Scott Bair's Stuntfire

[Keith Renecle]

Hi All,

I saw comments from Randy Smith in the Rules section on Scott Bair's big, slow flying stunters. That sounds most interesting. Has anyone got any scanned plans or even 3-views for one of them. I would love to see how he got them so light! Thanks.

Keith R

[EddyR]

Keith
 There was a article in one of the magazines many years ago. I have some pictures of his planes in my archives. I was there the day he crashed his large .60+size plane. It came apart like a free flight. He went all over the crash and explained each part and why he did it that way. I never saw him fly again after that. If Randy doesn't post any pictures I will look up mine. I do have the article also. He had ST/46 size models also. They were built like stick and tissue FF models from the early 50's using stringers in the body.
Ed

[Ward Van Duzer]

Not only was Scott a master builder of super light weight airframes he was a master of engine mods. Randy tol' me he had some Super Tigers bored and stroked out to .88 Cu. Ins.

W.

[Keith Renecle]

Thanks guys,

I remember some years ago, his famous article was reprinted in Stunt News I think, on how he measured the pressure and performance of the rich 4-stroke type of run. This guy was really innovative.

Keith R

[RandySmith]

Hi Keith

The plans and article are available thru Model Aviation mag.

I have other parts of plans to some others here.  These are big ships, 62 to 66 inch span, use  3 to 3.5 inch spinners, full round molded bodies (balsa over stringers and formers)
They use 15 to 16 inch props, 65 to 88 motors. 4.5 inch bellcranks large tails ,big light wheels  boat loads of fun to fly. High parasitic drag designs.
Fly at 6.2 to 6.5 lap times

Randy

[Doug Moon]

i would like to know how he built those large models so light?

[Brett Buck]

i would like to know how he built those large models so light?

  Read the  MA construction article, it was very informative.
   
    Brett

[Dennis Adamisin]

i would like to know how he built those large models so light?

Lotz of air instead of balsa.  Light weight fixed equipment.  Very good craftsmanship.  For a heavy builder like me, Scott's Stuntfires read like fantasy...

[RC Storick]

i would like to know how he built those large models so light?

Use obtainium wood

[RandySmith]

Use obtainium wood

No there is no wood in there that you cannot find, normal contest balsa, Spruce, ply, etc

Randy

[RC Storick]

  Maybe your not getting it? I have some wood here that is all contest wood. One block weighs 2.1 and the other weighs 1 OZ. I wonder if I could find all the wood like that if the plane would be half the weight? Dah Yes!

But it can be found if I had 15 years to build a plane.

My new beamer electric is almost framed out and it weighs 14.5 oz. I am shooting for 28 ounces finished no motor or battery installed. 700 squares Shooting for 53-55 oz ready to fly.

[RandySmith]

Lotz of air instead of balsa.  Light weight fixed equipment.  Very good craftsmanship.  For a heavy builder like me, Scott's Stuntfires read like fantasy...

HI Dennis
Not really, you could build one of them, and make it very light too , using the same Techniques Scott used, and if yours is 47 ounces instead of 45...who cares :-)

Randy

[RandySmith]

Maybe your not getting it? I have some wood here that is all contest wood. One block weighs 2.1 and the other weighs 1 OZ. I wonder if I could find all the wood like that if the plane would be half the weight? Dah Yes!

But it can be found if I had 15 years to build a plane.

NO I get it, what I said was he used normal 4 to 6 pound wood,(contest balsa) he did NOT take 15 years to build all his planes, These can be built lite with 5 or 6 pound wood...very lite as in 46 to 47 ounces, he also used things like spruce spars for the wings, heavier than balsa but much stronger.

Randy

[RC Storick]

send me some of that wood please I have a white pine spar in this new plane.

Lets look at some of the weights of this plane.
tank 1 oz
prop and spinner 1.5 oz
wheels and LG wire 2 oz
engine 12.5 Supertiger?
bell crank pushrods and horns 2.5
Tubing and hinges and etc hardware constant weights 1 oz
That's around 20 oz Conservative and the planes weight is 45 minus the 20 lease a total ready to fly airframe with cockpit at 25 oz. Impressive to say the least.

A canopy weighs 1 oz and paint on that plane is at the lowest 6-8 so that taking into consideration we have a 18 ounce airframe. I would say that is exceptional wood.

[Brett Buck]

Maybe your not getting it? I have some wood here that is all contest wood. One block weighs 2.1 and the other weighs 1 OZ. I wonder if I could find all the wood like that if the plane would be half the weight? Dah Yes!

