That's exactly what it does, but in some cases it actually helps people with their Bobcats!!!?!

Why????

People who have not set the angle of attack properly experience that long run-up and sudden vertical takeoff problem...

The spoilerons kill some of the lift permitting a more gradual rise off the ground... but this is NOT a good solution to the sudden departures... instead the original problem should be dealt with... the AOA should be fixed so that the plane's nose is a bit higher...

I have the spoilerons reflexed up about a 1/4 inch, with a small amount of down elevator mix. usually when i flip on the spoilerons, the nose will pitch up slightly. i think that this plane could also be flown as a flying wing without the rudder booms as the ailerons are quite effective when used as spoilerons. i was also surprised when the plane lifted off by itself, and it went beautifully. i have a higher nose gear setup according to Opjose's suggestion, and i never had a problem with manually rotating the airplane up. in any case it has done the same thing on my other flights today, saving me the hassle of manually rotating the airplane. i think that the speed of the plane plays an important factor with the spoilerons, as when i flip on the spoilerons at 1/2 throttle or more, the plane climbs gently. it may not be for everyone, but it's worth a try if you have a long enough runway either blacktop or concrete. most of the times when i rotate manually, the plane will yaw to the left as if the speed is not quite enough for takeoff, but i use about 3/4 of the 350 meter runway to really build up speed before taking off.

I made new shorter main legs to get my AOA right, also helps to reduce the bending moment so overall the gear is a bit stronger.

Thanks cyborg1. I test the spolierons after I repair my landing gear.

I find the Bob Cat to yaw or stall to the right when take off speed is too slow.

Bill

Once I levelled the elevator with the top of the horizontal stab take-offs were uneventful with gradual climb outs. No yawing or tendencies to jump up like a sky rocket. Of course this is at a decent speed for take off.

I just need to learn to slow this thing down for landings.

I had the same problems initially, until i started using spoilerons as per Opjose's suggestion. the plane handles better, and seems more stable in slower speeds with the spoilerons. what i usually do is on downwind approach for landing, i use about 1/2 throttle and take her far down before i make my turn into the final approach, when i use only 1/4 throttle. i level the wings and ensure that the glide rate is satisfactory, and i cut throttle as she crosses the threshold of the runway. at this time, she is about 3-6 feet off the ground and committed for landing. on touchdown, she rolls about 200 feet before she stops, and this in on a concrete runway. anyway, anybody have problems with the plastic cups fitting properly into the retract wheel wells? i did, and it bothered me, so i just used 2mm balsa to plank the entire retract area, making it clean and perhaps more aerodynamic.

Very nice job!

I've a new .50 in and a Falcon 1.20, so after seeing your work, I know what I'll be doing...

Add a little paint, and it will look awesome...

Thanks for the "tip"!

Have you considered dropping the ailerons after touchdown to act as air brakes during landing roll out?

Bill

i haven't thought about that...as it is, there is enough runway to land safely at my field, but that's a good suggestion which i'll try next weekend. let's see how she slows down then.

cyborg1...Awesome idea and job. I may need to try that. My retract pans fitted okay, but after a few hard landings they are toast. The intructions don't point out the fact that the main retract pans are specific to each wing, because the bottom is contoured for a specific wing. Once I realized they wre not the same and needed to be placed in there respective wings they fit fine.

But anyway, I think what you've done will even add more strength for hard landings as well.

The question above was asked yesterday but I have no experience with 3 blade pusher props and can’t answer the question. It always seems like two blade props are safer for the first few flights.

Bill

I can't seem to keep the Bobcat from ballooning up on touchdown when I give it a little elevator to soften the landing. Four landings, four bad balloon-stall-crash events.

I don't have spoilrons mixed in. I am using -50% expo on elevator. The plane flies beautifully and makes great approaches.

Today, the throttle linkage stuck and I had to fly the gas out. I took it high and when the engine died the glide was beautiful and uneventfull. It came in over the asphalt about 5' high and fast. It was about ready to touch down after 400' and I fed in just a smidgon of El when it ballooned strait up.

After recovering the ship I compared the amount of El movement with the tiny amount of stick and found the El moved approx 1/8" up.

Is this plane possibly tail heavy? If not WHAT? The El does not seem sensitive in normal flight, only in slowed down landing attitude.

Takeofffs, climb outs and flying this plane are a joy, but why can't I land the thing?.....anyone??

First of all, I would check the cg. is it at 10.5 from the leading edge? If it is, another way to check would be to fly inverted to see if it needs any down elevator input. If it climbs while inverted, then the plane is tail heavy. Then again, do you have the elevator set neutral for forward flight under power? If you have any excess elevator trim during level flight, when you are off power the elevator will be sensitive during landing as there is already some elevator input. I would do what Opjose recommended, that is to use spoilerons - about 1/8-1/4 inch up to control the angle of the nose during landing. It would help in slowing the plane for landing as well.

Hey,

I built one of these for a guy and not sure what to tell him to use for throws. I usually go with a lot of thow and use 30-40% expo, but I know everyone is not like that. What do you guys suggest for the average joe flying this plane. I told him to go with 1/8-1/4 spoileron. So what is good for elevator and aileron.

Thanks!

Tumbler

elevator throw would be about 1 inch up and down max. Aileron would be about 70% of full throw for high rates, and about 55-60% for low throws. These would correspond to the manual's recommended throws. Some people may find this a little twitchy, but you can always use expo to smooth things out.

Thanks Cyborg1 for the info.

The CG is right on 10.5" from LE at fuse.

I'll look at the El setting and mix in some spoileron.

This plane flies too good and looks too hot to give up on.

Thanks Man....So are you saying 1" up and 1" down on the levator?

Spoilerons are your friend at landing...

Give it a try it makes a big difference.

Once the mains are down, keep holding a bit of nose up... the plane will land nose high with the spoilerons...

Holding nose up bleeds off airspeed and prevents the plane from ballooning...

It will come in a bit steeper but with slightly less speed.

Yes, elevators are 1" up and 1" down max

I'm almost finished my repairs, once side is complete. I will most definitely use spoilerons on my next flight.

Cajun1...I understand the giving up, I felt the same way. I can flight the heck out of any other plane and land without issue, but this one is way different. I think I have it figured out.

Thank you to TUMBLER for helping me put this Bobcat together. Master builder!

I threw a new OS55ax on it and learned the hard way about proper CG. Ended up taking advise from OPJOSE and using Spoilerons, now flies like a dream. The one thing I've learned about this plane is it needs to be configured perfectly or it will F@#$ with you BIG TIME!





Check out the video :-)

http://www.youtube.com/watch?v=mnQsR...&feature=email

Welcome to RCU TBello! Congrats on the successful maiden. Once you get her dialed in she should be a sweet flyer for you.

Tumbler

TBello:

What gear are you using?

Do you have retracts installed?

SPRING AIR.... http://www.retracts.com

Bill Watton at Spring Air personally flys the retract ready Bobcat 50 and he went with the 702 system along with #152 struts for the main.

As far as the nose gear I ordered the Robart part #656 Fork Strut to fit on the Spring Air 702. Correct me if I'm wrong Tumbler....

http://www.Retracts.com/Retrax_700.htm
http://www.Retracts.com/Stuts.htm
http://www.robart.com/RoboStruts/380_Series.aspx

Because I take off and land on semi rough grass still debating with myself if it was a good idea or not. I've now cemented the base of the retracts
pretty good after maiden. I'll see where I'm at with her after 2nd day of flying mid-week.

Tim