How To Start Die Cut Threads Square To Rod

Thanks for all the help, for the record this is a homebuilt plane, being built per plans, and the design has been flying since 1933 or so. No attempts to deceive or cut corners, just doing what the print calls for. As it happens I am an FAA certificated Airframe & Powerplant mechanic, Private Pilot, and my degree is in Aerospace Engineering, so I'm not going into this blindly. I agree that from a purely mechanical standpoint, rolled threads are superior, that's why this part with cut threads has such generous factors of safety, and redundant wires, each of which is capable of handling the flight loads if the other fails.

But I digress, I was actually posting to update my progress. I ended up buying one of those Irwin die handles with the guide 'chuck' on it, and as reported, it's sloppy at best . What did work, was to remove the scroll portion of the die handle chuck, mount the die, then thread a longer 10-32 bolt into the die. The chuck fingers were then brought into contact with the bolt and snugged into place with the screws that came with the handle. I screwed the bolt out, then slid it over the rod to be threaded and started cutting. I've done 4 so far and every one has been straight to the best of my ability to measure.

I do appreciate the advice, and although my parts are a special case, I hope this method might help someone else who needs to cut threads straight without a lathe. The die handle was $19 at the local hardware store, so I figured I wouldn't be out much if I couldn't make it work, but luckily it worked out.

Patrick

P.S. Here is a pic of the finished brace wire in place. Can't see the threads, but trust me, they're in there and look good.

Piet tail wire fitting 1.jpg Piet tail pic 1.jpg
 
Ultimately, the pic above is what I ended up with functionally. If I had access to a lathe to make the proper guided tap handle though, I probably could have just single pointed the threads in the first place. All's well that ends well though, and I finally got decent threads cut.

Patrick
 
Never meant to imply nothing, seeing your background you should know wot you doing. You hear 'aircraft' and you think critical.

Nice work.
 
Hey! That dang contraption is made out of wood! Who cares about a couple of weak threads!
Nice work though.
So what are the rules about homemade parts on aircraft. If one is building a home built experimental aircraft I assume you can make your own parts? How does that work? A while back I made a few non-critical parts for an Aeronica.
Robert
 
Not that aircraft stuff shouldn't be done with care, it sure makes sense to follow best practices. Homebuilts are unique, in the U.S. they have to have a one time sign off by a FAA rep, then condition inspections once a year by the original builder or a licensed mechanic. Aside from that, anyone can do the actual build or repair work, and parts can come from anywhere if they can do the job. Auto parts, home fabbed, or factory parts can all work. Lots of freedom, which is as it should be if you ask me.

Patrick
 
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