Propwash

As long as you don't expect ott aerobatics then its fine, large loops etc no probs also mine balanced perfectly with no added weight anywhere. One mistake I did make was to use the standard silencer (which kills the engine) now using a BCM inverted silencer and the power gain is very noticeable. Ignition and battery mounted underneath undercarriage in a ply box, works very well. Will post pics if required.

Til,

Pictures would be nice, one of the guys at our field has one with a OS 120 4-cylce, flys scale like but not much else. I was thinking a MVVS 160 should be better than that.

Ross,
Would really like to see more pictures of your setup, especially the smoke system.
I was also wondering what you were using for a engine/muffler? I have installed a tap in the stock OS120 muffler and plan to add a preheater (12" length of copper tubing wrapped around header) and was wondering if this would work (never added smoke to glow setup, only gas). Also glad to see another RI'er on here... [8D]

Sorry for the delay,

I'll post some photos of the smoke set up for you tonight. I think it works pretty well and you can set it up to sit over the CG. As it turns out I'm a little tail heavy! It's a little tough on take off but in the air it is sweet and the landings are smooth and slow with no bounce. I was always told that "nose heavy flies and tail heavy dies" but it's not too far off.... maybe a 1/4 inch.

I tapped a nipple on upper bevel on the muffler of an OS 120. It is close to the header pipe and it appears to put out some heat. I'm running 30% and thought about wrapping the header with copper tubing as a preheater... did not because I of lack of tube. All in all it gets hot enough to make smoke and it was quick cheep and easy.

My club is having a FUN FLY on Sunday. You are more than welcome to join us! Send me an e-mail if your interested.

Ross 3951

Propwash-don,

I have a light weight 40cc engine I got from Brillelli that I plan to use on this plane. I know it my be a little over kill, but this is the engine I have at hand. The Brillelli 40GT only weigh a little more than a Zenoah G26 people are using on this plane so it should work fine. The Brillelli swings a APC 20x8 prop at 7100 RPM and that provides over 18lbs of thrust. Should be very nice on this size of plane.

How did you guys balance your GP Super Stearmans? I have a GP machine balancer and it seems the cabaines get in the way not the mention I guess I have to put the balancer on a wide board or something since the height of the plane is higher than the balance machine itself. I can get this to work alright, I was just wondering if there is an easier or better way to balance this bird?

Have a friend put a finger the right distance behind one end of the top wing tip, and do the same yourself on the other side's wing tip. Just raise it off the ground enough to tell which end is heavier and balance accordingly until it's level.

The easiest way to balance the GP Super Stearman at home is to clamp two pieces of wood, about 16 inches apart, to over-hang a table about a foot. Tape a long dowel (old push-rod) to the underside of the top wing, located per the instruction manual. This is your fulcrum, i.e. CG. Now place the model's fuselage between the over-hung sticks with the dowel resting on the sticks. Set the stab to zero by adding frontal weight, using a level on the stab. Done! (Update: The cabane interferes with one long dowel...use two dowels.)

Wing incidence.
Forget what you heard, forget what the so-called "expert" wrote in the modeler's magazine lately, forget what you see on the Tower website. Her's the straight scoop, proven with three Stearmans:
With the stab set at zero, the bottom wing should also be at zero degrees. The engine should be set at minus one degree. The top wing should be set at Minus two degrees.
Result: 1. the model will not climb when advancing the the throttle to full.
2. inverted flight will require less down elevator.
3. there will be less tuck to the wheels when flying in knife edge.
4. bounced landings will be a thing of the past.
Setting the upper wing requires two longer L-brackets at the rear wing struts. Do some trig to to find the new hole location in the bracket. Along with this, the cabane location will change at the fuselage, and the aft screws may miss the hardwood mounting block. I simply drilled new holes in the cabane.

Good Luck!

P.S. I also have an aileron connecting rod location that works properly.

Here are photos of my smoke system.

Materials needed: 1 - TME Simple Smoke Unit
1 - 4 oz fuel tank
1 - 4 cell battery
1 - 6" servo extension
1 - Y harness
1 - in line fuel filter
1 - 3' length of fuel tube
1 - 4" x 5 1/4" x 1/8" ply board
2 - 1/4" x 1/4" x 4" balsa sticks
2 - 10-32 blind nuts
2 - 10 - 32 x 1/4" screws
2 - small wood screws
2 - medium size wire straps
1 - 3" x 3" foam padding
1 - exhaust nipple

Most of this I had in my building area. the Smoke pump and a gallon of smoke fuel were the only things I had to buy. That was $100.00

Here's how I did It.

Assemble all the components and place on ply board. I used tape to hold the assembly together and test fit in the fuselage. I wanted the pump as far away from the rx as possible. I also wanted the 4 oz tank to be easy to plumb and have the clunk toward the tail. Once everything fit I removed the tape, marked hole locations and drilled holes for mounting the pump and tank. I used the blind nut and screws to bolt the pump to the ply board. The wiring from the pump was attached to the Y harness. One end goes to the rx by way of the 6" servo extension, the other end is for charging the pump battery. I followed the instructions that TME provided for plumbing the system. The wire straps held the tank, battery, tube and wires together.

I glued the 1/4" x 1/4" x 4" balsa sticks in the fuselage to make mounting rails. While the glue was setting I installed the 6" servo extension in the rx in a channel that is typically used tor retractable landing gear.

