Carbon Fiber Pushrods, how to?

[StevenatorLTFO]

So far, you guys have been great at answering my questions, as I explore getting back into this great hobby, after a long hiatus!

Tonights questions are as follows....

I have been reading quite a few of the build threads, and alot of them mention using carbon fiber pushrods.

1) Are there limitations as to what sized airframes they can be used on (2 meter, DLG, or whatever?)

2) Can anybody point me to a step by step tutorial on the net, or describe in detail whats involved with setting this up?

Thanks guys!!

Steve

[LVsoaring]

Copied and pasted from another thread that I posted on....

As for carbon pushrods, use .070, available from Aerospace Composites. www.acp-composites.com What I did was take the yellow plastic inner rod of a sullivan gold-n-rod, cut a bunch (8-10) of 1/8" pieces off it, and slip these onto the carbon rod. Use thin CA to hold them in place. You can CA threaded rod ends to the carbon rods, just make sure they are clean by soaking them in acetone (and drying them thoroughly)before gluing them, or the CA will not hold. Then, you can insert the carbon rod assembly into the outer pushrod housing. The gold-n-rod pieces keep the carbon rod centered within the outer tube, and prevent internal flexing. This technique can also be used with the steel rods ... if you don't want to go to the trouble and expense of carbon. I've used this method for years, it gives a very smooth, friction and flex free movement.


Just one additional caveat.... to assure this kind of set-up works well, the outer pushrod tube must be secured, i.e. no looseness or flopping around. Otherwise, all the work is for naught.

I'm interested in hearing about other methods in use out there!

Rick

[StevenatorLTFO]

Thanks for the post Rick, that helps out a bunch.

Do the runs need to be real straight, or will it flex a bit (for instance where the pushrod might leave the rear of the fuselage... and I'm assuming, that using one for doing a t-tail might be too much of a bend?

Steve

[oracle_9]

You should look at Mark drelas designs.

www.charlesriverrc.org

Especially in the allegro lite section, look at the "overall plan" in the diagram just above the boom it states it. Its a 2 meter sailplane. It uses 0.040" carbon fibre rods.

[LVsoaring]

You should look at Mark drelas designs.

www.charlesriverrc.org

Especially in the allegro lite section, look at the "overall plan" in the diagram just above the boom it states it. Its a 2 meter sailplane. It uses 0.040" carbon fibre rods.
I'll take a look at Drela's info, thanks Oracle 9, and yes, you're not gonna get a .070 carbon rod to bend up to a t-tail. but some gentle bending won't hurt a thing :)

[harleym]

Steve. . .get into File 7 at http://genie.rchomepage.com/. In there I provide some details on dealing with CF pushrods. I'm using them now in 5-6 pound big Genies and Genie Pros.