1fasthitman

Im planning on installing the os .91 fx in my Revolver. Ive previously been flying it with the .55 ax. How do I go about reinforcing the fuse and what speeds can i expect to see with a 12x8 prop?

NikolayTT

Peel off the whole surface of fuselage, wings, tail and coer with thin fiber glass. Then paint or
cover with monocote. Then better use 13x8, or 13x9 or 12x9 or 12x10. Then maybe you
come to 100-120MPH. Everything here is relative and lot of work assumed. Are you sure you
would like to go that far ? I have done but the flight is also too short because .91FX is
too "hungry" and there isn't much space for 2x bigger tank.

rwright142

Don't forget to balance afterwards. You'll need to add weight to the tail or move a lot of stuff aft.

NikolayTT

Instead of adding weight:
I reinforced the tail covering it with 2mm balsa on each side of the vertical and horizontal
stabs and then apply the fiber glass. That also requires changing the hinges and control
horns with stronger ones, and as well the control rods. Also, make sure to have separate
servo for each aileron and placed so to control point on the aileron is about 30-40%
from the outer end of the aileron. Surely all this might be not needed, but most likely
you would like to fly it more than couple times and then the repair will become needed,
i.e. better do it to avoit potential fatal crash due to fragility of the construction.

Yes, the amount of work is almost like 60% for building from scratch a new plane.
But then lasts quite long time; mine is already 3 years old and survived number
of not that friendly landings... Oh, yes, you have to reinforce the landing gear too
since your plane is quite for sure going to be about 30% heavier ...

mike boxtall

Why on earth would you want to put a 91 fx in to a revolver? If you just want to go fast, build a quickie 500 to fit a 91 fx. The Revolver is not a racer. Next time shop with your head and not your eyes. It is really alot cheaper!

NikolayTT

It is not the speed, it is durability of the heavier construction which
leads to higher wings load and then the speed gets higher but for
that one needs more power to handle. Quickie500 with .91 will
last maybe one flight ... or maybe even less ... thus is more
likely to be expensive trial without a flight ...

mike boxtall

I am all for powering a plane to its limits. I have a Revolver and have an O.S. 75ax in it. My point is how much longer do you really think that a revolver will last with a 91 in it. You can reinforce it all you want but all you are doing is adding weight to a plane that was not designed to have that much extra weight. Its airframe and was not designed for the speeds that the 91 will produce. I am not an engineer but I understand wing loading. The wing tube will fold or sheer out after that first or second flight. I haven't been flying for all that long, but I know that when I fly my planes I am being safe. All I was saying is that there are better planes out there for that motor. And safety is everyone's responsibility

mike boxtall

Also, is it really intelligent to put so much power in a plane that every time it is flown the pilot has to ask himself 'will it hold together this time?'

NikolayTT

Sure, it adds weight and you are right to look into those issues prior it is too late. But the problem
is that on the market there aren't many (if any at acceptable cost) planes which are designed to
last because is seems to me that is bad business plan for the makers and shops which make
more money when we buy more frequently, isn't it. As for the tube, you can add inside of it
another Aluminium or Carbon-fiber tube which fits well and the strenght will be preserved.
In fact those ideas are not quite "mine" only. Even in the big avaition several planes were
underpowered and then new engine fit in and then change the whole construction, for example
Thunderbolt, where they went from 1200bhp to 2000bhp and then changed the whole frame
and only the name was kept the same. That was not the case with the Mustang P51, they
planned with the Max-power engine at given weight and economic fuel use too. In this
sense, it seems the Aviation is always comming to the point how much power one can fit
in the fuse at lowest possible weight. Thus, .61 and 0.75 make to me little sense if I can
buy and use a good .91 since the weight is the same. Then it comes to the Constructor's
innovation how to strenghten the airplane to handle the power adding as little as possible
weight, isn't it ?!

mike boxtall

I understand what you are saying. But if you want to talk prices for planes that are designed to be quick with this motor in mind, There are quite a few from 'the world models'. IE: dago red and midget mustang and great planes has the little toni and the minnow. All reasonably priced. If you are going to put that much work into an arf why not buy a kit and build it properly suited to what you are going to be using it for. Or scratch build from drawings?

mike boxtall

Also strenght in the rod will be preserved if you go with carbon fiber, but not in the fuse of the aircraft or inside the wings. Reinforcing the fuse adds more weight to the overall structure and glassing the wings adds even more weight. My point is that there are more time efficient ways of going about this than buying something then taking it all apart. Doing things twice is not efficient either. If he wants the plane to do something other than what it is capable of, maybe he made a poor purchase and should have done a bit more research before hand. He would have saved cost of materials and down time of not being able to fly. You do not use a scew driver to pound in a nail do you.

