Using the Thread indicator

[Sammo]

I have a Warco 1236 and it has a thread indicator but I have no reference as to what the numbers represent. Except for the fact I know that I have to use the same number for consecutive cuts after the first. Until the material is removed from the chuck.

For example do I use a small number for fine threads or metric, or Imperial etc

Does anyone know what the individual numbers refer to which are 1 to 8 ?

 

[Grumpy Gator]

Sam, OK the simple answer. On this side of the pond when you single point thread :
For even number of threads you start on any even number.
For odd number of threads you start on any odd number.
***********Just Saying **********Gator****************

 

[darkzero]

Also if your lathe has a metric leadscrew the threading dial would only be used for metric threads & vise versa...so imperial leadscrew, dial is only for imperal threads. It can't be used for both, well there's an exception.

 

[Hawkeye]

If you haven't yet clicked on Darkzero's 'exception', I suggest you take the time to watch the video he links to. I've been using that method even with imperial threads, just to get used to following that technique. Definitely worth learning.

 

[benmychree]

I can't speak for lathes that are in the hobby category or machines with metric screws, but the numbers on the thread dials of industrial machines mark one inch distances traveled; if you have the spindle stationary and crank the carriage along one number and measure it you will see that this true. On these machines, the rule is odd threads, any number, even threads any number or line, half threads, opposite numbers, quarter threads one number only; if the thread is a factor of the lead screw, close anywhere i.e. if the lead screw is 4 tpi the half nuts can be closed for 4,8,16,32 tpi, etc.

 

[Sammo]

Thanks folks for your help with this one.
Much appreciated.
Sam

 

[lotechman]

I imagine that the thread dial is an indicator that locates an imaginary ruler that is travelling along the bed of the lathe. You decide if you want to start the thread on the one inch ruler mark or the two inch ruler mark. If you are cutting 11 threads per inch and decide that to save time you will also pickup on the half inch mark you will engage 5.5 threads into your work and RUIN it. For 12 tpi if you pickup on the half inch mark you will engage on the sixth thread so everything will cut as before.

 

[larry2c]

Maybe it's just me but I think there needs to be some clarification on this topic, here's a couple of pictures

This is a thread dial and is used to tell you when to engage the half nut lever when threading so your thread's only have one starting point.


This is a Trav a Dial and it is a device that lets you know precisely how far your carriage has moved

 

[darkzero]

Maybe it's just me but I think there needs to be some clarification on this topic

What kind of clarification were you looking for? Yes we have all been talking about threading dials not trav-a-dials

 

[lotechman]

If you want to experiment place a steel rule on the bed of your lathe then watch how much the carriage moves as you crank the handle and compare it to the thread dial. Each whole number is one inch of travel. If you had a trav a dial on your lathe you could compare without the use of a ruler. This obviously is all done with the lathe motor off.
The thread dial is really a travelling ruler that keeps track of the thread you are cutting. When I would explain this to students I could see the lights go on and they understood. No need to memorize which marks will work for which thread. It is quite obvious when you understand the principle.