Steve Guinn

I am a proficient solderer, but decided to purchase a 4-40 die and thread the unthreaded end of my control rods.

I carefully cut the threads after ensuring the original threads fit the die.

HORRORS...the gold-n-clevises pull right off of my lovingly crafted threads.

What's up with that?

Mustang Man-RCU

Steve,
I think the wire diameter where the rod is already threaded is a thou. or so larger than the remainder of the wire. If you have a micrometer you can check it. You will probably have to buy a slightly larger wire.
Steve

Steve Guinn

Thanks steve,

makes sense to me. Could not figure it out.

Time for plan B.

Steve

MHawker

My Feedback: (16)

I heard the same thing about this at our last club meeting. A guy stood up and said that the threads on the rods are "rolled" meaning (I guess) they are not cut into, but added onto the rod.

Therefore, when you cut with the die, you were taking away material when normally it's added (?).... Make any sense??

Mike

tailskid

My Feedback: (34)

I think there is a company (Rod 'N Chuck) that has just what you are looking for - a cheap way to make those 4-40 rods....

Jerry

dant-RCU

My Feedback: (3)

I have been using the Rodchuck system for over 4 years and it works just fine. I make both 2-56 and 4-40 control rods to any length I desire.

Here is the link to their webpage: http://www.rodchuck.com/

Dan

Steve Guinn

Mike,

I believe if the threads were rolled, there would be no material added or removed. The threads would be raised from the pressure of the indents.

Did you marry that wonderful woman yet? Why aren't you on your honeymoon?


Jerry and Dan,

thanks for the Rodchuck info.

susquach

My Feedback: (1)

Steve,

you've pretty much got it nailed. The thread rolling process squishes material from the grooves and delivers it to the threads....resulting in an increased diameter in the threaded portion of the control rod.
Would be interested in the results of the rodchuck system. Some years ago I tried making 4-40 rods from 1/8" welding rod and 2-56 from 3/32" welding rod, using an adjustable die. The result was a wobbley-fitting joint. Never could get the diameter of the rod to fit R/C clevises. If the Rodchuck system produces a tight fitting joint, it must be a custom tool, not simply a matter of using a larger diameter wire than standard stock.
Have you tried bicycle spokes?

Steve Guinn

No, haven't tried spokes yet.

dant-RCU

My Feedback: (3)

ddubya:

Yes, the Rodchuck system does produce tight fitting joints. To make 4-40 threads on 1/8 welding rod, the Rodchuck makes a two-pass cut. First pass is a 5-40 die that sizes the 1/8 rod the proper 4-40 diameter. Second pass is with the 4-40 die which gives the final cut.

In the 4 years I have been using this system I have never had a threaded clevis end problem of any kind.

Dan

rogerswin

My Feedback: (2)

Check your die. If it is one of the quality types it will have an adjustment screw that allows you to open it as required so as to not remove any of the diam. while cutting the threads.

Roger

slapshot

My Feedback: (15)

Been using Rod Chuck system for 4+ years, works great.

John

susquach

My Feedback: (1)

O.K. Dan and slapshot,

you've got me interested. Just a couple more questions: What size planes are you flying and what kind of clevises are you using ( nylon or steel ... Dan mentioned 4-40, but If I remember correctly, Rodchuck offers 2-56 as well ) ?

slapshot

My Feedback: (15)

I fly everything from a speed 400 Twister to a 40% Pitts. I use Sullivan clevis' and both 4-40 and 2-56. Rod diameter for the 2-56 is the same as commercial threaded 4-40 rod.

Slapshot

dant-RCU

My Feedback: (3)

I fly everything from electrics through 1/4 scale and use both
2-56 and 4-40 rods. Normally I use a Hayes plastic locking clevis or a DuBro plastic locking clevis on 4-40 stuff and Sullivans on 2-56.

Yes, Rodchuck offers both 2-56 and 4-40. They have recently updated their die tool and holder. I have the older version which works quite well for me.

