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Building Tips and technical articles. => ARF'S => Topic started by: Tom Schwartz on June 03, 2013, 06:15:38 PM
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I picked up an ARF Cardinal, and as I began assembly something didn't seem right with the flap throw.... At full down the flaps are at about 45 degrees up. At center, the flaps are about 20 degrees up, and at full up the flaps are only about 5 degrees down. I'm thinking the pushrod is too short. I measured it at 5 3/4" ???
Anyone else run into this problem?
Thanks
Tom
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Forget the numbers and get the flaps level with the bellcrank on center. One to one requires that both pushrods are the same heigth from center of the horns. It really is that simple.
Ed
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ARF/ARC and even kit control systems are often not going to work right. Check Tom Strom's post about his ARC Impact, a pretty high dollar ARC. He replaced the entire control system with Tom Morris stuff and after getting the wing straight and replacing the tail surfaces and flaps, got it flying well. There is quite a bit of useful info on this site about the ARF/ARC Profile Cardinal...like fuselage problems, flaps needing to be narrowed 5/8" and minor stuff like that. You should be able to dig out a lot with use of the search function. Don't let this discourage you, because the Profile Cardinal can be an awesome flier. It's just not quite right, as it gets off the boat. Just dig out the info and fix it! H^^ Steve
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ARF/ARC and even kit control systems are often not going to work right. Check Tom Strom's post about his ARC Impact, a pretty high dollar ARC. He replaced the entire control system with Tom Morris stuff and after getting the wing straight and replacing the tail surfaces and flaps, got it flying well. There is quite a bit of useful info on this site about the ARF/ARC Profile Cardinal...like fuselage problems, flaps needing to be narrowed 5/8" and minor stuff like that. You should be able to dig out a lot with use of the search function. Don't let this discourage you, because the Profile Cardinal can be an awesome flier. It's just not quite right, as it gets off the boat. Just dig out the info and fix it! H^^ Steve
Thanks, believe it or not, this is really the first issue I've run into with an ARF. I'm no expert, but I've put together about a dozen now, some are better than others... I'm just a little ticked I've got to dig into the wing. I'd rather be flying!
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Tom
Why do you need to open the wing? n1 Just get the bellcrank in the center position and lengthen or shorten the pushrod. Solder on a extension if it is needed.
All the adjustment is done at the horns.
Ed
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Tom
Why do you need to open the wing? n1 Just get the bellcrank in the center position and lengthen or shorten the pushrod. Solder on a extension if it is needed.
All the adjustment is done at the horns.
Ed
Ed, you might be on to something here..... LL~ I was too mad to see how easily it could be fixed.
Thank you sir.
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Tom I think we all have have had that problem one time at least. Cut off the end of the pushrod and add a new wire or 4/40 threaded rod with ball link on the end and wire it to the old pushrod. When everthing is in neutral solder it. Slight adjustment can be made with the ball link threads. I used slightly less than One to One on my Cardinal. It was a good flying plane. A lot of them had lead out failure. I sold mine to Ty and the leadout did break. ~^ ~^ ~^
Ed
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Since you are fine-tuning the control system you may want to try the Pat Johnston style bellcrank-flap-elevator attachment modification. Simply: bellcrank to flap (inboard or outboard, makes no difference), horn attached to other flap, pushrod from that flap horn to elevator. It makes adjustment easy and gives more room to attach the push rod to the horn using ball links or whatever. I fitted it to a Brodak P-51 and found it was much more responsive in the turns, more like a full sized stunter rather than a sport type stunter. With the big flaps of the Cardinal I would think it would be very effective. The picture pretty much says it all. 8)
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Tom I think we all have have had that problem one time at least. Cut off the end of the pushrod and add a new wire or 4/40 threaded rod with ball link on the end and wire it to the old pushrod. When everthing is in neutral solder it. Slight adjustment can be made with the ball link threads. I used slightly less than One to One on my Cardinal. It was a good flying plane. A lot of them had lead out failure. I sold mine to Ty and the leadout did break. ~^ ~^ ~^
Ed
Update;
After considering the many options offered here, I decided to cut the 90 off the end of the pushrod. I then picked up a 4-40 die and threaded the end of the rod. A threaded snap link added the extra length I needed and since it's pin was smaller than the flap horn hole I bushed it with some brass tubing. All in all, I think it's going to work out ok.
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Hope it works for you. I have had the same type connector on a couple of my planes. Wound up later installing ball links.
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Tom,
Just something to consider. Threading that rod may not give you enough bite to secure the clevis. The threads on the rod are probably only tall enough to hold the clevis with minimal surface area. I would consider threading the clevis onto the rod with J. B. Weld mixed into the threads. That should keep the clevis from coming loose during extended use. Just a thought.
Paul