Stuck Morse Taper in Warco Major 3024YZ

Hi Matthew, if someone has for some reason, used high strength retainer (Loctite 638 or equivalent for instance) to hold it in, you will probably need to heat it up to about 250 C with your wedges in place, as it would have to be removed while hot.

Regards Nick.

If it has been fitted permanently by shrink fitting, it is likely never to come out without being machined out.

Photos for anyone interested: My attempts with the vice and wedges.

And the pulled quill with spindle and offending tooling

Seeing what looks like evidence of rust on the spindle it may have rusted in place. It may be best to strip the assembly down and saw off the nose of the holder and carefully bore out the taper. If set reasonably accurately it should be able to bore out most of the metal and collapse the last slither. Then clean the taper well and rebuild..

Hi Matthew, unfortunately your wedges are not very effective, they really need to be able to slide over each other so that the other side of each is parallel, one in contact with the end of the spindle and one in contact with the collet holder. Looks like you don't have a very big gap though to achieve it. Might be possible to turn a bit off the collet holder to give you a bigger gap.

A rouge sketch to show you what I mean.

Regards Nick.

Edited By Nicholas Farr on 13/09/2022 11:16:56

I would be surprised (but not shocked) if "just" rusting together would hold up to everything Matthew has tried, he's imposed some fairly sharp shock loads, vibration and a lot of force, iron oxide doesn't usually have the mechanical strength to deal with all of those sequentially, but nevertheless it does seem to be getting down to very drastic options at this point.

I would personally be inclined to take the track Nicolas suggested and use gentle heat on the spindle first to try to release it before progressing to boring the toolholder out, it is possible (though hard to understand why) someone chose to Loctite the taper in after all.

In any case I think disassembly of the quill is unfortunately the logical progression whatever option is pursued at this point, even if heating worked without disassembly you'd still need to strip and re-grease everything after that.

One potentially silly question I have for Matthew as OP is "Would it really be a problem if you just treated the mill as having an ER32 spindle, and bought exclusively straight shank tooling to go in collets?"...

If he already owns a bunch of MT tooling, or wants to run large drills in the mill frequently, I can see the problem... But if not, the solution may be to just redefine the constraints so that the new problem is "Where can I get more esoteric items of straight shank tooling" (like boring heads, facemill holders etc.) which is far easier to solve.

Wow, what a story.

At this point I would strip the spindle and use heat& cold cycles and a big press. HOWARDT has expressed a better way and I applaud his civility.

I think that might involve cutting the tool head off with an angle grinder, it likely to be pretty hard.

And it's out!

Once the spindle was removed from the quill I was able to put in a vice with some EPDM for soft jaws, grab a pair of safety specs, then get a drift in and knock it from above with the 3lb hammer. I did have to 'batter the snot out of it' but with the bearings no longer taking any of the shock I figured this wouldn't be an issue. After about 20 heavy blows the taper popped off into a an old garden glove I had bunged over it to try and limit any damage it might cause when released.

I reckon I could have done this in situ if I had made up the top of the taper with a 3/8 socket screw as suggested, although I'm not sure I would have been brave enough to pound it like that when the spindle was still installed. There is some scoring to the spindle window from the drift.

After all that beating it took before disassembly I think I have damaged the bearings. One of the outer races has marks from the rollers, the other seems to have worn unevenly, so I am considering if they should be replaced while the spindle is out.

The bearings are not too bad, but as the replacements would not be very expensive and the spindle is out, I would treat it to new ones. Simply Bearings may have replacements which might be imperial sizes. Use lithium grease and leave plenty of space for the movement of the bearings to push the excess out of the way, overpacking is not a good idea. Clean out any rust and deburr the spindle when you clean it.

When I did the spindle mod for the Tom Senior, the bottom taper roller was an SKF and the top one was a Timken. I had bought a Toyo bearing, but changed the design halfway through and it was the wrong size.

Edited By old mart on 16/09/2022 20:37:36

Edited By old mart on 16/09/2022 20:40:52

Edited By old mart on 16/09/2022 20:43:04

If you can get replacement bearings cheaply and easily then doing so is probably worthwhile.

But from those pictures, and knowing it's only a mill, I would just refit the existing ones.

I would thoroughly inspect the MT socket inside the spindle before making any other decisions.

Those bearings look absolutely fried, a good lesson to hammer swingers, it would be criminal to put those back in the machine.

I'd replace those if I could, but it wouldn't bother me if I couldn't and if running a tenth-reading dial across the marks showed no flicker of movement in the needle.

Most of the hobby-grade milling machines out there have much less than perfect bearings.

I replaced the four bearings (two taper, two ball) in my Warco Minor in 2019 at a cost of £39.84

Although I don't see any evidence of this in the pictures of your bearings, when I dismantled my mill after buying it I found the top taper roller bearing was running completely dry as all the grease had melted and made its way down to the lower taper roller bearing that was very well lubricated.

Use a high temperature lithium grease as already suggested to avoid the same happening to you.

Graham

As somebody who spent his working life repairing and rebuilding machine tools I would always replace the bearings, just because you cant see or measure marks on the tracks you could have flat spotted the rollers or balls which will still do damage.

Martin P

Hi, I've seen much worse than those and they have had to be put back into service until the next Maintenace day, because no replacements were available in time, and production wasn't allowed to be held up. However, I would also change them as it has been stripped down, and I wouldn't what to strip it down again in a short period of time.

Regards Nick.

The bearings are badly damaged. The race pictured is brinelled. It will only get worse. There is probably similar damage on the rollers and inner race.
Given the relatively low cost of bearing there is no reason or excuse not to change them while the spindle is stripped. Unless you enjoy strippng and rebuilding the mill of course......

Robert G8RPI.

If the bearings show ANY sign of damage, NOW is the time to fit new ones.

Otherwise, you will be stripping it again soon.

You have invested a lot of time and trouble to get the ER chuck out of the spindle, so don't spoil the ship for relative ha'pporth of tar!.

This is your chance to put things right. Take it!

Howard