Need chuck thread cutting Wadkin Bursgreen BZL

[Richard Harris 5Participant @richardharris5]

Posted by John Hinkley on 03/11/2016 10:51:50:

Mark Smith 20,

Thanks for the heads-up on the tapers. The links will be useful to those who haven't access to those manuals. Unfortunately neither address the issue of the left hand thread on the spindle nose, leading to the possibility ( or probability ) of the faceplate/chuck unscrewing in use.

John

I am not a turner so I am trying to picture this. The LH thread is on the outbound side, which would be turning clockwise as you face it, correct? And the direction of turning the chuck onto the LH thread would be counter clockwise?

So if you want to remove the chuck, you are turning it clockwise to turn off? The same direction as the spindle will be turning?

Does that mean a chuck / faceplate could spin off?

Wouldn't it be the same on the inbound side then as well?

[Jon GibbsParticipant @jongibbs59756]

Posted by Richard Harris 5 on 03/11/2016 11:06:41:

So if you want to remove the chuck, you are turning it clockwise to turn off? The same direction as the spindle will be turning?

Does that mean a chuck / faceplate could spin off?

Think of it from the centre of the headstock looking towards each chuck in turn – inboard and outboard.

A RH thread for the inboard side and a LH thread for the outboard side is absolutely correct to tighten the threads when its turning towards the operator.

For woodturners, and I include myself here, turning on the outboard side requires a significant change of action that requires practice – particularly for those who've always turned inboard but it's entirely possible to get the muscle memory.

Jon

[KWILParticipant @kwil]

Richard,

Does that mean a chuck / faceplate could spin off?

Wouldn't it be the same on the inbound side then as well?

The intention is that whe the spindle is turning in the normal forward direction, the chuck/faceplate is always being "tightened" on its thread when under load. Starting the spindle will always ramp up faster, ie motor switch on, power off and the spindle slows as it looses inertia, and chuck/faceplate does not have a tendency to spin off.

[Richard Harris 5Participant @richardharris5]

Posted by KWIL on 03/11/2016 11:26:58:

Richard,

Does that mean a chuck / faceplate could spin off?

Wouldn't it be the same on the inbound side then as well?

The intention is that whe the spindle is turning in the normal forward direction, the chuck/faceplate is always being "tightened" on its thread when under load. Starting the spindle will always ramp up faster, ie motor switch on, power off and the spindle slows as it looses inertia, and chuck/faceplate does not have a tendency to spin off.

Posted by Jon Gibbs on 03/11/2016 11:21:00:

Posted by Richard Harris 5 on 03/11/2016 11:06:41:

So if you want to remove the chuck, you are turning it clockwise to turn off? The same direction as the spindle will be turning?

Does that mean a chuck / faceplate could spin off?

Think of it from the centre of the headstock looking towards each chuck in turn – inboard and outboard.

A RH thread for the inboard side and a LH thread for the outboard side is absolutely correct to tighten the threads when its turning towards the operator.

For woodturners, and I include myself here, turning on the outboard side requires a significant change of action that requires practice – particularly for those who've always turned inboard but it's entirely possible to get the muscle memory.

Jon

Oh thank you, that is good to know. This is how I hoped it would naturally work – with the direction tightening the faceplate, but that got me worrying it was going the wrong way for a moment

[John HinkleyParticipant @johnhinkley26699]

Oh, dear! I'm beginning to wish I hadn't reopened this particular can of worms!

I must confess to being a little confused by the use of the terms "inboard" and "outboard" when referring to the ends of the spindle. I assume this is specific to woodturning and that inboard refers to the end facing the tailstock and outboard is the end hanging out in the fresh air for a faceplate or large bowl turning.

Either way, I'm still convinced that the thread facing the tailstock should be a right hand thread, as I think has been established. So that leaves you with a thread going the "wrong" way on your spindle – or the spindle is installed end for end.

Over to you . . . .

John

[Neil WyattModerator @neilwyatt]

Posted by John Hinkley on 03/11/2016 14:06:29:

Oh, dear! I'm beginning to wish I hadn't reopened this particular can of worms!

I must confess to being a little confused by the use of the terms "inboard" and "outboard" when referring to the ends of the spindle. I assume this is specific to woodturning and that inboard refers to the end facing the tailstock and outboard is the end hanging out in the fresh air for a faceplate or large bowl turning.

Either way, I'm still convinced that the thread facing the tailstock should be a right hand thread, as I think has been established. So that leaves you with a thread going the "wrong" way on your spindle – or the spindle is installed end for end.

Over to you . . . .

John

My understanding is that the LH thread in question is the bowl turning one 'away from the tailstock'

Neil

[Richard Harris 5Participant @richardharris5]

Posted by Neil Wyatt on 03/11/2016 14:36:33:

Posted by John Hinkley on 03/11/2016 14:06:29:

Oh, dear! I'm beginning to wish I hadn't reopened this particular can of worms!

