Stuck Morse Taper in Warco Major 3024YZ

[old martParticipant @oldmart]

A drilling machine which uses Morse taper usually has an extraction slot for a wedge to remove the tooling. Very few mills have this feature, unfortunately. Morse taper mill fans are always people who are stuck with one and try to justify its shortcomings by telling potential mill buyers it is perfectly satisfactory. I repeat, as usual, if you are in a position to choose between Morse taper and R8, go for the latter.

[Dave HalfordParticipant @davehalford22513]

People fail to understand that a MT drawbar doesn't need to be cranked up to 70ftlb.

[colin hawesParticipant @colinhawes85982]

Posted by Matthew Furseman on 17/08/2022 21:04:44:

Posted by colin hawes on 17/08/2022 12:41:39:

Use the collet holder nut to apply force on tubular packing between nut and spindle nose. Colin

 

I gave this a go, I found an odd backplate that came with a lathe that happend to have the right ID and screwed it up above the collet nut with a couple of milling clamps as spacers against the spindle. I got it pretty tight but had to hold the belt drive on the top of the spindle to stop it rotating so this limited how much force I could put into it. No joy unfortunately.

Try doing the same thing again. Leave it for a while under pressure then, still under pressure, add more force by giving the drawbar a clout. Also more force can be added by givng   the collet nut spanner a good clout to create a shock load.   Colin

Edited By colin hawes on 19/08/2022 12:18:31

[HopperParticipant @hopper]

Posted by Dave Halford on 19/08/2022 12:00:11:

People fail to understand that a MT drawbar doesn't need to be cranked up to 70ftlb.

^^^^ THIS.

I think maybe some of the confusion arises out of R8 vs Morse. R8 is a self releasing taper, so a good heft on the drawbar nut helps snug it up nice and solid without causing the taper to jam up.

But the same heft on a self-locking Morse taper is A. totally unnecessary as the taper does the driving and retaining with the drawbar there as backup when side impacts temporarily jar it loose and B. pulls that slow taper up into the socket until the molecules in both are sharing electrons and chances of getting them to separate are diminished by the square of the force applied.

[Tony Pratt 1Participant @tonypratt1]

Posted by colin hawes on 19/08/2022 12:12:03:

Posted by Matthew Furseman on 17/08/2022 21:04:44:

Posted by colin hawes on 17/08/2022 12:41:39:

Use the collet holder nut to apply force on tubular packing between nut and spindle nose. Colin

I gave this a go, I found an odd backplate that came with a lathe that happend to have the right ID and screwed it up above the collet nut with a couple of milling clamps as spacers against the spindle. I got it pretty tight but had to hold the belt drive on the top of the spindle to stop it rotating so this limited how much force I could put into it. No joy unfortunately.

Try doing the same thing again. Leave it for a while under pressure then, still under pressure, add more force by giving the drawbar a clout. Also more force can be added by givng the collet nut spanner a good clout to create a shock load. Colin

Edited By colin hawes on 19/08/2022 12:18:31

Light side tapping will assist.

Tony

[colin hawesParticipant @colinhawes85982]

Posted by Tony Pratt 1 on 19/08/2022 12:19:52:

Posted by colin hawes on 19/08/2022 12:12:03:

Posted by Matthew Furseman on 17/08/2022 21:04:44:

Posted by colin hawes on 17/08/2022 12:41:39:

Use the collet holder nut to apply force on tubular packing between nut and spindle nose. Colin

I gave this a go, I found an odd backplate that came with a lathe that happend to have the right ID and screwed it up above the collet nut with a couple of milling clamps as spacers against the spindle. I got it pretty tight but had to hold the belt drive on the top of the spindle to stop it rotating so this limited how much force I could put into it. No joy unfortunately.

Try doing the same thing again. Leave it for a while under pressure then, still under pressure, add more force by giving the drawbar a clout. Also more force can be added by givng the collet nut spanner a good clout to create a shock load. Colin

Edited By colin hawes on 19/08/2022 12:18:31

Light side tapping will assist.

TonyB

Please ignore the last bit "giving the spanner a clout" as some gears are rather weak these days. Colin

[Anonymous]

Early Bridgeport heads, for use on horizontals, offered a choice of Morse or B&S tapers. I think the R8 taper was introduced in 1938 during the design of a completely new milling machine, which became the Series 1. All three rely on the taper to transmit power, and so are limited in the power that can be transmitted. The concept of the 7 in 24 steep tapers, such as the ISO series, for milling machines was first patented in 1927. With these the taper is for location, power is transmitted via seperate drive dogs.

Industry moved away from self-holding tapers in the 1930s as milling machines became more powerful. The R8 taper is only popular due to the success of the Bridgeport Series 1. Two of my milling machines use R8, and the third is ISO40.

