rc_wings

Hi Herb,

I would start with 80/100 differential and see how that works and adjust accordingly. As for the mixing I used the Ail --> Rud mix and I would say try 20% to start. I have a Beaver on floats and am using 30% which works great, and I use the stick if I need more rudder. Have assigned the mix to switch SA so I can turn it on/off as needed. You can assign it to any spare switch you have.

Another tid bit you may find useful for setups on the 14SG if you have not thought of it, is creating a default model in programming. Assign all your switches and basic programming you always use and save it. Next time you need to set up a plane, just copy the default model, then customize it for the new plane. I find this works great as I use throttle cut, Idle down, timer switches, timer resets, Dual Rates, and they are all on my default model. That way everything is the same each time, and in the same spot and I do not have to repeat the basic programming each time I set up a new plane. I have a default model for electrics too. Makes setting up a snap!

Yeah she ain't no 3D queen! But sure is one of the prettiest planes out there!!! IMHO. I gotta get building mine....right after the RV-4, and then the Stearman, then the Decathlon, the WACO, P-47, Skybolt........this may take some time!!!

DIVERHERB

Thanks Marko I will start with your recommendations and go from there. I don't fly 3D so that part doesn't bother me at all. You are right, she is really pretty in the sky. Hard to say which is prettier the "Pro" or my 1/3 scale SpaceWalker. Both are beautiful to watch fly. I know the feeling of having to many planes on the board, at the moment I have the Waco started and a TopFlight giant scale P-47 to build. Building is therapy for me. keeps my hands busy and my mind thinking. Having worked with my hands all my life I need that. Hopefully the wind will die down his weekend and I can get a real feel for the "Pro". It has been a windy year hear so far this year.

rc_wings

Let us know how the next flight goes Herb!

I have the smaller Topflite P-47....in the box...in pieces...tiny wood pieces...LOL. The biggie you have should be real nice!!! You gonna do it in the razerback version, or bubble? I will likely do mine in the razerback. Love that look on the old jug!

Take care,
Marko

DIVERHERB

Hi Marko, I am planning to build it as a Razorback. I think they look better, plus it seems that most are built as the bubble canopy type. I usually don't build total scale because of all work that is involved and mine sooner or later end up in pieces LOL. The Waco is now on the building board but I don't really see that taking to long to complete. My biggest problem is I will go to a show and see something that I think is soo cool I have to build one, then all of a sudden I have another project to my to do list LOL. To bad there are other things that need to be done beside building and flying.
On another note I programed aileron diff as you suggested 80/100 and will let you know how it goes this weekend. Hope you have a great week/

RICKSTUBBZ

12 lbs with the DLE 20 is good for me....
That means with my ST90 --- I should start out at 11 and if I can loose a pound in the build somehow, I'd be at 10.
I know how well the ST90 hauls around a 9 pound plane.

Good Luck on the next outing.....

DIVERHERB

Marko this may sound like a dumb question, but the way you wrote the aileron diff. has me a little perplexed. You did mean 80 down and 100 up didn't you? That is the way I have always set it up, but with the plane trying to dive a little w/aileron input it may make sense to go the other way to induce more drag on the outboard wing. So I was just wondering which you are suggesting before I head out for another test flight.

rc_wings

Hi Herb

sorry for the delay but we are out of the country. Yes I did mean 80% down and 100% up......just assumed you understood. I would not suggest trying the opposite at this point. Would recommend that you assign it to a switch if you are uncomfortable with the result. That way if something is seriously wrong with the differential mix you can switch to normal. I am pretty sure the 14sg allows for that but do not have my radio or manual with me. If the 80/100 does not correct much, then you can either try increasing it or then try the opposite. With it assigned to a switch, you can quickly revert to normal if it becomes squirrely. Been a few years since I flew my buddy's Pro, so can't remember how much throw or diff we had in it.

Maybe Rick has some ideas??

DIVERHERB

The aileron differential seems to have made a difference. Flew pretty good. Had to add some aileron trim to get her flying even. It balanced laterally so I may just add a little weight to the wing tip and see what happens. It flies well, real gently and no real surprises. Just a little fine tuning now. I think I may try a 16x7 or 8 prop to get a little more pulling power from the engine. At the present am running a 15zx8.

rc_wings

Good to hear Herb!

RICKSTUBBZ

Glad to hear the flight(s) went well.....

I need some cool pictures and/or video to help me get motivated to finish mine.

DIVERHERB

Rick has been a little windy here and I find that the Pro is not windy weather kind so I have not been flying it lately. As soon as the wind dies some I will put it up and see if I can get some video of it. In the mean time stop procrastinating and get going on yours, I think you will enjoy it.

rc_wings

Oh boy. Am in a conundrum! Many projects that need attention and just came home with another one. Always loved the Cap 10b and is on my acquisition list. Low and behold one shows up at a local swap. New in box (new since 1990) a Yellow Aircraft Cap 10b. Wow what a nice kit! Me thinks my tigger 2500 should work under the hood for this one! So fellow brothers......do I move it to the top of the queue or move the Pro to the front of the line?

Feeling terrible as I think I practically stole this kit! But I will get over it!

buzzard bait

About the CG, my experience with BUSA planes so far is that their plans show a very conservative CG. I always wind up moving the CG back quite a bit with their planes. I haven't had a Citabria Pro, so I can't be sure about it, but I would use one of the online calculators that use wing area, wing chord, tail arm, and stab area, and compare to the plans. The reports here, lots of down needed for inverted, difficulty entering spin, do suggest that the CG could be moved back.

I highly recommend the calculation route. Of course, flight response is the ultimate test, but the calculated results work out very well and it can save trying to get the CG forward when you don't really need to.

