Elliott dividing head spindle lock

[grim_d]

Hi all,

My Elliott dividing head has no spindle lock, it seems pretty sturdy but I'd still like it to have one.

Looking at the drawings for slightly newer heads it seems like there's just a pin (probably bronze?) that bears against the spindle? Easy enough to add.

But I am curious if anyone has an Elliott dividing head that may be willing to pop the nameplate off and snap me a photo of the lock assembly?

Cheers.

 

[Pete.]

A pin wouldn't be much use for locking a dividing head because it wouldn't line up with any hole whilst dividing except by chance. I think the pin is more likely for direct indexing or possibly compound indexing. Any lock would be a clamp I should think. My dividing head is very basic but it has a clamp.

 

[Hopefuldave]

Anywhere you could put a split cotter in to bear on the spindle? they grip pretty well.

Dave H. (the other one)

 

[RobCox]

I'll pop the nameplate off of mine at lunchtime and take a few snaps. I'm pretty sure its just a bolt with a brass/bronze end pressing on the spindle.

Rob

 

[Agroshield]

Which size head do you have? Which manual do you have? If it is the one that looks the same as at https://www.machinemanuals.co.uk/manual.php?p=102 the exploded diagrams on p.37 & p.39 show the locks. It is just a brass or bronze pad that bears on the spindle. Make it with a relatively fine thread for its diameter so the force is amplified.

 

[grim_d]

A pin wouldn't be much use for locking a dividing head because it wouldn't line up with any hole whilst dividing except by chance. I think the pin is more likely for direct indexing or possibly compound indexing. Any lock would be a clamp I should think. My dividing head is very basic but it has a clamp.

Perhaps pin was the wrong word? Something on the end of a threaded lever that just pushes on the spindle causing it to bind, not locating in any other feature.

I've no idea why they didn't include a lock on it!!

I'll pop the nameplate off of mine at lunchtime and take a few snaps. I'm pretty sure its just a bolt with a brass/bronze end pressing on the spindle.

Rob

Thanks, from the drawings I suspect that's what it is but it'd be nice to see how they've done it.

Which size head do you have? Which manual do you have? If it is the one that looks the same as at https://www.machinemanuals.co.uk/manual.php?p=102 the exploded diagrams on p.37 & p.39 show the locks. It is just a brass or bronze pad that bears on the spindle. Make it with a relatively fine thread for its diameter so the force is amplified.

It's a 10 inch I think, older than that type (I have no direct Indexing plate behind the spindle nor can I disengage the work to free spin...which is pain!

 

[RobCox]

Ah, mine's only a 7 incher.



Let me know if you still want pictures. I took it apart after I bought it for a good clean, so I've been there before! Shame I didn't get pictures then.

Rob

 

[grim_d]

Mine is technically a Victoria but it's all the same just no locking lever or provision for such.

Mine did come with all the toys though and I've since got a little 4 jaw for it too.

The tailstock doesn't match however, it's 1/4" taller so I've made a ally plinth from precision plate for the head to sit on.

 

[RobCox]

I've taken the side off of mine but there's not much to see. This is the unit I've got:



The locking screw, contrary to a suggestion above, isn't a particularly fine thread. 1/2", 13 TPI:




There's a loose brass plunger in the bottom of the thread to bear on a smooth part of the spindle:



and when you look inside all you can see is the casting which houses the locking screw:

Hope that's of some use.

Rob

 

[grim_d]

Thanks for those, I'm pretty sure mine looks almost identical inside, I'd probably have to dismantle it to put a lock in. Another project for the list!

It doesn't seem to suffer without a lock, there is zero measurable movement on the spindle but I really think it should have one as that could easily change with cutting forces.

 

[grim_d]

Well here we are then..I set it up tonight for compound dividing for my 63T gear and the geartrain backlash was too much to be comfortable with.

So I've pulled the head apart and going to put a lock in as a priority, I'll be putting it in the same place as the Elliott above.

One difference in our heads is that the worm gear on mine is split so it can be adjusted for wear, very interesting.

It's a beautifully made thing, hand scraped spindle and worm gear bores. Maybe it was a Friday afternoon effort and they forgot the lock...

Phone died so this is the only picture I could take.

 

[grim_d]

Made a start on this tonight.

Milled a pocket for the handle, felt wrong!

There was a rib in the way of the path of my drill and unfortunately I didn't have a long enough centre cutting endmill so I used my pencil grinder to create a flat spot and clearance for the drill.

Through with the drill after that,

Tapped M12 and deburred.

Hopefully tomorrow I'll have enough time to make the plunger and locking handle.

 

[Agroshield]

Milled a pocket for the handle, felt wrong!

But the finished pocket looks factory.

I hope you will copy the handle RobCox showed. If you can curve the end of the brass plug to match the spindle, it will have more bearing on the spindle. Even a V in it will have two lines of contact. Adjust the length of the brass plug so the handle points in the right directions when open and closed.

 

[grim_d]

I will be copying the handle to make it look as close to original as possible.

I've been thinking about the contact surface of the brass plug, thinking of ways of cutting an exact curve on it or as you say, putting a v-groove in it.

I don't think it will be too critical as it's not going to be relying on the friction between the plug and the spindle so much as pushing the spindle into the bore and binding it up.

See what happens when the time comes

 

[grim_d]

Didn't get as much time as I wanted at the workshop today but got the plunger and handle mostly done, just need to drill and tap the plunger to accept the handle then make my brass plug and cut the plunger to length.

 

[grim_d]

Handle finished, brass plug done (went with a curve on it)

Works tremendously, get the whole thing back together tomorrow.

Might nip a smidge off the plunger to move the handle round.

 

[Seadog]

An excellent job.