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FP1 Stuck arbour

Peter Colman

Stainless
Joined
Sep 22, 2004
Location
Rugeley UK
I have managed to get the horizontal arbour stuck my MT4 Deckel FP1.
How do I get it out ? I have tried undoing the draw bar as far as possible and striking it on the square end, I then applied a little heat to the protruding part of the spindle, still no good.

Next was to lock the drawbar square and fit a massive spanner to the flat in the arbour and lift its end with a hoist until the machine was off the ground, still stuck fast.

I have run out of ideas, would it be worth removing the spindle and trying to push the arbour out with a press, I suppose I could chop the end of the arbour off and then bore out the part in the taper to weaken it and then push it out.
These are desperate things to do so have you got any less extreme ideas?
Many thanks
 
I am not familiar with the Deckel machines but on other mills, when the arbor is stuck, it sometimes helps to arrange a "puller" on the outboard end of the arbor before striking the back end of the draw bar. The problem seems to be: the draw bar flexes and absorbs some of the force from striking the back end.
 
So I made a sleeve that fitted over the taper on the spindle and against the flange where the spindle comes out of the casting. I then fitted it over the arbour and a large washer a pack of spacers and tensioned it with the nut.
With the drawbar wound out fully and a clout with a heavy hammer still no sign of the arbour shifting.
Any other ideas please.
Thanks
Peter
 
We had best luck with a good slug with a big round stock to make a sold whack to the back side. 1 1/2 x 20inches might be good.
Hammer on a slug never seemed as good.

Yes you don't want to throw it hard enough to break the casting. Just a good push to wack. good that it be mild steel or brass if you have a brass slug handy.
 
Are you sure you have it unscrewed from the drawbar? The drawbar should push that out.

When you took the sleeve from the back, by the square portion on the end, could you unscrew the drawbar?

When I first got my FP1 (also MK4) I had a hell of a time getting the collet out of the vertical head, but the horizontal is a tad different in the way it is connected, as I recall. Yes, I just looked at the parts manual, there's a screw (18) that holds the drawbar in, but there's a step on the drawbar to prevent it from going through the casting, as best I can tell.

You will most likely need to take the screw out, unscrew the drawbar and pull it out the rear, then use a long rod and knock the arbor out. Also worth checking that if you take the screw out, could that be a sleeve bushing that removes out of the rear allowing the drawbar to be removed from the front. If that was the case, you might be able to tap the rear of the square after you get the screw out. I'd be careful so you don't break anything. :nono:

On the vertical head you tap the taper pin out of the sleeve, unscrew it and the drawbar falls out the spindle.

This is what I'm seeing in the parts manual:

deckel-horizontal-spindle.png
 
I have got the drawbar fully unscrewed and a collar over the front end of the spindle with a thick washer over it and 1" spacers to allow me to tension the arbour outwards,so all is under tension, I have tried hitting the square of the drawbar, but no good as yet, I will next try with the drawbar out and a stout rod in its place.
Keep the help coming !
Thanks
Peter
 
Never had an FP1 but on other tapered things I've found it beneficial to add mass to the holder to better transmit the impact to the task at hand. For example if you can have a helper hold 10 or 20 pounds against the external taper or your pretension device it might help to prevent the impact energy from moving the spindle shaft and rather drive the arbor out.
I don't know what the external taper is for so the usual precautions apply, meaning don't damage it.
 
Yes it might be good to but the spindle end up a solid like the vise.. then slug in a 1" X 20" crs round stock... yes if all screws and such are free and only the taper holding. Perhaps the speed of throwing basket ball with one hand so not to go crazy like a 90 MPH base ball and break something.

If an arbor had enough meat sticking out dry ice held to might not be a bad idea..no I have never done that,
 
If all else fails, that is next idea, I have left it under tension for a few days now so will try heat on the outside and an ice pack on the arbour.
I have been thinking about the long term, when (if) I get the arbour out, how about an adapter from 4MT to 30 international, I know that I will loose a bit of length but I can live with that, the adapter could possibly be held in with a version of the existing drawbar with a second one inside it to hold the 30 int arbour.
When I get it apart I will do some measuring, has anyone else tried this?
Peter
 
If I were you, I'd take the spindle off the machine so as to be able to put it on a press

Removing the spindle on those machines will take you much less than an hour and if the tool is stuck to the point you describe, it is the sole way you'll be able to work on the spindle properly without fearing to damage anything else.
Turn a push rod of the max allowable diameter and put it in place ot the drawbar, use penetrating oil, and I can't imagine the tool not coming out if "gently" forced out with a properly sized hydraulic press .