Dan

Ernie Misner

.............I am a proficient solderer, but decided to purchase a 4-40 die and thread the unthreaded end of my control rods..................

Does anyone know what the difference between control rod material and hard music wire is? Isn't music wire too hard to possibly thread with a die???

The package of Great Planes threaded control rods I picked up looks to have the threads cut rather than rolled, very nice job.

Ernie

dant-RCU

My Feedback: (3)

Ernie:

Music wire really doesn't thread well. The "Rodchuck" people say if you can file it you can cut threads on it and that rules out music wire. In fact, they specifically say you cannot cut threads on music wire.

I believe that in order to cut threads on music wire you have to anneal it first, then cut the threads, then harden it back (read that somewhere).

With the proper die setup, welding rods make excellent push-rods.

Dan

Ernie Misner

Thanks a bunch Dan. You are right on I now know. Before the morning was over, I read everything on the Rodchuck site. Yep, they say you have to aneal music wire.

I take it you are using the Rodchuck setup??? It's kind of pricey to get started, but sure does look nice.

Ernie

dant-RCU

My Feedback: (3)

Earnie:

Yes, I use the Rodchuck. Yes, it is a bit "pricey" on setup and you could probably work around this by just buying some good quality dies but their holder and handle assembly really makes cutting the threads very easy. Just chuck the whole thing in a vise and have at it.

Now, about being "pricey" - Yes, but if you are ever asked by anyone just remember -

A "Rodchuck" is an "official RC Hobby Tool" and as such the stated cost (price) is meaningless!

Dan

Ernie Misner

.............A "Rodchuck" is an "official RC Hobby Tool" and as such the stated cost (price) is meaningless..........................

It is good to know that I am "normal" then Dan...:-)

Now, about purchasing the dies that Rodchuck uses.... the first one sounded exotic? and the second one was a regular 4-40 die as I recall....???

Ernie

dant-RCU

My Feedback: (3)

Ernie:

Yes, you are "normal" insofar as this hobby goes.

The 5-40 die is not exotic but it is not found at every home improvement store. You can get one at most any place that caters to industrial types rather than "home improvement" types. I have seen them at some local tool stores and they can be ordered. Just be sure you get quality dies and not the "cheapies".

If you are going to get the dies and not the Rodchuck system then about the only thing that might be a little difficult or more time consuming is getting the threads started correctly on the rod. Remember, you will be making two passes for each end. If the first cut of threads (5-40 in the case of 4-40 rods) is not correct (canted, not concentric and perpendicular to the rod, etc) then the second pass is not going to be good either. The second pass (if correctly done) will cut (or re-cut) the 4-40 threads over the 5-40 threads.

Here is a tip. Since these are cut threads there is a stress point (or potential one) where the threads stop against the rod. You do not want to run a clevis or nut down onto the last thread. So, when you make the second cut, stop just short (4 or 5 threads) of the end of the 5-40 threads then you never have to worry about it. In fact, it is probably not a good idea to run a clevis or nut down to the last thread no matter how they were made.

As I said earlier, in over 4 years of using this system I have never had a rod/clevis fail.

Dan

susquach

My Feedback: (1)

This has been a really interesting discussion. Thanks guys for all the information. Dan, you are right-on with the obsevation that we need to be aware of what 's going on with stress and control rod stress/fatigue. I once lost a .60 size plane on it's first flight due to the elevator control rod failing at the location you mentioned. The rod was configured in a "Y" arrangement as specified by the kit maker. The clevis joined the rod about 3/8" ahead of the last thread and although not butted right to the last thread, the stress was transmitted to that point. That's the best I can make of it anyway. All this to reinforce your concern that we be aware of what's going on stresswise in our controls.
The tappering effect created but using two sizes of threads is important, in that it probubly deals with vibration/fatigue much better than an abrupt transition from threads to rod.