Inboard engine, inboard tank

So, I need some tips. Guess I need a clunk tank, right? Any engine run problems or odd behavior to look out for?

Still, Custom Models used the inboard mount as their "prefered" method on several of their profile planes. Maybe the fact that this is often called "Texas style" had something to do with it.

What engine are you planning on using on it out of curiosity? And does this mean that you are going to be flying another Magician?

So the builder was a fairly serious type. The only reason I bought it is because it was part of a kit/motor package deal. At $10, I couldn't turn it down. All it needs is a wing recovering. It has teeny tiny little wheels on it, so it must have been on pavement much of its life. I've been taking off of a basball infield lately (around shortstop, and I am standing in short left field. I try to land on the infield also, but don't always make it. But the outfield grass is so high, that it doesn't matter what size wheels you have. If it's landing over grass, I try to helicopter stall the planes in for a no-roll landing.

As to motor, I was thinking about using one of your FP 40s. I also have a Big Art OS-35-S. I have a Fox Rocket 40 with an extra head gasket and a venturi insert that would be interesting. I might play around with it some. Any ideas?

Matt's latest Stuka took nearly 200 flights before he had it trimmed where he was truly comfortable with it, and wasn't fully solved until 250 flights (and the second day of qualifying at the Nats). Most of this had to do with engine trimming and our unfamiliarity with the pipe. It was trial and error all the way until we found the winning combination. We tried two blade props, three blade props, different pipe lengths, different venturis, more nitro, the whole gambut. But before we got it trimmed, the plane fell out of the hourglass three times. Was the engine bad? Was the plane design bad? No. Once the engine combination was solved, the plane was basically trimmed (you never REALLY get through trimming--we are still working with slight "tweakings" after 400 flights) and it flies great. The engine is now running the way we think it should. Tension is as good as what we had with the previous plane and the Magnum .53 (turning the same prop, but with different pitch) and it has turned out to be an excellent combination.

What I am trying to say is, don't give up on a plane just because it doesn't fly right (or the way you want it to). If it isn't right, you need to work on trim, which, with the adjustable leadouts, etc., this new plane of yours will allow you to do. I would never build a plane again without all the adjustables. Matt has even resorted to adding a tail weight box to his last couple designs which allows him to easily add tail weight if necessary to get proper trim. (The new plane, by the way, now sports a magnesium back plate on the spinner and a magnesium head on the engine and no additional tail weight. But the easy ability of adding tail weight allowed him to determine where the CG should be.) Of course, it is always possible to wrap a little solder around the tail wheel wire, but that isn't as elegant of a solution.

Don't be afraid to try all of the variables until you get the plane into its best trim.

And of course we keep on trying. And one of those tries will be this new Magician.

>I didn't mean to give the impression that the Magician
>was a "bad" stunter. To the contrary, some people
>emerged from the BBs to voice their support of (lighter)
>ones.

Suggestion: have you ever considered trying to go "the wrong way," clockwise, like George does? You have to recover it -- maybe when you are examining the control system, you could just cut away the leadouts from the inboard wing, remove the existing tip weight (swap entire wingtips, maybe?) and "Voila" be flying with the engine and tank on the outboard side.

I successfully switched mouse operation to my left hand a few months ago, because I was getting pain in my right wrist near my thumb.
Wouldn't go back to righty. Old dogs can learn new tricks.

But if you are trying to learn to fly the other direction, you will either have to unlearn flying the "right" way, or you are going to have to fly with the controls crossed as if you were inverted when flying upright and upright when flying inverted. Gerry Phelps, who learned to fly clockwise as a boy (because that's the way his instructor flew) tried, on several occasions, to switch over. He said he gave up after wrecking a couple of airplanes.

I think in this case I would stick with the inboard mounted engine.

>I successfully switched mouse operation to my left hand
>a few months ago, because I was getting pain in my right
>wrist near my thumb.

Personally, I quit using a mouse in favor of trackballs, a couple of years ago; same symptoms were bothering me.
>

You'll also notice that this new Magician will fly much better with those false ribs. :-D

I have no experience with the I/B motor and tank mounting.

I just got a Magician kit, which is missing most wing parts, from a fellow club member as part of a trade. I could probably build a wing from the plans, but I would be much more inclined to move this kit up in the "build order" if I could buy a wing. Does anyone sell a balsa or foam wing for the Magician?

Tom Harvey

So, I would just suggest you build it. This way you can select your wood weights, use decent hardware, and do a first class job.

Leonard;

Have you got some addresses?

I have always thought there would be a good market for a company selling rib kits. A classic example for this is the old Ringmaster. The S1 wing ribs are the most challenging I have ever tried to cut - that center spar alignment and centering is a pain in the a**. The rub is if you want to fly a Ringmaster for OTS, you have to build the wing as Matt Kania designed it in 1950-1951 with all of its engineering shortcomings.

