Left Hand Taps

[TonyW]

In part this is also a reply to Chuck's question on outboard turning, as I have a UK Record Maxi 2 / Oz Woodfast lathe with a double ended headstock spindle, for both inboard and outboard turning. These lathes have a bracket and riser post to allow use of either the long or short inboard tool rests btw, similar to the old Graduate lathes.

With all of my other lathes over the years I have used glue blocks made from hard wood threaded for screwing directly on to the spinde. The Maxi uses an oddball thread size of 1.1/4" x 8 however, and although I have found a UK supplier of right hand taps in this size, for the inbound end, I can't find a left hand tap for the outbound. Has anyone found a supplier please, or will I have to make my own and if so how?

I have found such as outboard bowl turning very comfortable incidentally, being totally unencumbered by the lathe bed etc. and so even use it for small 8" bowls as long as my one and only faceplate isn't already in use, hence the need for the glue blocks.

TIA

Tony Wells.

 

[KenV]

Tony. 1 1/4 - 8 is a very common thread in the U.S.. Most of the larger lathes use that thread on the head stock.

Jerry Beall sell rh taps for that thread for threading wood. I think I have seen ads in Woodturning Mag from time to time.

Nova sells an insert for their chucks threaded both ways, and memory says they make a lh threaded insert in that thread. You do need a nova Chuck though.

 

[Skie_M]

Alternatively, if you find you don't like the idea of using wooden threads, you can go find some steel nuts of the correct thread size and sink them into some stock to create a wooden faceplate for turning projects.


Alternatively, if you just want to make a single temporary one, you can use solid wood ... cut a hole through the middle that's around 1 1/8th inches and manually thread it onto the spindle by hand.

Once you've got it on the spindle, take it off and soak the wooden threads in CA to make them harder, quickly wipe out any excess that tries to pool in the threads.

Once you have good strong threads, ensure it mates up against the shoulder on the spindle and then turn it round for balance, and true up the face to prepare for gluing.



The trick is to make whatever you are turning "lock up" against the spindle, so that it will register in exactly the same position every single time you chuck it.

The problem with wooden threads is, that over time, the wooden thread will wear out and become loose, and you lose the ability to lock against the spindle for reliable balance and true turning on center. This is why I like to use a metal nut as an insert ... it won't wear out like that, but it's a little more expensive.

 

[KenV]

Tony. -- the current insert list from Teknatool does not list the 1 1/4 - 8 LH threads any more. Have a turning mate who has the double threaded insert from a number of years ago, so there may be hope of a second hand one.

 

[edstreet]

sure that's not 1 1/4" - 7 TPI LH??

 

[dogcatcher]

I found my left hand taps on eBay and at Victor Machinery. No such luck on Victor Machine, here is there list of LH taps. Left Hand Taps - Inch Sizes - High Speed Steel.

eBay only has one listed, at $49.95 1 1 8 x 8 Left Hand Plug H3 N C H s L H Tap 930 300 4c | eBay

 

[TonyW]

My thanks for these replies. Unfortunately such as the tap Dogcatcher gave the link for works out a bit expensive by the time it arrives here as I have 20% sales tax and even a £10 collection fee to pay, so I will try using the actual spindle to form a thread and then reinforce it with CA as Skie_M suggests. If that fails I can use cheap faceplate rings I suppose.

My thanks again.

Tony.

 

[Skie_M]

Just remember to lock the spindle in position while you force the thread on...

If your lathe doesn't have a spindle lock feature, put a chuck on the other side and clamp a piece of mild steel or hardwood in it long enough to bind against the lathe bed... like a lathe dog.