tailskid

My Feedback: (34)

You mean like this?

galaxydriver

My Feedback: (2)

Yes! Did you just end up dremeling out the firewall a little to make it work? I assumed that it was going to slide right in...wrong.

tailskid

My Feedback: (34)

Noope, just installed it!

kahloq

Well, I did attempt a 2nd flight today...............

but.........

Got it all put together and set the battery on a charger to peak. Went and flew another plane while it topped off. Nice wind, about 5mph out of the south.

Got the P-51 fueled and then someone else with a gas plane wanted me to wait so they could get a flight in before I "hogged the runway in order to be able to HEAR the motor while in flight". So, by the time this gasser landed....20 minutes later....winds had shifted opposite direction and now were coming form the north, northwest.
Not optimal as Im not used to taking off right to left, but I was confident I could manage it.

Got the plane running and taxied it out...was a little hard to keep straight so aborted the first take off attempt(winds were a litte more from the west, north west now....
gasser guy suggested I throttle up a lot faster to to get rudder authority......
Got her lined up again and started the roll and shouldnt have listened to him...........
plane ground looped and went off into the weeds and tore out the right wing oleo strut!

Advice to all......dont listen to a pattern gasser flyer even if they mean well.....you know your plane better then they do and just do what you know works for you. I'd been ok had I just slowly advanced the throttle up instead of sorta throttling up at first then mashing the throttle like the gasser thought I should do.

Rip n Bank

Ouch! Sorry to hear of your Frankie's trip thru the weeds, and subsequent gear damage! Did it pull the strut out of the retract, the retract out of the wing blocks, or the wing blocks out of the wing??? Hope it's not the last one!

Had I been able to fly yesterday, and been out there, I would have strongly advised against a sudden throttle-up on the 220! I've found the torque turn is far more pronounced when doing so, and is very difficult to control with the short moment arm from the CG to the tailwheel.

And, in contrast to a long-tailed, "large rudder-ed" gasser, with a sudden throttle-up, Frankie's rudder authority doesn't kick in early enough to overcome the 220's desire to pull the 'Stang in a circle.

I've settled on a gradual throttle-up for take-offs, all while feeding in a bit of right rudder that, for the most part, has enabled me to keep my Frankie on the runway (and often, near the center) for my 10-11 take-offs,...so far.

Good luck on the repairs; hope you get her back in the air soon!

Rip

kahloq

Had you been there, you would have been my co-pilot of choice, not Jim as he knows nothing about glow motors, let alone 4 stroke torque monsters.
Anyhow, I've already fixed the damaged. It was minor. I did have to completely replace the retract housing, but the oleo was fine. Kinda funny how things work sometimes. When the incident happened, as the plane went into the grass/weeds, I saw the oleo strut actually being flung forward as the plane nosed over quickly. About 5-10 secs after this, a huge gust of wind from the west came though and I bet it would have really caused a more severe problem for the plane had it just lifted off or been on the initial climb out.

My only concern so far with the retracts is the plastic black linkage thats on the retract servo arm that connects to the metal clasp part on the retract mechanism. I can see after some use, that the plastic part can and probably will become deformed and may either come off the servo arm or snap.

Rip n Bank

Glad to hear the damage was minor!

I noticed from my hard landing somewhere around flight number 9 that the retracts (specifically, the flanges that bolt to the gear blocks in the wing) are fairly easy to deform. Had to remove the retract, clamp it in a vise, and carefully straighten the flanges back to their original orientation (and by doing so, making them weaker to resist future rough landings, of course).

Handling side, and especially front/rear torque loads, is not the forte of the H9 stock gear.

Judging by the ruggedness of the Robart 551/660 pneumatic system I'm now installing in my smaller 'Stang, I'm sure I'll upgrade Frankie's gear sometime in the not-to-distant future.

Rip

frisconick

Rip,

Did you ever get to try your 18x10 prop? I've been running the 17x10 Bolly, but picked up a 16x12 APC to try next. Will let you know.

Nick

Rip n Bank

Nick,

No, haven't had time to swap them out.

Had a great flight with Frankie three weekends ago on the 18x8, but was out on vacation the last two weekends.

Next weekend is Warbirds Over Denver, and I probably will stay with the "don't fix it if it ain't broke" strategy and stay with the 18x8 for that event. Perhaps the weekend after that...