I have been thinking about the long term, when (if) I get the arbour out, how about an adapter from 4MT to 30 international, I know that I will loose a bit of length but I can live with that, the adapter could possibly be held in with a version of the existing drawbar with a second one inside it to hold the 30 int arbour.
When I get it apart I will do some measuring, has anyone else tried this?
Peter

You shouldn't be afraid by your mishap.

Thousands of MT4 Deckels have been in use for decades so even if not perfect, the design can't be that bad.
I've been using MT4 FP1's for years, and I've never experienced the problem.

IMHO, it will be much more efficient and simple to re-think your tool tightening habits and/or check your machine so as to make sure the spindle does not overheat when working with it, than trying to convert it to 30INT (wich would probably leave you unsatisfied on a lot of points other than just tool release)
 
Not an FP1 guy, but....
Biggest danger with Morse spindles is running the machine for some period at relatively high RPM's then doing a tool change , inserting a
cool taper into a hot spindle bore is a sure way to have stuck tooling...

Before doing anything else, suggest you try running the machine at high spindle speeds for a time to warm up the spindle ...
Its a balancing act....run it enough to warm the spindle , but not so long that the heat soaks to the holder....
External heating won't give the same results..let the machine solve its own problem...

Run awhile then try releasing the tool, run a bit more..etc....Maybe you get lucky. At any rate its a low risk task...If its got oil it should not hurt anything trying this...
Cheers Ross
 
Not an FP1 guy, but....
Biggest danger with Morse spindles is running the machine for some period at relatively high RPM's then doing a tool change , inserting a
cool taper into a hot spindle bore is a sure way to have stuck tooling...

Another thing is not having the draw bar tight enough and the cutter grabbing the work twisting the holder tighter in the spindle, nothing like a taper that has been wrung together under torque?

Be careful with this stuff (and similar products). It is extremely flammable, so you should always make sure that your workspace is well-ventilated.

A bronze mallet might be in order here, something non-sparking?http://www.practicalmachinist.com/vb/images/icons/icon3.png

Dan
 
So I have tried running the spindle in top speed for an hour, the drawbar was in full extract position and I had the tube over the arbour with the big washer to keep tension on that way as well.
Tried chilling the arbour and clouting the drawbar with a big copper hammer but still it won't budge so I have to take it out and try a press to shift the arbour.
Watch this space
Peter
 
At this point I am watching in anticipation. I've read accounts of how some lathe hobbyists have had to machine their chuck off the spindle and such but it still seems unreal. I have NMTB 40 on my mill which I believe is not self locking. Does this mean I will not have the problem you are encountering?
 
I have NMTB 40 on my mill which I believe is not self locking. Does this mean I will not have the problem you are encountering?

A 40 taper is much steeper and has much less tendency to lock than a Morse taper.

Note: I did once have trouble extracting an SK40 holder for Deckel 20mm collets, because the holder had nothing which could be used to extract it (either by pulling or by pushing. The solution was to remove the retainer nut from the drawbar, so that the drawbar could go down further than normal, then put a collect back into the adaptor, then give a firm tap to the drawbar (which, in the absence of the retainer nut, was now free to move down the spindle). So these days I only use an adaptor which has an extraction nut. But in comparison with the Morse taper versions which can really lock in place, requiring heroic measures, the SK40 tapers are a breeze.

In this case, I think TNB's advice to remove the spindle, and use a proper press is the right way. This will support the inner part of the spindle, so there will be no force on the bearings.

Cheers,
Bruce
 
Regarding chilling the arbor, how did you do it? You´ll need some effective cooling.
Can you find some CO2 ice locally or make some of your own?
 








 
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