Frozen Morse Taper Arbor

[DiogenesIIParticipant @diogenesii]

^^^ it might not work in the same way – running a bead around the inside of a hollow tube will 'pull it in' as it cools, and they often just drop out – we used to use the same method to get the outer races of bearings out of housings that you couldn't get a drift or puller into..

 

 

 

Edited By DiogenesII on 30/05/2023 20:14:42

Edited By DiogenesII on 30/05/2023 20:15:09

[FulmenParticipant @fulmen]

Can you push it out hydraulically with grease?

[JohnFParticipant @johnf59703]

Trevor, Worth looking at pages 2 & 4 on the link I sent for some photos of Morse taper removal wedges which hopefully may solve your problem, you can of course make these.

I had a similar problem with a drill chuck in my lathe tailstock and ended up using extreme measures to remove it ! But of course no bearings to consider, however see the attached sketch of a possible set up to hopefully prevent any bearing damage by supporting the machine spindle thus enabling the use of a heavy hammer – say 4lb [2kg]

You need to support the spindle using these extreme measures by the use of a large tube that goes around your chuck and if possible lower the spindle onto the tube, if this is not possible use a tube large enough for the chuck to enter or suitable bar stock "parallels" and 2 maximum size bars to support the spindle keeping everything as close together as possible. This should prevent bearing damage. Stating the obvious put something underneath to protect the table. Apply as much downward pressure to the quill / spindle as possible as you apply the hammer blow.

To deliver the blow I would make a threaded slave bar from as large a diameter that will enter the spindle and a fairly short thread so that it screws into the arbor up to a shoulder — no or minimal load delivered to the arbor thread but the thread is protected and the shoulder delivers the blow directly to the arbor.

Not something I would suggest lightly as its an extreme measure but sometimes needs / must ! Hope this helps if all else fails

John

[HopperParticipant @hopper]

Try the advice several gave above of applying a steady pressure via either Brian Wood's suggestion of a plate captive behind the collet holder nut with jacking screws applying pressure, or a pair of wedges. Jack it/wedge it as hard as you dare and leave it overnight. Then in the morning, try adding a little more pressure if you can, and then try your impacting and heating/cooling etc again.

Chances are it will have popped off of its own accord before you get up in the morning. They quite often do that.

[not done it yetParticipant @notdoneityet]

Personally I think the OP has no idea of how wedges should be employed. These are not wedges inserted separately – they are a pair which overlap each other on both sides of the morse taper as they pass over/under the other wedge creating a very considerable force perpendicular to their direction of movement.

I have actually surface-ground the sides of my larger pair, so they slide more easily over one another (and across the morse socket and lip of the male taper). The angle of attack is very shallow such that the change in total width increases only very slightly with a relatively large distance travelled in the direction of force applied perpendicular to the extraction direction. If the OP thinks it is just a matter of using a couple of wedge shaped levers, he is mistaken.

The action is similar to that of an adjustable parallel – but with far shallower angle. A bit, but only a bit like that but it does give one the idea behind the principle where movement in one direction changes the size in the perpendicular dimension. If the OP had made a couple, he would have most likely already have separated his ‘frozen’ items.

I have removed umpteen flywheels from crankshafts (with tapers), using pullers. These pullers employ a fine thread and a large spanner and can provide fairly immense force – but also have often needed a ‘bump’, when the joint separates with a considerable release of energy as the two parts separate.

Anyone who has regularly changed track-rod ends on vehicle steering systems would also comprehend the force required to separate those joints, too. They, too, often separate very suddenly when the separation force finally overcomes the joint contact.

I’ll rest my case for use of wedges to separate tapers. Can’t really say much more without upsetting some, if I haven’t already.

Edited By not done it yet on 31/05/2023 07:17:15

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, like NDIY says, use two shallow wedges, as shown in the sketch below which I posted a while ago when someone else had a similar problem.

Regards Nick.

[HopperParticipant @hopper]

You can buy them ready made but are sized to go between the chuck and the arbor so you mught have to go a bit oversized on a collet holder. Easy enough to make if you have a mill. The shallower the taper they better they will work.

Edited By Hopper on 31/05/2023 09:15:47

[Neil LickfoldParticipant @neillickfold44316]

The spindle will need to be heated some, which will help. This happens when a cold tool goes into a warm spindle. It takes alot to get the initial movement to happen. So apply heat carefully to the spindle, with the tension already onto it. Around 80c will make a big difference to get it apart. A hair dryer could be used.

[not done it yetParticipant @notdoneityet]

Nick and Hopper,

Thanks for the pics. Saves a lot of my words!

