Removing a J2 arbor from a drill chuck

[Douglas JohnstonParticipant @douglasjohnston98463]

I have just acquired a good 0-10mm keyless drill chuck with a MT2 arbor. I want to replace the arbor with an R8 arbor for use on my mill but cannot remove the MT2 one. Somewhere in my workshop I am sure I have a pair of wedges for this task but I can't for the life of me find them. I last saw them about twenty years ago and vaguely remember having little success with them.

Is there any technique that others have had success with in removing an arbor or is it a case of once fitted they are there for life and I should just give up now.

Doug

[Douglas JohnstonParticipant @douglasjohnston98463]

[noel shelleyParticipant @noelshelley55608]

I seem to remember one trick was to open the jaws wide and drill a hole through the back and then use a punch. Warming the chuck may help. Put some washers on the MT2 so they sit on the back of the chuck and administer a sharp blow ? Good luck Noel.

[Martin ConnellyParticipant @martinconnelly55370]

I have managed to get them out of the chuck with a suitable sized open end spanner after wedges failed by splaying out. The arbors are soft centred so last resort is to cut them off and drill out. They are a cheap throw away item so not a big deal. Just size the drill to the smallest diameter of the J2 taper. Once the centre is gone the pressure on the face of the taper usually gets reduced to the point where the remains come off with the drill.

Martin C

[Clive FosterParticipant @clivefoster55965]

Assuming Albretch are typical you cannot drill and punch out the arbor from a keyless chuck due to the screwed spindle inside that controls the self tightening action.

Albretch service instructions here :- https://www.albrecht-germany.com/en/instruction/ with a nice picture of the innards. It might be possible to take the chuck apart with the morse taper still mounted, unscrew the spindle and punch out the taper via the hole.

Picture of the Rohm here :- https://www.roehm.biz/en/products/drill-chucks/spiro-series/ showing its the same layout as an Albretch. Main difference I think is a locks crew for the end collar. Allegdly Rohm instructions are around on the web but my Google Fu isn't up to it this morning.

Clive

[MacolmParticipant @macolm]

Not difficult if you follow the Albrecht instructions. The main problem is to undo the two halves of the main body. Well fitting half clamps to hold it in the vice and a chain wrench is best, but other means to grip it can be Jubilee clips or exhaust clamps, Protect the chuck with thin aluminium sheet. Dismantle over a tray!

Once dismantled, there is through access to knock out the arbour.

Edited By Macolm on 27/03/2021 12:47:53

Edited By Macolm on 27/03/2021 12:48:35

[DalboyParticipant @dalboy]

First thing is check there is not a screw in the chuck by opening the jaws and looking down inside if there is it will be a left hand thread. once removed or if no screw and the MT has a collar above the mt section, hold the taper and gently hit the collar with a hammer rotating as you do so this sometimes releases something on a taper. This is something I have done on power tools that have a taper fitting for drill bits and the like.

[Ady1Participant @ady1]

It's problably glued in and dismantling would make the job a lot easier

Track rod ends are similar and you can either use a big hammer or jury rig a joint separator

[MacolmParticipant @macolm]

I should have mentioned, if the arbour has a drawbar thread, a "slide hammer" technique will work with screwed rod, a nut and a sliding weight. Someone recently reported success with this technique. A sufficiently robust drawbar would also do, but many just have a hex sleeve retained by a small pin rather than an integral bolt head.

Treated with care, keyless chucks are excellent to use. Do not attempt to drill or hammer in the centre recess. The actuation thread occupies the central core.

[Douglas JohnstonParticipant @douglasjohnston98463]

Thanks for the replies, the chuck is a Metabo-Futuro one and might dismantle in a similar way to the Albrecht type so will give it a go.

Doug

[Peter TuckerParticipant @petertucker86088]

Hi Douglas,

I would make a new pair of split wedges; probably quicker than hunting for the old ones. The split wedges I made work a treat.

Hope this helps.

Peter.

[Douglas JohnstonParticipant @douglasjohnston98463]

Posted by Peter Tucker on 27/03/2021 16:05:23:

Hi Douglas,

I would make a new pair of split wedges; probably quicker than hunting for the old ones. The split wedges I made work a treat.

Hope this helps.

Peter.

That's probably a good idea Peter, and it is almost certain to make the lost ones appear. Like most workshops I have a gremlin that hides tools until they are no longer required and then gives them back.

Doug

[old martParticipant @oldmart]

If you end up deciding to leave the chuck and arbor together, there are R8 adaptors for tanged MT2 chucks. We have one chuck still with its MT2 taper which can be used in the lathe tailstock as well as the mills.

[Douglas JohnstonParticipant @douglasjohnston98463]

Posted by old mart on 27/03/2021 19:54:35:

If you end up deciding to leave the chuck and arbor together, there are R8 adaptors for tanged MT2 chucks. We have one chuck still with its MT2 taper which can be used in the lathe tailstock as well as the mills.

That sounds like a good idea since I have not managed to budge the M2 arbor. I am amazed at the grip these tapers provide considering the relatively small surface area of the taper. I suppose the previous owner may also have put some high strength Loctite on the taper before fitting and in that case it will never come apart.

Doug

[Clive FosterParticipant @clivefoster55965]

Arbors on keyless chucks generally go on tighter than those on standard chucks because the space beneath the end of the Jacobs taper is larger and slightly vented via the internal screw threads. So there is no pressure build up from trapped air in the end of the taper bore reducing the press in force as can occur with a normal chuck.

When asked to sort why one chuck wouldn't stay on its Jacobs taper I discovered that the taper bore was only just long enough so there must have been significant pressure build up when the taper was pushed home. Drilling the centre so the air could escape and fitting the arbor by rapping the end of the chuck on an alloy surface rather than simply pushing sorted it.

Rapping the end of the chuck with the arbor lightly dropped in place ensures it enters truly. The vibration also helps shift any air before it gets trapped. Belt and braces is to apply pressure after two or three raps. Generally if it doesn't hold with the rapping method you will find a damaged or scored taper where press insertion or hammering the arbor in has been attempted with the arbor slightly off line.

Clive

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