Denford Viceroy Lathe Problem

[madasamonkey]

Hi

I've recently upgraded from a Record CL3 lathe to a bowl turning Viceroy lathe (on single phase). Soon after I had the chance to get a full Viceroy with an outboard for bowl turning and a 36" plus inboard for spindle turning, very cheap,( but 3 phase).
I swopped the motor and electrics and thought I could save the Bowl Turning lathe for spares. I had an adapter made by a local engineering company to fit my Supernova chuck on the outboard with a Supernova2 on the inboard, brilliant set up I thought.
As the outboard is a reverse thread, the chuck keeps coming loose despite the locking grub screw. So I cant bowl turn as the bars on the inboard are too close.

Does any one on the forum know the answer?

Do I drill and peg the chuck on the outboard through the grub screw hole, or should I get a single phase motor etc for the spare bowl turning lathe and rearrange the work shop to fit two lathes in?

I'm new to the forum and would appreciate any advice

Thanks Simon

 

[Blister]

Not 100% sure on your lathe , but I think you need a left hand thread on the outside ? like a Union Graduate

Or a motor that has forward and reverse , so you can change direction on the outside end

to me it sounds like it is unscrewing off the shaft

Allen

:deer :ho2 :deer

 

[madasamonkey]

Thanks, that is the problem.

The outboard has a reverse thread, so to fit the supernova chuck the adapter had to have a reverse thread on the inside to fit the lathe spindle and a normal thread on the outside to fit the chuck. Yes it is untreading, as the locking worm screw cant hold it tight enough.

 

[maltrout512]

I have a metal lathe chuck bolted on to the face plate which has the right thread (left-hand) for using on the bowl side of my wadkin if that makes sense.

 

[CHJ]

You need to have an insert locking screw fitted with an indent in the chuck body for it to register in.

In addition to help prevent any movement that could work on the locking screw register over time thus loosening it, you need to assemble the insert thread to chuck body with Loctite.

 

[madasamonkey]

So as I thought I need to drill through the locking worm screw hole into the adapter thread at right angles, so the worm screw 'pegs' the chuck to the adapter and put locktite on the threads (adapter threads) as a belt and braces.

Thanks for your help Simon

 

[CHJ]

So as I thought I need to drill through the locking worm screw hole into the adapter thread at right angles, so the worm screw 'pegs' the chuck to the adapter and put locktite on the threads (adapter threads) as a belt and braces.

Thanks for your help Simon

That's it, the locking screw acts like a dowel and is the primary safety device that stops the chuck flying off but the Loctite will prevent any fretting from minor movement.

 

[madasamonkey]

Morning

Now drilled my chuck adapter, checked it twice, got it right despite numb hands.
Now I need a longer grub screw and my local engineering supplier is still on hols!
So I thought I'd look on internet for some cheap loctite as I cant do owt else til the new year and yikes!
How many different types are there, any body know which one I need?
I think 225 sounds best, am I correct?

Thanks all for your help, Simon

 

[CHJ]

Does not have to be " Loctite " brand, loctite tends to be used as a generic name for locking compounds.
Bondlock for instance.

Your main problem is going to be small quantity portion for a one off use.

The last pack I used was Loctite® 243 but it's not super critical for what you need.

Interesting PDF guide

 

[madasamonkey]

Just bought 10ml of 243 off fleabay for £4.50 delivered, now to see if it turns up before the engineering supplier finishes his mince pies and opens up again!

Thanks

 

[madasamonkey]

Loctite turned up today and the engineering company reopened, so all now drilled, dowelled and stuck back on the lathe.

Thanks everyone for their help

Now to find time to try it out

Simon

 

[Davyboy]

I would not recommend trying to use a RH thread chuck on a LH thread outboard spindle under ANY circumstances, with or without Loctite or locking screws, it's a serious accident waiting to happen!!! Obtain a chuck with the correct LH thread & that will solve the problem permanently!!!

 

[madasamonkey]

Since that last message, I decided to contact Teknatool technical department and see if they thought the method I had used was safe. As they sell both RH and LH adapters to fit their chucks on lathes. Below is their reply.

Hi Simon,
We use a method for securing our inserts to both of our lathes models which have a reverse function - essentially the same thing a locking grubscrew which is located in a groove on the spindle. In our case we make a grubscrew with a 'bias' at the end which pushes the grubscrew positively locking towards the spindle bearing. Using this method we have had no safety issues with it - but care needs to be taken when taking the chuck off the spindle that the grubscrew is unscrewed to clear the spindle - otherwise damage to the spindle threads could result.

However in your case, although it sounds OK - we would need to see close up photos and drawings of your modifications to comment further if what you have modified is safe.

As a general comment I think you would find it very hard to find chucks commonly available with dedicated lefthand threads.

Regards

So I think I'm safe and will carry on turning!

 

[OldWood]

I know this is hindsight to the conversation, and again I have not used a chuck on the tail of my lathe so I may well be sounding off with a load of rubbish.

But why did you get rid of the 3 phase motor when for all of the cost of the 1 ph replacement you could have got an electronic inverter and thus variable speed and reverse ? And surely that is the key to your problem in that you are running the lathe in forward with a left hand threaded chuck. Single phase motors will not speed vary but it is not that difficult to wire them up with a reversing switch.

Apologies if this seems that I am not really understanding what the problem is.

Rob

 

[CHJ]

Rob, there is no problem with the left hand threaded insert that connects to the lathe.
The problem that the original poster had was that his chuck is fitted with an adapter insert that has a Right Hand thread between chuck and insert which has potential to come undone, letting the chuck come loose and leaving the LH insert still on the shaft.

This has been solved by inserting a locking screw and bonding the thread of the insert to prevent any chafing working against the locking screw.

 

[madasamonkey]

Yes as above, running the lathe in reverse would still have been a problem as the outboard has LH thread

PS I still have the 3 phase motor and the bowl lathe stored away in the corner

 

[OldWood]

Oops sorry - it was nearing my bedtime and I wasn't really taking in what I was reading !! :roll:

Rob