Thread: Removing seized mt2 chuck from spindle

20181023_213014-1.jpg Here is a picture of the spindle. I think I'll let it be, I think maybe the previous owner somehow managed to get the chuck to twist inside and maybe friction welded the two pieces or over tightened the draw bar causing the pieces to lock up really tight.
I'm quite lucky that it is a collet chuck and not a drill chuck as there is a possibility to use small fly cutters and other tooling rather than just end mills.

What about putting the chuck in a water/ice mix and heating the drawbar with a propane torch?

Hi Guys,

Looking at that picture, I reckon that a pair of taper wedges between the chuck and spindle along with a sudden heating of the outer could crack that joint.

May be clamping the wedges in the vise to apply a constant pressure, a brass plug and steel rod down the spindle, apply rapid heating where the taper is and a solid whack with a lump hammer would do the trick.

I would guess that its been pulled up excessively tightly. Hardened chuck and soft spindle !

If you use it without the drawbar it will drop out sooner or later.

Did you try putting a length of tube over the collet chuck against the spindle and tighten the collet nut against the tube?

Originally Posted by BaronJ

Hi Guys,

Looking at that picture, I reckon that a pair of taper wedges between the chuck and spindle along with a sudden heating of the outer could crack that joint.

May be clamping the wedges in the vise to apply a constant pressure, a brass plug and steel rod down the spindle, apply rapid heating where the taper is and a solid whack with a lump hammer would do the trick.

I would guess that its been pulled up excessively tightly. Hardened chuck and soft spindle !

I've tried wedges in the past but the wedges were too soft and would start to bend.

Originally Posted by shedhappens

If you use it without the drawbar it will drop out sooner or later.

Did you try putting a length of tube over the collet chuck against the spindle and tighten the collet nut against the tube?

I have been using the mill with a loosened draw bar but it hasn't fallen out yet.
I will have to give that tube idea a try, maybe it might just work.

"I will have to give that tube idea a try, maybe it might just work."

Crank it up hard and if it still will not let go ,,,add heat

rusel
You could try using a 75mm diameter fly cutter with a dull cutter in it running over a 50mm wide piece of steel with your draw bar loose and adjust the rpm up and down.
Bob

rusel,

I have a Emco FB2 clone that has a MT2 spindle similar to yours, fitted with a M10 drawbar, allen key head.
The top end of the spindle has a machined fine thread.
My mill came with a screw-on fitting that engaged the thread, with the end opening just big enough to allow entry of the key.

You insert the drawbar finger tight, screw on the fitting, insert the key and bring the drawbar back to the fitting.
Any subsequent movement of the key is applying force to the drawbar.
The differential thread sizes, fitting to M10, ensure the fitting does not release.
I always hold the MT2 taper item (frequently a collet chuck) with a spanner so that there is no net twist of taper in spindle.

On some occasions I have had a taper stuck.
Applied considerable force as described above, then struck the key with a hammer - pop !

From the photo, there may be a suitable thread on the spindle.
If there is, measure it and let us know.
I will do the same on my spindle and, if the same, you are welcome to borrow my fitting, I am located in Kingswood.
Should the threads be different, can you make a suitable fitting ? If not, I can make it for you.
John

Hi guys you need to direct your suggestion to 'ml018'
I'm just a suggester also......

oops, sorry rusel.

ml018,
The offer still stands.
My spindle end is 17.98 mm and the thread 17.92 x 1.0 mm.

John

Originally Posted by electrosteam

oops, sorry rusel.

ml018,
The offer still stands.
My spindle end is 17.98 mm and the thread 17.92 x 1.0 mm.

John

Yep, the nut on my spindle was originally missing. The thread measures 17.8 x 1.0mm.

Originally Posted by .RC.

Need to get a bigger hammer I think. 10lb would be a start.

What RC said, if a hammer doesn't work, either press it out or use a bigger hammer. If it won't press out, use a bigger press.

If the drawbar is screwed in loosely but not tightened you shouldn't damage the threads, but probably won't do the nut on the drawbar many favours. Sometimes I'll use a copper hammer in between the work and the hammer, but it does seem to absorb some of the force too.

Assuming you're doing this at home, heat the spindle with a MAPP torch as quickly as possible, while trying to keep the stuck taper as cool as you can. Take a club hammer of similar decent size persuader and give it your finest. MT2 isn't a very big taper and one way or the other it will release.

Originally Posted by Pete F

What RC said, if a hammer doesn't work, either press it out or use a bigger hammer. If it won't press out, use a bigger press.

If the drawbar is screwed in loosely but not tightened you shouldn't damage the threads, but probably won't do the nut on the drawbar many favours. Sometimes I'll use a copper hammer in between the work and the hammer, but it does seem to absorb some of the force too.

Assuming you're doing this at home, heat the spindle with a MAPP torch as quickly as possible, while trying to keep the stuck taper as cool as you can. Take a club hammer of similar decent size persuader and give it your finest. MT2 isn't a very big taper and one way or the other it will release.

spindle.png The problem is difficult to clamp the spindle down so that the force when hitting engages the entire face of the spindle bottom. I am able to put it in a large vice but the hardened spindle face is thinner and all the force is directed against that thin portion (like on the diagram) against hardened vice jaws. This face is what sits against the needle roller bearing and any slight bends to that surface could have a negative impact on the accuracy of the spindle.

I used propane but the spindle took too long to heat up so I might have to try MAPP gas. I don't want to damage the spindle as it will be almost impossible to find another one and having one made would probably exceed the cost of buying a new or pre-owned milling machine.

Why put it in a vice?

Since you have it out my preferred option would be turn it upside down grab the spindle and hit the drawbar against something very solid.