Rip

kahloq

I'm also seriously considering putting in a heading lock gyro in this plane for takeoffs. For some reason, mine seems a little more touchy on takeoffs then Bo's. Of course, it could be his experience on the plane as well, but a lot of my other tail draggers arent as hard to keep straight. In any case, using a gyro should keep the plane straight as an arrow during takeoff, but, I'd have to disengage the gyro after takeoff. If I forget, it could cause difficulties.
However, in the switch ON position, maybe I could have it set to be functional up to 3/4 throttle and then automatically shutoff once the throttle goes beyond 3/4. From 0 to 3/4 is where most planes exhibit the problems associated with taildraggers anyhow. And once in the air, even if I forget to shut it off, it wouldnt be active in the general throttle range I'd be flying. Im usually am at close to full throttle most of the time.
I may get one just to fiddle with and see how well it keeps the plane straight on the ground.

kahloq

Ok...bought a futaba 401 gyro. Gonna read the manual and try and install it tomorrow. Unknown when I'll get the plane back to field. This weekend is possible, but might also be going to Warbirds over Denver depending on what others are doing. I might also have to put in a super fast high torque servo(more then the HS5845MG already in there) in order for the gyro to be able to control the rudder fast enough. Speed is 1.2 on the HS5845, but JR has a super torque servo with a speed of .6....might have to get one...but the servo cost is $114. Ill test it on the current servo first. I als might put in a 2nd servo instead of buying a super expensive one. This way, the tail wheel and rudder would have their own and wouldnt be as hindered by two things giving resistance on just one servo.

I'll report back if anyone is interested.

Tisoy909

My Feedback: (21)

Kahloq,
Thats an interesting thing you are going to do for the rudder, my only question is if you will have the gyro set to correct at only 3/4 throttle and below, what if when on approach for landing the heading of the plane changes for any reason such as a gust or even a drift, i would imagine that because we are at a low throttle setting, maybe just above idle while on approach, that an input created by the gyro could cause a tipstall as i know its not good to input too much rudder on these bigger warbirds while going slow n low on approach. another thought is if during normal flight and at a lower throttle speed it would cause an uncoordinated opposite rudder input. We dont always make banking turns at full throttle right. Just curious how you would counter this, because if it would work im all in myself, on the other hand im worried the gyro could cause a completely unnatural feel and cause the death of frankie, dont want that!
Thanks.
Louie

kahloq

I agree with your concerns Tisoy. The tx toggle switch to ON position would be heading hold and hopefully be able to program a mix to only have that ON to function up to 3/4 throttle. Now....once in the air...the idea is to turn the toggle switch to off position(which would be rate mode at a very small gain %). This would nullify the gyro. The idea for only "ON" to work up to 3/4 throttle is in the case that you forgot to turn the toggle switch to OFF position. Now.....in heading hold mode, the gyro will hold that last rudder position that you let go of. So, if yopu never touch the rudder in flight...it will want to maintain that direction(hopefully only to 3/4 throttle). If, during the flight, you use the rudder at all, that resets the heading hold to that direction. So on landing, if you use rudder at all manually, that will reset the direction, but if not...a wind gust will only effect the gyro to the point that it will maintain that direction.

If below 3/4 throttle in the idea above, and the heading hold is still "ON", and you are say on the downwind leg of a landing setup....during the final bank turn using ailerons, yes, a heading hold would throw in opposite rudder, but that should really only keep the plane going in a straight line(like a show pass with wing tip low). I dont know if this would cause a tip stall eventually or not, but upon seeing the plane not wanting to actually turn into the desired bank direction, inputting rudder manually would override that last rudder position.

With that question/concern in mind, I had also thought of putting the rudder and tail wheel on separate servos and only having the gyro work the tail wheel. This would elimiante any possible issue with flying/landing/etc.....but, once the plane lifts the tail on takeoff, the gyro becomes useless. I would think this would be fine anyways since at this point the rudder has enough air moving past it to actually keep the plane straight. Any thoughts on that?

