Replies to This Discussion

Permalink Reply by Thomas Richardson on April 21, 2009 at 8:03am

I was given the values for the CH701 by Caleb just on Friday and they were, 30lbs for the Rudder and 20lbs for the elevator.... Hope this helps.

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Permalink Reply by Kostas Rossidis on April 21, 2009 at 11:18am

thank you Thomas

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Permalink Reply by Ralph Sanson on April 26, 2009 at 12:40am

There doesnt appear to be that information in the plans, construction manual or owners manual.
When my plane went for initial inspection I was told the rudder cables appeared overtight.

The rudder cable tension will vary if the nosewheel is under compression (due to the steering pushrods sliding up and down). It should probably be checked with nosewheel clear of the ground.

The elevator tension is problematic, because the stick bellcrank is offset one side of the stick so the cables get looser or tighter when aileron deflection is applied. In practice mine is rigged so the stick springs back to neutral if it is moved right, but the cables become loose for left aileron deflections. this can be balanced somewhat by setting the bungee cord that controls the crossover to the cable that needs pulling across.

While I'm mentioning this, I would avoid obvious "fix" of bending the stick bellcrank inwards to be on the same axis as the torque tube. I doubt that would eliminate all the problems and it might severely weaken the deformation strength of that part when loaded.

Welcome any proper information on this, i've had nil replies from ZAC and agencies to date

Ralph

PS I just saw the response from Thomas that seems to say the elevator can be rigged with tension. Anyone done this and if so do you get a sore arm holding the stick outward all day?

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Permalink Reply by Kostas Rossidis on April 26, 2009 at 1:34pm

I measured my cables today rudders were at 25 lbs elevator at 10 lbs. I adlusted the elevator to 20 lbs and rudder to 30 lbs,no time to fly the airplane today.Elevator cables always felt mushy since day 1 and I fly my airplane since 2001.I was experiencing slight elevator vibration at speeds below 55 mph.That vibration is minimized when I extend 1st notch of flaperons.My explanation is that at low speeds airflow around the elevator is not very smooth for some reason.When flaperons are lowered air is deflected downwards thus eliminating the airflow vibration.Of course I am not an expert on the matter and maybe happens only on my airplane.As soon as I fly again I will try all these different speed flaperon configurations

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Permalink Reply by Ralph Sanson on April 27, 2009 at 12:51am

Thanks kostas,

I have not felt 'vibration' as such in the elevator system, however on occasion when doing a glide approach with flaps up there has been a pitch unsteadiness in the airframe of low rate maybe half or one per second.

This stops if I bring the engine up a bit from idle, or if flaps are down. The Jabiru engine is direct drive to 2 blade prop, and the idle can roll about a bit on long approaches, in fact if the idle setting is too low the engine could stop, where it would normally run very smoothly if not for a long approach or short landing. I feel the propwash, because it directly flows to the elevator, is the source of this effect on my aircraft. In any case this is a slow speed effect, not experienced in any other situations.

we really need instructions for tension setting of the elevator and to what position the stick is fixed to set this tension correctly, as I have been told from other owners the offset geometry of it is in the design of the 701 and a loose/tight elevator situation is normal. This has been the situation for the last 5 years, If anyone can locate this instruction from the plans I would like to see it.

Ralph

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Permalink Reply by Thomas Richardson on April 27, 2009 at 4:33pm

While I am certainly no expert, I would have to guess that all tensions would be set with the control surface in the nuetral position, much like it was done when originally rigged. as I am at this exact point in my assembly , any input on this would be greatly appreciated.

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Permalink Reply by Dan Robinson on September 16, 2009 at 9:29pm

My AP buddy emailed engineering about elevator tension and the reply was 35lbs. I have a copy of the reply if I can email it to someone to help it would be no problem.

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