Boxford goes crunch! Now refuses to turn.

[Ian Rees 1Participant @ianrees1]

After the great advice I got on here earlier regarding feeds on my Boxford, I decided to give it a try. Everything was going well, I was just taking tiny cuts and using plenty of fluid. I increased the size of cut, marginally (we really are talking small cuts here, less than 0.5mm off the diameter, as I'm trying to get a feel for the machine). Then she started to labour a bit and all of a sudden made a horrible crunching noise so I stopped everything.

Apart from a minor stiff spot in the gear train, I could detect no real problems there so I tried starting up again with the leadscrew disengaged but the same noise happened. I've traced the problem to inside the headstock casing, there's a sliding gear to put the main drive in neutral before you engage the backgear, this locates the belt pulley with two pins that fit into holes on the face of the gear. I've looked at this part before and thought the pins didn't go into the holes very far but just assumed that was the design. Now it seems my fears may have been right.

Sorry for my lack of the proper terminology for these parts but what can I do to get my lathe turning again?

Do I need new drive pins? Or does something need adjusting?

[Ian Rees 1Participant @ianrees1]

[Tim StevensParticipant @timstevens64731]

It is always difficult to diagnose such problem with a (necessarily) vague description, so bear with us.

Could it be that the pins you describe are there to lock the back-gear (low ratio) to the drive pulley, and normal drive (high ratio) requires the pins to be disengaged? I am not familiar exactly with the Boxford gearing but this is a common arrangement. So, could your 'sliding gear' be moving so that both ratios are engaged at the same time?

In a car or motorcycle gearbox there are interlinks to prevent two gears at once, but in my experience a lathe is not such a foolproof design. Have a good look anyway and report on what you find. It may be that there is a catch or linkage which is not there or not properly adjusted.

And I hope that an actual Boxford owner is getting over his mince-pie-fest and reading your query soon.

Regards, Tim

[Ian Rees 1Participant @ianrees1]

No, it's the other way around on this one, if you leave it engaged and engage the backgear at the same time, it locks the spindle (although I've been warned not to use this for tightening chucks etc).

To anyone familiar with a Mk1 Boxford, this would be easily understandable (I hope), even with my dreadful explanation.

I've asked the question in the Yahoo group as well. The more I use this machine, the more I think it needs a thorough strip and clean. I'd do the same with any stationary engine I bought but I'm not so sure about putting a lathe back together.

[Ian Rees 1Participant @ianrees1]

Some pictures (hopefully). Sliding gear engaged, disengaged and the control knob.

 

Edited By Ian Rees 1 on 30/12/2015 17:56:46

[BazyleParticipant @bazyle]

There are two levers used to engage the backgear on the Boxford. One is on the front or top depending on model and slides the big Bull gear off the pins that link it to the pulley block. Doing so allows the spindle to rotate free of the pulley and so in 'neutral' as you say., It may be that the lever for this is loose on the shaft so it has slid out of full contact. The way the bull gear is moved is by having a groove in it rather like a pulley in which a bronze shoe runs linked to the operating lever. As this gets no lubrication as it is difficult to get at over 50 years it will have worn. A LOT. This would allow the gear and pulley to drift apart and just be on the ends of the pins.

The other lever is on the left side rear of the headstock and moves the layshaft back an forward. It will lock the spindle if it is brought forward when the bull wheel is still engaged t other pulley. DO NOT use this as a way of locking the spindle. DO NOT allow this lever to move while still running.

[BazyleParticipant @bazyle]

Ok now see your pictures.. Your pins are unusually short. Are they loose? The engaged position is not looking very close to the pulley, it should be right up against it, so I think it is a worn shoe.

[Michael GilliganParticipant @michaelgilligan61133]

This diagram and parts list might help clarify.

**LINK**

MichaelG.

[Ian Rees 1Participant @ianrees1]

I was wondering if I could adjust the eccentric bit on the lever to make the pins and gear engage a bit better but it's looking more and more like this machine needs some proper attention, rather than a lot of quick fixes.

Thanks for the replies, Bazyle, you're spot on, again.

[kevin beeversParticipant @kevinbeevers61752]

check that the pullys are inline with the holes in the gear,somtimes the pully will slip round if you have crashed so you will find that the pin is slightly out of line and you strugle to get it in this has happend to me there is a grubscrew in the pully slacken this then slide lever over and keep moving the puly until the pin pops in the hole of the gear then lock the pully.Kevin.

