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Building Tips and technical articles. => Building techniques => Topic started by: Joe Messinger on August 25, 2008, 11:13:28 AM
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Hello,
I bought a supply of ball links from Tom Morris a few years ago. I have used them on most of the planes I've built since then but find that on the control horn on the flaps with two ball links attached, there isn't enough room to get both (rod from bell crank to flaps and the rod to elevator) connected to the horn one above the other. The ball links are too wide to pass by each other. I've been using one ball link and one clevis to make the connections. Anyone out there have a solution?
Thanks,
Joe
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Check with Mr. Morris. I believe he makes flap horns with wider spacing between the holes for just this purpose!
w.
P.S. NEVER use clevices!
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Hello,
I bought a supply of ball links from Tom Morris a few years ago. I have used them on most of the planes I've built since then but find that on the control horn on the flaps with two ball links attached, there isn't enough room to get both (rod from bell crank to flaps and the rod to elevator) connected to the horn one above the other. The ball links are too wide to pass by each other. I've been using one ball link and one clevis to make the connections. Anyone out there have a solution?
Thanks,
Joe
You can always do this...
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You can always do this...
That's a cool Ringmaster---had to look twice to make sure! (the flaps of course!).
The main issue with doing it that way is that you have a couple between the two control rods that tends to twist the horn. To be honest, I am not sure how big a deal it is.
Another way is to only use the ball link on the Bell Crank to Flap horn, and then use a simple L bend with soldered washer flap horn side of the elevator rod. Then put a ball link on the elevator horn. This still makes a couple, but the coupling is 1/2 or less of the 2 ball links on opposite sides solution. Another way is to make the little cone standoffs shorter. That will also reduce the size of the couple. I did that one time on my lathe because I had clearance problems---especially in the tail of the plane with the normal standoff.
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Thanks to all for the suggestions for the ball links. I'll check with Tom Morris on the horns for ball link set ups on any new planes I might build.
Richard: I will try the offset links as you show in your photo. Nice looking plane you have there! Is that a Ringmaster with flaps?
Thanks again,
Joe
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That's a cool Ringmaster---had to look twice to make sure! (the flaps of course!).
The main issue with doing it that way is that you have a couple between the two control rods that tends to twist the horn. To be honest, I am not sure how big a deal it is.
There's no real problem, Alan. Joe's using a Tom Morris horn, too, and nothing is gonna twist one of those!
Ralph
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Richard: I will try the offset links as you show in your photo. Nice looking plane you have there! Is that a Ringmaster with flaps?
Thanks again,
Joe
Thanks Joe. This setup is quite substantial. It is the Extra heavy duty DuBro horn and has the extra flat washer on each side to help prevent any flexing on the elevator ball link. I think taking some metal off of the brass cone would be a good idea in reducing the size/mass of the coupling.
The plane is the new 526 sq inch Ringmaster 526 designed by Dee Rice and Pat Johnston. Power is B40 and flys like a dream. There is also a 526 S version available which is non-flapped. If you want bigger, there's a Ringmaster 576 and 576 S also available. These are from the new Ultra-Lite series. The fuse is hollow, LE is composite/hollow, and spar is CF reinforced.
These ain't yo mamma's Ringmasters! mw~ LL~
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I go one step further and just use one bolt through both ball links with the horn in the middle. There's a bit of a twist effect on the horn, but as long the horn is stiff it shouldn't be a problem.