Tisoy909

My Feedback: (21)

Kahloq,
I believe the idea where you suggested using the gyro solely for affect on the tailwheel, you may want to test out first. First off, because it wont be tested in conjunction with any flight control inputs and less dangerous to the aircraft. The problem i think we may have is the amount of corrective action it would have on the pull to the left affect upon accelerating. The thing is, if i can recall correctly from my flights, is that the left pull effect really only begins once the tail is already up or on its way up, thus it may have little or no weight on the tailwheel to have sufficient traction to counter the yaw affects, but im not certain on this and i dont think it would hurt to test a gyro on the tailwheel first other than time you would invest to install a seperate servo for the tailwheel, gyro and programming time. Now, you first mentioned how you would have the gyro active in conjunction with 75% throttle and less. I myself am using the JR 9303 pcm, and i know theres plenty of programmability in these newer computer radios but just how much quite frankly I havent explored, there seems to be endless combinations of programability, just havent gotten patient enough to sit down and do this myself but of course I should. Now, I was just thinking that perhaps connecting on from your idea of having the gyro active in a certain throttle configuration, that a certain configuration of one or two items is how you will get this thing to work the rudder at the right time. As food for thought, I know that the configuration of gear down flaps up and lets say 50% and up throttle is a unique configuration to our takeoff runs if im not mistaken or atleast to mine. Perhaps programming something like this whereby the gyro is only in affect during that configuration may inhibit the gyro strictly to the takeoff run. As we usually are using some degree of deployed flaps in the landing sequence, and gears are up for most part of the fight, unless you're doing a gear deployed show pass of some sort, but maybe just do it with some use of flaps, as a show pass gear down means dirty and thus means flaps too. and even then the gyro would still be inactive. Well anyhow. this is a juicy challenge isnt it.
best wishes.
Louie

kahloq

Thats an interesting idea. Have the gyro active ONLY when the flaps are in the stowed position while gear is down. I dont use flaps to take off with, but do use flaps for landing so that would work.....EXCEPT.....if there is a strong headwind where you wouldnt need any flaps. I also use the JR 9303 (2.4) and as you know the flaps are a 3 position switch, not a dial so theres no way to just put in a tiny amount of flaps for the purpose of deactivating the gyro in this setup configuration. That is unless your mid position flap setting is so low as to be basically useless(for purpose of landing in strong headwind) and your full down position is whatever. I use half flaps at mid position and full flaps at the down switch position. Seems to work well for me. I dont want to hinder landing ability by removing a flap position just to turn off a gyro.

I also dont know how I would set this up to be programmed to TWO variables..ie flaps only in the up position AND landing gear down.

Not sure yet how im gonna set this up. On my plane, I do see where the left torque effect is prominent even well before the tail lifts, in fact this is the biggest problem area keeping the plane straight, so gyro on tail wheel only should work at least initially. But, as we all know, there is a transition period from tail wheel authority to rudder authority that could present a problem.

There have been ppl that have used gyros on warbirds in various threads and the idea was to get the plane from zero to flying straight down the runway. With it on tail wheel and rudder, that would be no pilot input on the rudder and many have had success doing this. But, you gotta remember to shut it off once airborne. Considering that the available switches left on my 9303 are the two on the sides of the radio that are not switches, but variable ratchet type levers, this makes me nervous about accidentally bumping the lever moving it out of position.

So far, I think the simplest approach is to just have the gyro on a switch and turn it off once airborne. But the safest approach would be just on the tail wheel only, yet we dont know how well that would work trying to actually take off.

frisconick

I don't have any experience using gyros, so these may be stupid questions, but...

Does the gyro "learn" the characteristics of the plane or is its behavior strictly programmed by the user? For each degree of heading change, how does it know how far to deflect the rudder to get back on course? If the plane's heading doesn't "improve" in a few milliseconds, does the gyro "know" to dial in more deflection? Will it know enough to lighten up on the rudder as it approaches the desired original heading, or will it oscillate back and forth as it narrows in the desired heading? Can you override it with the rudder stick once it's engaged (just in case something, or someone gets in the way of the plane, or if the gyro goes nuts)? Since it won't know how fast the plane is going (i.e., how much air is going by the rudder), will it tend to overcorrect at higher speeds? I'm also kind of with Louie in that I'd be afraid of adverse course adjustments when not wanted (or not needed).

I too have the Saito 220 in mine, but have not had a big issue with it veering left on takeoffs. I tend to advance the throttle pretty quickly to about half to get the air moving past the rudder. Once the tail lifts and I have some speed up, I'll advance some more. We have a 650' paved runway. I taxi out in the middle and try to keep her on the mains until close to the end where I'll pull back for a gradual climb out. Looks much cooler than yanking it off the ground as soon as that big engine will allow.

Nick

frisconick

One other thought....with a gyro engaged on takeoff, if there was a gust of wind just after liftoff where the gyro decided to kick in a bunch of rudder, there might be enough roll coupling and loss of airspeed to cause a stall and crash????

