Thread to Taper Adapter

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Kerrowman

Established Member
UKW Supporter
Joined
17 Mar 2021
Messages
60
Reaction score
3
Location
Penzance
I have a wood turning lathe that has a 3/4in x 16tpi threaded tail stock which sometimes I will need to replace with a Jacob Chuck to hold a drill. These Chucks I understand are normally fitted with a taper so I wanted to ask if there is an adapter to fit my threaded tail stock, once I’ve removed what’s there now, which will then hold the taper (MT1?) of a Jacob Chuck?
The pic is of my setup.
Thanks
 

Attachments

  • 06257D23-A20E-4F51-825D-9AFEE1CFCCF0.jpeg
    06257D23-A20E-4F51-825D-9AFEE1CFCCF0.jpeg
    173 KB · Views: 37
I don't think there is a standard adapter to do what you want but it could be made.
 
Yes so far I have not found a taper adapter on the end of a thread that I can put into my tail stock. Any thoughts on where I might find one or get one made?
 
I have never seen such a thing either. it is an odd arrangement for a lathe, which obviously doesn't help you if you have such a beast.
 
After a lot of hunting around I’ve got a suggestion which is to use an M33 to 3/4 16 adaptor then screw in a threaded arbor (see pics) and then I just need to find a good Chuck that fits straight on to an MT2 taper. How does that sound?
Such chucks must exist?


C86B55FB-F154-483A-BFA9-4F379DA1E8DF.png9B1EE463-FCFA-4EDD-8C38-59D14138777E.png
 
Kerrowman, no that will not work, what you need is an adapter with a 3/4 x 16 female thread then either an MT2 female on the other end or a JT2 male taper on the other end to hold the chuck.
Option 1 MT2 means you can use any tool with a morse taper
Option 2 JT2 means you can use only the chuck mounted on said adapter
Hand drawn sketch of option 2
One point what is the thread form UNF, UNC, BSW etc ? I.e. 55 deg or 60 deg form, where was the machine made may be a clue
 

Attachments

  • image.jpg
    image.jpg
    164.6 KB · Views: 11
Sounds like a plan. The MT2 option 1 seems more useful for other tools especially as it seems this will need to be custom made. How deep would the female MT2 need to be? Some of the tapers fixed to chucks look to be approaching 100mm long.
My thread is UNF.
 
the mt2 wont work, because that is a long taper usually found inside the tailstock.

I think this is a non starter. you could probably get something made but it is likely to be expensive.
 
Option 2 for use with just a chuck should be ok but again it will need to be custom made. I need to weigh up the cost and effort against how often I need to drill a true hole at the end of a stock instead of turning a hole.
 
Looking at the picture I very much doubt there will be a taper in the tailstock. Why don't you just get a chuck with a female screw thread fitting. Then all you need is an adapter between the male thread on the tailstock, and whatever is in your chuck. You will still probably have to get it made, but a damn sight cheaper than a taper. Having said that how rigid and accurate is the tailstock and the thread through it. If it wobbles around then you will never be able to drill an accurate hole with it anyway. Looks like it was only designed to be a between centres support, and I'm guessing the thread isn't all that tight a fit. If that's the case then as you wind the chuck forward with the handle it will move about so you won't get an accurate hole. If you were going to go to the trouble of having an adaptor made then you might want to get the same people to replace the tailstock screw with something that's a better fit. All assumes that the tailstock actually moves along the bed without any play.
 
Marcos, the MT2 option would work but the converter unit would be much longer, probably around 5 inches to accommodate the taper, could be shorter if a No1 taper was used.
However a few quick checks and it would be possible to make an MT1 taper directly into the spindle but I can foresee a possible problem with the centre shown in the OP’s first photo. The centre seems to be just a bearing pressed directly onto probably a short section of the threaded bar reduced to suit? This option does leave only a thin wall section between the thread root and the taper max diameter (0.091 to 0.095)
Kerroman, how is the centre attached? Also what size of holes do you need to drill? What make is the machine ?
 
Just a thought but does the manufacturer do an alternative tailstock to take a chuck? I think you will have problems however you try and do this as the tailstock doesn't appear to run on any sort of machined surface, so setting it up straight for use with a chuck would be a pain. I would forget about tapers unless there is one there already, getting an MT taper machined into it would cost a lot, even if there's enough meat to allow for it. Like I say, cut the end of the threaded shaft and make an adaptor for that thread to a threaded chuck. You would need a second adaptor to suit your existing rotating centre, so you can still use that. To make the two adaptors would be simple and cheap. Unfortunately I suspect you're going to find that the machine isn't going to be accurate enough to do this anyway, clearly not what it was designed for. First thing I would do is assess how much play there is in that tailstock screw. Whatever play there is, that is how inaccurate any hope you still will be.
 
Just a thought but does the manufacturer do an alternative tailstock to take a chuck? I think you will have problems however you try and do this as the tailstock doesn't appear to run on any sort of machined surface, so setting it up straight for use with a chuck would be a pain. I would forget about tapers unless there is one there already, getting an MT taper machined into it would cost a lot, even if there's enough meat to allow for it. Like I say, cut the end of the threaded shaft and make an adaptor for that thread to a threaded chuck. You would need a second adaptor to suit your existing rotating centre, so you can still use that. To make the two adaptors would be simple and cheap. Unfortunately I suspect you're going to find that the machine isn't going to be accurate enough to do this anyway, clearly not what it was designed for. First thing I would do is assess how much play there is in that tailstock screw. Whatever play there is, that is how inaccurate any hope you still will be.
Blooming auto correct. How inaccurate any hole you drill will be!
 
Don't suppose it would be the right thread, but if you only need to put a drill type chuck on there, Picador used to make one with a female thread to screw on to their saw shaft. No idea if Picador even still exist.
 
The lathe looks as if it might be a Lidl/Aldi and as such is designed for use as a boat anchor (and not even a good one) and not actually for turning anything. For what you're likely to spend faffing about look to upgrade it.
Was trying to let it down gently, but you are quite right. Might be up to turning lightweight stuff between centres but **** all use for anything else I'm afraid.
 
Well as the cat is out of the bag those lathes do have a reputation. I take it it's this one or just like it with another badge

I would just take it as an introduction to turning. Do some basic spindle turning and then a small bowl or so with the face plate. It really is not worth throwing any money at. The guy doing the video actually takes a good practical approach to it and explains its limits. For some who just do handles and spindle work for general woodwork projects it does what they need.
Bolt it down to a bench of some kind and play with it as is. If in a while you want to move up then get something better and keep that to turn into a disc sander. Don't worry most turners soon out grow the first lathe. In my case an old Record CL24.
Regards
John
 
Back
Top