But it can be found if I had 15 years to build a plane.=

   Scott's airplane was built more-or-less conventionally with very careful analysis of the structural design, you know, that egghead stuff that doesn't matter. It was not unique at the time in the wing loading, several people (like Larry Robertson) had airplanes about the same weight, but I think Scott's held up better and were stiffer than the very light airplanes Larry built. They certainly had more effective "power".

    You can get all the light wood you need if you know where to look and have the right connections. I have two big boxes that average about 3.9 lb. You have to change the design to take advantage of it, you can't just take a fixed design and replace the 7 lb 1/16 with 3.5 lb 1/16

   Brett
 

[RandySmith]

send me some of that wood please I have a white pine spar in this new plane.

Lets look at some of the weights of this plane.
tank 1 oz
prop and spinner 1.5 oz
wheels and LG wire 2 oz
engine 12.5 Supertiger?
bell crank pushrods and horns 2.5
Tubing and hinges and etc hardware constant weights 1 oz
That's around 20 oz Conservative and the planes weight is 45 minus the 20 lease a total ready to fly airframe with cockpit at 25 oz. Impressive to say the least.

A canopy weighs 1 oz and paint on that plane is at the lowest 6-8 so that taking into consideration we have a 18 ounce airframe. I would say that is exceptional wood.

Scott's engine weighed 8 ounces for a 74  not 12.5
Scotts Bellcrank pushrods horns was lighter than 2.5 ounces  yada yada  yada,  If your trying to say the planes did not weigh between 43 and 47 ounces you would be wrong. I have them here plus more, they do still today weigh mid 40s
I am not sure why we have a fight about the weights of his StuntFires?

Randy

[Ted Fancher]

Scott's engine weighed 8 ounces for a 74  not 12.5
Scotts Bellcrank pushrods horns was lighter than 2.5 ounces  yada yada  yada,  If your trying to say the planes did not weigh between 43 and 47 ounces you would be wrong. I have them here plus more, they do still today weigh mid 40s
I am not sure why we have a fight about the weights of his StuntFires?

Randy

I can vouch for both the weight and the fabulous craftsmanship and innovation Scott put into his ships...at least the one I flew which was probably the one in Keith's picture.  If not, they were essentially identical.  The thrust to weight ratio was ridiculous and the ship could be flown competitively at the lap times Randy stated.

I'm a pretty good builder but the thought never occurred to me to try and do what Scott did.  It was amazing, that's all I can say.

Ted

p.s.  I'm going to try scanning my file copy of the Stuntfire article to see if I can get it readable on line.  My copy isn't great but if it works I'll try scanning the whole thing and posting it.

[RC Storick]

Every time I try to relate any ideas everyone thinks I am bashing the concept. STOP IT! I can post here too!

Did I anywhere say it didn't weigh that amount? F NO

And as to a 8 ounce engine where are these motors?

Brett I will buy all the wood you would like to sell at 3.9 LBS

[Ward Van Duzer]

Yes Ted,

It's readable but you didn't get the bottom of the page...


Ward

[David_Stack]

Good Afternoon All;

  Not certain this will be accessible by non-AMA members, but here is the article from the MA archives:

https://library.modelaviation.com/ma/1983/8/stuntfire-60

r/
Dave

[Trostle]

Hi All,

I saw comments from Randy Smith in the Rules section on Scott Bair's big, slow flying stunters. That sounds most interesting. Has anyone got any scanned plans or even 3-views for one of them. I would love to see how he got them so light! Thanks.

Keith R

Keith,

If somebody has not already got it done for you, I can copy that Scott Bair article from the August 1983 issue of Model Aviation and send it to you.  Let me know.

Keith

[RandySmith]

Good Afternoon All;

  Not certain this will be accessible by non-AMA members, but here is the article from the MA archives:

https://library.modelaviation.com/ma/1983/8/stuntfire-60

r/
Dave

Hi Dave

Thanks , It shows for me.
I just weighed a few of these, The fat one with a big case engine ST60  weighs 47 ounces, The large one with 66 inch span and over 700 sq in weighs 45 ounces.
The one here that is now in grey primer weighs 23 ounces with fuel tank built in. when built as Scott  suggest they are very light and amazingly stiff for the weight.  They do not require 2 or 3 pound wood, 5 pound wood , and a careful finish,will net you a mid to high 40s weight stuntship. The wing spars are spruce, not balsa, and still the wing comes out very light, it is thick so that helps it to be stiffer.
The link Dave posted shows photos of how this is built

Randy

[Brett Buck]

Every time I try to relate any ideas everyone thinks I am bashing the concept. STOP IT! I can post here too!