Andrew

[duncan webster 1Participant @duncanwebster1]

If you are going to hit it again please arrange some packing between the bit with the female taper and the table. Putting impact loads through the spindle bearings is not good

[MacolmParticipant @macolm]

If a lathe is available, I suggest making an aluminium or brass sleeve to be clamped up with the collet nut as before. It needs to be good and solid, and the nut tightened once again as hard as possible. If it only catches on the spindle by a little, make a steel support spacer and split it with a saw so that it can be fitted to support the sleeve, and both clamped.

Now run the spindle slowly, and heat the sleeve with preferably two blow torches to something like 250C. It needs to be as quick as possible so that only the sleeve gets hot. This should produce expansion of 20 parts per million times 200C – about 4 thou per inch. A medium thump on the drawbar at the same time is worth a try.

[Matthew FursemanParticipant @matthewfurseman25697]

Posted by Macolm on 19/08/2022 22:14:21:

If a lathe is available, I suggest making an aluminium or brass sleeve to be clamped up with the collet nut as before. It needs to be good and solid, and the nut tightened once again as hard as possible. If it only catches on the spindle by a little, make a steel support spacer and split it with a saw so that it can be fitted to support the sleeve, and both clamped.

Now run the spindle slowly, and heat the sleeve with preferably two blow torches to something like 250C. It needs to be as quick as possible so that only the sleeve gets hot. This should produce expansion of 20 parts per million times 200C – about 4 thou per inch. A medium thump on the drawbar at the same time is worth a try.

Thanks, I have a lathe, a very old drummond. It's a bit of a chore to use and it's 3/4" spindle thread limits it's duty a lot. With patience I could make this out of brass or aluminum. I've also got a Smart and Brown Model A, which I imagine would do this in a blink, but it's not running yet.

I've started milling out the plates to make the wedge as suggested by other posters. This is my first time on a mill so taking things slow. I've squared them up, with the drawbar loose, and it hasn't dropped yet! Ready to put the taper on them now, have to work out how to hold them to get a repeatable angle.

[Matthew FursemanParticipant @matthewfurseman25697]

Posted by duncan webster on 19/08/2022 16:50:13:

If you are going to hit it again please arrange some packing between the bit with the female taper and the table. Putting impact loads through the spindle bearings is not good

Hi Duncan,

Thanks, I am worried about the bearings. I would really rather not have my first experience with a mill be to strip the spindle and change the bearings. I've only run it up to 300rpm so far and it's happy there, but can go to 2000rpm which I imagine is quite different and damage to the bearings would be much more apparent.

The collet holder diameter is about the same as the spindle nose which makes it hard to get any support in there, once I have these wedges made up I can at least use them to support the spindle while smacking it.

[Matthew FursemanParticipant @matthewfurseman25697]

Posted by oldvelo on 19/08/2022 02:14:55:

Look for any signs of heat discoloured metal on the morse taper socket.

By the amount of force used already it is possible that the mill has had the cutter stop and the spindle spin on the morse taper long enough to get red hot and when stopped has welded them solid.

More likely the pervious owner used big long spanner to winch up the drawbar way too tight.

Insert the morse taper of the tool half way into the socket then slap it firmly home.

Advice I was taught Use the correct size spanner on the drawbar,

Hold the spanner in your fingers put your thumb on the spanner at the centre line of the spindle.

The amount of torque applied with the fingers is enough to hold the drawbar firm.

I can't see any heat damage on the outside of the spindle nose, but I'm far from a metallurgic expert. I'll take a pic next time I'm in the workshop and post it.

[Howard LewisParticipant @howardlewis46836]

If you fully extend the quill, could you use a heat gun on the upper end, so that the heat travels down and expands it, with tension is applied by either wedges or the sleeve and clamp nut?

Sleeve and clamp my would be my choice. A lot of office can be applied with a 1.5 mm thread.

This should reduce the risk of heating the chuck as well as the quill.

Howard.

[Howard LewisParticipant @howardlewis46836]

When I had an open ended sleeve stick I made a crude extractor to release it.

A 1/4 BSF thread can exert an enormous force!

Since the mill was hors de combat, the slots had to be cut (Not very neatly or accurately ) with a hacksaw.

Once the mil was again useable, I made a new piece using a slitting saw for the slots.

I made another version, in case the 5 – 3MT sleeve stuck in the lather.

The picture is the first one in my albums, if anyone is interested.

The nut at "The business end" is there so thatb the split sleeve can be forced through the open ended sleeve, before being expanded by the small cone (Loctited to the studding ) as the outer nut is tightened.

I now use the type of open ended sleeve with an extractor nut!

Howard

[colin hawesParticipant @colinhawes85982]

I don't know about the Warco Major but my Warco Minimlll has a hole in the quill housing that can be aligned with the the spindle to lock it. One rotates the spindle by hand until the holes align and insert a steel bar. This a useful feature I say this in case the Warco Major has this hole which would take any strain off the gears with reference to my previous comment Colin

[Howard LewisParticipant @howardlewis46836]

Following on from Colin Hawes' comment, presumably there is either no slot for a taper drift, or there bis no tang on the device stuck in the spindle?

