Carbon rod problems?

[Michael Wright]

Just a thought,..... I have just laid me sweaty paws on an 'Wot4 XL' and I was thinking of replacing the push rods with carbon rods to reduce weight and size to make fitting possibly easier. In the dim canyons of me mind I think I recall a discussion years ago about carbon rods causing radio problems. I will be using 2.4 gigs radio.

Any body remember this?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Phil 9]

the weight saving of carbon pushrods will not make any difference to that model.

 

if weight saving is your only reason for swapping them I would say save your money

Edited By Phil B on 29/12/2011 13:06:21

[Frank Skilbeck]

The problem with carbon fiber is when the fuselage is built from it, the aerials have to be run outside or the fuselage acts as a shield to the signal.

 

You should have no issues with carbon pushrods, I have a PA Addiction which has a carbon reinforced fuselage with a 6100 DSM2 park fly Rx in it, no control problems at all.

[Vecchio Austriaco]

the original pushrods have been from steel I suppose? so there will be no difference as also steel may disturb the signal. but if we speak about a 2mm pushrod I don't see a lot of danger...

[david houghton 2]

I have just replaced 1/8 th steel push rods with 3/16 th. carbon tube , I was shocked to

find how fragile and splittable this tube was ? When sandpapering the end to assist

adhesion it split very easily ! 100 in. topflite Stinson SR9 with 3ft. pushrods.

solid carbonfibre rods are obviously the minimium.

Beware If carbon tube has any interference in flight ie. rubbing or chatter it is liable

to fail? Question has any member views on upvc type rod for steerable tail wheel

 

pushrod ,Its flexable and does not shock the servo on rough landings.

[Myron Beaumont]

Leave it to F1 guys & RR compressor blade technology that they perfected eventually. It works! Not meant to be bent is it ? Remember the computer designed catamaran that broke up shortly after an excertion into the real sea in Cornwall from Lostwithiel a couple of years ago ? It doesn't like (the twin unsupported hulls in that case )being slightly bent does it ?

[Ernie]

Hi Michael, If you want to save weight, and increase performance, use a closed loop system made from plastic coated stranded steel wire

 

ernie

[Guest]

. I use slightly epoxied bent threaded control rods pushed inside small dia tube rather than rod - just as stiff and strong , and then when epoxy cured I use thin CA on end of rods to avoid splitting. the ca soaks into the fibres and glues them together

 

john

[Alan Cantwell]

most el cheapo carbon tubing is the stuff used on kites, this has a lot of glass in the carbon, i machine carbon tube at work for F1 use, steering columns, suspension parts etc, smallest i do is 12mm diam, with a 9mm bore, i get the stuff in 4foot lenghs, it wont even flex, let alone bend, if its a glossy OD, and you can flex it, leave it alone cyno, by the way, makes true carbon brittle, glue of choice is Hysol,

[Erfolg]

As many of the contributors, I have used (& use) Carbon pushrods, I have not experienced any issues.

 

On many if not most indoor models, it is completely normal.

 

I have read that metal to metal contact such as rigging wires can cause problems. It is only recently that I have realised I have a number of metal to metal contacts with horns (made from aluminum) and metal clevis. I have never had a hint of an issue with this arrangement.

 

As has been suggested Carbon Fibre Fuselages have been known to be an issue, requiring an aerial on the outside of the fuselage.

 

If you have a problem, I will be surprised if it is the carbon push rod. But you never know.

[Myron Beaumont]

We all know that trees (99% wood including lots of carbon)  have a strange magnetic / electro magnetic attraction field effect on models .I wonder whether wooden push rods are as much to blame as carbon fibres for terminal arrivals but we've never realised it before & we're continually being blamed for incurring pilot error by onlookers which we' re always having to deny

Edited By Myron Beaumont on 04/01/2012 21:09:28

[Martin Harris - Moderator]

RF is funny stuff and despite what the radio experts will tell you, obeys no rules!

 

I had a model on 35 MHz which tried to fall out of the sky in exactly the same place in the circuit time after time when I tried to fly an approach - so much so that the only way to get it back down in one piece was to land on a different runway.

 

The cure was simply to take the aerial out of its tube in the fuselage and let it dangle from behind the wing. My theory was that it didn't like running parallel and close to the closed loop rudder cables. Whatever, moving it cured the problem instantly and permanently so closed loop might not be the answer if you happen to hit the wrong length of wire or some other seemingly random factor - although I believe 2.4 GHz might be less prone to this.