Is anybody familiar with the source and availability of 2 axis gyros suitable for use on tailerons ? It would probably have to have a built in mixer. Thanks.
Mike

Hi Mike,

Hope all is well with you. Saw Ray a few weeks ago at PGRC.

I suspect you won't find such an animal ... but you never know what might be out there! But I think there is a pretty simple solution ... use a "standard" two-axis gyro .. or two single axis gyros on yaw and pitch, wired to the "traditional" rudder and elevator outputs from the RX to the gyro, then take the gyro servo outputs and put them into an aftermarket mixer that combines the yaw and pitch signals to drive the v-tail. There seem to be many ... here is one: http://www.dionysusdesign.com/produc...roducts_id=174 and here is another: http://www.gadgetparadise.com/121901/index.htm

Only disadvantage is that is "wastes" the built-in v-tail function of the new radios, and is a bit more work to set up. But I think it's probably the only way to use a gyro with a v-tail.

FWIW, I have a not-quite-new-in-box .. but never flown .. Futaba 2-axis gyro that I am unlikely to use .. yours if you want it.

Happy to make a small contribution to one of your masterworks! Just let me take the A-10 for a hop and we're square (just kidding...)

Dave McQ

Futaba makes (or maybe made) the GY352 dual axis gyro. I think ACT in Germany may make one as well.

Hi Dave,
The after market mixer is an interesting idea. Futaba made the GYA352 which is out of production. It had a built in V tail mixer. Ray probably told you what it is going in to for TG next year. The test bird will be ready to fly at months end, which will leave just enough time to finish the competition version (assuming.....) We will have some yaw and side slip issues without some form of correction on roll and pitch onboard as the original plane could not fly without rate gyros on all axis. The A-10 was getting too easy to fly for Ray, so I needed to make something to challenge him a bit. Irb75 thanks for the suggestion. I had previously e mailed ACT, their response just came in yesterday, and it does appear they have the beast in question.
Regards
Mike

Hi Mike

Im friends with Ray, and Woody. Nice job on the A-10!

I was starting to work on some relaxed stability systems to try and get a F-23 flying with a sane CG. I found this on youtube very interesting.

http://www.youtube.com/watch?v=1_Eh3pMC-1o

Searching RC groups i also ran in a person making a programmable mixer that has the ablity to plug in sensors. The thread is in the exotic aircaft vtol section.

http://www.rcgroups.com/forums/showt...=777427&page=2

User name Clarkst also very interesting.

My goal is to move the CG of the F-23 back so that it is so far back that it is easier to position equipment and so that it fly's better. The F-23's that I have seen need the CG so far fwd to be stable that they fly very nose heavy.

PS I saw your Mitsubishi Raiden J2M3 on rcscalebuilder, man that's impressive how did it fly? I made a small combat one and it flew nice but did not turn too well.

Aloha Duke

Hi Duke,
Ray and Woody have spoken of you often. (In nice terms of course). Thanks for the pointers on RC Groups. I am going to have a bit of a moving CG issue as the plane I need to put the gyro in has wing that sweep, roll control is via spoilers and tailerons and there are some variables in performance that I am still uncertain of. Ray has been looking at the original aircraft's behavior and has given me some good tips, but this does not always manifest itself in the model.
The Raiden was around 1/5 scale. I built it around 7 years ago. It has a twin cylinder 64 cc gas engine. It flies very well, take off and landing require careful elevator control to avoid nose overs. Prop replacements seem to have taken place on several occasions.

Hi Mike

I owned a DCU F-14 and it flew nicely but it was truck like. Especialy with the wings back. I really would like to make a Mig23 one of these day's but that pie in the sky. We have had 3 DCU F-14's out here in Hawaii Mine .91 DF my friends John C. .91 DF and Bill DeRego 2 X Artes Super Bees. We have flown all 3 with wings back, I did mostly just rolls and racetrack patterns. I don't think that any of us looped them, again not exactly light on the sticks, esp with the wings back. Johns and Bills used roll gyros and that seemed to help when the wings are back.

With the wings swept the roll had lots of momentum and overshooting was very easy.