NikolayTT

Well, you are right, the Kit is a solution but I am in this hobby already for about 30 years and then
and usually disagree with the Kit Designers on many issues, as I disagree with the ARF designers too
and then ARF takes less time to modify, at least the parts are cut, aligned and glued. In fact time
to time there are good ones Ready-to-Cover airplanes and that is the best by they are expensive
compated to the ARF which I just "undress" and cover in the way I wrote. As for the kits I am
scratch building things which are not on the market and there I get the ultimate pleasure.
Since you mentioned that you are not an engineer, I am a bit currious what is the major
profession you practicise - maybe that is quite behid your approach and view on the
matter, is it ? I am electronic engineer, and that is one of the two hobbies which turned
very nicely into profession; the other one hobby, airplanes, still remains hobby, let see
if turns into money earning, so far is only spending...

mike boxtall

I have bought arfs also and the glue inside them needed to be redone in many areas around the gas tank and servo bays. As for the quality i agree with you completely, needs to be better in many cases. I have not tried a ready to cover yet, but I have had a few accidents to my credit and have had to completly rebuild from a broken airplane. I am a carpenter by trade for 15yrs only. I have been in construction since 1987. I just bought my first full build kit from a friend, a super skybolt. That is my winter project. I have already found a few spots where I am going to have to make it stronger.

1fasthitman

Thanks all for the help. I am still happy with the revolver even though it still wont ever have the speed I dream of. Maybe Ill settle for a .61 or a .75 to go in it. To address the suggestion of a quickie 500 racer, I prefer a little larger and more scale looking plane, hence, the revolver.

Stickbuilder

One other point to consider. I used to fly Race models. I went so far that I was burning crankshafts (the connecting rod pins) every weekend. When you consider the cost of the modifications to an engine like the MOKI 3.6 twin (porting, ignition conversion, tuned pipes, carb mods, etc) and then you are puking a crank every week, it gets real pricey real quick. Of course cracking 200 is a real rush, but you had best have an airframe that will handle the job. I would caution you against trying for 125+ with an ARF. They (mostly) are not stressed for that air pressure, nor are the covering jobs up to the task. I would reccomend a glassed finish for anything approaching those speeds. That adds weight, and that requires a larger plane, which requires a larger engine, which requires.....The dog never stops chasing his tail. Been there, Done that. The cash register keeps on ringing, and your pockets keep getting lighter. However, It is tons of fun. Best of luck.

Bill, AMA 4720
WACO Brotherhood #1

mike boxtall

In regards to the Quickie 500. There are kits available from the Dominator class which are 60 size. I had a really bad need for speed. So I went out and bought a GP Viper. Only around $120.00 new. Then I stuck an O.S.46 AX on the nose with a 9X8 apc prop. With 15% cool power I was spinning that little prop @ 14300rpm. I have no idea how fast it really goes but every time I do a high speed low pass out of a dive I can hear people in the pit area saying 'woah' then laughing to themselves about how long it will be before I pile it in. Honestly I was not ready for how fast it was going to be at first and had a few scares. Just learning how to fly ahead it and not behind it took me awhile. I will probably never get into racing but I do have a really fast fun little sport flyer that did not break my bank. Also Hangar 9 just came out with a 50 size Sundowner. That might be a better home for your 91fx. I have an O.S.75 AX on my revolver. I have not flown it yet, gotta wait till spring. Even with the 75 it was still tricky balancing it. The plane was not designed for the 75. Its a 46-55 plane.

hydro182

We clocked a revolver with an os 55ax on radar at 114mph, not sure of the prop used, I was pretty impressed so I bought one. I disagree about needing to be fully glassed to do 125. My scatcat clocked 156 yesterday and it is only monokote and balsa.