Twin Headstock 5″ Boxford! now has more centre height

[Ian PParticipant @ianp]

I needed to make some aluminium end caps for an underwater camera housing, the size of the camera dictated that they were larger in diameter than my 5" AUD could accept. However, I was in the fortunate position of having recently bought an (incomplete) 4-1/2" Boxford and came up with a cunning plan.

I rebuilt the headstock and mounted a variable speed motor directly on it. A pair of Vee blocks and a length 12mm bar maintain spindle alignment plus some square bar to pack up the headstock from the bed.

The loss of tailstock does not matter for this particular job and obviously screwcutting is not possible, Whilst I have not yet tried it, the power cross feed should still be operative using the original headstock drive.

One side benefit of doing this lash up is that I am now fully decided that I will convert my underdrive lathe to rear drive. I will use either a polyvee or a timing belt drive and once and for all, get rid of the long segmented belt that is forever slipping.

Ian P

The V block and packing picture was taken when doing a trial assembly, its slightly better now.

 

 

 

 

Edited By Ian Phillips on 26/07/2013 21:22:53

[Ian PParticipant @ianp]

[BazyleParticipant @bazyle]

Rather ingenious tough only possible for pwople with multiple headstocks.

The belt slip can just as easily happen on a rear drive too. Are you by any chance using one of those truely awful plastic segment belts I saw at a show. An old belt and a bit of corrosion might increase the grip.

[Speedy Builder5Participant @speedybuilder5]

My underdrive with fabric impregnated segmented belt doesn't slip – and I have used it for more than 20 years now. Must admit, I find it a bit difficult to take the belt appart for maintenance, but only done it twice.

Bob H

[Speedy Builder5Participant @speedybuilder5]

Never thought about it before, but if you mounted a rotary table on the bed, could you use the power feed to pull a tool through a component to cut keyways etc, or would it strain the half nuts etc too much?

[NJHParticipant @njh]

Hmmm Bob

I think I would prefer to use the hand wheel and rack to plane it out in easy stages.

Norman

[Ian PParticipant @ianp]

Posted by Bazyle on 27/07/2013 15:42:15:

Rather ingenious tough only possible for pwople with multiple headstocks.

The belt slip can just as easily happen on a rear drive too. Are you by any chance using one of those truely awful plastic segment belts I saw at a show. An old belt and a bit of corrosion might increase the grip.

I considered doing this before I had a spare headstock. I was going to raise the existing headstock and tailstock by 1/2" by making correctly profiled raising blocks.

It seems to me there would be a small but ready market for converting 4-1/2" Boxfords to 5" (and 5" to 5-1/2". (if you are reading this JS, I will be your first customer!)

The spindle belt on my machine (probably original) is die-cut segments of some sort of laminated rubberised material a bit like vehicle tyre sidewall. The underdrive boxford is a bit of a dogs breakfast because it has three belts and two countershafts, In the 15 years I have had the lathe I have never changed the speed by moving belts, I use a VFD and only occasionally have to use the backgear.

The rear drive lash-up in the picture is much quieter and smoother than the underdrive so I think I will do a proper conversion (whether I make it 5-1/2" or not).

 

Ian P

 

Edited By Ian Phillips on 27/07/2013 19:39:16

Edited By Ian Phillips on 27/07/2013 19:41:42

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