Need to buy or make 4-40 control rods 3 5/8" long threaded on both ends. Scoured the online vendors and found nothing. Anyone know a source for off the shelf premade sizes ? Not in love with the "all thread" look but will use if only option. Thanks</p>

Suggest you go to a Sears and purchase bare welding rod(s) of a size 3/16" that fits the size of threads needed and cut to length and thread the ends.

This is a cool place to get mechanical stuff: http://www.servocity.com/html/threaded_rod.html

You can get CF tubes that just fit over 4-40 threads. then you put a 4-40 locking nut on both ends leaving 3/4" thread on the ends. I've done this and it works well, but I like to put a "Z" bend on one end and a clevis on the other.

I make my rods using all thread but I add an aluminum sleeve over the thread all that the ends screws up to. This will give the control rod good strength in the compression direction.
This will work with clevis ends or ball liks in 2-25 or 4-40. I prefer to use ball links. (see atatched pic of the elevator linkage on my 1/3 Cub.
Later!!
Anthony

http://www3.towerhobbies.com/cgi-bin...TURNBUCKLES+++

https://www.lunsfordracing.com/

Also,
I've order here a few times,, expect about 10days for delivery
these will work with 4-40 plastic ball links and clevis,, will not work with 4-40 metal hardware http://www.sdshobby.net/hexagon-stai...em-p-5330.html

That looks vry sharp, Anthony. I am going to copy your technique!

Thanks Skip,
It makes for a very strong slop free linkage.
Anthony

I just made up my control rods but was going to buy some carbon fiber rods to slip over my 4-40s. I just happen to have several tubes full of aluminum tubing so I will see if I have any with the 4-40 ID and give it a shot. Never once have I given that a thought. Cool!!!

Thanks fellas for all the immediate responses. I am new to this forum and very impressed with the results thus far. My control rod issues are clearly resolved.

Another option that works very well is these.

[link]http://centralhobbies.com/control_linkage/pushrod3.htm[/link]

I use them on pretty much all of my birds up to 35% ers.

Central Hobbies makes some nice pushrod sets. Carbon rods with Titanium ends. The carbon rod is cut to length and then you JB Weld the ends on. I have a few sets on a couple of my planes and they have worked perfect.

http://www.centralhobbies.com/contro...e/pushrod.html

SunDevilPilot

Good thinking Aussie!

I must have been typing my post while you posted yours...

I guess that is two votes.

SunDevilPilot

Great minds think alike Sundevil

Since I discovered the Central Hobbies units a long time ago, I have not used much else. They just work well, look good are very light and are very strong. I did a "strength test" on a 3mm one a couple of years ago and stopped when I got to it holding up over 50kg as I don't have any servos in my planes anywhere near that power. The trick I have fouind with them is to use JB weld (as suggested by Centrals) and to make sure the rod is clean internally (I use a pipe cleaner and some Industrial alcohol).

GB,
Let me know what you think. The beauty of the aluminum tubes are you can cut them to length with an x-acto knife. I cut them just oversized then sand them to length to get a perfect fit. Also if you are using ball link ends the aluminum will compress into the ball link when tightening for a solid fit.
Later!!
Anthony

I've used heat shrink tubing to disguise the all thread too,, very quick, easy and cheap

Scale,

At least in larger planes, the issue is not what all-thread looks like - in longer lengths the all thread isn't ridgid enough in compression. The aluminum tube and CF tube methods mentioned above solve that issue. The turnbuckles work very well also.

Greg

I didn't have any of the correct size on hand. There will be a road trip sometime in the next weel so I may be able to pick some up. I have some really big controls on my new plane and just 4-40 rod makes me wonder/worry.

I am using these rods on a 33% Cub and 33% Waco with a 3W-157 engine. They seem to be more then up to the task.
Later!
Anthony

And again, thanks everyone.  Leaning toward the aluminum tube sleeve with ball link ends.  dw

Well where there is a will their there is a way. Standard 4-40 threaded rods, cut to length, build up the end that has to be threaded with silver or any solder and thread, Hey if tinned right it will hold

A lot depends on the type of plane. Anthony could use cooked pasta on his cub and get away with it. I have bent 4-40 all thread with 60 size stunt planes. There is a lot of material removed from all thread and it tends to bend very easily. Having ends hold is never a big problem.

These are the quickest adjusting rods on the planet, no wonder they are out of stock
right now. I have bought many for my planes.

Cheers
Tim

http://www.troybuiltmodels.com/items/HAN3555.html

+ 1
If using the "tube over the threaded rod" method, it is a good idea to glue the tube over the rod once you have got the lengths right. Way back when I used that method (I used Carbon tube) I used to mask the thread I wanted to keep and coat the rod with epoxy then slip the tube over the rod. Another guy I know uses CA and trickles it into the tube.

If Using the "Cooked Pasta" method - Capellini is ok for 2-56, Vermicelloni is best for 4-40 and Bucatini is best for light weight applications (Maybe an F3A plane)

[link=http://www.math.psu.edu/belmonte/spaghetti.html]Dynamic buckling of thin rods [/link]

If your model is smallish and doesn't produce much vibration, the all thread will work. The ally tubing needs to have a good wall so that it can be tapped

But beware if it's engine powered.....all-thread is typically not made from better steel and will fatigue relatively fast. I made the mistake once 25 years ago give or take. Never again. And aircraft grade ally tube should be used not the cheap tubing from the LHS

The better solution by far is Aussiesteve's recommendation or make your own with carbon tubing and higher quality steel bolts with the heads cut