Frank Sopwith

Guys,
lost mine after ten years of happy flying,
We hit hit each other during formation flying and my tail was completely chopped off, see this spectacular picture:



cheers,

Frank

valleyk

Some more pictures and still don't have nerve to maiden it.

TXAG96

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Beautiful Pup valleyk!

Don't worry. They fly great. I maidened mine this summer. I have a home made belt drive on mine.

valleyk

Thanks same to yours. I guess you read the book No Parachute too. Best ww1 aviation diary I ever read. Could you help me out and give me an Idea of where the CG should be from the lower wings leading edge?

pimmnz

1/4 the way back from the top wing leading edge to bottom wing trailing edge, plane in level attitude.
Evan, WB #12.

TXAG96

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Yes, The book was the inspiration for the paint scheme. It was a great book. I balanced mine per the plans which shows the balance point on the top wing I think. I will try to pull the plans out tonight and let you know.
With the belt drive I built I did not need to add any extra weight.

TKFOKKER

Hi Guys
I have a question on who is runing a belt drive on their Balsa USA Pup. Toni Clark? Mick Reeves? What set up is best, and prop size. Average weight of plane? So on and so on?
Thanks for all your inputs.
TK FOKKER
Tom Kosewski

foodstick

Toni Clark sells a G38 powered belt reduction system, swings a 32/18 .. My Pup flies great at 42 pounds. It will never be fast, but it flies so scale like.. I love it.. that big prop has an interesting sound when she loads up thru the corners as well, sounds cool at about 2700 rpm at the prop..
here is some of my onboard footage Oh I wanted to add,The weird rattling is my muffler working loose. I bought this motor off a crashed plane and the muffler bolts had been broken off in the head, so I was fighting the muffler working loose.. I THINK I have it fixed now.
http://www.youtube.com/watch?v=OsDWTn2C5VI

abufletcher

VERY cool that you can pan the camera!!! And VK, what a stunning job you did on your Pup. And Frank, at least that was an honorable demise.

foodstick

I didn't realize I hadn't commented on Frank being SHOT DOWN, it is a bummer, but spectacular.

I have looked at his plane more than once online, and I actually think he emailed me a pic? or posted some pics on request before. With a handle like Frank SOPWITH, you are bound to stick out in this thread ! I hope you build another, or get something just as nice in the air soon Frank.

TXAG96

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Valleyk- Sorry it has taken me so long to get back to you. The balance point is about 8.25 to 8.375 inches from the leading edge of the top wing which is about 2.25 to 2.375 inches from the leading edge of the lower wing. I flew it again last weekend and it really is a nice flyer.

TKFOKKER - I built my own belt drive but used ratios similar to the Toni Clark. I am using a Fuji 50 because that is what I had. I am also turning a 32-18 prop and it will spin just over 3000 rpm on the ground. 32 inches is just about scale for a 1/3 pup. Mine weighs right at 30 lbs. With the belt drive I did not need any additional weight to balance. It is covered with Sig Koverall put on with Sig Stix it. I used water based polyurethane instead of dope to fill the weave and then Behr latex for all the painting. I have Pull-Pull on the rudder and elevator and a servo in each lower wing for the ailerons. Mine is pretty basic but I am surprised foodstick is at 42 lbs. I find that the plane prefers to fly slow. Or at least I like it better that way. It is a real rudder plane. The ailerons are effective but the rudder is the key. I think I fly it at around half throttle or less most of the time even at take off.

Teus

Tom,

I fitted my Busa Pup with the Schlundt gear drive in combination with the ZG-62 and a Zimmerman exhaust as suggested in the Toni Clark catalogue. My Pup weight about 36 pounds and is a great flyer. This drive turns a 34x20 prop with 3000rpm. The 34" prop give just enough ground clearance. Also power to spare with this drive. Normal cruise speed around 1/3rd throttle. One minus for this gear drive is that the fly wheel is up front as you can notice in the photo.

foodstick

Maybe I should re weigh mine? I can't say I really recall when I did.. perhaps I am wrong.. I do however have those really heavy steel and hard rubber wheels off a buggy? or golf bag? I built a removable lifting tail, and covered with unrated ceconite for full scale experimental planes. I didn't really even try to stay light. I have read a few people that claim the heavy ones flew the best in wind, so I just didn't care... hahahah, it has so much wing !

vertical grimmace

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That looks great Tom. Can't wait to see it fly.

TKFOKKER

Gents thanks for all the input. My first pup weighed in at 42 lbs. I flew it off a old sach's 4.2 swinging a 24-10 I had great sucsess with her for 24 yrs. Lost it to a new radio refit and wrong programing. Anyway this 2nd pup i really wanted to have a belt drive in her that is why I asked. So I will most likely install a Toni Clark seeing I already have a z-38. Plane is about 70% framed. I will be covering with unbleached linen clear doped and finished in Dick Kings Rhinebeck pup from the early 70's
TK

TKFOKKER

Heres my old pup I lost last year.
TK

vertical grimmace

My Feedback: (1)

If anyone is interested, I have Q75 I am looking to get rid of. Seems like it might be a good engine for this plane.

crashwilson

Back again for some advice on this 1/3 scale Sopwith Pup. I built this plane according to plans, in the process of completeing the tail section, I made the decission to glue the horizontal on were it goes.Here's my question! With a impedence gauge on the center section with the fuslodge level, I have a 1 degree negative angle, which is great, But my horizontal stab. is at 1 degree positive.I have to pick my level up about 1/4 inch to have the horizontal stab sit level.How much of a problem will this be? If you look at it with the naked eye it looks level.

TKFOKKER

Vertical
What would the price be on the Q-75?

valleyk

This plane is not flying very well. The maiden required all the elevator trim up to keep the plane from nosing down. Well I thought maybe I had too much positive incidence on elevator so brought it down from +3 to +1 degree. Also I reduced maybe 1/4 pound on the dummy engine because it may be nose heavy. Well the second flight showed no improvement. I think I know what the problem is too much down thrust. When you let off gas she climbs rapidly when past 1/2 throttle she noses down. My question is if I reduce the down thrust by 1 degree will this remedy the problem.

foodstick

I think you are on the right track valleyK ... I think the old generic rule in most kits was maybe 3 degrees right and down.. Whenever I put a gas engine in a plane I usually have good luck usuing 1/16th washers between the mount and firewall. Looking forward as if you were in the cockpit I would use.

one washer on the bottom left .
two washers on the top left .
one washer on the top right .

With this setup the motor needs to be mounted about 1/4 inch above center, and 1/4 inch to the left of center, (looking from the cockpit)

p.s. if it glides well with the power on idle , its almost gotta be a thrust line issue.

TKFOKKER

Mount your engine flat on he fire wall, and fly her!! I have never put down thrust in any model i've built over 35 years.
TK

abufletcher

That's the way I feel. The original rotary engines certainly weren't mounted with down thrust. That being said, if your model isn't flying right with the engine mounted at 0-0 and it's not possible to alter the wing incidence/decalage then playing with the engine thrust would seem to be the only option.

TXAG96

My Feedback: (1)

I agree with TKFOKKER. I have no down thrust at all in mine.

eagledancer

0-0 thrust is where i have set mine. and this is my second pup. wing and tail incidences set as per plans. i do use quite a bit of down elevator trim but have found this to be normal on most ww1 planes that i have flown