Anyone used R/C bowden?

My son did next step in building, but he decided to use bowden (7 strand steel wire in plastic tube) instead of pushrod to the elevator – probably after consulting with his mentor … yes R/C flyer.

It is difficult to argue over Atlantic, but I really affraid it will not work. Did anyone try R/C bowdens on such small beginner models? Shall I stop him and let him to rework it? It is already in, as visible on picture.

It will work, provided the outer sheath is firmlt anchored at several places along the length and the end is supported properly at the exit to prevent flexing / deflection.

He should be able to easily replace it at this point with a standard pushrod, unless he has progressed to the point where he no longer has access to the bellcrank.

I have used flex cable on some trainer type C/L planes, and it works O.K., makes the controls a bit stiffer due to the increased friction, but on a trainer it shuld not be a major issue.

The stiffness and amount of control would be my two major concerns. The RC types don't have near the amount of pressure on the controls as we do (evidence the number of failures CL types have experienced with quick links). If he can change it, he should. If he can't, he can do so the next time he repairs it.

Tell him next time to check with his dad.

Remember the Monoboom fast combat model? Didn't it use this type of cable for the elevator control?

It's a phase he's going through (controls joke).

LAST EDITED ON Apr-27-04 AT 11:49 PM (CDT)
 
I recall seeing an OTS type stunter locally that somebody built with this kind of pushrod. I asked how it worked, and the response was not favorable. I think it would make it much more difficult to teach himself to fly. Old technology works pretty well.

A pull-pull system might be more sensible, but you'd have to be able to adjust the slack out, no springs. With different expansion rates, adjusting might be frequently required. Steve

>
>My son did next step in building, but he decided to use
>bowden (7 strand steel wire in plastic tube) instead of
>pushrod to the elevator – probably after consulting with his
>mentor … yes R/C flyer.
>
>It is difficult to argue over Atlantic, but I really affraid
>it will not work. Did anyone try R/C bowdens on such small
>beginner models? Shall I stop him and let him to rework it?
>It is already in, as visible on picture.

Was just wondering exactly WHAT model is this, and what will the powerplant be? THANKS!

I have not used these on C/L but I don't even like them on R/C,
too flexable. As to the comment on control surface load being more on C/L than R/C. That is not correct at all. The pitching moment of A high lift wing such as a glider coming out of a dive, then level at high speed can generate tailplane loads that exceed the total weight of the model and shear the tailplane right off.

For R/C soaring, I liked to use a 1/16 piano wire pushrod in a bowden sleave driving a fully flying tailplane hinged on its AC.

Closed loop (pull pull) bowden cables work very well, and don't come out of adjustment. I've used C/L wire closed loops too. For R/C, there is no better, more accurate centering, stable, slop minimising control system than a wire closed loop. At least none that I have found. However getting the right tension in the closed loop system is the key to best results.

The worst performing but easiest to set up system is Gold-N-Rods these need readjustment every time the sun comes out or goes behind a cloud.

For C/L, I doubt accurate centering is as much an issue as in R/C comp soaring. But I think a closed loop would minimise slop for C/L as it does in R/C. I just use the old piano wire pushrod system for C/L but don't do comp. I can see advantages in a closed loop system if control flutter and flap elevator centering or slop are problems. Mass ballancing of control surfaces is always good practice to eliminate flutter.

It is a small model 40" span which is very easy to build (except taht foam LE) and which has very succesfull flying ability. Several of them was built by builders working alone without permanent contact to eprerienced C/L people. That was reason why I recommended him this model. I do not think that the bowden will NOT work. I affarid that it will make the first flights difficult because of free play, possible flatter or reason which I do not know now. I just did not try it yet and thus I am not lucky he try to do it way which I can not proof, secure or comment.

But may be it is good way ho to test it.

So after all he decided to use regular pushrod. ... I would like to see it in air

That is very nicely done! Hope he has good luck with the flights. Is there any information on his college plans?

Steve, I think the picture looks much better than the reality is

BTW I have only 1:1 corel drawing. It is not full selfexplaining plan for beginners ... I am too lazy sometimes . If you want I can send it in corel or exported to 1:1 gif

Thank you for the offer but what I was asking about was your sons university plans. Is he going to try to get a scholarship here in the united states?

He did all differential examinations so he will formally fulfill everything to finish US high school. Next year he will do again the same here in Slovakia. We have different system here, so he will need whole year. Afterwards he wants continue in US, but it is financial problem. He is speaking about MIT and also enjoyed university in Kenosha, but everything is open (more dream than reality). I think it will be better to do first two years here on some of Slovak universities. However he will have now some consultations with people from different universities, so may be he will surprise us

>He did all differential examinations so he will formally
>fulfill everything to finish US high school. Next year he
>will do again the same here in Slovakia. We have different
>system here, so he will need whole year. Afterwards he wants
>continue in US, but it is financial problem. He is speaking
>about MIT and also enjoyed university in Kenosha, but
>everything is open (more dream than reality). I think it
>will be better to do first two years here on some of Slovak
>universities. However he will have now some consultations
>with people from different universities, so may be he will
>surprise us

There are lots of grants and loans here and tuition at state universities is still a good bargain, if you are a resident. I spend a lot more on toy airplanes than Wisconsin in state tutition. It still is possible to work your way though school also. I did. The first year or so a state school is not a handicap.

Kenosha the only Kenosha I know is Kenosha Wisconsin? I am a UW Parkside Grad.

>>>Kenosha the only Kenosha I know is Kenosha Wisconsin? I am a UW Parkside Grad.<<<

Yes Dave, he was there on IOI 2003 Olympiad and enjoyed for first look ... the question is if there is also some practical reason

What you think about that university?

Igor,

I sent you a private message on this.

I used to help with this contest when It was a state contest for high school students. But that was a long time ago.