Stuck chuck ....

[morrisman]

I have this pre war 13" Holbrook lathe , its really almost ready to be melted down .It weighs over 1.5 ton and its only got a short bed .

Anyway the back plate is jammed on the spindle . Holbrook used a double register on the spindle nose , a 2 1/4" BSF thread 3/4" long is between the two registers

Advice on another forum . Is to machine up a tapered plug and use the plug locked in the spindle taper to hold the spindle .

I have measured the taper in the spindle. it is .025" per inch or .3" per foot . I cannot find any taper like that in any books I have . I need to know the angle to off set my top slide . Can anyone work out the maths .... ?

Some pics of the nightmare . BTW the gearbox is almost a work of art ! The spindle runs in 3"diameter white metal bearings .

Mike

[Techo1]

If I am interpreting your figures correctly the angle to offset the compound slide is .71616 degrees.

Looking at your setup in the first picture again I would say it is more likely that you would have to set the angle at 1.4321 degrees.

[morrisman]

If I am interpreting your figures correctly the angle to offset the compound slide is .71616 degrees.

Ok sounds good , I thought it was under one degree .

I think over 4" the taper would be .1 "

[nadroj]

Is there anything on the other end of the spindle that could be gripped?

Jordan

[morrisman]

Is there anything on the other end of the spindle that could be gripped?

Jordan

Not really , there is only a short length of spindle outboard of the headstock casting , where a gear is located on the spindle end . The advice I got is to lock the spindle at the back plate end , doing this will negate any twisting effect over the length of the spindle eg if it was locked at the other end . My plan is to use a long bar and hang a weight off the end of the bar and leave it under tension , while heating and cooling the back plate . If that fails I will have to turn it off, which I really don't want to do as its a complicated register and I need a intact back plate , so I can copy it

[Michael G]

Can you make up some sort of clamp that will hold the spindle between the gears and immobilise it? If you could I would suggest that plus penetrene and a few sharp blows to the backing plate may work.

Michael

[morrisman]

Can you make up some sort of clamp that will hold the spindle between the gears and immobilise it? If you could I would suggest that plus penetrene and a few sharp blows to the backing plate may work.

Michael

Hi

I don't want to risk damaging the gearbox .

I did try this, I selected the lowest gear 15 rpm and placed a 1 " gal pipe in the 3 jaw chuck and gave the end of the pipe a few blows , all that did was bend the pipe .

[Stustoys]

, all that did was bend the pipe .

Well you should be pretty happy about that :D

Stuart

[Michael G]

I did try this, I selected the lowest gear 15 rpm and placed a 1 " gal pipe in the 3 jaw chuck and gave the end of the pipe a few blows , all that did was bend the pipe .

You've been lucky then - the reason I suggested a clamp around the non-gear bits was to spread the load. jamming something in the teeth or selecting a gear applies a lot of pressure to a tooth and may encourage it to break (DAMHIK)

Michael

[Techo1]

Does the machine have power connected Mike? If so, and if it can be run in reverse, I can suggest a method that will probably undo the chuck although the method is a bit primative.

[shedhappens]

Why not bolt another plate to it with a big nut welded to the centre, with the g/box in a neutral position zapp it with an impact gun, 3/4" or 1" square drive if you can, you might loosen it without even holding the shaft.

shed

[nadroj]

Does the machine have power connected Mike? If so, and if it can be run in reverse, I can suggest a method that will probably undo the chuck although the method is a bit primative.

Worked for me a couple of times. :)

Jordan

[nadroj]

Some suggestions for removing stuck threaded chucks here: http://tinyurl.com/37znlsc

Jordan

[steamingbill]

I saw a variation of the long lever spanner method somewhere - the chap set up the long lever and tied a rope or chain to the end of it and dangled a very heavy wieght and left it overnight - said it worked every time. Have seen other posts advocating applying gentle heat.

http://modelenginenews.org/techniques/stuckchuck.html this might be worth a look.

Bill

[Machtool]

Advice on another forum . Is to machine up a tapered plug and use the plug locked in the spindle taper to hold the spindle .
I cant see a tapered plug having enough grip to hold the spindle stationary, if you have all ready tried the low gear and bend the pipe routine. The plug will just slip.

