How To Start Die Cut Threads Square To Rod

Thanks for the replies so far. I have a good quality die, and the threads look good. No tearing or galling using Tap-Magic, so that part is ok. The finished part is bracing wires for a homebuilt airplane tail, so I need a known quantity for material specs, and the main length really can't be allthread for a variety of reasons. Factory produced flying wires run about $3000 for a set, so that's why the desire to manufacture my own. The rod is precision 3/16" 17-4 PH so it machines pretty well. Worse comes to worse I can hire the threading out, but wanted to try at home first. I've got enough raw material to make quite a few tries at it and still come out ahead, so I might just try one of the guides die holders. Thanks again,

Patrick
 
Another vote for using a small square against the material. If the part is upright in the vise, rotate it every few threads to average out human error.
 
A split die, screwed opened fully, a bevel ground on the end of rod. A piece of wood about 3" thick and about a foot long with a 3/16"hole drilled in the middle. Push rod through hole and fix die holder to wood, after centering die over rod and turn wood or rod (drill)?. When done, adjust die and finish. Have done 6' of 1/4 rod like this and it works very well for me.
John.
 
psween said:
Thanks for the replies so far. I have a good quality die, and the threads look good. No tearing or galling using Tap-Magic, so that part is ok. The finished part is bracing wires for a homebuilt airplane tail, so I need a known quantity for material specs, and the main length really can't be allthread for a variety of reasons. Factory produced flying wires run about $3000 for a set, so that's why the desire to manufacture my own. The rod is precision 3/16" 17-4 PH so it machines pretty well. Worse comes to worse I can hire the threading out, but wanted to try at home first. I've got enough raw material to make quite a few tries at it and still come out ahead, so I might just try one of the guides die holders. Thanks again,

Patrick
Click to expand...

Aircraft parts ?

Why is it that no one ever puts that in the first post ?

Perhaps the originals are roll threaded instead of cut so they have lower chance of separation at the thread root
 
I have that Irwin, self aligning die holder Mikey posted about. It's a bit quirky but it does work.
For doing a run of those, I would make a jig that attaches to the die holder, bored out to the rod diameter and held centered and square to the die.
That being said, I agree with Steve 626 the threads might need to be be roll formed, you don't want the thread to snap at 5000' above the earth...
 
Could you drill a hole in a block of wood that fits tight to the rod. Maybe 4" -5"long or so x 2"x 2". Then screw a 1"x 2" the length of the tap handle. Kind of like a propeller looking jig. Clamp the tap handle with fencing nails or hose clamps to the 1x2 centred on the hole. Then slip the hole assembly over the rod. The tap handle could be moved either way before you tighten it up.This will help keep everything square. Kind of red neckish but if you use hardwood it should work. Not sure how many you need to do. Lathe would be best like others have said.
Cheers
MartinW
 
Disregard my post above. I thought it was a model airplane:eek 2:. I think they are $3000 a set for a reason.
Martin W
 
Cut threads are full of "stress risers" and this is a stress critical part that upon failure does what?

We never have had any issues threading but we never do more than a turn before backing up to break the chips.

Lots of oil if needed then very slow and they come out "fine"

But for aircraft things are much different.

You need to confirm how part is engineered and how threads are specified.

Next you need to be able to certify the part meaning to properly test it to be certian it is up to the task.

Side note: this thread is a "discoverable document available to the public" which means that if said part fails and someone looks they can discover a home made not certified part was used...



Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 
If your BUTT is relying on that part to keep you up in the air I would get approved part ,
or make one that exceeded Oem strength for its purpose , and have them tested
Are you building a plane or has the original part failed , and why ?.
If it is a critical part , don't skimp on it.
 
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