Business and markets > Wanted

Acme thread tap

(1/4) > >>

HaroldCR - AKA Fla.-Deadheader:

 Needing to make gearbox gears. Saw youtube about using normal bolt thread tap, but, want acme threads if possible.  Gear to be 3.5" dia. or so. Will be used for up/down of new sawmill carriage I am about to start on.

Ox:
Are you asking where to get one?

A quick search and I see they're easily available.  A 1/2" was around $50.  Most look like a double thread on the same tap - first it's cut in the traditional beveled threads, then the square shoulder of the acme thread is cut, all on the same, quite long, tap.

HaroldCR - AKA Fla.-Deadheader:
Hoping to find a GOOD used one, not Chinese crap. Something from a machinist estate sale, possibly. I would like a 5/8" one. I have searched most places I could find, online. Most are either over $100.00 or Chinese.

 I have found youtube vids showing how to machine one, but, I need to tighten up the slight sloppiness of my homemade metal lathe and also my sloppiness of the brain, to figure out the math.  ::)

bandmiller2:
Most areas have used machinery dealers, probably your best hope. Gears are mostly a standard item, company like Boston gear or Mc Master Carr may have them. I have repaired non critical gears with missing teeth by drill, tap in set screws weld and grind to shape.  Frank C.

joasis:
The problem with ACME thread profiles is the nature of the thread, i.e., it is 28 degrees total, 14 each side, and a tap will be probably dead on, and your hand ground threading tool, unless you use an insert, will be ground to fit a gauge, and then remember, it has a "thickness" of the thread, top and bottom.

ACME is a profile typically used for applications where the thread form has a maximum exposure...meaning a lot of material to ride on, and the fit will be class 1 typically.  Used for obviously, jack screws, and bar clamp screws...stiff like that.

If you need to place a gear on the end, the obvious answer is to use 2 ACME nuts, either side of the gear, and drill a set screw in as well, or cut the diameter down to say 1/2 inch, and then use a key and set screw to hold the gear if space is an issue.

Just as an added thought,  most ACME taps I have ever seen are two or even three tap sets...starting, mid, and final cleanup. Dies are the same way.

Hope this helps.....I am a machinist. Or was in a past life.  ;)

Navigation

[0] Message Index

[#] Next page