Lathe spindle nose threads

[Ueee]

Hi All,
I've wondered over from the metalworking section to ask if there are standards for lathe spindle noses. I have to make a new spindle for someone, he is looking at a chuck with an M30x3.5 thread. I need to know if there is a standard length and register diameter for wood lathes or not. My wood lathe has a 1" dia thread so i can't just copy it.

Cheers,
Ew

[Big Shed]

Ew, my wood lathe has an M30x3.5 spindle thread.

Let me know exactly which measurements you need and I will get to it.

I can also lend you an M30x3.5 female thread insert for a Vicmarc chuck to test your male thread.

[Ueee]

Thanks Fred,
I guess i need the length of the threaded section and if there is an unthreaded register it the rear like a metal lathe or not?
Do you have thread wires? If so a simple measurement over wires would be fine, otherwise i'll try to get the guy to buy the chuck so i can cut the thread to suit.

Cheers,
Ew

[Big Shed]

I will do a rough sketch, yes it has an unthreaded part behind the threads.

I do have thread wires but only imperial I think, but can only measure with digital calipers as I do not have a micrometer.

[Big Shed]

OK, just found a pdf on LittleMachineShop and it appears you can use the imperial wires with metric threads, apparently the 0.081" set of 3 are the ones to use.

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCQQFjAA&url=https%3A%2F%2Flittlemachineshop.com%2Finstructions%2FThreeWireMethod.pdf&ei=U8WSU8ngOsTRkwWV6oDIBw&usg=AFQjCNFVKHYUjnxnOm8U_DS0QRJ54xOPiA&sig2=s2IVIXtwEvS7M9nBIdUqwg

I am only a "book machinist" you know:rolleyes:

[Big Shed]

Here is the rough sketch with sizes Ew.

As I said before happy to post a spare M30x3.5 Vicmarc insert if that will help test your spindle.

[Ueee]

Thanks again Fred.
Shopcalc gives a 3 wire measurement of 30.868, so your measurement of 30.77 is right on what it should be with some clearance. I'm happy to cut the thread to the wire size, once again it comes down to comparative measurements VS absolute measurements....

I'll let you know how it goes once the job is done, and of course if anyone else wants a custom spindle for their lathe......:D

Ew