Nick

kahloq

Fris..... a heading lock gyro in heading hold mode will maintain the heading it was initiallized with and will use as much or as little rudder needed to maintain that.

As far as cross wind gusts, I dont see that as an issue since the plane would be "pushed" sideways and the rudder is only correcting to keep the plane relatively straight. This is what ppl have to do manually when landing in a cross wind so it shouldnt cause a stall. What can cause problems is if the gyro is not turned off and you go to make a bank turn with ailerons, the gyro will try to "correct by inputting opposite rudder...hence keeping the plane in a straight flight path with one wing low.


yes, you can override the gyro by simply inputting rudder manually. A heading hold gyro in head lock mode will adjust the heading to the last rudder input by the tx so you can move the rudder stick to avoid something or to counter an unwanted rudder movement by the gyro(like if you forget to turn it off once airborne).

Now...that being said, my first takeoff attempt(after the initial gear collapse incident) went relatively ok. I was able to get the plane off the runway decent, but it was heading towards the side of the runway at an angle. I didnt feel it was super sensative then, but I still had a hard time keeping it straight down the runway. However, on the 2nd takeoff attempt, the plane was all over the place and is why I suffered damage. And yes I did put in right thrust on the engine mount.
So, I want to put in the gyro on the rudder/tail wheel so i dont suffer MORE issues trying to taking off thus avoiding more damaged.

I, for some reason, have things go wrong on a somewhat frequent basis that are usually out of my control. I dunno why, just happens. For instance, yesterday, I was flying my Edge 540. Great plane. Flies really nice. But, Murphy's law always bites at some point. In this case.....the glow plug simply worked its way out of the motor while it was flying and obviously it deadsticked. This has never happened to me before. Plane did suffer some major damage but is repairable. I DID check the glow plug before starting the motor. So, why did it come out? Dunno. It wasnt the first flight on the plane either.
My point is, Im trying to do anything i can to avoid having things BAD happen to this P-51. Already I've had two incidents with it and Im not happy right now. The first was the gear collapse. Nothing I could have done would have prevented that, was just a bad servo arm. If something again happens to this plane, as long as it isnt damaged badly, it will probalby end up being a hangar queen and only brought out for events. I am so beyond tired of having things happen to my planes, hence why I am trying to do anything I can(like a gyro) to have a better chance of keeping the plane in one piece.

frisconick

I feel your pain. I've spent my share of time fixing planes that haven't behaved (or my thumbs haven't behaved). I have two warbirds: this one and a H9 Corsair. The Corsair has a very short fuse and is a handfull in cross wind take-offs, but I probably have a hundred+ flights on it over a two year period. The P-51 doesn't seem to "wander" quite as much. As long as the wind is pretty much down the runway, even the Corsair is pretty easy to control. If there is much of a crosswind, I'll usually just leave the warbirds home and fly something more forgiving. I've owned larger boats in the past with auto-pilots (same basic priciple: heading change, adjust rudder to get back on heading), but there was a lot of tweaking and setup to get it to maintain course smoothly. And they do actually "learn" the characteristics of your boat, so after a while, it will know how much rudder to add for any given x degrees/sec of course change, etc. Please keep us informed on how it goes.

Thanks,
Nick

kahloq

For those using a JR 9303, look on pages A-37 through A-39 for details on setting up a gyro in the TX. There is some interesting auto-programmed mixes in there that will dampen the gyro effect progressively if the pilot moves the rudder stick off neutral.
Now....for this radio, they want you to put gyros on either the AUX2 or AUX3 channels since they are 3 position switches. This allows for an OFF position at stick 0, a gain setting at stick 1 position and another gain setting at stick position 2. I would assume with a heading hold gyro, the stick position 1 would be heading hold mode and stick 2 would be normal rate mode. I will have to test this out as I dad previously thought setting up the gyro would be a 2 position switch and the manual for the gyro mentions a 2 postion switch to go from heading hold to normal mode. Of course, I also believe I can set up the gyro on any 2 position switch, but by doing so, I would not have access to the dampening effect mentioned above if programmed on AUX2 or 3. Considering the discussion we've been having, i think having the dampening available would be a good thing, but it depends on how this futaba 401 will react to these auto-programmed type features.

If you cant find your manual for the 9303 or just want to look at this quickly, here is link to online manual:
http://www.horizonhobby.com/ProdInfo...Res_Manual.pdf

kahloq

Ok...I got the gyro installed. Seems to be working ok. But, think I need to get a faster servo in order for the gyro to effect the tail wheel and rudder fast enough.

