DIN 55027 spindle nose release

[Craig thompsonParticipant @craigthompson45186]

Hello, I am currently working on a Excel CU-500M lathe. This has a DIN 55027 nose, however I cannot seem to find a listing for a special spanner to release this?

Am I looking to hard, perhaps it is just released by hand, is stuck, and needs a strap wrench as a help?

Also after the handbook for this lathe, the aluminium headstock plate is all but cleaned off all of its markings for settings. Anyone had any luck contacting Excel about older models, or would I be better off going to ZZM, as they list this as a current model.

Many thanks ahead of any replies.

[Craig thompsonParticipant @craigthompson45186]

Special spanner?

[Clive FosterParticipant @clivefoster55965]

Craig

If a new headstock plate can't be got a a sensible price an effective way of quickly making a long lasting replacement is to find a decent picture, copy it and use one of the inexpensive plastic laminators to encapsulate it.

Or spend some time in a drawing or CAD program to make a nice pure black on white drawing. Rolling your own lets you put other useful bits on too or change out the pictograms for something easier to follow.

I've made several over the years using my bottom of the range Maplin A3 and LiDL special laminators. Oldest is probably 15 years old by now and still fine.

Clive

[JellyParticipant @jelly]

Posted by Craig thompson on 20/10/2022 04:52:03:

Hello, I am currently working on a Excel CU-500M lathe. This has a DIN 55027 nose, however I cannot seem to find a listing for a special spanner to release this?

Are you looking for a spanner to release the spindle nose itself, or to release chucks from the spindle?

My experience of the bayonet-type (DIN 55027) spindle noses has been that they're invariably machined into the spindle with the bayonet lock-ring slid over the spindle during assembly and permanently captive.

Releasing the chucks should only need a normal spanner to undo the bolts and the ring should then freely rotate to allow you to take the chuck off the taper (maybe with a tap with the leather hammer, if it's on particularly tightly).

[Craig thompsonParticipant @craigthompson45186]

Many thanks for this Clive and Jelly, I did remove the bolts, gave the chuck a whack with a copper hammer, and the chuck came off aok, onto a block of wood, placed beneath, but this seemed a bit of an effort.

I was looking for some form of quick release, like the knurled collar would be rotate a cam, to enable the chuck to be removed in a minute, not the ten minutes of removing each individual bolt, and refitting them into the next chuck.

Also the threads would be prone to wear?

[Clive FosterParticipant @clivefoster55965]

Its pretty normal for a chuck sitting on the short tapered spigot to need a bit of a donk to come loose. 6 of my 8 camlock mount ones need a, moderately gentle, thump with the heel of my hand to remind them to come off. The 2 that don't are big, heavy and old. Copper mallet is going too far tho'. Time for forensic inspection and careful clean up. There may be a mark or two raised just enough to grip.

If yours is the bayonet ring version of the DIN 5507 its not neccessay to remove the nuts. Should be small enough to pass through the keyholes. If its not a bayonet ring time to figure out how to make a two piece ring that can be joined in situ, I'd arrange a glued and pinned pair of stepped joints, so its much easier to use.

Realistically the plain studs and nuts version of the DIN 5507 is functionally "just" a metric dimensioned offshoot of the A series mounts. As such its not intended for regular changing.

Clive

Edited By Clive Foster on 21/10/2022 09:12:30

[JellyParticipant @jelly]

Posted by Craig thompson on 21/10/2022 07:23:57:

Many thanks for this Clive and Jelly, I did remove the bolts, gave the chuck a whack with a copper hammer, and the chuck came off aok, onto a block of wood, placed beneath, but this seemed a bit of an effort.

I was looking for some form of quick release, like the knurled collar would be rotate a cam, to enable the chuck to be removed in a minute, not the ten minutes of removing each individual bolt, and refitting them into the next chuck.

Also the threads would be prone to wear?

I've grabbed a photo of mine when I was swapping chucks last night.

There's a rotating lock ring with a "backward 6" shaped hole which allows me to pass the studs through complete with their nuts. It becomes free to rotate with only minimal loosening of the nuts.

It you don't have the lock ring, but it bolts up from the rear then it's a non-standard implementation as DIN 55028 / BS4442 Part 1 / ISO R702 Part 1 nose, bolts up from the front with cap-screws.

(Side note R702-1 isn't designed with chuck changes in mind anyway as it's generally specified for holding chucks on Turret Lathes [and these days CNC "Swiss" lathes] with a bar-feeder, where you'd never actually remove the chuck.)

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Craig thompson on 21/10/2022 07:23:57:

.

I was looking for some form of quick release […]

.

To be honest, Craig … I think you are in the process of re-inventing the camlock fitting

.

MichaelG.

[Author]

Posts