Now you have a nice punch. It'll go through rib balsa with no problem.

Brett Buck made this recommendation a while ago. Makes sense, but having never used a CF rod in construction I am not sure as to how exactly to install it. Any hints?

>
>>simplify it by using a
>>carbon fiber rod instead. It
>>would be much easier to
>>cut holes than rectangles, and
>
>Brett Buck made this recommendation a
>while ago. Makes sense,
>but having never used a
>CF rod in construction I
>am not sure as to
>how exactly to install it.
> Any hints?
>
>Regards - Bob Kruger

Just use it just like a regular spar, and use sharpened brass tubing to make the holes. Use Cyanoacryalate to glue the ribs to the spars - it's usually a lot better than epoxy on graphite parts. For the ringmaster, I would use maybe a 5/16/8mm graphite tube. Cut it with a Dremel cut-off wheel.

Anything would be an improvement on the stock system. David's Ringmaster wing fell off in a round loop.

I guess what I am asking is whether there is some obvious technique which I am not aware of.

Thanks, Alan

I don't know if it's obvious, but one way is to use a jig similar to the one shown on the Mustunt plans.

This is clearly a case of a thousand words instead of a picture!

Take a 2x12" piece of 1/8 plywood and drill a spar-sized hole in it about 3" from one and, and more-or-less in the center. Then draw a line down the middle centered exactly on the hole. Measure the distance from the desired spar location to the nose of the ribs. Mark this distance from the center of the hole in the jig (towards the short side of the plywood), and then glue another piece of plywood across jig perpendicular to the longitudinal line.

To use the jig, center the rib on the line, and butt the nose of the rib against the stop. Holding it all from moving, flip it over and use the hole a guide for your sharpened brass tubing.

Brett;

I checked Lonestar, but the only spar close to that in size was only 39 inches long. Do you know of a source for longer tubes? Or, is there a prefered method to splice them together.

> Anything would be
>an improvement on the stock
>system. David's Ringmaster wing fell
>off in a round loop.

As originally set up, the Ringmaster got most of its strength from its massive LE. That, coupled with the near pine density in many of the Sterling kits made for a LE and Spar that was certain to resist breakage. Did David do a lot of hollowing of the LE?

I would also be interested in knowing how he cut his ribs. Because of the long, thin nature of the airfoil I was not successful in getting the ribs cut using the two template/stack method.

At the risk of generating a stress riser, it might be basically ok to stop at the last rib that the CF rod naturally is longer than. It is the central part of the wing that benefits the most anyway, and it is true that the leading and trailing edges are pretty sturdy. You might check with ACP (Advanced Composite Products (?)). Isky's has a link to the correct site, but I haven't been able to log on there for a couple of days. If you feel like you need a full length span, one idea would be to find another CF tbe whose ID= the OD of the 8mm tube, and slip it over the two 8mm halves.
One thing that I did when I hollowed out my oak-like leading edges was to glue in some (much lighter) balsa "shear" webs at the backside of the leading edge. It gives some place to glue the rib edges to. Also I didn't hollow out the sheeted area of the leading edge.

Yes I know it is a lot of work for a Ringmaster!

You don't necessarily need a clunk tank, although it will work. Just mount the rigid tank with the wedge next to the fuselage.

Whether or not it runs differently depends on the engine. The most recent incarnation of idea was originally developed by another of us "rokit sientists", Frank Williams, for the ST60. The 60 has a tendency for fuel to pool at the top of the bypass with the outboard cylinder, which builds up until something disturbs it and it flows into the cylinder and puts out the fire temporarily. This is another gas flow problem with similar reasons to the Fox, although not with the same result. Putting the cylinder inboard doesn't allow the fuel to pool up, but instead it runs back into the crankcase. Not all 60's do this, just the ones where the bypass goes well above the port.

Note that Frank discovered the Fox "burp fix" when he tried putting the cylinder inboard, and it instead of burping on outsides, it started burping on "inside" corners! As soon as it became obvious that the cause is internal to the engine, the real fix shortly became evident.

If your engine turns out to be sensitive to this sort of thing, it will run differently, but if not, it will run just the same.

As Leonard points out, putting the cylinder and tank outboard does greatly reduce the need for tip weight, so I would only use an inboard mount to solve a run problem, not as the default plan. As your airplane is already built, just use as is and don't worry about it.

This is an interesting airplane. After rechecking it, I note that the nose moment is the same as a stock Magician (no wonder the builder made a tripler). The tail is longer, so he had to have cut a new fuse blank. And it does have the aforementioned half ribs added. And the lightening holes in the fuse.

All it really needs is wing convering, and some paint. Believe I'll use some Plyapan in one of the colors. Or maybe I'll Rit dye some newer color.