[Ian Rees 1Participant @ianrees1]

Thanks Kevin but I think this needs a proper looking at. I’ve got everything out of the way of the spindle now, just need to know how to get it out and check if I’ve missed anything. There’s marks of previous butchery on here but the bearings seem to be well greased.

[Martin ConnellyParticipant @martinconnelly55370]

Oil on gears is less likely to form a grinding paste than grease on gears. Is there a Boxford recommended lubricant for these gears?

Martin

[Ian Rees 1Participant @ianrees1]

As far as I know, Boxford recommend grease for gears and oil for everything else. I’ve got a couple of different types of grease and some 68 slideway oil, maybe some sort of gear oil is needed?
Proper lubrication techniques is another question I’ve been thinking about asking.

[Tim StevensParticipant @timstevens64731]

A lubricant I have found useful for such jobs is spray (aerosol) chain lube. This is a sticky product which goes on very thin and can penetrate well; when the solvent evaporates the residue is more a sticky grease than an oil. Ideal for leaf springs, brake cables, ball joints, etc, as well as (obviously) roller chains.

Cheers, Tim

Edited By Tim Stevens on 31/12/2015 11:08:31

[Ian Rees 1Participant @ianrees1]

I’ve got a few different tins of spray grease, that could be something to try. First of all I need to remove this spindle, which seems to be stuck fast. I’ve heard that the rear bearing needs to be removed first but I’ve got no idea how to do that, there’s very little metal for any kind of puller to grip on to. Also, very little info on the net, that I can find…….
I’m also quite lacking in the tool department, most of my stuff is for taking lawnmowers and small engines apart so this will need to be a DIY fix.

Edited By Ian Rees 1 on 31/12/2015 12:38:07

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I agree with Tim, chain & cable lubricant is good, sticks like …. to the proverbial blanket.

Regards Nick.

P.S. Don't use it in bearings though.

Edited By Nicholas Farr on 31/12/2015 13:07:10

[Ian Rees 1Participant @ianrees1]

Spindle is out, I had to pull it through with the rear bearing still in place with a long length of M12 studding in the end. I’ll see if I can order some new drive pins and a new shoe for it. Thanks for all the help.

[Neil WyattModerator @neilwyatt]

Shame you haven't got a lathe – you could turn up some new drive pins…

:-0

Sorry…

Neil

[Bob Brown 1Participant @bobbrown1]

I have some parts from a CUD and had a look at the headstock and the pins that disengage to allow back gear to be engaged look long than the ones in the picture probably closer to 3/8" sticking out. My AUD does not have the same arrangement as it is a later machine and the pins are spring loaded and only one lever on top.

[Ian Rees 1Participant @ianrees1]

These pins look a bit home-made to me, in fact, there’s signs that this lathe has been apart before and not necessarily by someone who knows what they were doing! Mind you, I don’t know what I’m doing either.
I’ll put some more pictures up later, some of you might be able to shed some light on them.
Neil, that thought had crossed my mind but it’s been so long since I did any lathe work, I’m not sure I’d have the ability even if I had the machinery. My brother does have one of those tiny little Swedish lathes though, maybe we could turn some pins up on that before he gets rid of it. He bought it sort of by accident and doesn’t like it much.

[Bob Brown 1Participant @bobbrown1]

Ian, you have a PM

[Ian Rees 1Participant @ianrees1]

A better look at the shortness of the pins.

The damage done. Looks like I'll get away with it but if anyone thinks this is too bad, let me know.

Plenty of bronze deposits and the worn shoe, which is still quite a good fit but I'm hopefully going to order a new one anyway.

This is puzzling, are these repairs to the bullwheel or is it supposed to be like this?

Finally, some signs of previous butchery and, is there supposed to be a felt washer in this piece? The parts diagram says felt washers back and front but there are none on this machine.

Happy new year everyone

[Speedy Builder5Participant @speedybuilder5]

Yes, they are snapped tooth repairs. Typically you drill and tap the root of the snapped tooth and screw some threaded rod in, give them a bit of a bash to stop them moving, then file the tooth profile back. Had a Southbend with the same repairs.

[Ian Rees 1Participant @ianrees1]

Ah, looks like someone maybe used the backgear to lock the spindle. I must admit, I did it myself before I read on here that it’s a big no no! I’m still flummoxed as to how you’re supposed to lock the spindle on these lathes.

[Bob Brown 1Participant @bobbrown1]

The pins do look short, I make them about 1/4" and a shade under 1/4" diameter.

[Author]

Posts