Thread Dial Indicator positions

Hi all,

Does anyone know if there is a thread dial indicator position chart somewhere for downloading? tired of waiting for '1' to come around all the time.

many thanks

You can engage on any whole number, the half divisions are for threads with say sixteen and a half TPI

Hi Stuart
Micks correct also another trick is to leave the half nut closed . withdraw tool after reaching the end of thread you want to cut & reverse the lathes back to start postion until the thread is finished . Handy when cutting metric on an imperial lathe
Nobby

Assuming you have a lathe with an *8 tpi leadscrew and a 16 tooth pinion on the indicator, the indicator is likely to be marked with four numbered lines and possibly an intermediate division between each whole number. For any even numbered pitch you can engage on any whole number. For odd numbered pitches engage on opposide numbers, ie., 1 and 3 or 2 and 4. If you are cutting a threadwith half pitches such as 12.5 tpi you must always engage on the same number.

The half divisions can be used be used if the pitch is divisible by four but I rarely (never?) bother with them.

Hope that helps.

Russell.

Thanks folks, I have made a small table and put it above the lathe for reference. It is a Raglan 5" and the leadscrew is 8tpi and the dial cog has 16 teeth so i'm sure the comments above will apply. The indicator has 4 main positions (although 0deg and 180deg are confusingly stamped 1 and 2), and 4 half positions. The halfnuts can be engaged inbetween these divisions also, giving 16 positions in total that the halfnuts can be engaged, although i'll think i'll stick to the 8marked positions.

Hi Stuart & Guys
If in any doubt close on the same No each time.
You may have seen my dog clutch on this forum . It lets the gear train to be in constant mesh Similar to the Exe lathe I used to have . Its fitted to my flat bed drummond I have refined it now with a lever it works fine
Nobby

Or you could build John (Bogstandard) Moore's ingenius swing up toolholder and forget about disengaging OR winding the tool back.

Here's my version

Hi Tel
What a brilliant bit of kit . I will have a go at making one of these. It would make this a lot easyer

Nobby

Hi Guys
As anybody sussed out Tels last picture yet. Due to elf a saftey I cant say whay us kids done with somethin like this?

Nobby

Hi Nobby

Its not a very big one..... When the Elves weren't watching and when I was a kid there was a concrete practise cricket pitch in the middle of the school oval. when we made em we left the heads on the bolts. Can you still buy matches !!

Cheers

John

Edited By John McNamara on 01/06/2012 14:49:40

Hi

My spelling is awful enit . John Swan rings a bell ?
Nobby

Good try Nobby, but it's not one of 'those' - tho I have made 'em in the past.

Hi Tel
This thread is about closing half nuts etc . Could it be a half nut ? I'm of down the shed to do a bit of turning
Nobby

Nope, it's a full, unmodified commercial 1/2" BSW nut on a screwcut thread that stops short of either end of the bar.

Ho ho, I see what you are suggesting Nobby

Let us in on the secret Tel!

Neil

Tel, i can think the first bar was treaded and the nut was screwed into. Then the second bar was fastened to the first bar and treaded on the rest of the second bar. All work done on the lathe. Right?

Hi All,
I suspect that the right hand end is a piece of brass bar tapped and screwed onto the thread which goes all the way to the right hand end of the left hand piece. I think it was then turned down until its diameter is just larger than the crest diameter of the thread.

Les.

Hi Les & Guys
Les did you put lock tight on the the small thread on the R/H diameter before screwing it on ?
Just fihing ?
Nobby

I went a bit mad when I first made the swing up tool holder!

The 'secret' is a variation of this

**LINK**

Hi Les
Thank you for posting a link. Would this be a thread in a thread ? I may have a puzzle for you ?
Enjoy your srewcutting .
Today I have just been crescoating my shed/ workshop
Nobby