One caveat is that with a reduced stab you can't move the CG back as much. The calculator will take that into account, because stab area is one of the values you have to enter.

Nice to see the light construction, should be a beautiful flyer.

Jim

DIVERHERB

Okay need a little input here. After trying numerous "fixes" I can not get the Citabria to stop climbing without done trim to the elevator. Its not a lot but still there. The next thing I am going to try is adjusting the wing incidence. I am thinking that I should raise the front of the wing. Am I right or am I going to make matters worse? It fly's pretty nice but for this and it is something I can live with but would like to have it better. This is the first "high" wing I have built so I don't have a lot of experience with them. I need to get more stick time with this thing as it still gives me fits on take offs. It can get pretty squirrely on take off.
Any input would be appreciated. Thanks

iron eagel

Have you tried to put a bit of down thrust to the motor?

buzzard bait

Raising the front of the wing will increase the incidence and make it worse. You can raise the trailing edge and make it better. If you could trim the stab by raising the leading edge (opposite of the wing) then that would be best, but you probably can't do that. But what's wrong with just leaving in the down trim in the elevator?

Also, iron eagel's suggestion might be worth trying, though I suspect it won't do the job.

For tracking on take off, many people use toe-in on the wheels; i.e., viewed from the top looking down, the wheels angle in toward the center, from back to front. A little, about 2 degrees should be enough.

DIVERHERB

I tried a little down thrust in the engine and it did not help, I did not think it would as engine speed did not really affect it. It did after I added down thrust. I actually added a little more +incidence to the wing and it did not really change anything so that is why I was asking if maybe going the other way might help. I guess I will have to live with it. Changing the incidence on the stab would be a major job so that is going to have to stay the same, it would not be worth the work. I guess the trim added to the elevator will have to stay. Just would rather have everything straight and level..Thanks for the toe in tip I will give that a try, may alleviate some of the squirrelly behavior on take offs. Thanks

iron eagel

Sounds like living with a bit of trim is the solution. The toe in will really tame the ground handling during takeoff but you will have to stay on the rudder a bit.

RICKSTUBBZ

Hey there Herb,
Not much for me to add.
Except --Do you have some expo in the rudder to help with the takoffs? These short coupled planes can be tough to tame...

buzzard bait

Good point. Expo usually enough, dual rates if you like a lot of rudder in the air but you're struggling on take-off. I'm not one to use dual rates, but I had a tail dragger once I couldn't get off the ground because I had a lot of rudder throw for crisp stall turns; dual rates made it way easier on the ground.

Jim

rc_wings

Herb,

If you do not like excessive expo for normal flight on the rudder, you can set it up on a switch so you have lots of rudder expo for take off, then once airborne, you can switch it to a preconfigured setting with less expo. I have done this on a Smith Mini plane, as it is a bit squirrely on the ground, then once up I can switch it to a setting that is better suited for flight. Toe in is a good tip too, to help with ground handling.

As for the other issue...did you verify the incidence with the plans? With those cabane structures it is easy to build them off slightly, so good to check with an incidence meter to be sure. I cannot recall what they call for in the plans, but suspect "0" may be worth trying, if they call for something other. Also....she isn't too tail heavy is she? Not a good thing on the Pro, as I know from experience. That may be a cause of your need of "down" trimming.....possibly??? Just throwing out some ideas.

iron eagel

Herb,
Where you know it's not a thrust line issue, then just shim the rear cabane mounts 1/32 at a time till you have eliminated the need for trim, it shouldn't take that much. By lowering your incidence you can eliminate any need for trim, I forgot yours was a open cockpit not a full cabin, (open cockpit it no big deal all you have to do is shim the wing) with the cabin you end up having to refinish the fuselage. If you want to make the roll more brisk I have found +throw of around 40 degrees on the ailerons makes it very responsive but you end up needing expo on them when you try to land.

DIVERHERB

Thanks guys for all the input. I tried changing the thrust angle without fixing the problem, created a problem at w/o throttle so I changed that back. I have changed the incidence some but it did not seem to effect it that much. Maybe I will try a little more as it is easy to accomplish and can be changed back without a problem. I try to stay away from a lot of expo in my rudder, as I guess unlike a lot of flyers I find it gives me more trouble. I tend to feed in rudder and when it is not giving me the desired results I feed in more until all of a sudden it "jumps". So I prefer to set up the rudder with no expo so the response is exactly what I input. I built a Pitts "Lil Stinker" 1/4 scale and it was probably the worst at ground handling I have flown, just took a lot of practice. On my planes they actually say you cannot measure the incidence ? but they give you a measurement and that is correct. The incidence given for the stabilizer is correct. I was real careful about the C.G. as on the plans they where pretty adamant about not deviating from it, saying "parasail wing design" the c.g. is critical. Plan to fly it a little more during the week and will try the toe in change and more incidence and see how that works out. The trim is not that much as I had stated, its just the first time I have not been able to rectify a trim issue. I just think that all control surfaces should be even when flying level . No big deal. I will say that it is a nice plane to fly and lands easily and has no bad tendencies that I have found yet. I will try to get some inflight photos of it as soon as I can to share. Thanks again for all the input.

iron eagel

I have had the same issues with rudder and expo.

rc_wings

Many people do not like expo and I can understand why. I never used it for years until my planes became more capable. I like to move the sticks a lot, and with some of my more aerobatic planes, I find that expo allows for more movement around the centre and will "soften" things up a little. Almost a must with 3D planes. It does take some getting used to though. I always tell folks to use whatever works best for their own flying style....just don't forget about the tools available in the radio that may help.

Hope to see some more pics Herb!!!!