Can i use threaded rod for pushrod application without any issue? I was told the rods are weaker because they are threaded all the way up the length of the rod. What do you guys think? Here is a link as an example

http://www3.towerhobbies.com/cgi-bin...?&I=LXFV06&P=0


There isnt any contact on wood. However it would be for a Showtime which is a pattern/3D plane. I am trying to make a control linkage so that I can use a clevise on once side and ball link on the servo end. Any suggestions?

I often make pushrods using threaded Rod. It is weaker because of the thread being cut into it but there are 2 ways that I use it.
For short rods (say a couple of inches long. I just use the rod itself - 4-40 as a minimum. For long rods, I epoxy a length of carbon fibre tube over it to increase the rigidity.

The above mentioned works on smaller aircraft.definately put a sleeve of sorts around any exposed length.

You can use a standard 4/40 push rod with a threaded coupler on the un threaded end
You wind up with 4/40 threads on each end..

Walt...

intothewind.com is a great source for sleaves to cover any size of rod. Cut to length and hold in place with a locking nut leaving about an inch on each end for your connector. Just be careful about the hazzards related to CF dust if you should choose carbon fiber over fiberglass rods.

Fly safe, Glover

ro347

Threaded rod has its value in application in low pressure/tension and vibration areas such as short distances of 2-3" with clevises on both ends. Glow engine vibrations over a period of time are damaging to all types of metal. I have had music wire (true music wire) installations break at the made up Z bend in planes lucky enough to live several years on pushrods around 12" runing unsupported from servo to horn, elevator, rudder etc. Was in a Q-500, another in a pattern ship, so the potential problem is there from long term metal fatigue. Have also had solder llink clevises/music wire applications fail when one side of the clevis fell off. This seamed to come about around in the 1990 when companies such as Great Plans became larger and run by the bean counters. There was a time when fastners such s engine 4/40 & 6/32 cap screws would break as you torqued them down, or in just a few flights. This stuff was being sold based on the lowest cost to the distributor rather than quality. This was in the same time frame engine fastner problems in commercial aircraft was comming about causing several crash disasters. Suppliers were providing inferior quality product to almost everyone, aircraft manufacturers, military contractors etc. . Its still tough to find decent quality fastners. Do yourself a favor and save a bunch of bucks. Find a local fastner supplier and buy a assortment of typical standard and metric cap screws where you ca specificy the quality you need. Yes, you will probably have to buy in 100 unit bulk, but the price per unit will be a small fraction of what you pay at the hobby shop and you always will have what you need. 100 4/40 cap screws will run atound $6.00 which is 0.06 each VS 4 for $1.50 which is .37 cents each of junk convenient packages. Fastner providers should be required to show the quality of product on their packages, honest ones do!!!! Am not sure how we can find quality clevises? Anyone?

IMHO, your going to a lot of work with expensive CF & threaded rods, etc. I have two show times and Yak, I use ball links on both ends with the H9 push rods. The H9 push rods are a little pricey, but they work as a turn buckel with right hand threads on one end, left hand on the other, with a simple square in the middle for a small wrench to adjust length. I guarentee this setup, and that you'll never go back. It's VERY simple to make adjustments. No trying to hold the with pliers in one hand, and trying to screw clevis onto the other. They come in one inch increments. Can't hardly go with these.

Forgot to mention, these H9 rods are tungston

Found a picture of my setup.

djr1007

Yea, have QQ Yak 54 where pushrods like H9 except lighter came with plane. Like them very much, easy to use and adjust. Have never tried the H9 rods as too many variables on each install, and too anxious to get in the air at this stage. Per your recommendations, will give them a shot on the next bird. Would be a big plus on these type systems if you could cut and thread as needed. Thanks for the imput. Never too late for a old dog to learn new tricks. ENJOY