Thread Dial Indicator positions

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Thread Dial Indicator positions

This topic has 38 replies, 14 voices, and was last updated 8 June 2012 at 13:48 by Clive Hartland.

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30 May 2012 at 09:37 #91800
Stuart Davies 3
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@stuartdavies3
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
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30 May 2012 at 09:37 #22113
Stuart Davies 3
Participant
@stuartdavies3
30 May 2012 at 09:50 #91802
mick
Participant
@mick65121
You can engage on any whole number, the half divisions are for threads with say sixteen and a half TPI
30 May 2012 at 10:08 #91804
Nobby
Participant
@nobby
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
30 May 2012 at 10:50 #91807
Russell Eberhardt
Participant
@russelleberhardt48058
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.
30 May 2012 at 21:36 #91822
Stuart Davies 3
Participant
@stuartdavies3
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.
30 May 2012 at 22:03 #91825
Nobby
Participant
@nobby
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
1 June 2012 at 00:23 #91868
Terry Lane
Participant
@terrylane
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
1 June 2012 at 11:10 #91879
Nobby
Participant
@nobby
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
1 June 2012 at 11:14 #91881
Nobby
Participant
@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
1 June 2012 at 14:48 #91887
John McNamara
Participant
@johnmcnamara74883
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
1 June 2012 at 15:45 #91888
Nobby
Participant
@nobby
Hi

My spelling is awful enit . John Swan rings a bell ?
Nobby
1 June 2012 at 22:45 #91933
Terry Lane
Participant
@terrylane
Good try Nobby, but it's not one of 'those' – tho I have made 'em in the past.
2 June 2012 at 10:41 #91951
Nobby
Participant
@nobby
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
2 June 2012 at 13:33 #91964
Terry Lane
Participant
@terrylane
Nope, it's a full, unmodified commercial 1/2" BSW nut on a screwcut thread that stops short of either end of the bar.
2 June 2012 at 20:49 #91981
Sub Mandrel
Participant
@submandrel
Ho ho, I see what you are suggesting Nobby

Let us in on the secret Tel!

Neil
2 June 2012 at 20:59 #91984
Jens Eirik Skogstad 1
Participant
@jenseirikskogstad1
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?
2 June 2012 at 20:59 #91985
Les Jones 1
Participant
@lesjones1
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.
2 June 2012 at 22:14 #91992
Nobby
Participant
@nobby
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
2 June 2012 at 22:30 #91994
Terry Lane
Participant
@terrylane
I went a bit mad when I first made the swing up tool holder!

The 'secret' is a variation of this

**LINK**
2 June 2012 at 22:48 #91995
Nobby
Participant
@nobby
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
3 June 2012 at 22:26 #92043
Terry Lane
Participant
@terrylane
Yep, it is a thread in a thread, so to speak – I actually used short bits of cut off screws – drilled and tapped the body pieces, screwed 'em together quite tightly, screwcut, took them apart, fitted nut and reassembled, again quite tightly, until the thread lined up again.

Now for some odd reason the pics of the tool and the close-up of the 1/2" version seem to have disappeared?????

Edited By Tel on 03/06/2012 22:29:19
4 June 2012 at 04:16 #92052
Terry Lane
Participant
@terrylane
… and now they are back! All very spooky!
4 June 2012 at 13:12 #92070
Nobby
Participant
@nobby
Hi Tel
Looking at your lift up tool holder. would some sort of handle on it help to lift it at the end of a cut ?
if you were close to the chuck .
With the photos I have a job seperaating them if i put 2 on. I think that they were edited .
When I used to program milling M/Hs with the heidenhain controler you could progam a lable in a lable
Soory drifting away from the thread
Nobby
5 June 2012 at 00:11 #92077
Terry Lane
Participant
@terrylane
No lifting involved mate, the tool lifts of its own accord and rides back to the start position when you reverse the lathe motor. The only time you need to lift it clear is to inspect the work.

John documented his build pretty comprhensively here – **LINK** it's pretty long, but go right through it – well worth the read
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