Mine went in stupid brain and thumb error. Johns had #1 quit on take off departure stall and spin into asphalt. Bills had a landing incident in a heavy crosswind, repairable.

I was thinking if you could move the cg so that the f-14 was flying correctly with the wings back, when they swept fwd you would adjust the gain on the pitch gyros up, and control the unstable cg setting with the gyros to make it flyable.

The mixer intrigued me because of the function of the pitch gryo would be critical to flight I would want a stand by that I could manualy switch to. Im not sure it that mixer will do it but it I think it has the capacity to do it.

Also I forgot this but the new Weatronics 2.4 receivers have a receiver with 3 gyros built in.

I checked out the ACT too looks good, proven and available which makes it a good option.

Good Luck Mike, I can't wait to see what you are making!!!


Aloha Duke

Hi Duke,
I also did one of the DCU F-14's many years ago. We flew it with a pair of PST 600's, it was not very nimble, and fuel capacity/weight issues limited the flight time to around 5 minutes. With the wings swept I needed to stay at full power. The Weatronics might be interesting, I am not sure if they are actually out yet, I know they showed it at Jetpower. My only issues are a lack of desire to be a guinea pig with the plane I am building, and the 12 channel limit. Even with the multiple servo outputs I probably need more channels. the 14 MZ with the MDPX will give me adequate channels using a powerbox royal. A 23 would be an interesting project. The cg shift versus center of lift shift on swing wings was often speed dependent. If you look at the pilots manual on an F-111 they chart this. This obviously won't translate to a model as transonic and supersonic speeds don't come into play, but this accounted for a partial lack of cg shift problems on the real aircraft.
Cheers
Mike

Hello Mike

Ill let you know how my relaxed stabilty experiments go should be fun, hopefully not destructive. Im most likely going to mess around with it next year, too much stuff to work on now.

Nice to know it wasn't just me thinking the F-14 was not exactly nimble

Yes I agree the Guinea Pig factor is not one to mess with too many things to go wrong in a R/C plane already. At least the ACT gyros are already on the market.

Great chating with you, that Raiden is just too cool great job!!!!



Aloha Duke

Hi Duke,
I will certainly look forward to hearing the outcome of your experiments, they sound quite interesting.
Regards
Mike

Hey Mike,

Has anyone tried rigging up a sliding weight on tracks in a model F14 or F111 that is shifted by a worm drive or pulley arrangement? It seems to me that this would be the best solution to the c of g shift issue. Movement of the balancing weight could be mixed to the wing sweep channel. I don't have the electronic knowledge to set it up but I am sure it would not be too hard for someone who does.

Hang on.....maybe I do. The counterbalancing weight "trolley" could be shifted on bearings by a pulley arrangement hooked up to a model yacht sailing winch....plenty of power and precise control already engineered into it. I know this is off topic but Andy N. mentioned that you had an F111 and I was curious to hear your experience.

Regards,

Craig.

Hi Craig,
The CG shift turned out to be virtually a non issue. The changes in center of lift and staying within a reasonable static margin allowed the test model to fly with no problems. It required a bit of trim change but that was all. We had considered a sliding weight before testing but it adds unnecessary complexity and creates the possibility of problems if it fails.
Regards
Mike

Try Al's hobbies. They have dual axis gyros.

http://alshobbies.com/shop/lookupsto...3240&Desc=gyro

Hi Mike,

Thanks for the feedback. It is good to know as I am considering an F14 in the future but was interested to hear the experience of others about whether the shift of the centre of lift was much of an issue. Apparently not. Thanks again.

Regards,

Craig.

Hi Craig,
My only experience with an F-14 was an old DCU kit that I converted to turbine around 8 years ago. It was around 1/10 scale and on the heavy side after conversion. It was difficult to set up a fuel system for more than 5 minutes of flight. There were no significant CG shifts, but some retrim was required. A pitch axis gyro might be beneficial if you are worried about too much shifting. The ACT gyro will pass a taileron mix and work only on the pitch axis. I suspect however that you won't really need it.
Regards
Mike