Then I set the unit on the rails and assembled the plane to check the CG. This was done several times before it was correct. Once satisfied the ply board was screwed to the rails and the system was tested wings off. I set the flow rate as recommended in the instructions provided, assembled the plane and went for a test run.

Thanks for the great pics Rich!
I like the "rails" idea... as it's sort of modules and easy to remove in case you had to get down under it.
I'm probably going to go with a little bigger smoke tank, so might have a little issue getting it directly under the C.G.
I'll let you know how I make out with mine (was hoping to maiden this year... we'll see)

Here's a pic of that preheater tube I bent around the OS 1.20 header, granted, it wasn't easy (used a pc. of flex cable inside the tube, bent it around the header pipe, then painstakenly pulled/removed the flex cable from the tube while retaining coiled shape)
As you mentioned... I probably won't need this but it'll be intersting to see what it does...

It looks like it's going to be a wet Labor Day weekend so I"ll have time to work on my planes.

I too was thinking about a larger tank for my smoke system. If I move the rx and smoke battery's to the "lead box" in the cowl, that should open up more space in the fuselage and will put useful weight in the nose. They will have to be insulated from heat but otherwise this should work.

The battery's will be faster / easy to get to under the cowl than in the fuselage. IMHO removing the wings on this plane is a pain. I transport and store the Stearman fully assembled and ready to fly.

I like the copper preheater! I should have done this in the beginning. While the plane is apart I will install some copper tube and see if this makes a difference. I agree that this will be an interesting test.

Ross 3951

Hi Rich,
Yeh, weekend looks like a bust eh?. Monday (our club's Fun Fly) it is suppose to clear up but maybe still a little windy.

I was also looking into mounting the smoke pump and pump battery where the lead box usually sits as I was hoping this weight would be good enough to get the CG correct. (btw, are you using an OS 1.20 pumper and also lead in the box for CG?... and if so, how much lead?)

(pic below shows where I was thinking of mounting the pump... battery would get mounted on top of firewall...just worried about vibration of engine though...?)

Hey Tom,

If Monday looks good I may head up your way. Our Fun Fly has been postponed. That's the third time this season. It would seem like the higher up's have not been watching the weather channel.

It took about a pound of weight up front and it sounds like a lot but that O.S 120 pulls it well. The rx and smoke battery's were moved up front today and a larger smoke tank went in the fuselage. The only thing I didn't get to was the preheater. That has to make a different's. I need to go to the hardware store in the morning and copper tube is on the list.

Vibration may be an issue but that would otherwise be an ideal location for your pump. If it came down to it, mounting with a rubber shock pad should work and you'd still have room for your battery on the firewall.

What does Doctorgo mean by minus 1 and minus 2 degrees? Does he mean he is putting +2 degrees incidence on the top wing and +1 degree incidence on the engine?

Copied from his post...

"With the stab set at zero, the bottom wing should also be at zero degrees. The engine should be set at minus one degree. The top wing should be set at Minus two degrees."

Negative (minus or "-" ) incidence... not positive (plus or "+" ).

I don't recall a post about anyone having problems with the aileron control rods.
I installed them according to instructions, and can only get about 3/8 of an inch down control on the bottom wing aileron because the top wing aileron control rod straightens out on the control horn and can not travel any further. I'd prefer not to keep drilling holes to find the right place.

I test flew my Stearman today and it flys great! I have a Zenoah G26 on it and it balanced perfect right at 5 1/2 inches. I used the Dubro air filled wheels and had no bounce. I did go with the four aileron servo hook up because I just could not get the correct throws and the right hook up with that aileron connecting rod no matter how much I tried. With the four independent servos on the ailerons I was able to get the exact throws and boy does it roll nice and fly scale. I'm very happy with it. It is very stable in the air and very controllable.

Skyventures,

Check out post 161 of this thread. Somewhere in that area is very helpful info regarding this issue. Apparently there was / is an amendment to the manual. I followed the recommended new location (I believe it was 3/4" from the TE on top wing) and that was that.

Ross3951

Okay all of you Super Stearman fans, check out my video!!!

http://www.rcuniverse.com/mvp/videolink.cfm?postid=2985

Live and learn!!!

Do the wings come off for transportation?

Thanks for the video Lou55

Yes its something so easy to forget and the video is just a good reminder at how quickly this plane loses speed.

Good to hear that the plane is / is getting rebuilt.

Til

Amazingly the wings stayed on. I pulled out the landing gear (easy fix as the glue joints broke), broke the prop and cowl, and took out the two right wing halves. I already had a replacement gear and had the fuse and gear back in pristine condition the next day. I've received the new cowl and N-struts and am waiting for Tower to get the wings in. I do intend to replace the engine as the 1.20 Magnum flew the plane nicely but purely scale. I may go with a large 2-stroke as the plane has an on-board glo-driver to keep it reliable at low rpms and with a 18x6 may be able to horse the plane around a little.

I noticed in the video your take off, I also have a super stearman. She is a handful on the ground alright. What I did to help was toe the wheels inward . I cut a washer in half and put the two pieces on the back sides of the axels and tightened them down. This really helped her track in a nice line on take off and landing as well because as you know she needs to come in fast. Hope this helps, Phil

Thanks for the tip. When I first built the plane it didn't seem as bad if I just gunned it but for some reason it got worse. May have been the inflatable tires I put on. If you look at the Maiden flight video it did the same thing though.