[Leslie]

Hi

I was looking through my husbands plan collection over that last horrible snow storm. There I came across a quantity of oldtimer plans that look just so interesting. Plans such as: Buzzard Bombshell; Bulldozer; OldTime Satyr; Cloudster; and the Viking to name only a few.

I take note that these are similar in design, being high-wing with short noses and long hind quarters. They all seem to have their under-carriage placed well forward.

In the future I would like very much to try building one, but, have concerns about proper balancing. They all look to be tail heavy to start with, and once R/C gear is installed to upgrade the original free-flight characteristics, I imagine balancing issues would increase.

Do the pro's just pile lead into the front of these to balance? I can't believe that simply adjusting the battery position would be sufficient, especially considering there would be a fuel tank in the way. How are these beautiful planes balanced?




I hope someone knows. Thanks. Leslie

[cassat]

Yeah Leslie,

You need to set up a folding picnic table down the back road behind the forestry school
when the bears are out and pin down the plans. The tail feathers were usually built
with select balsa called AA or AAA grade....which meant super light. Sig Mfg became famous
for being able to supply these different grades or weights. Nowadays, we just build them
and modify a few sections according to our keen flying common sense as you have already indicated.
Williame should be able to add to this!

Cassat

[Leslie]

Originally Posted by cassat

Yeah Leslie,

You need to set up a folding picnic table down the back road behind the forestry school
when the bears are out and pin down the plans. The tail feathers were usually built
with select balsa called AA or AAA grade....which meant super light. Sig Mfg became famous
for being able to supply these different grades or weights. Nowadays, we just build them
and modify a few sections according to our keen flying common sense as you have already indicated.
Williame should be able to add to this!

Cassat

Hello Cassat

I'm not exactly sure what back roads and bears have to do with it, but, I certainly do not need to pin plans down on a picnic table to get an intelligent answer. May I please take the liberty to assume that you are just totally drunk. Have a good one.

Leslie

[cassat]

Nah, I'm still alive an kickin. I guess you missed the part about the Balsa weights and grades. AAA being the lightest grade.It is the force of mass leverage...kind of a physics thing from an engineering persective!

Regards
Cassat

[ricksed]

Hi Leslie, I just completed an oldie called a Kloud King that needed a pound of nose weight to balance so I extended the nose by 3.5 inches and moved the engine ahead.It changed the look of the plane a little but sure made it fly better.

[tom0187rc]

Hello Leslie


Here is a link to a company in Ontario that sells Buzzard and other old free flight kits for Radio Control. They may have sugguestions for best way to balance .Send them a e-mail since sell these kits sure have sugguestions for you.

http://www.soy.on.ca/BUZZARDbombshell.html

[RAMJET]

you could also use the new micro servos hitsc hs-55 /65, planes like this would need very little power to controll the surfaces & the very light weight of the small gear would help preserve the flight charistics of this type of plane .you could also use pull pull on elevator& rudder with kevlar cord or dental floss , this helps save the weight of pushrods in the tail .Roger

[ddruck]

I use to fly free flight 30 years ago, these models were not balanced in the usual 30% but close to 45 to 50%, they had a lifting tail airfoil which was the reason the cg was further back and they were designed to float with no change of attitude, the motors were quite heavy and the rest of the plane quite light that is why the nose was short. The modern versions of these should have a little longer nose to get the motor out and to get the radio under the cg or forward, but it is still a floater so control surfaces should be fairly small since you are just correcting a free flying plane, usually just small cut out tabs, this is no windy weather or 3d machine.

Dan

[Spitball]

ddruck has it right - most of these designs have a lifting tailplane and the CofG is like he said. Spirit of Yesteryear (SOY) is a good source of O/T kits, some down-sized for small electrics. The nose moment can certainly be made a bit longer if you're building from scratch - the engines were comparatively heavy and had an ignition coil, small capacitor (condenser in those days), and a couple of cells, usually AA size to power the ignition.
I do believe Leslie, that the landing gear was placed well forward to save the propeller from coming to grief as they were often hand carved. Sometimes makes the take-off a little squirrely!
Hitec HS-81s would be perfect for this application, on what were referred to as Class B power jobs! (Around 0,29 cu.in. displacement.) Small electrics would be about half-A. (0,049)
Now you're entering a whole new world of pleasure, Leslie - welcome.

[Leslie]

Hi

First of all, thankyou all for your generous replies, I'm finding this especially interesting.
I'm developing a mindset of what would be required to build one of these truly inspiring air pioneers, and only with your help. I believe the prerequisite would be to select materials with acute attention to weight and quality. The idea of Ramjet's "pull-pull" system with dental floss intrigues me. I intend to research the rigging of such an adventure and aquire a drawing of the system.
Also, I'm wondering if the CG was a little further back on the originals due to a lifting tailplane, would a modern drawing take that into account. eg. the Buzzard Bombshell plans we have are from RCM and show servos; they were probably converted from a freeflight drawing example.
I'm not sure if I'd care to make the nose longer, as I'm afraid that may remove from the character of the plane and make it something entirely different. Perhaps adding one of those heavy Higgley nose-cones is an alternative.
Anyway, I'm going to make a discision on what oldtimer plans out of the horde I would like to build off of, and then formulate a building plan based on your input and help from my hubby.
Maybe one day it will even fly if I can build it.

Leslie