Howard

[Matthew FursemanParticipant @matthewfurseman25697]

There's a slot, I could put a drift in there so that the spindle is locked as Colin suggests.

The taper is threaded, so no tang, I tried an MT4 drift but it touched the far side of the arbour before contacting the top of the taper. I drive a pair of drifts back to back in, but one of them got mauled up.

[old martParticipant @oldmart]

Remove the drawbar, check the threads and cut a short section of suitable bolt with a screwdriver slot added to screw into the end of the stuck tool. This should be screwed in at least 1 1/2 diameters and show in the slot, so measure carefully first. Then your wedges will extract the tool easily.

[Martin ConnellyParticipant @martinconnelly55370]

You should be able to make an L shaped piece of steel that can fit into the slot and contact the top of the collet chuck but leave enough room at the top to put the drift into the slot.

Martin C

[MacolmParticipant @macolm]

I am not sure I have picked up the spindle design details. If the quill extends and it has a vertical slot for a morse ejection wedge, then there might still be hope to eject it that way. In this situation where things have been over tightened, poor tooling is very unlikely to succeed, it must be as solid as feasible..

 

Plan A. Suppose the drawbar thread is M10, and the drawbar hole is 13mm diameter. Get an M10 cap screw, turn down the head to go inside 13mm, remove the drawbar, attach a hex bit to something long, eg some plastic tubing, and manipulate the cap screw down the spindle and screw into the morse arbour so that the head makes solid contact. It need not be tightened, though that might improve chances.

 

Now use a proper morse wedge to attempt release. The real article is correctly heat treated, and the top edge fits the slot radius. File tangs are dangerous and much less effective! Try smearing the ejection wedge with moly grease to minimise friction. You may still need to hit the wedge pretty hard.

 

Plan B. Turn up a T piece from 0.250 thick steel (for MT2 slot) that slides inside the arbour thread at one end, and the top of the T about 0.560 in wide and similar in height to the non existent tang. Poke this into the ejection slot and manipulate down into position, then try to eject as in Plan A.

Edited By Macolm on 21/08/2022 19:01:18

[Howard LewisParticipant @howardlewis46836]

When you manage to get it out, IF you want, you can buy screw in tangs for 2Mt and 3 MT tooling.

But obviously precludes the subsequent use of a drawbar.

A drawbar prevents the holder m,dropping out. But it is not necessary to apply much torque to it.

Running with the drawbar slightly loose, and cutting with an End Mill,as already suggested may shake the chuck loose. Some times it happens even when the drawbar seems to have been tightened sufficiently!.

It may be that it will require some time milling just for the sake of it, so that the chuck and the quill heat up together , so that the interrupted cuts provide enough vibration to shake the chuck free.

Howard

[Matthew FursemanParticipant @matthewfurseman25697]

Posted by Howard Lewis on 23/08/2022 16:06:55:

When you manage to get it out, IF you want, you can buy screw in tangs for 2Mt and 3 MT tooling.

But obviously precludes the subsequent use of a drawbar.

A drawbar prevents the holder m,dropping out. But it is not necessary to apply much torque to it.

Running with the drawbar slightly loose, and cutting with an End Mill,as already suggested may shake the chuck loose. Some times it happens even when the drawbar seems to have been tightened sufficiently!.

It may be that it will require some time milling just for the sake of it, so that the chuck and the quill heat up together , so that the interrupted cuts provide enough vibration to shake the chuck free.

Howard

Thanks, keeping a drawbar seems like the safer prospect, I'm keen to modify the spindle to make it self extracting if I can find a suitable design. I've been milling some wedge plates with the draw bar undone by a couple of turns. Most of the way through that now and no sign of it easing up.

[Tony Pratt 1Participant @tonypratt1]

Are we there yet?

Tony

[peak4Participant @peak4]

Following on from Macolm's Plan A above.

If your mill drill is the same/similar to the Axminster one, there is a manual Here; see p18 for the extraction details.
https://www.axminstertools.com/media/downloads/505109_manual.pdf

I'd be looking at replacing the drawbar, though not screwing it in to the chuck yet, and looking sideways through the oval extraction hole.
This should show how far the 3MT arbor sits below the base of the hole. Make a slug to screw into the top of the arbor, or as suggested above, which might be better, find an Allen screw to extend the arbor into the hole, and proceed with your proper extraction wedge.
The advantage of an Allen screw, is that you could use a long length of hex bar to remove it if need be.

Bill

[Matthew FursemanParticipant @matthewfurseman25697]

Posted by Tony Pratt 1 on 25/08/2022 22:22:52:

Are we there yet?

Tony

Not yet, I've started on the tapered wedges, I think an M10 socket screw would fit, I don't have hex bar but knowing that's an option if it does get stuck would be useful.

Progress is slow, this is my first time on the mill and work is mostly consuming me at the moment.

[Author]

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