Thinkin about a BIG FRIQUIN TAP>>>>

[spunky1974]

Why I love the US patent service .....just when I'm bored. I go there and find new projects. Anywho, I was wanting to tap a 3 inch diameter by 6 foot pipe internally and didn't have a clue what to do. So, I'm gonna make a huge FRIQUIN TAP to do it and thanks to USPO for the design....LOL

LARGEADJUSTABLETAP.pdf

[Geof]

Originally Posted by spunky1974 Why I love the US patent service .....

I agree you do have to love the US PTO. Especially when they entertain an application for something that was designed probably close to seventy years ago. Replaceable chaser taps were a standard way of cutting internal threads on big turret lathes. Have these clowns never heard of "Prior Art"?

If you plan on driving a 3" dia. tap in steel you are going to need a humongous amount of torque.

[HuFlungDung]

What prevents you from taking it to a machine shop and have the thread cut with a lathe?

[spunky1974]

Well the reason for not taking to a shop for lathe work is I wanna do it onsite for the application ......784 feet up on a solid granite mountain.....hehe. Also, I have to keep in shape so twisting this badboy oughta do it....lol

[Geof]

Originally Posted by spunky1974 ... I wanna do it onsite for the application ......

Have you searched for manual threading/tapping equipment for large pipes? I seem to recall seeing a rig one time that had a type of reduction drive operated by a ratchet lever. Everything clamped onto the end of the pipe and then as you worked the short ratchet lever it slowly (very slowly!) turned the threading head. The advantage was you did not have to clamp the pipe down immensely firm because the mechanism was mounted on the pipe and you did not need a thirty feet long lever to get enough torque.

[Kevin Taylor]

I was thinking of thred milling til you said on a side of a mountain Good luck Kevin

[RICHARD ZASTROW]

spunky1974, Here's a long shot. Climax makes portable machines for on-site applications. One of their machines can bore and I hope might do internal threads etc. They also rent their equipment. I'll see if I can get more info for you.

try this www.cpmt.com


DZASTR

[spunky1974]

Thanks guys for all the help ......I already finished the project ....I'll post pics here when I go back up the mountain and take some.....