Boxford restoration

[mr migwire]

Aint gold... i recently took delivery of a lovely little boxford which looked the part, and seemed to function ok (powered up and spun the chuck). i was out in the workshop today and was swithering on whether to do a complete strip down or a quick paint job just to pretty it up.

well after wiring the motor for 220 3 phase and re-installing it i hooked it up to the vfd and ....nothing, not a sausage. after a bit of investigation i came to the conclusion the switch doesn't work with 220 3 phase, i think the contactor is a 440v setup. if you manually close the top of the contactor with an insulated screw driver the lathe runs and the contactor will indeed stay closed however once power is shut of and reapplied you will have to manually close the contactor again. looks like i will need a new switching option.

i couldn't get the back gear to disengage so decided to do a full strip down to investigate whats going on with the gearbox, after a bit of work i finally got to the point where the box was sitting on the bench and it looks like someone has been changing gears whilst the machines been running, two teeth are missing from one of the gears which shouldn't trouble the running to much, but the spring and ball bearing arrangement that hold the back gear selector in position is causing the lever to jam, further stripping down revealed the dimples the ball bearing locates in are actually pretty deep with sharp edges and wont allow the lever to move.

does anyone have a link to a manual for the box, and does anyone know how the gears interact with each other is there some form of clutch for back gear?

i will post picks as and when i get a chance so stay tuned for a full restoration of this wee lathe...

 

[mr migwire]

a few more...

 

[gordon stephenson]

No clutch on the back-gear, only change when stationary, Does yours have the screw-cutting gearbox? Mine was 3 phase, I changed the motor for a single phase 240V. It had a longer frame than the original and had to cut a circular hole in the end panel to accommodate it, There is a shear pin in the headstock,Make sure it has not been replaced with something too strong,
Oops, you had it stripped while I was posting.

 

[mr migwire]

it does have a series of change wheels on the end for the power feed but no screw cutting box.

 

[Wedg1e]

I had a 1ph AUD and now have a late-model 3ph VSL. The inverter is wired to the motor via the original reversing switch which is kosher as long as you don't switch it while the motor is running. A safer option would be to use the reversing switch to control the inverter's REV function. Either method takes the 440V contactor out of the equation and most inverter makers say the output should go straight to the motor anyway.
Shame about the damage on yours; although my VSL has wear and tear it's not been monkeyed. My AUD was in slightly better condition but a man can only have so many lathes

 

[zx9]

Good luck with the re-build. I'm still green with envy, can you tell.

 

[mr migwire]

im looking at using the vfd as it does allow a control box to be fitted with a fwd / rev switch and speed controler, will need to fettle the back gear etc and sort out the ball bearing that holds the lever in position.

 

[Shox Dr]

as Wedg1e says, vfd straight to motor, use the STF/STR (fwd/rev) etc commands on the vfd to control the motor.

 

[mr migwire]

the only problem i have is i use the vfd for my ajax saw to, so i may have to purchase another for the lathe,

 

[mike os]

So fit a socket to the vfd? And plugs to machines

 

[Pete.]

Broken teeth on the back gear pinion is usually down to someone engaging back gear to lock the spindle then whacking the chuck key to release the chuck from the spindle.

 

[Seadog]

Tony at Lathes.co.uk offers a repair service for the back gears.

 

[mr migwire]

Broken teeth on the back gear pinion is usually down to someone engaging back gear to lock the spindle then whacking the chuck key to release the chuck from the spindle.

thats what i thought, no progress report today, been at the railway all day, next instalment tomorrow.

 

[Wedg1e]

So fit a socket to the vfd? And plugs to machines

What I did was mount the VFD in a box on the wall complete with a pair of contactors. These are selected by a front panel switch and route the VFD output to either lathe or mill. The machines have their start/stop buttons routed through the 'opposite' contactor so you can't accidentally start the wrong machine... all simple to do.
You could easily add extra contactors/ switches to run three or more machines - not at the same time of course - although having said that, if you have the lathe spindle motor running you can then switch the coolant pump on and it works fine, provided you're not trying to run at such a low speed that the coolant pump couldn't shift any fluid.

 

[mr migwire]

i may be going down the single phase route. ive had a call from a mate who knew i was looking for a lathe. he has a friend who has a boxford languishing in his shed, its single phase with a rear mounted motor and is apparently a bit of a mess due to a leak in the shed roof, im going to collect it this week mainly due to the fact its free gratis. there like buses you wait for one and a few show up at once..,.

 

[Seadog]

I'd recommend using 3 phase. It's a whole lot smoother, and the versatility from being able to vary speed at the turn of a knob cannot be overstated.

 

[mr migwire]

well i managed another bit today, stripped the old paint from the cabinet and cracked on with getting it into the new livery, i had another look at the gearbox since removing the back gears and noted the driven gear is also missing a good few teeth, this means the back gear will probably not run properly and so i will only have the higher speed settings available, still a very usable lathe though and good enough for me to learn on.

 

[mr migwire]

here's a close up of the driven gear that engages with the back gear...

 

[Wedg1e]

Hmmm, yes that would make slow running a bit problematic. If you stick with the 3-phase VFD then you can at least slow down the spindle to make parting-off etc. a lot easier.

 

[hareng]

If you stick with the 3-phase VFD then you can at least slow down the spindle to make parting-off etc. a lot easier.

Why, don't it have a gear box/pulley to alter the more than adequate speeds available as standard fitment 210 to 1400 rpm. I wouldn't want to part off at lower end of the higher speed range in any material.
Back gear good for threading and reaming.