But if you wanted to try that, no need for maths. A lot like your first picture, just use the indicator of the other side of the taper, mag base on your top slide, and just clock the taper until the top slide is true to the spindle taper.

I still think that's bad advice, you'd have to seat that plug with a sledge hammer if it was to have any chance of locking. That will expand the spindle, working against the cause.

Regards Phil.

[morrisman]

I cant see a tapered plug having enough grip to hold the spindle stationary, if you have all ready tried the low gear and bend the pipe routine. The plug will just

But if you wanted to try that, no need for maths. A lot like your first picture, just use the indicator of the other side of the taper, mag base on your top slide, and just clock the taper until the top slide is true to the spindle taper.

I still think that's bad advice, you'd have to seat that plug with a sledge hammer if it was to have any chance of locking. That will expand the spindle, working against the cause.

Regards Phil. Yes Ok the DTI on the top slide for making the plug ... I will do that, good advice . I might try a draw bar and pull the plug into the spindle , or could I use some low strength Loctite on the plug to hold it ? The method of using a weighted lever and leaving it over night - means the plug does not have to withstand a sudden jolt , it just needs to be a firm grip . Anyway that's my theory. Because the spindle has a double register , the back plate might be stuck solid . Mike PS this guy has the same lathe and this is what he did , machined it off https://picasaweb.google.com/116617985245342015523/Holbrook#5710091324886262162 https://picasaweb.google.com/116617985245342015523/Holbrook#5710091584839222386 https://picasaweb.google.com/116617985245342015523/Holbrook#5710091487445120354 https://picasaweb.google.com/116617985245342015523/Holbrook#5710091249430842322 https://picasaweb.google.com/116617985245342015523/Holbrook

[philbur]

How did Holbrook intend for the spindle to be locked in order to remove the chuck/backplate?

Phil:)

[morrisman]

How did Holbrook intend for the spindle to be locked in order to remove the chuck/backplate?

Phil:)

Hello

It is not a problem normally when the chuck is being taken off regularly and the spindle register is oiled a bit . In this case , the chuck has been on the spindle since Jack Kennedy was the US President and people in Australia were paid in Pounds and Shillings .

I have made up a tapered plug from aluminium ( it is definitely a .025" per inch taper ) , as the ally is softer than the spindle it will hopefully not damage the taper in the spindle if it slips . I tapped the end of the plug 12mm , I will buy a length of threaded 12mm rod and use it as a draw bar . For such a massive lathe the spindle only has a 1 1/4" bore .

[philbur]

Hello

It is not a problem normally when the chuck is being taken off regularly and the spindle register is oiled a bit . In this case , the chuck has been on the spindle since Jack Kennedy was the US President and people in Australia were paid in Pounds and Shillings .

I have made up a tapered plug from aluminium ( it is definitely a .025" per inch taper ) , as the ally is softer than the spindle it will hopefully not damage the taper in the spindle if it slips . I tapped the end of the plug 12mm , I will buy a length of threaded 12mm rod and use it as a draw bar . For such a massive lathe the spindle only has a 1 1/4" bore .

That doesn't answer the question?

Phil:)

[Machtool]

That doesn't answer the question
As much as I like you like a brother for having the right name. Answer is at post # 1.

Holbrook used a double register on the spindle nose , a 2 1/4" BSF thread 3/4" long is between the two registers
Break that free and you're home. Any way you look at it, it's a screwed spindle nose.

Phil,

[philbur]

As much as I like you like a brother for having the right name. Answer is at post # 1.

Break that free and you're home. Any way you look at it, it's a screwed spindle nose.

Phil,

Hi Phil,

I’m not sure of the relevance of your answers to my question?

Threaded spindles were very popular in days gone by, however chucks get stuck on these threads for a whole varieties of reasons. People who don’t know any better put the lathe in low (back) gear and then heave on the chuck and only succeed in breaking a couple of teeth on the bull gear. Manufacturers like Holbrook would have been well aware of this risk so would have provided a means of locking the spindle to enable the chuck to be safely unscrewed without the risk of overstressing the gear teeth.
So my question remains, has the OP looked for how the spindle is locked for chuck removal.

