How to release MT1 taper

[Rowan Sylvester-BradleyParticipant @rowansylvester-bradley37244]

How do I release the tailstock MT1 chuck or centre from my Portass PD5 lathe?

Thank you – Rowan

[Rowan Sylvester-BradleyParticipant @rowansylvester-bradley37244]

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Rowan, if the tailstock barrel is the hollow type, a piece of steel bar, probably 3/8" diameter long enough to reach the Moorse tapper, and then hit the end of the bar with a hammer.

Regards Nick.

[Clive FosterParticipant @clivefoster55965]

Rowan

As Nicholas says the tailstock poppet barrel is hollow. Either a gentle tap with a hammer on a suitable drift as Nicholas suggests or make up a slide hammer style knocker by using a longer drift with a handle on the end. Spare file handle perhaps or just a simple graspable size lump of metal.

My experience of loose drift rods is that they to be good at the self hiding thing and vulnerable to being used as stock material. Something slightly more engineered hung on a hook close to the machine or held by a terry clip tends to be easier to find.

Clive

[Brian WoodParticipant @brianwood45127]

Hello Rowan,

I can confirm that having just looked up the model on http://www.lathes.co.uk which shows a hollow tailstock barrel. You may find the archive material on that site interesting. My father's ML4 bought in 1945 had a very similar tailstock and he kept a long bolt with a flat plate end to it as the knock out 

Regards Brian

Edited By Brian Wood on 29/11/2022 15:39:56

[egaParticipant @ega]

Posted by Clive Foster on 29/11/2022 15:32:40:…

My experience of loose drift rods is that they to be good at the self hiding thing and vulnerable to being used as stock material. Something slightly more engineered hung on a hook close to the machine or held by a terry clip tends to be easier to find.

Clive

Users of the Myford lever-operated tailstock can simply unclamp the lever and use that as a drift; to facilitate this my clamp has a ball handle. I mostly use a drawbar, however, and this is loosened a couple of turns and tapped to release the taper tool (the copper hammer is in a terry clip!).

[old martParticipant @oldmart]

It would lessen the impact forces on the threads and nut if the quill was locked before removing the tooling.

[Mike PooleParticipant @mikepoole82104]

My preference is for a brass bar or at least a brass tip on the end to avoid any harm to the tool being ejected. Probably not absolutely necessary but it can’t do any harm.

Mike

[Ady1Participant @ady1]

I got fed up of banging mine out with a hammer and drift and made a 6mm slot like the big drills have

Sometimes they can get pretty tight

Tap the taper release drift to shove it out, its a roundbar welded to the back of a triangular flatbar

And always remember to lock the tailstock and tailstock spindle before assaulting it by whatever means you employ

Edited By Ady1 on 30/11/2022 01:18:30

[Anonymous]

Posted by Clive Foster on 29/11/2022 15:32:40:

Rowan

As Nicholas says the tailstock poppet barrel is hollow. Either a gentle tap with a hammer on a suitable drift as Nicholas suggests or make up a slide hammer style knocker by using a longer drift with a handle on the end. Spare file handle perhaps or just a simple graspable size lump of metal.

My experience of loose drift rods is that they to be good at the self hiding thing and vulnerable to being used as stock material. Something slightly more engineered hung on a hook close to the machine or held by a terry clip tends to be easier to find.

Mine's a piece of hex bar, maybe 18" long, stood in the corner by the lathe. Definitely low-tech. I just slide it in and, with about an inch to go, sort of throw it like a javelin (while loosely holding whatever's in the barrel with the other hand of course). The mass of the bar is enough – no hammers or anything fancy. been using the same bar for 20 years (it's shorter now though)

[MacolmParticipant @macolm]

Not tried this, but might work to dislodge a tight Jacobs taper.

Drill centrally through the chuck as suggested previously, but make it a small hole for a tight fit on a 3mm (say) steel rod. Now with the arbour downwards, fill the space with oil. Enter the rod (only just) and strike it sharply with a hammer to pressurise the space. The difference in areas should multiply the force on the end of the arbor

Some of us will have removed plain bushes from a blind housing in a similar way. It is surprising that this works even with a very loose fit, but the leakage is small for a sharp blow.

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