Need chuck thread cutting Wadkin Bursgreen BZL

[mark smith 20Participant @marksmith20]

Why not buy this, put it through and see, it just might work?

**LINK**

[Ian ParkinParticipant @ianparkin39383]

Buy one of those quick…its a bargain if you have a lathe with that nominal thread

[Paul BarterParticipant @paulbarter66156]

Hello there, Sorry to read of your pain! I have a BZL, great lathe, the outboard thread is 1" x 8 tpi lefthand whitworth thread form. These threads have a rounded thread form, I got my tap from Tracy tools.hope this helps

regards Paul

[Brian OldfordParticipant @brianoldford70365]

Where in Shropshire are you?

[HopperParticipant @hopper]

Posted by Richard Harris 5 on 29/10/2016 13:48:14:

edit: So hang on, are we saying both the Axminster chuck & the spindle thread are a 1 x 8 UNC LH thread? But for a more or less unknown reason doesn't fit?

I don't know if its been verified that the Axminster chucks are UNC or BSW. You probably should chekc with Axminster. Either way, a UNC thread should screw onto a BSW thread of the same TPI.

Your Dad's measurements indicate that the diamter of the spindle thread is oversize (1.001&quot. That is the most likely reason it does not fit. Until you run a file over that thread and clean off the tops of the threads to bring them a few thou under 1.000", nothing standard is likely to fit on there. Usually the OD of a nominal 1" thread will be something like .995 or even .990" to allow clearance.

The 1" thread on the spindle of my old Drummond is .980". Chuck location is done by the plain register behind the thread, so it matters not how sloppy the thread fit is, within reason.

[not done it yetParticipant @notdoneityet]

Could you elaborate on what you mean by the other side?

Here you go. Other side of the headstock. Other side of the spindle. Maybe I should have written other end of the spindle.

Not rocket science. PresumabLy (again) there is a right handed thread on that side? Youcould use some engineering blue to determine where the unecessary contact is being made if it is not obvious by measurement.

[John OlsenParticipant @johnolsen79199]

In my admittedly limited experience of cutting screw threads of this general size, eg to fit my ML7, there is not very much difference between "Won't fit" and "goes on". This means that when screw cutting you need to take quite small cuts as you approach the final size…of course that is not possible in this case, but does suggest to me that either the spindle or the chuck needs a tiny bit more taken off. Iit is a bit of a pain cutting things to fit the ML7 Spindle anyway, because you probably can't get at it to try the fit while the job is in the machine and you don't want to disturb the job while screwcutting. I made a dummy spindle nose that just fits a chuck so as to have something to test the fit with, and successfully made a backing plate for a collet chuck using it.

Ideally whoever is cutting the thread in the chuck should have the spindle available to try the fit, but this would mean dismantling the lathe.

John

[Richard Harris 5Participant @richardharris5]

Posted by Don Cox on 29/10/2016 14:13:17:

I don't know if this is of any help, but last year I had dealings with Peter Child wood turners' supplies regarding a chuck and thread converters both LH and RH for my Myford ML8 and they were very helpful. Sadly they are no longer trading but their website remains accessible here with info about available headstock threads: http://www.peterchild.co.uk/chucks/threads.htm

Don

Thanks Don. I had came across Peter Child's site before but unfortunately he doesn't list our model.

[Richard Harris 5Participant @richardharris5]

Posted by Ian Parkin on 29/10/2016 15:11:00:

Richard

I can do it with the existing chuck/faceplate but that involves making a stub thread to check the existing faceplate then modify (if needed) the new axminster chuck…it would be better with the spindle

Ian

Thanks Ian, very kind of you. All makes sense. Will discuss this properly if it comes to this. I'm giving him a call this evening to see what route he'd like to take…

[Richard Harris 5Participant @richardharris5]

Posted by mark smith 20 on 29/10/2016 15:48:40:

Why not buy this, put it through and see, it just might work?

**LINK**

Thank you Mark. It seems confirmed that it's a BSW thread now so I'm reluctant to buy a UNC tap. But I guess the difference is extremely small, as has been touched upon. If we go that route, I don't think my Dad will mind paying a little more for the BSW tap.