Phil:)

[Machtool]

People who don’t know any better put the lathe in low (back) gear and then heave on the chuck and only succeed in breaking a couple of teeth.

I did try this, I selected the lowest gear 15 rpm and placed a 1 " gal pipe in the 3 jaw chuck and gave the end of the pipe a few blows , all that did was bend the pipe .

Are you Bloke's singing from the same hymn book?

Phil, you're 3 days late, how the does he get that chuck off????

[BaronJ]

On my Myford lathe there is a pin that when pushed in locks the spindle ! Its at the tail end of the spindle where the gear train is and it pushes into a hole drilled into the large belt pulley.

[j.ashburn]

Why not bolt another plate to it with a big nut welded to the centre, with the g/box in a neutral position zapp it with an impact gun, 3/4" or 1" square drive if you can, you might loosen it without even holding the shaft.shedMike that idea has worked for me before ,but first I would heat the backing plate as quickly as you can with a large tip oxy acet or oxy lpg .A dull red then let it cool on its own, idea get the plate as hot but not spindle. Then try your rattle gun or even a larger piece of pipe over a socket bar and a large club small sledge aim is to expand plate not the spindle. Old threaded spindle noses don't need much to lock up solid.Here have a large piece hex about 2in from memory and a square milled 1 end and the other plain removes your 4 jaw and 3 jaw with socket rattle gun or FBS.With unknown old clunkers my suspicions would have been a chuck only machine most its life the taper may been bored out so larger dia work pieces go further in. Being british manf suspect h/s be morse no 4 or 5 and tail stock no 4.Your machine looks far better than the pics of the restored one looks like it used up every bit of its commercially viable life.By the way is not an ex Kreisel machine Warragul they used to have some rippers through the glass window at front. Hope another bit helps said the monkey raising the water level in the river. Cheers John.

[philbur]

Are you Bloke's singing from the same hymn book?

Phil, you're 3 days late, how the does he get that chuck off????

I thought the chuck was already off and he was trying to work out how to lock the spindle in order to screw the back plate off. My point was that manufacturers of quality lathes with threaded spindles usually providea means of locking the spindle specifically for the purpose of unscrewing the chuck/back-plate. What did I miss?

Phil:)

[j.ashburn]

I thought the chuck was already off and he was trying to work out how to lock the spindle in order to screw the back plate off. My point was that manufacturers of quality lathes with threaded spindles usually providea means of locking the spindle specifically for the purpose on unscrewing the chuck/back-plate. What did I miss?Phil:)Phil not that many did that some had their own set ups ie Colchester. Nothing would be more scary than a 100kg chuck or any sized chuck for that matter unscrewing and hopping off the bed and scooting across the floor making mayhem. Lots and lots old machine shops had earth floors and duck boarded for some minor ''creature comfort' '.An old John Lang lathe we had for years had a screwed in pin we made to hold the chuck backing plate if used in reverse that was often used to wind back the saddle. A real man killer to work it made the ''gravy'' run even on a freezing cold day. Tail stock was so heavy that you had to drive the saddle down lassoo the tail stock with its own chain and bring it up either winding handle or driving it up under power. The motor had such a high inertia start that it would or could unscrew the chuck,lather we modified it with a clutch between motor and gearbox.If you wanted to cut a thou .001 it would do it. Langs made some of the finest machines.

[philbur]

Phil not that many did that some had their own set ups ie Colchester. Nothing would be more scary than a 100kg chuck or any sized chuck for that matter unscrewing and hopping off the bed and scooting across the floor making mayhem.

Hi, Iwas referring to a mechanism to lock the spindle in order to allow the chuck tobe unscrewed for the purpose of removal, not a mechanism for preventing thechuck from accidentally unscrewing when in use.