Did I anywhere say it didn't weigh that amount? F NO

And as to a 8 ounce engine where are these motors?

Brett I will buy all the wood you would like to sell at 3.9 LBS

   I have to save it for my numerous proposed mythical projects. I will post a picture later, at least you can see it. I am changing the design a bit to use it, no more 3/32 fuse sides for me. Phil got a bunch of blocks that were in 3 lb range, maybe even in the upper 2s.

   It's all about connections!  I will ask if my supplier wants to be revealed. It was quite an operation.

     Brett

[Brett Buck]

Thanks guys,

I remember some years ago, his famous article was reprinted in Stunt News I think, on how he measured the pressure and performance of the rich 4-stroke type of run. This guy was really innovative.

    The analysis you speak of was about the best engineering work I have seen applied to stunt. The pressure data was the input to my instantaneous torque plot. I think I have the article all put together as a PDF and I might be on the PAMPA website somewhere, so I will post it here later if I can find it.

    BTW it proves beyond a shadow of a doubt that the engines really do 4-stroke, and also why it doesn't lose half the power when it starts firing half the time.

   Brett

[RC Storick]

  I have to save it for my numerous proposed mythical projects. I will post a picture later, at least you can see it. I am changing the design a bit to use it, no more 3/32 fuse sides for me. Phil got a bunch of blocks that were in 3 lb range, maybe even in the upper 2s.

   It's all about connections!  I will ask if my supplier wants to be revealed. It was quite an operation.

     Brett

Exactly what are you saying about me? not only have I built at least 10 airplanes here on the NET I have posted pictures of everyone on of them. I too also have a scale and can weigh stuff just like everyone else.

You can ask your supplier but I doubt he doesn't want to sell more 3 LB wood.

[Ted Fancher]

Should have paid attention to the thread while I was trying to figure out how to scan and post.  Saw the full article from AMA just now so I removed the redundant posts.  Thanks, David.  Much more accessible your way.

Ted

[Ted Fancher]

Exactly what are you saying about me? not only have I built at least 10 airplanes here on the NET I have posted pictures of everyone on of them. I too also have a scale and can weigh stuff just like everyone else.

Sparky,

For Pete's sake, lighten up.  Brett didn't say anything about you or your building.  He pleasantly let you know that his stash of beautiful wood (I've seen it and PTG's and Uncle Jimby's and it's as good as he suggests) and the fact that it wasn't for sale because he has plans for using it.  His "Mythical" comment was a self deprecating poke at himself for his infamously slow rate of construction compared to his rate of thinking about doing so.

The only thing going on in this thread is admiration for another modeler's skills.  That's a good thing and it's the only thing it is about.  Nobody is throwing rocks.  OK?

Ted

P.s.  Scott's engines were super light for their displacement because he made his own oversized parts to stuff into smaller crankcases.  Scott was a great modeler and it's appropriate to discuss and praise what he had done.  You build and finish as good as anyone around and should be comfortable in a discussion of excellence.  That's all this is.

[RC Storick]

If you look back at my first post I tried to figure out how to get a 18oz airframe, Then I get a snide remark followed by another from another direction. In no way did I ever say that it didn't weigh 46 oz. Its a remarkable piece of work and I was trying to think how this was accomplished. I live in the show me state where we must be dumber than dirt and I need to see it. Thanks for posting the article.

[phil c]

Actually, if you look up some engineering data on balsa the strength to weight ratio goes up as the density goes down(assuming the light stuff is not wind checked).  Saw the same point in an article by Hal De Bolt.  He said he could build lighter by using somewhat oversized, very light balsa, even for things like gussets, bulhkeads, and stringers.  The larger sections are stiffer, and can be more easily tapered such as at the tips of the wings.

Phil C

[Brett Buck]

Exactly what are you saying about me? not only have I built at least 10 airplanes here on the NET I have posted pictures of everyone on of them. I too also have a scale and can weigh stuff just like everyone else.

You can ask your supplier but I doubt he doesn't want to sell more 3 LB wood.

   I am not saying anything about you. I just don't know if my supplier wants to be innudated with requests for more 3 lb wood. This is not a commercial operation and it was a very messy thing indeed.

   I don't understand the problem here.