[Richard Harris 5Participant @richardharris5]

Posted by Paul Barter on 29/10/2016 18:03:28:

Hello there, Sorry to read of your pain! I have a BZL, great lathe, the outboard thread is 1" x 8 tpi lefthand whitworth thread form. These threads have a rounded thread form, I got my tap from Tracy tools.hope this helps

regards Paul

Oh thank you Paul, wonderful to hear of someone else using this machine. Doesn't seem so commonly written about at least. You point to what many have suspected, the Chuck was cut with a metric thread and the original spindle is imperial. I think we'll be getting a BSW tap to remove a little material from the chuck.

[Richard Harris 5Participant @richardharris5]

Posted by Ian Parkin on 29/10/2016 17:52:19:

Buy one of those quick…its a bargain if you have a lathe with that nominal thread

Just a passing comment about these taps, will they be comfortable cutting through the stainless steel of the chuck? I don't know much about it's hardness or material tbh. I trust a gentle back and forth action should do the job safely enough…

[Richard Harris 5Participant @richardharris5]

Posted by Brian Oldford on 29/10/2016 22:06:38:

Where in Shropshire are you?

My Dad is 1 mile outside of Much Wenlock in Shropshire

[Richard Harris 5Participant @richardharris5]

Posted by John Olsen on 30/10/2016 06:38:48:

In my admittedly limited experience of cutting screw threads of this general size, eg to fit my ML7, there is not very much difference between "Won't fit" and "goes on". This means that when screw cutting you need to take quite small cuts as you approach the final size…of course that is not possible in this case, but does suggest to me that either the spindle or the chuck needs a tiny bit more taken off. Iit is a bit of a pain cutting things to fit the ML7 Spindle anyway, because you probably can't get at it to try the fit while the job is in the machine and you don't want to disturb the job while screwcutting. I made a dummy spindle nose that just fits a chuck so as to have something to test the fit with, and successfully made a backing plate for a collet chuck using it.

Ideally whoever is cutting the thread in the chuck should have the spindle available to try the fit, but this would mean dismantling the lathe.

John

Thanks John. I'll pass this over to my Dad when I discuss it with him later as well. That's sort of encouraging to know. Hopefully this tap threading idea will work out okay…

[Richard Harris 5Participant @richardharris5]

Posted by Hopper on 30/10/2016 00:12:31:

Posted by Richard Harris 5 on 29/10/2016 13:48:14:

edit: So hang on, are we saying both the Axminster chuck & the spindle thread are a 1 x 8 UNC LH thread? But for a more or less unknown reason doesn't fit?

I don't know if its been verified that the Axminster chucks are UNC or BSW. You probably should chekc with Axminster. Either way, a UNC thread should screw onto a BSW thread of the same TPI.

Your Dad's measurements indicate that the diamter of the spindle thread is oversize (1.001". That is the most likely reason it does not fit. Until you run a file over that thread and clean off the tops of the threads to bring them a few thou under 1.000", nothing standard is likely to fit on there. Usually the OD of a nominal 1" thread will be something like .995 or even .990" to allow clearance.

The 1" thread on the spindle of my old Drummond is .980". Chuck location is done by the plain register behind the thread, so it matters not how sloppy the thread fit is, within reason.

Thanks Hopper. I guess I'm just suspicious as to where it really is oversized, given that I got a different measurement to my dad when I was there .

Thank you to everyone who has helped. I think we'll be able to tackle this reasonably easily now. I'll update you, hopefully with positive news

[mark smith 20Participant @marksmith20]

Posted by Richard Harris 5 on 31/10/2016 13:48:30:

Posted by mark smith 20 on 29/10/2016 15:48:40:

Why not buy this, put it through and see, it just might work?

**LINK**

Thank you Mark. It seems confirmed that it's a BSW thread now so I'm reluctant to buy a UNC tap. But I guess the difference is extremely small, as has been touched upon. If we go that route, I don't think my Dad will mind paying a little more for the BSW tap.

Understood, there were a few BSW taps as well for a little more, still very cheap compared to buying new.

Such as :

**LINK**ssPageName=STRK%3AMEBIDX%3AIT

[Richard Harris 5Participant @richardharris5]

Posted by mark smith 20 on 31/10/2016 14:00:28:

Posted by Richard Harris 5 on 31/10/2016 13:48:30:

Posted by mark smith 20 on 29/10/2016 15:48:40:

Why not buy this, put it through and see, it just might work?

**LINK**

Thank you Mark. It seems confirmed that it's a BSW thread now so I'm reluctant to buy a UNC tap. But I guess the difference is extremely small, as has been touched upon. If we go that route, I don't think my Dad will mind paying a little more for the BSW tap.

Understood, there were a few BSW taps as well for a little more, still very cheap compared to buying new.

