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Picture of Make an Acme Tap
In this article I will describe how I made myself an acme tap for tapping soft materials.

Step 1: Fabricate Guide Blocks

Picture of Fabricate Guide Blocks
The first item I made for this project was a pair of guide blocks to hold the threaded rod stock with. I made mine uniform, and square, then drilled holes out of the center of each. I used some phenolic cellulose material I had on hand, I am sure other materials are equally as suitable to use.
 
Snidely704489 months ago

An angle grinder might work to cut the grooves. They wear down pretty quickly, but I've never heard of one coming apart.

pfred2 (author)  Snidely704489 months ago

What wears down quickly and does not come apart? You can try to cut the gullets by hand, but I doubt you are going to get very even grinds that way. It is fairly critical that the tap be symmetrical in form in order to function properly in use.

mwoodworth22 years ago
Grinding on the side of a grinding wheel is really dangerous because it can cause the wheel to shatter and send shards everywhere.
pfred2 (author)  mwoodworth22 years ago
I've heard that. I've never seen it happen though. Perhaps it happens if a wheel is severely undercut? That I could see happening, so try to keep the wear even is the best advise I can give. That grinder has a shield on it so even if the wheel did break on it, which is not going to happen, it is not going to go all over the place. Some grinding wheels are even designed to be used on their flat faces. I have a couple of those. They are not a whole lot different than plain grinding wheels.
rimar20003 years ago
Interesting your device, pfred2. I have done some of these taps, but in a improvised way, with only one longitudinal channel. As the tap was used on wood, it worked. Never I tried to thread soft metals (alum, copper, etc) with it.
pfred2 (author)  rimar20003 years ago
I need mine to thread plastic but I am thinking about making another and trying to harden it.