Unlike the description above, on the 3 position switch for AUX2, the gyro is turning off at the center position(which is position 1 not 0). Im ok with this since the up position(position 0) from there puts the gyro in normal rate mode and the down position from center gives heading hold mode(position 2).

So, it is working on the ground(so far as I can test without taking it to the runway). If i slide the nose(while in a stand) to one side, the gyro does act on the rudder/tail wheel to effectively stear it back to original heading. It will move the rudder proportionally according to how much off center I move the nose and will hold it there until the nose is back to original direction. So, if it were on its wheels moving forward, it will progressively let off on the rudder the closer it gets back to original heading. This is what we want I believe. Right now, I have the gain in the TX set to 50% on normal rate and 85% on heading hold. On the gyro itself, i have not touched the sensitivity since its not "hunting" or constantly trying to move the rudder back and forth. I probably could up the sensitivity some, but would rather try a faster servo first.

I can also steer the plane on the ground with the rudder stick which overides the gyro. Once I let go of the rudder, it takes control again while ON(in heading lock mode). So, I should be able to initialize the gyro by turning the rx ON in the pits, and then taxi the plane out to runway and line up. Once I let go of the rudder, it should assume that heading and try to keep it there.

But, I wont know for sure until i actually try to test it for real. In any event, i can turn it off remotely via the TX.

jpjedi

My Feedback: (1)

Wow Kahloq,

That is a cool experiment. I have a JR 770 Gyro here so I will follow your adventures closely and thatn maybe decide to use it as well It all sounds very sensible and logical to me so far and I would prefer to have it on a manual switch only.

I am a heli flyer as well and I confirm the 9303 has plenty of options to get this setup like you want.

good luck![8D]

kahloq

Ok well....one thing I wish the gyro had was a remote LED light so i could tell from outside the plane whether the gyro initialized properly(steady red light).
So, since there isnt one, Im gonna have to mount the servo in the cockpit behind the pilot seat somewhere. BUT....and this is a BIG BUT!!!!!.....the intructions state to keep the gyro out of direct sunlight otherwise the gyo can heat up and cause weird issues. So, what to do...hmmmm.
My idea is now to cut a square hole in the cockpit flooring behind the pilot and mount balsa rails on the underside. Then, affix the gyro to a flat piece of wood and then screw that into the balsa rails from underneath. Next, I would put a piece of dark transparant plastic over the square hole and retain it with screws in case I needed to make some adjustments to the sensitivity, etc on the gyro itself.
Now, I would be able to see whether the red light is on, steady, flashing or whatever, but the dark transparant plastic would block most of the sunlight. Plus, the gyro would be relatively inside the fuse so any heat would be dissappated within the entire fuse with it being able to escape somewhat out the tail wheel cover area. Another option would simply be to put an opaque piece of wood over the the top of the gyro with only like a tiny drill hole through which you could see the red light.

I also have some tiny electric fans. If absolutely necessary, I could mount a fan next to the gyro and tie the power lead into the same line the gyro switch is on(you know..the one where it knows where the TX switch is currently positioned). That line is only a red power lead to the gyro..basically a simple on/off signal. When the switch is on, the fan should start running. I have used this fan before hooked up to a 2 cell lipo inside my B-17 in order to provide a bit of airlfow over the 6 main lipo batteries. It uses only like .50 volts over the course of 30 minutes.

GSK

The Rudder should give a kick when it initializes , do not move the machine until that happens .
Having flown Heil,s for over 15 years and have some experience with gyro,s I would not have the courage to put one In an aircraft to help me control it on take off .

Really keen to know how it goes .

As for my Frankie I have moth balled it ,as I have spent so much time and money on the rubbish retracts , they are a disgrace .
I am unsure at the moment whether to spend any more time on It .

The model is a very docil aircraft , lands well .I have no worries on take off as I tend to open the throttle slowly at first, steering it down the runway until It reaches flying speed which is about the time I am giving It full power , it will take off comfortably on just over half throttle .

Good luck
G.

kahloq

The futaba 401 I have does not give a kick when it initializes in heading lock mode. If something is wrong, it will either flash the red light or the rudder will go hard over and stay there. But, I cant see the flashing red light currently, so unless it throws the rudder hard, I dont know if it initialized correctly or if there is a problem where I need to reset it.