Such as :

**LINK**ssPageName=STRK%3AMEBIDX%3AIT

Yep, got that one on my watch list

Having not done much threading… I have to ask, would it be worth buying tap 1, 2 & 3? Or should I just aim for the final one? In my mind, I am guessing these are deeping cuts as you go down the numbers. 1 being the shallowest, 3 being the deepest. Is it something like that?

[mark smith 20Participant @marksmith20]

Just my view but i would go with a second or taper, as the finishing tap probably wouldn`t initially engage with existing thread immediately and by using the second tap for instance you would have some engagement and more likely to go in straight.

Also you would be cutting slightly less off initially with a taper or second tap until it reached the full threaded area of the tap.

Someone else may have a different view.

Taps are usually taper , second and finishing . with the finishing having the greatest amount of fully developed threads.

[Richard Harris 5Participant @richardharris5]

Thanks Mark!

My dad ordered a set of 3 taps. So he should be able to start with the taper and work his way through to get a good fit.

Is there any risk of cross cutting the thread here? Or should it slide in to the current thread relatively easy? Debating whether I should drive back to help him out one day…

[HopperParticipant @hopper]

Posted by Richard Harris 5 on 29/10/2016 13:08:44:

…

Thank you Hopper, that makes sense.

The only thing I'd add is that when I measured the spindle OD at various parts my average was 25.22mm, which is 0.99291339 – so reasonably undersized?

But you are right, the spindle should fit. It is confusing. I'm reluctant to tell me Dad to take a file to it because he can be somewhat heavy handed… Maybe I'll suggest he gives it a fresh cleaning over with some wire wool and checks the start of the threads first. Difficult when you're a good 4 hours drive away…

I suppose at this stage, the only measurement that matters on the spindle OD is the very end bit at the start of the thread. A light filing of the first turn or so of the thread might be all it needs to ease it in.

Not much chance of cross threading an existing 1" BSW thread. The taper or second cut tap should follow the thread in as long has he holds it somewhere near to square to the job.

Edited By Hopper on 03/11/2016 04:06:32

[John HinkleyParticipant @johnhinkley26699]

I've arrived very late to this discussion but it looks like there's something very strange going on here. I think it is entirely possible that, at some stage in its lifetime, the spindle has been removed and re-fitted the wrong way round. Compare the fourth picture down on the lathes.co.uk site, following the link provided earlier in the thread. Assuming that the orientation is that the "chuck" end is to the right, it is plainly a right hand thread, as you would expect it to be to prevent the chuck – or more likely for a wood turning lathe, a centre or faceplate – unscrewing during turning procedures. The opposite end has a left hand thread, again as you would expect for bowl-turning, etc. Also, referencing the same picture, what appears to be a removable collar, matches more closely the "register" shown in Richard's close-up of the spindle thread. There is no mention of a taper in the nose of the spindle, nor can one be seen in the photos. I'm not "au fait" with woodworking lathes, so I don't know if its normal to have a taper at both ends or not. Doubtless someone on here will enlighten me.

My final piece of evidence, Watson, is the Warco table, supplied by John Gibbs, which clearly lists the T04M under the right hand thread section.

I suggest that the OP has another look at the lathe to ascertain whether my supposition is anywhere near the truth. It may mean you end up with a chuck with the wrong thread but that could be better than try to field a flying chuck as it unscrews from the spindle and launches itself across the room!

And finally, surely someone on here lives nearer than Richard to his father and could pop in and have a peek after a private exchange of addresses?

John

[Richard Harris 5Participant @richardharris5]

Posted by Hopper on 03/11/2016 04:03:07:

Posted by Richard Harris 5 on 29/10/2016 13:08:44:

…

Thank you Hopper, that makes sense.

The only thing I'd add is that when I measured the spindle OD at various parts my average was 25.22mm, which is 0.99291339 – so reasonably undersized?

But you are right, the spindle should fit. It is confusing. I'm reluctant to tell me Dad to take a file to it because he can be somewhat heavy handed… Maybe I'll suggest he gives it a fresh cleaning over with some wire wool and checks the start of the threads first. Difficult when you're a good 4 hours drive away…

I suppose at this stage, the only measurement that matters on the spindle OD is the very end bit at the start of the thread. A light filing of the first turn or so of the thread might be all it needs to ease it in.

Not much chance of cross threading an existing 1" BSW thread. The taper or second cut tap should follow the thread in as long has he holds it somewhere near to square to the job.