I tied mine together as one of the pair can easily go flying when the joint parts.

The screw extraction aid for adapter sleeves is still on the Arc site.

I believe the older) Clarkson collet holders used a threaded ring – possibly more for stiffening support for the whole MT arrangement, but would also aid taper removal?

One only has to look back on the forum where inclined planes have been used as force multipliers. Machinery/vehicles are loaded onto trailers by use of ramps; I unloaded my Centec from a trailer using an ‘inclined plane’; I unloaded the ~100kg base of my surface grinder by gently sliding it down a ramp; I unloaded my Raglan lathe from my Citroen Saxo using the same method. My brother shifted out his old Aga and shifted in its replacement with the aid of slightly sloping rails – out was hard work as it was up-hill but the slope was shallow enough for him to easily control the one going in.

Oh, and blacksmith drills, with tangs, are historically removed from heavy drills using a cross wedge driven in from the side (acts perendicularly downwards because the tang is curved).

I am very confident that the wedges and perhaps an additional impulsive force from a metal mallet will break that taper free – unless it was pulled in by a gorilla and severely shrink-fitted as well. There is always the exception…

[Trevor GaleParticipant @trevorgale]

Sports Latest: GALE ATHLETIC 1 – COLLET ARBORS 0.

The fixture went well into extra time after far too many fouls, and there were fears that it would end up in a draw, barring a very heated penalizing shoot-out. In the end, the referee abandoned any hope of tempering the players as they became extremely hot under the collar with the situation. The one and only goal of the match came just as the Arbors lost their grip when the Gales flamed up the centre field and then delivered their final hammer blow which landed in the net.

The final effort involved rotating the mill head to horizontal (I didn't want the heat that I was going to use going upwards towards the bearings or any oil in the head), inserting a drawbar-sized steel rod in to meet the top of the arbor, then (again) freezing the exposed part of the chuck arbor,

I then used a small blow-torch to heat the collar which holds the arbor. I periodically turned the collar (using a spanner on the chuck arbor which was of course jammed in) to heat the collar evenly around, and occasionally giving a hammer (5Kg hammer) blow to the top of the steel rod.

For safety I obviously had the fire extinguisher at hand, and to protect the bed I laid a sheet of plywood atop the table with my car's fire blanket on top of that.

It took about 15 minutes of heating with the torch flame before one of my intermittent hammer blows showed some movement on the arbor. A few more (gentler) hammer blows caused the arbor to loosen and drop out of the collar neatly onto the fire blanket.

The temperature of the collar immediately prior to the release was around 270 degrees C according to the pistol-type IR thermometer I had at hand, and it was sufficient to ignite a safety match rubbed across the surface of the collar!

Examing the arbor afterwards showed no sign whatsoever of any corrosion or foul matter, in fact it looks as if it has just been carried away from the retailer; the inside of the collar taper also looks immaculate. To be on the safe side I am ordering a new collet chuck with arbor, and of course I will now proceed to check thoroughly the head to check for any other damage that may have arisen, and also check and lubricate the bearings.

As far as the wedges I used earlier are concerned, for clarity I did have the 2 with sloping form as someone showed in a drawing above, I made these up during the beginning of all this effort!

Thanks again for the many responses and helpful ideas that so many people gave me on this topic, it just shows the value of the forum and the general helpfulness of the model engineer.

[Brian WoodParticipant @brianwood45127]

Hello Trevor,

Thank you for bringing us all up to date with the result, it is always satisfying to hear of a good outcome to one of these battles. It also seems that there were no equipment casualties either, an added bonus.

Great relief for you of course; you will now be older and wiser in future use!

Well done

Brian

[Ady1Participant @ady1]

Well done you. Thought I'd quote a prior post which I have taken note of:

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Posted by old mart on 30/05/2023 16:48:19:

As I say, again and again, if you have a choice between MT3 and R8, always choose the R8. Morse taper was designed for drills and works very well with them, not mills. Ignore the Morse taper fans, they are wrong, these stuck MT threads are a perennial feature of the forum. Just check out the number of stuck R8 threads.

Edited By old mart on 30/05/2023 16:50:13

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[Brian WoodParticipant @brianwood45127]

Hello Ady 1,

I could add to that, but not be able to take advantage [ the Dore Westbury mill was not offered in R8 form] by repeating an earlier entry of mine in this thread and recommend buying open drill sleeves with a threaded nose and castellated nut for easy extraction from MT bores.

Once extracted the MT fitting still in the sleeve can be readily knocked out

Brian

[Howard LewisParticipant @howardlewis46836]

Thanks for the the update.

Glad tp know that you won, even if in extra time!

Howard

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