock that moves bullwheel is too worn or broken to disengage it. So check this first. Later lathes put this lever on the top.

Then the lever on the left moving towards the front engages the backgears, if they are not damaged. If you move the side lever like this but not the front lever then the spindle is locked. Do not use this feature to hold the spindle to apply force to undo a stuck chuck or you will break teh gears. That is a very common problem.

[jilly5599Participant @jilly5599]

Yes it’s the model A with the motor behind the headstock, same as the one pictured

[Paul LousickParticipant @paullousick59116]

I have a Southbend and I believe that the Boxford is a clone. When engaging backgear, you have to disengage a drive pin on the side of the gear as shown below. The spindle is then driven thru the gears and not directly from the pulleys.

[Clive Brown 1Participant @clivebrown1]

The Boxford isn’t quite the same:- Two pictures showing fast and slow back gear positions, the lever on the front may need the spindle to be jiggled to get it to engage.

[BazyleParticipant @bazyle]

OK so it takes 2 levers. The front one is sort of removing the pin which on the South Bend is linking the pulley to the bullwheel. When disengaged, (lever to left, = pin out) the pulley should rotate freely on the spindle. Look in at the back and you should see the gear moving when you operate the front lever to produce a 1/4 in gap between gear and pulley block. This is where wear or breakage might not move it enough.
Note that there is a small groove looking like a pulley groove at the chuck side of the gear which needs one drip of oil a month and there is a screw at the bottom of one of the pulley block grooves which is an oil hole needing a couple of drips too only when using the backgear. Don’t overdo it to avoid slippy belts but don’t forget or the pully welds to the spindle.

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