CAN'T INPUT A THREAD LENGTH

[Jan.vanderlinden]

Why can I not input a thread length?
It stays grayed out.

[martin54]

I would need to watch the thread milling tutorial again but I think the thread length is determined from other options like the tool being used & tyhe max depth I've never tried to alter it myself, just went with what ever value it was from the max depth I set

[Tailmaker]

It has to do with the fact that the software only calculates increments of half thread loops.

If you choose top-to-bottom, the thread start will be right at the surface with a flat loop making a nice chamfer and then go down in the mentioned half-circle increments so that you don't exceed the max depth. The milling direction will be "climb" for a right hand external thread.

If you choose bottom-to-top, you have more flexibility in the thread length, since it is max depth minus a certain offset (not sure how that is calculated). However, the software will not generate a start chamfer on top (in the current version) and the milling direction is "conventional" for right hand external threads.

[kstrauss]

I believe that the maximum thread length is calculated as:
L = M - O - P/2
where M is the max depth specified in Cutting Depths, O is the tooth offset defined in the tool database and P is the thread pitch in your Thread Definition.

[DJ-Bino]

Why can I not input a thread length?
It stays grayed out.
THREAD CUTTING.JPG

Hello,
when I look at your picture I immediately notice
that you specify a maximum depth of 3 ".

But entered 8 "at pitch below. I think
that was not a good idea.

If you use real values then the thread length will be displayed correctly.

[Jan.vanderlinden]

What I'm trying to do is make a 1" X 8TPI thread.
This is a standard UNC thread.
The only thing it will not allow me to do is specify the thread length.

[Jan.vanderlinden]

Sorry all.
Now I see what I did wrong.
An 8" pitch relates to .125" between threads.
Amazing what a second cup of coffee does...