Edited By Hopper on 03/11/2016 04:06:32

Thanks Hopper, I'll keep this in mind. I think he'll have the taps by next week so I will try and go over to help if possible…

[mark smith 20Participant @marksmith20]

John there is usually a MT 2 hole in the inboard side ,larger side of the spindle.

It is more usual to have a chuck on the inboard side than the outboard side.

http://www.wadkin.com/uploads/files/Wadkin%20BZL%20Lathe.pdf

Edited By mark smith 20 on 03/11/2016 10:23:38

Parts manual

http://www.advancedmachinery.co.uk/content/document/BZL%206%20MANUAL.pdf

Edited By mark smith 20 on 03/11/2016 10:25:27

[Richard Harris 5Participant @richardharris5]

Posted by John Hinkley on 03/11/2016 07:34:01:

I've arrived very late to this discussion but it looks like there's something very strange going on here. I think it is entirely possible that, at some stage in its lifetime, the spindle has been removed and re-fitted the wrong way round. Compare the fourth picture down on the lathes.co.uk site, following the link provided earlier in the thread. Assuming that the orientation is that the "chuck" end is to the right, it is plainly a right hand thread, as you would expect it to be to prevent the chuck – or more likely for a wood turning lathe, a centre or faceplate – unscrewing during turning procedures. The opposite end has a left hand thread, again as you would expect for bowl-turning, etc. Also, referencing the same picture, what appears to be a removable collar, matches more closely the "register" shown in Richard's close-up of the spindle thread. There is no mention of a taper in the nose of the spindle, nor can one be seen in the photos. I'm not "au fait" with woodworking lathes, so I don't know if its normal to have a taper at both ends or not. Doubtless someone on here will enlighten me.

My final piece of evidence, Watson, is the Warco table, supplied by John Gibbs, which clearly lists the T04M under the right hand thread section.

I suggest that the OP has another look at the lathe to ascertain whether my supposition is anywhere near the truth. It may mean you end up with a chuck with the wrong thread but that could be better than try to field a flying chuck as it unscrews from the spindle and launches itself across the room!

And finally, surely someone on here lives nearer than Richard to his father and could pop in and have a peek after a private exchange of addresses?

John

 

 

Thanks John. I've had a very kind offer and have no issue with traveling, so not to worry. But hopefully we'll be able to get this sorted out without anything more involved

 

Your observations are half noted throughout. There are anomalies with the spindle which I've been confused with as well. On many photos, they show the larger diameter thread of the spindle (which we assume is 1 x 8 BSW) on the inbound side, including on original documents from Wadkin Bursgreen.

 

Studying this photo it shows the larger diameter thread, which in this case is on the inbound side pointing towards the tailstock, is a right hand thread, correct? It is perplexing, as on mine and Paul's, the larger (1 x 8 BSW) is definitely Left Hand and on the outbound side.

 

However, even the original photos from Wadkin show some differences. For example, the larger faceplate being fitted on the outbound side, which on their diagram is the smaller thread. Whereas on ours, the large faceplate matches the largest thread size, which is on the outbound side.

 

Similarly, Paul (on page 2) notes that he has a BZL himself and that his outbound thread is also 1 x 8 BSW LH.

 

Perhaps two different people have swapped the spindles over years ago. Would there have been a reason for this?

 

But the fact that the original larger faceplate fits the outbound side to me seems to suggest Wadkin Bursgreen may have just changed some of the specs over the production run. From the "operating instructions, maintenance and parts list book. Wood turning lathe type 6" BZL" I got from Wadkin Bursgreen, who otherwise don't keep much info on their "antiques", it says:

"The spindle is threaded at both ends to recieve chucks and faceplates. All centres with a No. 2 morse taper shank will fit over the taper bore in the spindle end, which is over the bed. The centre can be ejected from the spindle by means of the knock out rod provided, being placed down the center of the spindle and given a sharp tap"

Neither end has any means of receiving a morse taper on the lathe my dad has. I wonder if Paul's does?

 

edit: just to mention another difference / variation, ours does not have the removable section over the bed for larger diameter  turning (which could have been useful! but oh well).

As I'd wondered before, perhaps the spindle has been replaced at some point. Or perhaps the production run changed slightly over time. Eitherway, I think we will hopefully be able to get it working soon, once we try re-threading the chuck.

Edited By Richard Harris 5 on 03/11/2016 10:51:26

[John HinkleyParticipant @johnhinkley26699]

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

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