ER32 collet chuck holder stuck in spindle

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CraigLD

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I'm having a silly, but frustrating problem. I have a cheap 7x14 Chinese lathe with a MT3 taper in the spindle and it came with a typical bolt on 3 jaw chuck. Last year I bought an ER32 collet chuck holder for it so I could use collets to hold stock. It wasn't this one, but was similar:

https://www.amazon.com/Morse-Holder-Milling-Spring-Collet/dp/B07YWQ8LYN/ref=sr_1_5?dchild=1&keywords=MT3+ER32+Collet+Chuck+Holder&qid=1614347850&s=hi&sr=1-5

I have used it a number of times over the last year and it works great. I did notice quickly that it needed a drawbar as the holder would start getting loose when turning. Following an example I found somewhere, I made a drawbar. I think it used a M12 threaded rod.

Anyway, this last time I used it, I clearly tightened the drawbar way too much and now I can't get the holder out of the spindle. I have tried various techniques such as loosening the drawbar half a turn and hitting the end with a hammer as well as removing the drawbar and inserting a 3/4" brass rod and hitting it, but the holder doesn't budge.

Can anyone suggest a method of removing the holder without disassembly the entire headstock, which was my next approach?

Thanks in advance for any help for what is clearly a stupid newbie problem
 

goldstar31

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'Classically' you will need to remove the draw bar and you have the cloice of putting a brass end made to a close fit ot the old dodge of inserting two old kitchen knife blades at 180 degrees apart and progressively tap progressuvely bot in - until the chuck arbour ;jumps'

Actually I've just removed 4 'fretted' cutter blade bolts from my branch shredder.

What will have happened is the taper on your lathe collet is a little off centre.
With worsening eyesight, I have to do things now largely by feel but I'd go knives or thinned screwdriver blades. Beware things can jump on release. You see, I'm the sion of a blacksmith, I've removed fretted flywheels from full size tuned old BMC Minicoppers and tightened then back at 140 pounds feet with a scaffolding tube and a spring balance reading 70 lbs;)

Be Careful


Norman
 
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Charles Lamont

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Use a bigger hammer! No, seriously, but don't whack it hard. Lots of light blows on the brass rod with your heaviest hammer will be most likely to move it. I don't know why, but tapping with a big hammer works better than slogging with a small one. If it does not come out after 20 min or so, you might need to take the spindle out for a warm-up.
 

fcheslop

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Use a good heavy hammer as it dont bounce like a toffee hammer
A mash hammer is ideal about 4lb
You may do more damage pussy footing about
Known as a Birmingham screwdriver this end
 

Ken I

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Use a length of M12 threaded rod as your drift - preferably high tensile - screw it fully bottomed out into the drawbar hole. If you can machine the end to get it against the bottom of the drilled hole, even better. This to help not to damage the thread.

Spray some penetrating oil where you can and leave it overnight.

Put a nut / washer on the outboard end with a few millimeters clearance - to prevent it flying out.

Go with Charles & fcheslop - the bigger the problem - the bigger the hammer.

Personally I would smite it mightily with a 4lb copper hammer.

Those Chinese lathes (like mine) normally have a flange ended spindle for chucks with an MT3 bore for collets - you can try heating with a largish butane torch - you can probably go 65°C (just too hot to keep your hand on) or 100°C (gob sizzling hot) without risking damaging anything.

The problem with the big hammer approach is you may Brinell the bearings - so I would go for heat to minimise the size of the blow.

Regards, Ken
 

teeleevs

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If your lathe has a large flange as Ken suggests you might be able to put a collar between the nut and the collar to help put some pull on the chuck to soften the blow. Another trick would be to do some heavy cutting without the draw bar, see if it will work loose. Also what is a trap when fitting a Morse taper item into a spindle that is warm from use while the taper item is cold, when the two normalize, they will be very tight.
Best of luck
Ted from down under
 

GrahamJTaylor49

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Hi Craig,
Use a big copper and hide hammer, also known as a Birmingham screw driver.
Works wonders.
 

BaronJ

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Anyway, this last time I used it, I clearly tightened the drawbar way too much and now I can't get the holder out of the spindle. I have tried various techniques such as loosening the drawbar half a turn and hitting the end with a hammer as well as removing the drawbar and inserting a 3/4" brass rod and hitting it, but the holder doesn't budge.

Can anyone suggest a method of removing the holder without disassembly the entire headstock, which was my next approach?

Thanks in advance for any help for what is clearly a stupid newbie problem
Hi Craig,

One of the problems with long tapers in spindles is the taper moves into the spindle as the spindle warms up making the taper a tighter fit.

Its going to be more difficult to remove but if you run the lathe for a little while and can feel the spindle getting warm, give it another few minutes ! This will allow the spindle to expand and loosen the taper slightly. Now is the time to knock it out.

Never put a cold taper into a warm spindle ! I have a small 4 inch "T" bar wrench that I use on my mill, it is never tightened more than two fingers tight.

It will come out, you just have to be firm with it, I use a lead hammer to remove the MT2 collet on my Myford. And it does take more to get out than it does on the mill.
 

goldstar31

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Whilst we await the findings of the poster:( I have both a set of ER25 and 32 collets plus holders for my Myford lathe and my Quorn tool and cutter grinder and am being driven mad by the 25mm bore on a nice workable and proper ONE INCH.So far, I have been reluctant to get a No3MT shank to utilise the ER32's on my Sieg C4. I thinjk the remarks require little further explanation other that the wory now that the hardness of the ER stuff will result in shattering if ' the Fixing and *******' school is the only solution.

I await comments to what for me is - more than worrying.

And yes, I have a set of genuine Myford collets and the usual jumble of 6 and 8mm ones

Norman(

or worried Blue Eyes):confused:
 

almega

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Not sure of your configuration, but you could also use a pair of wedges made for the purpose to push against the headstock and collet nut, putting a large clamp on them and drawing the wedges together, forcing the collet out of the spindle. Sort of a variation on goldstar31's suggestion. For future reference, I put a small dab of "Never-Seize" on the taper before installing. It still requires a minor whack with a "Chicago screwdriver" to get it out but I have not had it really stuck in a long time. Heating the spindle may help as well but not so hot as to affect the grease in the bearings.
 

CraigLD

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Thanks for all of the comments and suggestions. I did finally get it out and what did finally work for me was what had been suggested by several. I used a larger "hand sledge" with the 3/4" brass rod (which is the largest diameter I can get into the back of the headstock) and a series of firm rather than hard whacks. With my chuck back on and using a test dial indicator, the spindle runout seems to be no worse than it was.

Next time I use the collet holder, I won't be so aggressive in securing it. ;)
 

a41capt

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A piece of dry ice (frozen CO2) inside the collet holder and the application of heavy hammer blows from the rear should be adequate. I use this “metal shrinking” technique for pressed bearings and it works like a champ
 

Peter Murphy

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Ken I

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I used to use my drawbar mounted ER32 but eventually went to flange mounted so I could pass the stock through.
Also to reduce the stick out to reduce part off chatter :-
ercollet1.jpg

Its actually an adaptor from a smaller lathe on a larger flange - the recessed location bore was turned to final size reverse mounted on a pre-turned bar to get the flange dead nuts accurate.
The slots are for a hook spanner for loosening / tightening in conjunction with the ER spanner. Drawing attached for dimensions if anyone's interested.
I made these myself on a larger lathe at work.

I have a similar flange for my Vertex 6" RT
ercollet2.jpg

This flange does "float" and has to be clocked true.

FYI

Regards, Ken
 

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