Stuka Stunt Main Forum · 22 of 22 known posts recovered
The print shows the lead out adjustment to slide 3/4" in front of the bell crank and 1.5" behind the bell crank. I hope this is correct?
Gary Weaver
To those who know me: I responded as you might expect. It was very, very funny. I deleted it.
Gary, trust the plans, not your instincts. Literally thousands of Fancherized Twisters have been built and flown.
As to doubler length, *pick one* and move on...
Dan
I don't want to make a mistake its a lot of trouble to fix it.
I pick the 12.5" double.
It seems to me the lead outs should never go forward past the center line of the bell crank. If there is already one mistake on the print then it is logocal to assume the lead out could be drawing in the wrong location. 1.5" behind the center of the bell crank seems to be plenty of movement.
Gary Weaver
The bellcrank location is not relevant to the leadout position, the CG is.
What's important is where the leadouts come out relative to the CG, mostly*. I think the CG wants to be well in front of the bellcrank pivot in this case.
Brett
* dynamically, it doesn't matter. Practically, it does matter a little because you don't want them to bind or have to bend to follow the line sweep.
I don't have what I need.
I can not buy what I need in town.
The local hobby shop is a DUD they have parts for RC cars.
I can't find what I need online because I have no idea what the real names are or what it is listed under.
I hate to pay a bunch of postage for a $2.00 item, I will probably need other things later but I have no idea what that will be either.
A bicycle spoke makes a great bell crank linkage but I don't have one of those either.
Gary Weaver
Ooops.
Gary - you are correct. I did the plans, and just checked it in CAD. Top view is longer than the side view. Lots of people have reviewed the plans, but you are the first to catch it. My thanks.
The side view is the correct version. I will correct the plans and send an updated version on to Leonard.
V/r
Bob Kruger
Gary Weaver
Tom Morris makes the control stuff I use. The website to get his stuff is below. If you are unable to find it near you, buy it from Tom. This is real stunt flying equipment.
Chris...
The cutter is a simple thing to build. I used a 1/2" diameter piece of steel tubing. I sharpened the tubing razor sharp on one end. I set the flat end of the tubing on a small piece of plywood and glued it there with epoxy. I places the cutter in the jaws of a pair of plyers with the plywood touching the jaws. I place a piece of plywood on the other jaw and clamp the plyers shut to make the cutter lay flat on the other piece of plywood. I put a rubber band on the plyer handles to keep them shut while the epoxy dries. I put epoxy on both pieces of plywood to attach them to the plyers. After the epoxy is dry the rubber band is removed. Clamp it on a piece of balsa and squeeze the handles and it will cut right through the balsa. I mark the lead out wires on the ribs then cut the holes. It sames having the holes cut in the wrong place if you cut the holes before assembly.
Gary Weaver
Why go to the trouble of concocting an extra tool? Why not just cut the holes for the leadouts while the ribs are flat on the board, before assembly? If you remove some extra material (except to the detriment of strength!), who cares? The lighter the inboard wing with its lead out holes, the less tip weight is needed. The only time that I know of that the accuracy of any holes thru ribs is critical, would if one used some sort of jig that required their use. From what I can see of your picture, you don't jig your ribs in this manner.
You are right it is much easier to cut out the rib holes before assembly. I usually assemble the ribs on the spars with no glue then make the lead out locations. I take the wing apart and cut all the holes then reassemble the wing, then glue it. I just screwed up this time. I assembled the wing and marked the lead outs. I realized I have no glue so I drove across town to get some. When I returned home I glued the wing, then I realized I screwed up. No matter I can still cut the holes.
Gary Weaver
I can not buy what I need in town.
The local hobby shop is a DUD they have parts for RC cars.
Gary Weaver
Try the RC car guys again. Ask for Associated balls and ball links. Used as adjustable ends for suspension pieces on, for example, the RC-10.
Superb solution to all of your rod-end problems.
I hesitate to ask, but are you a member of PAMPA? So many of your questions have been addressed many times over that it appears as if you are not availing yourself of a really good source of information, Stunt News.
To wit, in current issue I had written description *and* pictures of control linkage which will meet your every need. All available at your local hobby shop, especially one specializing in RC cars...
Dan
Gary Weaver
If I'm not nistaken, thats what Silhavy and the Cleveland guys were using inthe 6o's.
BIGS
I asked once, did not get an answer...
"I hesitate to ask, but are you a member of PAMPA? So many of your questions have been addressed many times over that it appears as if you are not availing yourself of a really good source of information, Stunt News."
"To wit, in current issue I had written description *and* pictures of control linkage which will meet your every need. All available at your local hobby shop, especially one specializing in RC cars..."
Dan
Gary,
25 degrees flap and elevator movement will likely be adequate if the CG is kept at around 15-20% of the average chord. If you're much forward of that you might find you want a little more movement. You can always increase flap AND elevator movement by moving the bellcrank to flap pushrod to a hole closer to the pivot on the flap horn. This will increase the amount of deflection for a given amount of handle movement.
You can increase (or decrease, of desired) the amount of elevator movement by moving the pushrod closer to the pivot on the elevator horn. This is something you might find you'd like to try if your Twister comes out very light.
By speeding up the elevator throw relative to the flap you do two things to make the ship respond to control inputs more aggresively. First the additional elevator throw (for obvious reasons), second the reduced flap throw reduces what is known as negative pitching moment. When the flaps are deflected down they make the wing want to pitch "forward", i.e. nose over. This is exactly what would happen if the elevator pushrod broke and you gave up control. The flaps would go down, the elevator would trail flat in the slipstream, and the airplane would slowly pitch nose down.
If you don't need all the lift the flaps are providing you can reduce their throw and the airplane will be more responsive because of the reduced pitching moment.
Make any sense???
Ted