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Garell
24th April 2006, 06:55 PM
Hi all

Just wondering if anybody knows of a chuck that has a 7/8" x 16 Whit thread or a chuck that has an insert that size. I am after a chuck for my lathe and unfortunately that is the thread size.

Regards Jamie

Jim Carroll
24th April 2006, 07:06 PM
Jamie are you sure of the size as a standard thread is 3/4" x 16tpi.
What type of lathe is it.

Garell
24th April 2006, 07:25 PM
Hi jim

My lathe is an old coronet major 1976. Unfortunately Coronet Major (Red) pre 1977 have a thread size of 7/8" x 16 Whit. After that they went to the standard of today. this is a previous post about the machine, http://www.woodworkforums.ubeaut.com.au/showthread.php?t=25487&highlight=coronet+major

You can also visit

http://www.lathes.co.uk/coronet%20major/index.html they have a good description of the lathe.

http://homepage.ntlworld.com/g.malthouse/cmajor01.htm is a aquantance in england that has one.

http://www.coronetwoodworking.co.uk/Home.html and these people are the only stockest for parts, and there in england. I have brought from him before.

so thats my delema.

Regards Jamie

Sprog
24th April 2006, 08:26 PM
Teknatool have a blank insert (insert N) which can be threaded to match your lathe size

http://www.teknatool.com/products/Chuck_Accessories/Chuck_Inserts.htm

Garell
24th April 2006, 08:46 PM
Well after some searching i found that these people have the insert. But you guesed it they are in england. Now i just have to find out if i can get it here.

Thanks sprog. I might have to use that as a last resort. The tap for the head stock will probably be the same price as getting some one to turn the thread in there for me.

hughie
25th April 2006, 01:20 PM
Jamie are you sure of the size as a standard thread is 3/4" x 16tpi

Jamie,
If the thread is non standard then a tap will not be available. This practice is quite coomon amongst manufacturers to insure an income from thier spares. It would need to screw cut on a lathe, if you dont have access then it could prove to be expensive.
hughie

Greolt
25th April 2006, 06:55 PM
3/4 " UNF is 16 tpi

7/8" Whit is 9 tpi so it won't be whitworth

Jim Carroll
25th April 2006, 09:44 PM
Finally found my thread bible
7/8 x 9tpi is BSW or UNC depending on depth of thread.
7/8 x 11 tpi BSF
7/8 x 14 tpi NF or UNF or pipe thread
7/8 x 16 tpi conduit thread.

So if it is what you say then if you can find an old electrician that used to thread their own metal conduits they may have both the tap and die to suit.

You would need the N insert and a metal lathe as you need to put the insert into your chuck then put the chuck in the lathe lathe and use a dial guage to make sure the chuck is running true then drill and tap the insert in this position.

If you try to do it any other way you have no guarentee that the thread you are tapping will run true when you put it on the lathe.

Garell
26th April 2006, 09:22 PM
Thanks Jim

I managed to find a web site that stock the insert and chuck's. Unfortunately its in England, so it looks like I'm getting it from there, that way it save all the hassles and will probably be cheaper any way.

This is the place if you are interested. http://www.toolpost.co.uk/system/index.html

regards Jamie

I might still try timbecon, I know there is a dealer in Tasmania that might have it. I can only try. Other wise its England for more parts for the machine.