Need Help!- Thread Milling a Taper

[automizer]

I am looking to make some manifolds that require a few different NPT threads. ( 1/4, 3/8, 1/2, 1-1/4) I have no problems with NPS but I can't figure out how to mill out a tapered thread. As well I have not looked yet but I do not know the degree of taper for a npt thread. I will be running this threw a Haas control, any suggestions would be appreciated.

[ProProcess]

I believe the taper is 1.78333Degrees from center.
Here is a link to Harvey Tool's site that has the tool you need...

http://www.harveytool.com/products/p...keyword=thread

Scroll to the bottom.
I've used them and they work well.
Good Luck.

[chrisryn]

A npt thread taper according to the machinist handbook is .75" per foot. Depending on which tool you use it should come with software that will generate the code you need.

[ProProcess]

The .75" per Foot is a diametric designation
i.e. the diameter is tapered .75" per 12." of length.
Which in turn work out to be around 1.789 from center.

[chrisryn]

Alot depends on the cutter I thread mill ALOT of pipe threads NPS and NPT. I have a 4"-8 NPT that I use a single point thread mill on it has a special G code that it runs so that it can spiral down to make the taper. I then have a 1.5-11.5 NPT that uses same path as my 1.5-11.5 NPS we just change out the multi tooth insert because the insert has the taper angle on it. There is alot of factors to look at to awnser your question.

[neilw20]

Do on a 4th axis rotary table (if you have one) tilted to the desired angle.
If you have a tiltable head like my SX3 then you can cheat with the helix angle too. Then just use a lathe insert to do the cutting.

[automizer]

Ok so this will not be a simple as I had hoped. I have no 4th axis so that ones out, I'm coding by hand so software is out. A macro maybe?
ProProcess I like those tools that maybe the route I need to go, I have a single point threading tool and I was hopping to use it.

[chrisryn]

I have a threadmilling macro laying around some where let me find it and I'll send it to you.

[Kiwi]

automizer
Attached is a program I have written. This may help.

[dcoupar]

Try this: http://www.vargus.com/vardex/templat....aspx?pCatId=9

[dertsap]

download a demo of machinist toolbox
it has simple cnc functions

[automizer]

Well Now I have some options to try
dertsap I downloaded the demo of machinist toolbox a long time ago and have not touched it maybe I should dig it out.
dcoupar Have you used this software?
Kiwi that is a cool program, what made you write it?
chrisryn if you could find that I would love to play around with it.