    Brett

[EddyR]

Let me say this about Scott's plane. I saw it fly and after he crashes it he showed me all the pieces and how it was built. His motor stopped at the top of the circle and the plane dropped. My experience has been that when the motor stopped at the top of the circle the plane would continue over the top and glide to a landing. Scott's plane was so light it had no weight to carry it and the drag was high so it just turned in at him and with out line tension what can you do.. I had the same thing happen to me at Jacksonville many years ago. I was flying  my 48 ounce USA-1 slow at 5.8 and the motor stopped pointing into the wind at the top of the circle and it turned in at me and destroyed itself on the pavement. I have built a few very light stunters and I do not think they are very good all around models for are event. Just my thought on what was a very nice model.
Ed

[RC Storick]

  I am not saying anything about you. I just don't know if my supplier wants to be innudated with requests for more 3 lb wood. This is not a commercial operation and it was a very messy thing indeed.

   I don't understand the problem here.

    Brett

OOC my mistake.

[Brett Buck]

Let me say this about Scott's plane. I saw it fly and after he crashes it he showed me all the pieces and how it was built. His motor stopped at the top of the circle and the plane dropped. My experience has been that when the motor stopped at the top of the circle the plane would continue over the top and glide to a landing. Scott's plane was so light it had no weight to carry it and the drag was high so it just turned in at him and with out line tension what can you do..

   I never saw one crash, but I did see it land, and when the engine quit, it was going to land pretty quick. The stupid FAI 1-lap landing would have been pretty much impossible. The airplane I saw had an ST46 modification, was even lighter, and also had an exhaust throttle coupled to the bellcrank. Deflect the bellcrank, open the throttle. Just like Igor is doing with his accelerometer.

     The slow-motion part was something to behold. I have flown that slow but not with any sort of authority (6.1 at the 98 NATs) but seeing it when you are used to watching ST46 and 40FSRs bomb around the pattern was an eye-opener.

    I don't think this sort of approach was ideal but the fact that it was so well done was remarkable.

    Brett

[Brett Buck]

OOC my mistake.

  No harm done!

   But I hope you understand that as far as I know, we have no real problems right now. We might disagree over some things, and we will defend our positions,  but I certainly have no personal issues with you. If I did, it wouldn't be played out over the public forum, that's for sure.

   Brett

[RandySmith]

If you look back at my first post I tried to figure out how to get a 18oz airframe, Then I get a snide remark followed by another from another direction. In no way did I ever say that it didn't weigh 46 oz. Its a remarkable piece of work and I was trying to think how this was accomplished. I live in the show me state where we must be dumber than dirt and I need to see it. Thanks for posting the article.

Hi Sparky

You didn't get a snide remark from me.. you said "I didn't get it"  ..  I just posted that the wood was  not anyting special, just regular contest balsa, not 2 or 3 pound wood, it is as I stated , the design and techniques  is what makes it light , ME " not getting it"  had nothing to do with the post.
Or the weight of the plane that people asked about.

Randy

[RandySmith]

Let me say this about Scott's plane. I saw it fly and after he crashes it he showed me all the pieces and how it was built. His motor stopped at the top of the circle and the plane dropped. My experience has been that when the motor stopped at the top of the circle the plane would continue over the top and glide to a landing. Scott's plane was so light it had no weight to carry it and the drag was high so it just turned in at him and with out line tension what can you do.. I had the same thing happen to me at Jacksonville many years ago. I was flying  my 48 ounce USA-1 slow at 5.8 and the motor stopped pointing into the wind at the top of the circle and it turned in at me and destroyed itself on the pavement. I have built a few very light stunters and I do not think they are very good all around models for are event. Just my thought on what was a very nice model.
Ed

They were exceptionally good planes for our event, still are today, they are just like many other planes , not fun to land in high winds, so far as engine failures, that was an extremely  rare occurrence. They performed very well in winds, you just have to get them down on the ground quickly when the fuel runs out... just like a lot of other planes I have flown.

Randy

[RC Storick]

Scott's engine weighed 8 ounces for a 74  not 12.5
Scotts Bellcrank pushrods horns was lighter than 2.5 ounces  yada yada  yada,  If your trying to say the planes did not weigh between 43 and 47 ounces you would be wrong.
Randy

This is that statement that got me going. No mater what I post people someone is trying to prove me wrong. No where did I say it was not 47 ounces. These weights I posted are normal weights for things everyone uses. I did not know he had a custom made unotainum supertiger .60. The bell crank weighs as much as the one I use so the weights of 1/8 wire are around the same all over the world same with lead out wire.2.5 oz included all hardware in this instance. I never mentioned anywhere about the airframe except that it was exceptional at 18 oz. I was trying to figure hardware constant weight to see what the wood weighed. I was not privy to any use of custom made hardware so I could only weigh what I have on hand.