I must confess to being a little confused by the use of the terms "inboard" and "outboard" when referring to the ends of the spindle. I assume this is specific to woodturning and that inboard refers to the end facing the tailstock and outboard is the end hanging out in the fresh air for a faceplate or large bowl turning.

Either way, I'm still convinced that the thread facing the tailstock should be a right hand thread, as I think has been established. So that leaves you with a thread going the "wrong" way on your spindle – or the spindle is installed end for end.

Over to you . . . .

John

My understanding is that the LH thread in question is the bowl turning one 'away from the tailstock'

Neil

Correct. On our machine: LH thread outbound, RH thread inbound.

Are we going to die? :O

[John HinkleyParticipant @johnhinkley26699]

Good. Glad we got it sorted . . . . . Or did we?

I'm off for a cuppa; my brain hurts.

John

[Richard Harris 5Participant @richardharris5]

So the taps arrived with him, set off 3.

I explained how to use his lathe to make alignment easier and start the threading. But then after the weekend he says he felt it was too risky and didn't feel like doing it himself. So he has a friend at work who is very familiar using a engineering lathe to do it.

Their idea is now to buy a 1 x 8 BSW LH die and make an adapter for it.

Can someone else comment? To me, this makes no sense. Both the chuck and the lathe are 1" diameter – a thread adapter will not fit unless:

a) the bore out the chuck (for which, we don't know how much material is actually in there)

b) the take the spindle off and turn it smaller (for which, they'd need a 1 x 8 metric die to fit the current chuck thread).

Am I confused?

[HopperParticipant @hopper]

Posted by Richard Harris 5 on 08/11/2016 10:18:14:

So the taps arrived with him, set off 3.

 

I explained how to use his lathe to make alignment easier and start the threading. But then after the weekend he says he felt it was too risky and didn't feel like doing it himself. So he has a friend at work who is very familiar using a engineering lathe to do it.

 

Their idea is now to buy a 1 x 8 BSW LH die and make an adapter for it.

 

Can someone else comment? To me, this makes no sense. Both the chuck and the lathe are 1" diameter – a thread adapter will not fit unless:

 

a) the bore out the chuck (for which, we don't know how much material is actually in there)

b) the take the spindle off and turn it smaller (for which, they'd need a 1 x 8 metric die to fit the current chuck thread).

 

Am I confused?

Yes. You are confused. There is no such beast as a 1'' x 8tpi metric thread. Until you sort out what threads you are dealing with, you will get nowhere.

First step should be to call Axminster and ask them whether the thread on the chuck you bought is 1" BSW or 1" UNC.

Making an adaptor to fit a 1" x 8tpi LH threaded chuck on to a 1" x 8tpi LH threaded spindle makes no sense at all.

 

Edited By Hopper on 08/11/2016 11:02:19

[Richard Harris 5Participant @richardharris5]

Posted by Hopper on 08/11/2016 10:52:56:

Posted by Richard Harris 5 on 08/11/2016 10:18:14:

So the taps arrived with him, set off 3.

 

I explained how to use his lathe to make alignment easier and start the threading. But then after the weekend he says he felt it was too risky and didn't feel like doing it himself. So he has a friend at work who is very familiar using a engineering lathe to do it.

 

Their idea is now to buy a 1 x 8 BSW LH die and make an adapter for it.

 

Can someone else comment? To me, this makes no sense. Both the chuck and the lathe are 1" diameter – a thread adapter will not fit unless:

 

a) the bore out the chuck (for which, we don't know how much material is actually in there)

b) the take the spindle off and turn it smaller (for which, they'd need a 1 x 8 metric die to fit the current chuck thread).

 

Am I confused?

Yes. You are confused. There is no such beast as a 1'' x 8tpi metric thread. Until you sort out what threads you are dealing with, you will get nowhere.

First step should be to call Axminster and ask them whether the thread on the chuck you bought is 1" BSW or !" UNC.

 

 

RIGHT, I am confused! Thank you Hopper.

 

So the chuck is definitely at 1" x 8 LH UNC threadform, confirmed by Axminster. Imperial (- sorry).

 

So the idea of running a tap through the chuck makes sense still? As well as confirming the OD of the spindle thread, and if needing, lightly removing some material.

 

But they're both still the same OD, 1". How can they be making a thread adapter? Without the aforementioned issues?

Edited By Richard Harris 5 on 08/11/2016 12:00:08

[HopperParticipant @hopper]

Simples: they can't be. Your Dad has got his mate's advice mixed up somehow.

