- Aug 16, 2016
- Reaction score
- Paragould, AR
Putting the pitch servo under (or very close to) the stab is an idea used for some planes. It could work with this, but that model is often tail-heavy to begin with, so it would need a LOT more noseweight since the servo would be so far back.Or just put the servo under the stab with a short rod to the elevator and route the servo wire forward. I dont think the ekevon idea will work well on this plane with a large fixed stab. Or remove the tail, put some wingtips for lateral stability and enlarge the ailerons and make it more like a true wing, ala klingberg
I was not planning to make adjustments to the aileron area or CG location. I felt the ailerons were already pretty good size for the model & wing shape.Are you going to increase aileron suface area or move cg? Normally when you give down flap an airplane with a stab will pitch up, not down which is the opposite of what you want, some will pitch down but hard to know, can you do test glides before committing to a high speed boost?
I wish you luck in your adventure here and look forward to hearing the results.Over the years of flying my T25 (30 flights?), the elevator performance was never particularly good. Once you get the model up in the air, you are pulling back the elevator "for all its got" to simply prevent a dive. I was already considering some augmentation of the aileron controls (through transmitter programing) to get the ailerons 'helping' the elevator control.
Originally, my T25 had one aileron servo and one elevator servo. It now has a servo controlling each aileron, and no elevator-dedicated servo. I am using an "elevon" or "delta" setup on my radio so that the ailerons can be 'both up' or 'both down', like a flying wing.Question? To clear up my confusion does it have an active elevator servo and 1 aileron servo, or is it 2 independent aileron [now elevon] servos with no elevator?
I question my own sanity all the time. I put this idea (elevon control on a T25) for input. I certainly appreciate your comments.I wish you luck in your adventure here and look forward to hearing the results.
I don't want to second guess your reasoning and I have not seen your model fly so all of the following is just speculation based on many years of observing people doing pretty much everything, right and wrong, with R/C airplanes at one time or another including myself. I have also seen people do things that I knew would not work and they worked very well so I will hold my judgment until your experiment is completed.
I concur with frank that almost always deploying flaps in a downward direction on an aircraft with a rear horizontal stabilizer causes the plane to pitch up.
Your description of the gliding part of the flights seems to suggest more of an out of trim situation than a control surface issue. Most rocket gliders I have flown have different trim settings for boost and glide. Even if it's just to allow for the weight of the expended fuel and if you are staging a D12 to a D11 that would cause a significant CG shift. If you are holding full up after boost just to stay level you may have a nose heavy condition after the boost. Particularly if the elevator has little control authority. A tail heavy aircraft will show lots of attitude change with very little throw.
Just thinking out loud. Looking forward to you solving your problem.
Absolutely do this, I'll explain why:Having gone on and on about the "elevon" control, I must admit that I had already considered mounting a small, powerful servo [Futaba 3114] in the wing near the left boom, in a manner similar to Post #7.
This would allow me to keep the elevator AND individual servo aileron control. Which, in turn, would allow me to set up "flaperons", to slow the T25 just before landing. I need to do some glide tests.......
I would definitely run the elevator, I used a small servo on the stab (on the kit built version), I ran it on F and G motors no problem.
I helped the aft CG problem by moving the wing forward, I have a build thread on here somewhere.
I bought that one and promptly blew the tail off of it. I let it fly too level on a G12 and it built up too much speed. I built a new one but made a lot of changes and molded my own fuse. It flew OK, I never noticed any tip stalling but I did not try to use flaperons. Sorry if I don't understand the gist of this thread but if you tried to fly this without an elevator, I think it would be a short flight. Very shortLink to a kit I sold on eBay years ago, several photos: https://georgesrockets.com/GRP/ebay/2011/StratoBlaster.html