I purchased a 701 and am working on the condition inspection.

The builder installed electric flaps, but either there is no UP limit switch or it is incorrectly set. If I hold the switch up, the top bellcranks (?) will lock flat against the top of the fuselage. Correct, no aileron action at all. I'm not sure where to begin adjusting this.

Any help out there?

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What kind of or model of servo did he use.  A lot of them have internal limits.

I don't know the brand but it is marked JS-TGZ-U1.

I finally figured out that the problem is that the actuator moves 100mm. I have ordered one that moves only 2in.

My attempts at replies have been hit and miss, about 50-50. I am getting the hang of that, but if I log out I'm not sure I will find my way back here.

I have no receipt or other information on the servo.
As best I can tell, I can’t post a picture of my servo.
I can see JS-TCZ-U1 (might be TGZ) 100mm

The superduty we are building has a rayallen servo that has internal limits on the servo.  I would guess yours is the same or similar.  I would change the length by threading it into the control horn shorter or longer depending on the direction needed.  This may be your fix,  or you may have to cut some length of the rod off.

That is odd. Without a stop how could one rig the flaperons to achieve consistent deflection settings to ensure the aircraft stall speeds are also consistent?  Is there a down travel limit? You could revert to the much simpler manual flap rod setup.

I share your question, but it is worse than odd since it is easy to raise the flaperons to the point that there is not enough distance between the upper bellcranks and the bottom of the baggage compartment to allow for full roll control.

There is a down travel limit, but so far I have not been able to find out what the maximum angle of deflection should be.

My plan is to try to adjust the length of the tube or rod between the actuator and the bulkhead at the front of the seat to which the rod is attached. If there appears to be a reason NOT to change the length of the rod/tube, a limit switch can be installed (or adjusted if already existent within the actuator) to set the up flaperon position.

The manual flap actuation might be simpler than installing a limit switch, or at least no more complicated. I would prefer the manual setup anyway - less to go wrong with time. I have the plans, but have never even seen another 701 than the one I purchased. Before starting more wiring, I will take a careful look at going back to manual operation.(The bungee for the manual rod is already in place.) Thanks for the response.

Correction, I think the bell cranks lock flush against the top of the fuselage, not the bottom of the baggage compartment. They lock against the airframe.

This is the tag on the actuator. Perhaps someone can make out enough to determine if this is what comes from Zenith.


This is the actuator.

No worries Bert. Zenith did not offer an electric flap option for the 701 so what you have was borrowed elsewhere and implemented by the builder or a PO.  It might be a 750 setup but I’m not familiar.  The control surface deflections are a Zenith drawing found here under the Gear, Wheels, and Controls section https://zenithair.net/builders-page-for-the-ch701-stol/. If you can’t access the page contact Zenith and inform them you are the new owner of a 701 they will assist you ( actually do this even if you can) :)   Also, please go here http://www.newplane.com/amd/CH2000_Service.html#5,%20STOL%20CH%20701 and familiarize yourself lots of important safety info there. Also, if you have any other 701 questions at all I’m happy to assist.

I registered with Zenith shortly after buying the plane.

I went to the link(s) you provided and it looks like I have a lot of printing to do. I have no internet service at the airport (32 miles away) so my reference material kinda has to be hard copy.

I know the electric flaperons are not standard on the 701, but had no idea where the electric actuator came from. This plane also has vortex generators on the wings instead of slats. Since there are no plans for extreme off-airport operations, I do not consider that a big deal. The short T&O should still be fine.

I can't thank you enough for the guidance to the safety information.

Knowing the objective, I think I can make a way to get there or find someone who can make it.

I found your linear actuator on Amazon.com https://www.amazon.com/Electric-Actuator-JS-TGZ-U1-Linear-Multi-Fun...

which is a decent place to ask questions about the item as most sellers want to be on Amazon with a good reputation. I did note it states you can adjust the length of the stroke by adjusting the length of the lever arm, but that the limit switch is internal and cannot be adjusted. 
Good luck!


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