He should be able to screw the 1'' BSW LH taper tap into the thread in the chuck by hand, on the bench. It should go something like a third or half way in before much resistance is felt. He should be able to wind it in further with a tap handle (or shifting spanner if he has no tap handle). All it should need to do is clean up the thread flanks to match the BSW 55deg thread form, which is actually less than the 60 deg UNC threadform, so should pretty much wind right in. Once he has wound that one through the chuck therad, should be able to repeat with the intermediate tap and finally the plug tap. No need to set it up in the lathe to clean out an existing thread. It should only be a matter of removing a few thou of metal. The tap should follow the existing thread, pretty much like screwing a nut and bolt together.

Then if the chuck will not screw on the spindle, it is a matter of cleaning up the thread on the spindle to fit in the cleaned-out chuck thread. This can be done with a fine file, or with a 1" BSW LH die.

Edited By Hopper on 08/11/2016 12:02:00

Edited By Hopper on 08/11/2016 12:03:15

[Richard Harris 5Participant @richardharris5]

Posted by Hopper on 08/11/2016 12:01:33:

Simples: they can't be. Your Dad has got his mate's advice mixed up somehow.

He should be able to screw the 1'' BSW LH taper tap into the thread in the chuck by hand, on the bench. It should go something like a third or half way in before much resistance is felt. He should be able to wind it in further with a tap handle (or shifting spanner if he has no tap handle). All it should need to do is clean up the thread flanks to match the BSW 55deg thread form, which is actually less than the 60 deg UNC threadform, so should pretty much wind right in. Once he has wound that one through the chuck therad, should be able to repeat with the intermediate tap and finally the plug tap. No need to set it up in the lathe to clean out an existing thread. It should only be a matter of removing a few thou of metal. The tap should follow the existing thread, pretty much like screwing a nut and bolt together.

Then if the chuck will not screw on the spindle, it is a matter of cleaning up the thread on the spindle to fit in the cleaned-out chuck thread. This can be done with a fine file, or with a 1" BSW LH die.

Edited By Hopper on 08/11/2016 12:02:00

Edited By Hopper on 08/11/2016 12:03:15

Wonderful. Thanks Hopper. Thanks for clearing that up in my head. Will have to report back to him…

[not done it yetParticipant @notdoneityet]

Weell, I read it a the friend at the engineering place was simply going to make an adaptor for mounting the die to some machine! It only needs to be hand held, shirley? Taking naff all off an already formed thread?

Or is it really a metric bsw/unc/totally unknown thread which will be messed up completely by yet another guesser?

The face plate should be cut to fit the spindle. Every time. A basic principle. Do it right. Job should have been done right in the first place – the spindle should have gone to axminster(?) in the first place.

[Richard Harris 5Participant @richardharris5]

Posted by not done it yet on 08/11/2016 13:09:52:

Weell, I read it a the friend at the engineering place was simply going to make an adaptor for mounting the die to some machine! It only needs to be hand held, shirley? Taking naff all off an already formed thread?

Or is it really a metric bsw/unc/totally unknown thread which will be messed up completely by yet another guesser?

The face plate should be cut to fit the spindle. Every time. A basic principle. Do it right. Job should have been done right in the first place – the spindle should have gone to axminster(?) in the first place.

Exactly yes. My dad & his friend are clearly confused about something, yet to clarify it with them.

We 100% know what the threads are. The chuck – UNC. The spindle – BSW. So we are indeed taking hardly anything off, and it can be done by hand, as Hopper pointed out.

I've cut threads from scratch before on my small lathe, and it's quite straight forward. So if he gets a new faceplate etc (although I believe the chuck has a faceplate adapter that fits on the front), he / we / his friend can do this properly aligned on the lathe…

… BUT as it is, not too complicated…

[mark smith 20Participant @marksmith20]

I have a similar problem but the opposite ,i have two good chucks that need back plates for a south bend 1 1/2 x 8 UNC spindle , problem is the chucks that came with my lathe had nice backplates but they were threaded for a boxford at 1/1/2 x 8 BSW and dont thread on properly.

Ive done some external threading on the lathe but how does one redo the same threads only with a unc single point cutter (ie the treads already in the back plates which will be internal) .??

The lathe has a gearbox and thread dial indicator.

The first photo is of the four jaw chuck back plate showing how little the chuck will thread on.

The second two photos are the 5" 3 jaw chuck  showing the internal threads.

At the moment im using the 6" 4 jaw temporarily fixed to a south bend dog drive plate which does have the correct thread but is less than ideal.

By the way the taps for these are like gold dust and cost upwards of £100 second hand on ebay due the amount of south bend owners in the US and elsewhere.