Its a great job in engineering.

[RandySmith]

You started off saying it was obtanium wood, I simply  posted it was not this lite because of the wood,  That was not a snide remark in any stretch of the imagination. He had one that was 47 with a  stock weight ST60,  that anyone can get .     The lite 74 will bring it down to 43 ounces. It is a wonderfully engineered airplane, and  me " not getting it" was still nothing to do with the weight of the plane...  That was why I stress it was not the parts you listed or the use of 3 pound wood.
You need to come by my shop some time when you are near.. you may be interested in many thing I have here, it would be fun too.

Randy

[Kim Mortimore]

Could flap stiffness be an issue, or does the light overall weight take care of that?

I have heard that the strength/weight curve for balsa does not continue to improve all the way down to the lightest stuff there is, but maxes out somewhere in the ~4 - 5ish lb range.  Does anyone have the straight skinny on this?  

[Brett Buck]

Could flap stiffness be an issue, or does the light overall weight take care of that?

     Everything stiffness could be an issue, however, if you want to fly 6+ second laps, this was the only way to go about it at the time. The structural design was well-addressed, it wasn't just taking a conventional design and making the parts lighter of cutting away a lot of it. The fuse, for instance, it pretty big. That added to the parasitic drag as intended, but also added to the cross-sectional area, meaning it is stiffer for a given weight, or lighter for a given stiffness.

   Whether that was worth the other compromises, who knows?

    Brett

[Ted Fancher]

This is that statement that got me going. No mater what I post people someone is trying to prove me wrong. No where did I say it was not 47 ounces. These weights I posted are normal weights for things everyone uses. I did not know he had a custom made unotainum supertiger .60. The bell crank weighs as much as the one I use so the weights of 1/8 wire are around the same all over the world same with lead out wire.2.5 oz included all hardware in this instance. I never mentioned anywhere about the airframe except that it was exceptional at 18 oz. I was trying to figure hardware constant weight to see what the wood weighed. I was not privy to any use of custom made hardware so I could only weigh what I have on hand.

Its a great job in engineering.

Yes it was!  Again, something I don't think I'm personally capable of reproducing and can only say "Awesome".  In addition, Scott was/is (I'm sure) a perfect gentleman and a pleasure to be around.  I thoroughly enjoyed our sole one to one visit and the opportunity to fly a unique stunt ship.

Ted

[Ted Fancher]

     Everything stiffness could be an issue, however, if you want to fly 6+ second laps, this was the only way to go about it at the time. The structural design was well-addressed, it wasn't just taking a conventional design and making the parts lighter of cutting away a lot of it. The fuse, for instance, it pretty big. That added to the parasitic drag as intended, but also added to the cross-sectional area, meaning it is stiffer for a given weight, or lighter for a given stiffness.

   Whether that was worth the other compromises, who knows?

    Brett

Brett,
Scott flew the airplane very, very well.  Whether he ever took competition flying to heart, I don't know.  The airplane would have required some "getting used to" for somebody used to flying lard bellied stunters like me but I've little doubt one could get used to the slower pace of the experience.  There was no lack of corner and, with his amazing modded engines, no line tension issues under the very nice conditions in which I flew it.

Ted

[Randy Cuberly]

Every time I try to relate any ideas everyone thinks I am bashing the concept. STOP IT! I can post here too!

Did I anywhere say it didn't weigh that amount? F NO

And as to a 8 ounce engine where are these motors?

Brett I will buy all the wood you would like to sell at 3.9 LBS

Bob Whitely has an 8 oz .75 Double Star in his Raven and a 7 oz 65 double star in his Derringer.  It's possible!!

I built a730 Sq IN.  Geo XL that weighed 53 oz with a 11.5 oz Belko Engine and muffler installed.  I didn't do anything very special and it had hollowed (and reinforced block construction for the top, bottom and cowling.  It didn't have anything like a concours finish but it wasn't all that bad before fuel was spilled on the BRODAK Dope that wasn't fuel proof.
I havn't seen Scotts airplanes but don't have any problem believing that it could be done with a little care and proper design.  I could build another GeoXL under 50 OZ easily.