Phil:)

[j.ashburn]

HelloIt is not a problem normally when the chuck is being taken off regularly and the spindle register is oiled a bit . In this case , the chuck has been on the spindle since Jack Kennedy was the US President and people in Australia were paid in Pounds and Shillings .I have made up a tapered plug from aluminium ( it is definitely a .025" per inch taper ) , as the ally is softer than the spindle it will hopefully not damage the taper in the spindle if it slips . I tapped the end of the plug 12mm , I will buy a length of threaded 12mm rod and use it as a draw bar . For such a massive lathe the spindle only has a 1 1/4" bore .Mike my Dr Zeus overall pocket data says no3MT = .6023 per ft . No4 is .6233. .025 X2= 0.600 a little wear or galling and not far off John.0.025'' per in you say 0.025 X12=0.600 hope it helps J A.

[mcostello]

South Bend has no provision for locking the spindle to remove their threaded on chucks.

[morrisman]

Mike my Dr Zeus overall pocket data says no3MT = .6023 per ft . No4 is .6233. .025 X2= 0.600 a little wear or galling and not far off John.0.025'' per in you say 0.025 X12=0.600 hope it helps J A.

Thanks for the ideas John .

Phil from Uk . Reading through the Hobrook manuals , there is not any reference to any lock for the spindle . Apparently most if not all of the lathe manufacturers of yesteryear , did not provide any method for locking the spindle , I wish they had . My Hendey has no spindle lock either .

Back to the problem, I have made the lever that bolts to the back plate , I used a piece of flat plate with 3 holes drilled in it , same hole pattern as the back plate . I have welded a 2 metre long 40mm square section tube to the plate . My main problem might be the ally taper plug in the spindle bore , I hope it does not slip , I am tempted to use loctite on it to hold it .

Anyway I will give it a try tomorrow when I have the draw bar here . I don't have a oxy heat source only a BBQ gas torch which does not have enough heat output but its better than nothing .

I think the odd taper that Holbrook used in the spindle is actually for a adapter that accepts a MT 3 or 4 centre Mike

[Stustoys]

The pessimist in me is worried those pieces of tube are to long for their diameter....... but I guess it depends just how stuck stuck is.

Stuart

[philbur]

Phil from Uk . Reading through the Hobrook manuals , there is not any reference to any lock for the spindle . Apparently most if not all of the lathe manufacturers of yesteryear , did not provide any method for locking the spindle , I wish they had . My Hendey has no spindle lock either .

That’s disappointing, my Boley does and I believe Myford, Hardinge, Monarch and Atlas, to name but a few, also have a locking arrangement. It was worth asking the question I think.

Phil:)

[BaronJ]

Hi Guys,

I've found the picture of my Myford lathe spindle locking pin. Its just to the left of the spindle.

[Ueee]

Hi Mike,
I did wonder if that was you on the Holbrook Yahoo group.
Welcome to the wonderful world of Holbrook ownership.....
Cheers,
Ewan

[Ueee]

Mike the C10 has a shortened version of the MT4, i made an adapter by cutting down an MT4 socket. My machine is far later than yours though at 1947. I've forgotten what age Nick said yours was likely to be.

[morrisman]

Mike the C10 has a shortened version of the MT4, i made an adapter by cutting down an MT4 socket. My machine is far later than yours though at 1947. I've forgotten what age Nick said yours was likely to be.yes Ewan, its me on that group ...... no secrets anymore ! OK your MT4 adapter for your C10 worked out , good idea . This 1938 Holbrook of mine is a weird taper in the spindle . It does have the nice single tooth clutch system for threading up to a shoulder . The bed has suffered from inept users near the headstock, but is still good enough. Anyway plan A has not worked, the taper plug I made to hold the spindle is slipping :((:(( I might try something more brutal, a lump of wood jammed into a gear . Wood is more forgiving , hopefully, no broken teeth will result . I will win this war by being patient and its a battle of attrition as they say . Mike

[morrisman]

Plan B : I have used this method to hold a spindle before , its a little brutal but it works, a jaw from a chuck is positioned to hold a gear .

The weighted basket can be moved along the bar to increase the leverage , I have added more weight . I will heat up the back plate each day , let it cool down .. see how it goes , it may take a few weeks to come free .