Edited By mark smith 20 on 10/11/2016 15:19:52

 

Edited By mark smith 20 on 10/11/2016 15:22:04

Edited By mark smith 20 on 10/11/2016 15:24:10

[NJHParticipant @njh]

Richard

Not an answer to your question I'm afraid but a " thank you" for posting that image of the lathe. When I was a lad ( back in the days when Adam was too) my Dad had a woodworking business. He purchased a lathe just like the one you have posted ( although his was grey) and, when he worked weekends, I would often go with him and "play" on the lathe. I still have a fruit bowl and table lamp somewhere around the house!

Happy memories

Norman

Edited By NJH on 10/11/2016 16:45:26

[mark smith 20Participant @marksmith20]

Hi Richard ,did your dad get it sorted out???

I posted above about my problem with BSW 55 degrees back plates and needing them to be UNC 60 degrees.

Well i just done one by picking up the threads using a homemade cutter from a broken centre drill ground to 60 degrees . It was fiddly to set up being an internal thread and clearance etc… but i took a very little off and the result is my back plate goes on perfectly.

I watched a you tube video on how to pick up the threads ,as i had never tried it before and it was very easy.

 

Edited By mark smith 20 on 12/11/2016 13:16:10

Looks a lot better as well.

 

 

 

Edited By mark smith 20 on 12/11/2016 13:31:51

Edited By mark smith 20 on 12/11/2016 13:33:47

[Richard Harris 5Participant @richardharris5]

Posted by mark smith 20 on 12/11/2016 13:12:09:

Hi Richard ,did your dad get it sorted out???

I posted above about my problem with BSW 55 degrees back plates and needing them to be UNC 60 degrees.

Well i just done one by picking up the threads using a homemade cutter from a broken centre drill ground to 60 degrees . It was fiddly to set up being an internal thread and clearance etc… but i took a very little off and the result is my back plate goes on perfectly.

Oh excellent, glad to know it was sort of in some way helpful. Well done for working out the problem!

Yes, are are now sorted. Just this evening.

It took them 1 month to work out what we all agreed on here within a matter of days. Painful.

They had this idea of making an adapter, but eventually agreed it was far too much work. Which it obviously was! It would involve cutting several threads and making parts that fit together. They then got very worked up about the whole thing – I don't know why. It 3 weeks later, this chap he gave it to finally mounted it and put the tap through it. He was concerned that it had only just grazed it…

… and of course, he took it home this evening and it fits perfectly.

All fine now. Thanks for all your help!

[Richard Harris 5Participant @richardharris5]

Posted by NJH on 10/11/2016 16:44:48:

Richard

Not an answer to your question I'm afraid but a " thank you" for posting that image of the lathe. When I was a lad ( back in the days when Adam was too) my Dad had a woodworking business. He purchased a lathe just like the one you have posted ( although his was grey) and, when he worked weekends, I would often go with him and "play" on the lathe. I still have a fruit bowl and table lamp somewhere around the house!

Happy memories

Norman

Edited By NJH on 10/11/2016 16:45:26

You're very welcome Norman! I may try and get some more photos of it if we make something over the Christmas period.

[Richard Harris 5Participant @richardharris5]

UPDATE:

So I actually saw the lathe over christmas and noticed it isn't actually setup right. Ugh.

The chuck on the outbound side – that has caused this massive faff – isn't on all the way. It's threaded on fine, feels nice and snug, but it's just sitting on the threads. It doesn't go all the way onto the "cuff" part of the spindle… if that makes sense? Do you know what I am trying to describe?

I've had a look and the chuck isn't very deep, so I am not sure boring out the inside of the chuck would work very well., or at least, it may not take it all the way in deep enough. We need around 12mm to get it all the way onto the cuff.

Is it acceptable to cut off the end off the threaded part of the spindle? So that there is less threaded part, and it will slide onto the unthreaded / flat part of the spindle?

Or should we start by boring the chuck first?

He noticed it because he had bought some large donut type jaws with small rubber buttons, so you can hold a bowl and finish the bottom of it more easily. With the larger diameter, there seems to be a pronounced wobble on it. But, it is quite minimal to my eye, for wood turning.

[Richard Harris 5Participant @richardharris5]

I also just looked at his chuck on the inbound side, and the fit is absolutely atrocious. I do not know how he is still alive, or how he didn't think this was unusual. The amount of play on it as you screw it in, there must be at least a 2-3mm difference. Luckily, that chuck has a simple backplate, so it would be easy to swap for a thicker backplate, and then thread it properly.

[NJHParticipant @njh]

Richard

Do not attempt to modify the spindle in any way – it is probably hardened in any case. The "cuff" that you refer to is the register and, whilst the threads on the spindle and chuck draw the two items together it is the close fit between the registers of chuck and spindle that ensure alignment. The end of the chuck backplate should be bored such that it is a close fit on this register.

Norman

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