Randy Cuberly
PS: In good air conditions (5-6 MPH wind) the GeoXL would fly an excellent pattern at 5.9 to 6 sec laps on 57 ft lines. Part of which was in the particular type of run of the Belko long shaft engines and prop.

[RandySmith]

Could flap stiffness be an issue, or does the light overall weight take care of that?

I have heard that the strength/weight curve for balsa does not continue to improve all the way down to the lightest stuff there is, but maxes out somewhere in the ~4 - 5ish lb range.  Does anyone have straight skinny on this? 

Hi Kim

It could be in some planes, I don't think this was one of them, The planes were so lightly loaded, and flew at much slower speeds, so they turned very well, even in high winds. As I said the biggest problem in winds was the landing, and getting it down quickly, as long as you did that, you were OK.
The StuntFire can be built by many people, it is not that difficult and flies very well with a ST 60 , or a PA 61 51 65 etc.....

Randy

[Dan McEntee]

    I just skimmed the article a bit and saw that he used 15-5 props! Wow! I just can't imagine a lap time over 6 seconds and the airplane pulls up verticle for the wingover! I would really like to see that done! The airplane loosk like it's built like a large , free flight scale model. I'll dig the mag out when I get home and read it through completely. With that type of fuselage construction, can you imagine what a Hawker Hurricane Stunter would look like?
   15-5 rev-up on a ST.60? All I can say is WOW!
   Type at you later,
     Dan McEntee

[Brett Buck]

Brett,
Scott flew the airplane very, very well.  Whether he ever took competition flying to heart, I don't know.  The airplane would have required some "getting used to" for somebody used to flying lard bellied stunters like me but I've little doubt one could get used to the slower pace of the experience.  There was no lack of corner and, with his amazing modded engines, no line tension issues under the very nice conditions in which I flew it.

  I watched this one's immediate predecessor, and talked to Scott about what he was doing at a contest for a good long time. He was about the first person I was able to actually relate to on the topic of the engineering of the airplanes. The coupled exhaust throttle just amazed me, I had tried various throttle gadgets but never on the exhaust. Mine never worked, his seemed pretty close!

     He was the first person to clue me in to the idea of structural analysis, as well.

      The bit about stiffness was more a comment on what we have seen over the years - one wonders if it was going to fly the same every time for years, at least with the sort of consistency you need. That's *why* they are built like tanks now in many cases.

     Brett

[Allan Perret]

Bob Whitely has an 8 oz .75 Double Star in his Raven and a 7 oz 65 double star in his Derringer.  It's possible!!

I wasn't aware of any DoubleStars larger than a 61.  Are these custom made ?

[Randy Cuberly]

I wasn't aware of any DoubleStars larger than a 61.  Are these custom made ?

Well, I'm not sure I would call them "custom made", but they were made in very limited numbers for Roy Trantham...They are only marginally available from time to time.
They are quite a bit different than the production style Doublestars and much smaller physically.  They run very well but are finicky about set up...require adjusting compression, intake size, and nitro content..They are definitely an experts only engine.
Personally I'll stick with my PA's and RoJetts...I don't think the extra 3 or 4 oz is any handicap and these engines are pretty much turnkey and run very well under almost any conditions.
In fact I prefer the PA65 with my setup (mostly stock) on a Randy Pipe even to a PA75.
The run quality is just about perfect time after time after time, and it does it on 6 oz of fuel or less.
I'm not criticizing the Doublestar engines..Bob's run like clockwork, as do Lou Wolgasts', but it did take a fair amount of fiddeling to make that happen...and they are essentially uobtanium...
The engine in Bob's Derringer is a perfect match for that airplane and it growls through the pattern...relatively low RPM four stroking runs with lots of power.

Randy Cuberly

[Keith Renecle]

Keith,

If somebody has not already got it done for you, I can copy that Scott Bair article from the August 1983 issue of Model Aviation and send it to you.  Let me know.

Keith

Thanks Keith, I did managed to get the article from the MA page but thanks for your kind offer. Thanks too for all the other info and I reckon that Randy is a blessed guy to have those models. Next time anyone flies one it would be great to see a video on You Tube (hint......hint!)

The "other" Keith

[Randy Powell]

I would note that with 'spidery" structures, you can use heavier wood of somewhat smaller dimension and get pretty much the same result. I've build airframes like this that are in the 650-700 square inch range and weighed under 20oz sans engine, gear and tank. My problem isn't building really light structures. It's keeping my finger off the paint trigger.