Threaded holes.

[cmmspm]

Hello again,

Yes it's me again. I think maybe I'll change my forum name to "Novice".
Anyway...

We have some parts with quite a few threaded holes, and some feel that threading each hole with a plug is really not an option. Does anyone know of a way to check a threaded hole w/out having to use threaded plugs in the holes.

Thanks again,
John

[\v/inston]

yes you can enter the pitch of the thread when you use auto circle.

[#2#]

Hello again,

Yes it's me again. I think maybe I'll change my forum name to "Novice".
Anyway...

We have some parts with quite a few threaded holes, and some feel that threading each hole with a plug is really not an option. Does anyone know of a way to check a threaded hole w/out having to use threaded plugs in the holes.

Thanks again,
John

Are you wanting to check the location of the threaded hole? If so, yes, what \v/inston said. Let us know if you need more instruction.

Are you wanting to check the size of the threads? If so, no, you need to use a thread plug in each hole.

[cmmspm]

Yes Goodluck, the locations from hole-to-hole. I could had been a bit clearer on that I guess

I really could use some more intruction if you wouldn't mind.

Thanks,
John

[#2#]

Yes Goodluck, the locations from hole-to-hole. I could had been a bit clearer on that I guess

I really could use some more intruction if you wouldn't mind.

Thanks,
John

You want to measure your holes using autocircles. If you open up the auto circle window you can input xyz locations for the holes. You will need to also input the depth at which you want them measured, the vector of the holes, the diameter of the holes, the number of hits, the start and end angles. I usually do 2 full circles (0- 720º) with 22 hits - I'm in no hurry. Down below the start/end angle info is a box marked pitch. In here you input the thread pitch. For all english threads enter the value of 1/threads per inch. So, if you have 1/4-20 holes input .05. For all metric threads enter the value (convert to inches if necessary) of the second number in the thread discription. For M20 X 1.5 you would enter 1.5 if your program is in metric or .059055118... if your program is in inches.

This will cause the probe to spiral as it moves around the hole so that it hits the same point of the thread all the way around. Of course, there is no way to assure that the probe will touch on the crest of the thread so diameter data from this method is useless (hope you don't have MMC applied). If you do you will have to measure the diameter by another method.

I usually run slow and double check to ensure that the probe is moving in the correct direction (out of the hole if moving in a counterclockwise rotation and a right hand thread) as I have had a little trouble with it. If it moves wrong I usually make the pitch negative and that fixes the problem.

[VADER]

Auto features

Auto circle

Location X, Y, Z

Number of hits

Check I.D.

Enter minor dia. for hole size

Enter pitch

[\v/inston]

can you post the thread size?

example: M16 x 1.5

if you have a metric thread like the above example then you would enter 1.5 for the pitch in the properties box for an auto circle. adjust your depth accordingly.

the probe will spiral up the thread at the said pitch.

finding the pitch for and american thread it a little more complicated.

EDIT: WGLS - ima little L8

[cmmspm]

can you post the thread size?

example: M16 x 1.5

if you have a metric thread like the above example then you would enter 1.5 for the pitch in the properties box for an auto circle. adjust your depth accordingly.

the probe will spiral up the thread at the said pitch.

finding the pitch for and american thread it a little more complicated.

EDIT: WGLS - ima little L8

There are actually several thread sizes in this part.

I will list them:
10-32
6-32
8-32
4-40

[cmmspm]

Apparently I am, also, Winston. lol

Thanks guys, I will give it a shot.

5 mins 'til noon. almost Miller time.

Have a great weekend guys and gals.

[#2#]

10-32 enter .03125
6-32 enter .03125
8-32 enter .03125
4-40 enter .025

[VONDY]

To find the pitch value of a inch thread it is 1/the number of threads per inch.
Exp. 1/4-20 UNC-2B = 1/20=.050 pitch

[cmmspm]

Thank you all for letting me pick your brain.
I got it to work for me.
Goodluck, you suggested that I run it slow. How slow is slow? What is the best depth to be checking a hole at?
And finally, if your checking a hole location that is threaded for a Heli-Coil, it's the same equation to get the pitch I would assume. You would just have to use the minor diameter of the thread for a Heli-Coiled thread? Or would the Heli-Coil have to be put in to check it?
Thanks,
John

[#2#]

I just run it slow the first time through in order to ensure that the probe is spiraling in the correct direction. After that I run "normal" speed. Sometimes for very small pitch values it is hard to tell if it is spiraling at all. If this is the case I just enter a bogus pitch value of .1 temporarily. Then, you can see it move and after seeing that it is moving in the correct direction I go back and change (cursor on the feature and F9) it to the actual pitch. One day I may trust it enough to not have to do the visual check but not yet.

I usually check at a depth at .15 or .10 but it depends on the overall depth of the hole, probe size, thread pitch, whether there is a lead in angle, etc.

You should be able to check the thread for a heli-coil and the pitch would be the same equation. Yes, you would need to use the minor diameter of the heli-coil thread.