[morrisman]

Well, no luck so far , the back plate is still firmly stuck . I have heated / cooled the back plate repeatedly and added more weight to the lever .

Next idea is to buy some dry ice and shove it up the spindle , around the register . The nearest supplier is BOC Dandenong so I wont be doing the ice thing til next week maybe .

There is another possible option. The design of this headstock allows easy removal of the whole spindle , the spindle sits in large plain bearings with bolt on caps , like a car crankshaft . If I remove the spindle with the back plate still firmly attached . What next ? Mike

[jhovel]

Hi Mike,
I've been there on a much smaller scale though. To get it to move you reallyneed shock loads, rather than a steady torque of the weight on the lever. Could you give the leaver a good whack with a sledge hammer about where you have the weight hanging? Maybe immediately after heating up the backing plate to give yourself a fighting chance

[.RC.]

A way out there idea would be to find someone with an 1 1/2" drive rattle gun... Machine up a 1 1/2" square and somehow affix it to the backplate.. Get the big rattle gun and rattle it loose...

[Combustor]

Hi there RC,
That big rattlegun sounds like an interesting idea. Even my 1" brute will move damn near anythig I put it to. Big advantage is that you don"t have to lock bolts or shafts firmly, the impact does the job. Just walk it past a stuck nut and it surrenders. Should be possible to find a u/s 1" or even 3/4" socket with an adaptor, and weld it to centre of a plate bolted across the backplate. Need an unrestricted 19 or 25mm air line to deliver the grunt. I have a fairly small engine powered compressor only good for 110 PSI but with about 3m of 19mm hose direct from tank, results are impressive. Worth a try if it can be esily arranged.
Combustor.

[morrisman]

Hi there RC,
That big rattlegun sounds like an interesting idea. Even my 1" brute will move damn near anythig I put it to. Big advantage is that you don"t have to lock bolts or shafts firmly, the impact does the job. Just walk it past a stuck nut and it surrenders. Should be possible to find a u/s 1" or even 3/4" socket with an adaptor, and weld it to centre of a plate bolted across the backplate. Need an unrestricted 19 or 25mm air line to deliver the grunt. I have a fairly small engine powered compressor only good for 110 PSI but with about 3m of 19mm hose direct from tank, results are impressive. Worth a try if it can be esily arranged.
Combustor.Yes The rattle gun may do the job, I do have a 3/4"drive rattle gun. As you say, the larger air hose will help provide more air volume , ive only got the small hose ATM Thanks for your ideas, I think it will work .

[morrisman]

Well it is off :2tsup:

Plan Z worked

Some water ice mixed with salt, shoved up the spindle and left for a while to cool down the inside around the taper .

Then using two BBQ gas torches together , heat was applied around the back plate for 30 minutes .

I had the long lever and the cage full of heavy weight attached while heating .

It was a final heave on the lever that ended with a CRACK sound . It came free .

[WCD]

Congratulations - a struggle crowned with success!
I hope you downed an ale afterwards to celebrate.
Bill

[morrisman]

Congratulations - a struggle crowned with success!
I hope you downed an ale afterwards to celebrate.
Bill

To be honest, I was wandering around in a daze for a while. I could not believe it actually came free . Just goes to show that patience and persistence will win at the end of the day :)

[nadroj]

Hallelujah - well done.

A friend had a Hercus 260 stuck chuck problem that didn't have such a happy ending.
He removed the spindle from the headstock and thought he'd get away with gripping it in the jaws of a big vice. When it didn't, the spindle was destroyed. The chuck was really stuck fast. We eventually removed the chuck at least, by welding a heavy plate to the spindle so it could be positively gripped. It took a frightening amount of leverage to get it off.

The moral is: Do not over tighten a threaded chuck. Just wind it gently up to the shoulder, is all it wants.

Jordan

[PDW]

The moral is: Do not over tighten a threaded chuck. Just wind it gently up to the shoulder, is all it wants.

Jordan

The moral is - get a lathe with a camlock or at least L series spindle nose. A problem avoided is a lot better than a problem solved.

I only have one lathe left with a screwed spindle nose, and it's getting sold as soon as I return home.

PDW