Thunderbird kits

[Lyle Spiegel]

I apologize if I'm repeating an old mropic.
Can anyone comment on differences between Brodak kit and the RSM kit?
Thanks

[Dennis Adamisin]

Hi Lyle
The Brodak kit is of the "Original" T-bird with the upright engine & turtledeck style canopy.  The RSM is a later T-bird with inverted engine & bubble canopy.  Brodak says 54" span & 569 squares, RSM says 56" span and 570 squares.  Think they are pretty close aerodynamically but have not actually compared the plans side by side.  Really cannot go wrong with either of them.

[Air Ministry .]

Mk 1 & Mk II Thunderbirds ?


The BOOTOM one is the BIGGER plane .


Some guy in the World Chaps used a Mk II with the bubble canopy shipped back , to the rear of the wing , sunburst paint job , for a ' differant ' look . Looked Good .

[Lyle Spiegel]

Enjoying looking at plans posted by Air Ministry.  Interesting that neither plan has the unique differential flap setup that was in the Veco kit of version 2.
Does anyone know how the differential flap setup came about? Did Bob Palmer or anyone else use tht setup back in the day?

[Andrew Hathaway]

If you look closely, the second plan shows the differential flap setup.  It's the later Veco/Dumas kit version.  The flap horns are different heights, one horn on each flap with a Y in the pushrod. 

The RSM Thunderbird is smaller than the Veco/Dumas kit. 

[Air Ministry .]

Ive built Thre of these , all with differential flaps . And Elevators ! . ( 1 / 32 in. diff horn , shorter inbd. . Intrestingly the ' bluepants ' ( Henri stouffs ) has a ASSYMETRIC TAILPLANE & wing . Bigger Inboard . )
Vee Tail - anheadral , needs dual pushrod ends .




The Folkerts I used them on the flaps ,
NOW I prefer a mega stiff control set up . No Torsional Twist - but free moving ,
I think the Diff set up is good for ' throwing it out ' against the lines , Also for real slow flight - That 35 ship , above , at 68 / 70 foot , 10 x 4 three blade on the OS 35 . Definately better / more consistant tension
The one on 55 foot ( say 58 total - same as Gieske ! - ) Told it was hingeing - hitting hard squares in firm steadish cool 18 Kt wind . BUT was fixed tip weight ( Earlier Plane ) & I didnt really give a toss , as it
let you hammer the squares , or was because you hammered the squares . Not the modern larger chord outer flap . Which our Dutch freind imforms us is to get Sq & Round / Tip Weight balance .- eveness .

But nothingll steer without the lines tight , when your fighting it ( Not Calm Air ) So I think for a any weather ' lets go flying ' plane , theyre not a bad idea - and save tip weight .
Id vary the line length / weight  for calm / moderate / breezy  flying - at the same model trim .  say 55 x .018 , round 60  x .015 , and out at 70 .012 , but youll break em if it turns in , out , across
and snaps the lines tight hard . ( You gotta run WITH it -  let out your arm as it grabs ) So thats that on that .
The hook up dosnt want to be all wobbly - 2.4 / 3 /32 min on the little one , 2.7 mm ( 12 Guage ? ) on the larger .
Intrestingly , removing the elevator slop on the Green IDf one , it couldnt steer straight for quids , till I ' re slacked ' em .  5 mm T E  ' wobble ' Reqd . For good groove ( and in rounds ) Aft C G & Snappy Square
CORNERS . Even in GALES .Hold on clench your teeth keep your eye IN and Run Real Quick if it snaps loose free flighting . Grabing it tight removes a good deal of inirtia before it hits , if you cant save it .
Soft Ground Recomended  . For learning the P's & Q's of dealing with adversities . Like DONT get the Nose Up , if you recover inverted, upwind . Or youll be sprinting & dodgeing all over again .
2 nd houglass corner & into Clover . A balancing game , SNAP it in & itll skive of over your right shoulder - If you run downwind quick you may get it before it hits - upwind . See ' P's & Q's - >

Folkerts is at home in the Wind , whiffem . !

[John Park]

Juhani Kari, who placed second at the World Champs behind Juri Sirotkin with a kit Mk. 2 T'bird, used the same control set-up (differential flaps, over-and-under leadouts) on his own Nakke design.  I've got a copy of the original Finnish plan, and it's amusing to note that whoever drew it got things the wrong way round - the inboard flap horn is shown longer than the outboard horn!  I wonder if anybody's actually built a Nakke like that - and if so, what was it like to fly?

[Lauri Malila]

Juhani Kari, who placed second at the World Champs behind Juri Sirotkin with a kit Mk. 2 T'bird, used the same control set-up (differential flaps, over-and-under leadouts) on his own Nakke design.  I've got a copy of the original Finnish plan, and it's amusing to note that whoever drew it got things the wrong way round - the inboard flap horn is shown longer than the outboard horn!  I wonder if anybody's actually built a Nakke like that - and if so, what was it like to fly?

Yes, that's a mistake in the original Nakke Drawing. I's been verified from Kari's friends, and from the orange-black Nakke in the Finnish aviation museum. So, it should be the other way round like in Thunderbird. L

[john e. holliday]

In the early 60's I built a Veco Thunderbird.  The instruction sheet showed where the front formers could be turned over for an inverted engine set up.  I opted for the up right for easier engine starting.

[Steve Helmick]

If you look closely, the second plan shows the differential flap setup.  It's the later Veco/Dumas kit version.  The flap horns are different heights, one horn on each flap with a Y in the pushrod. 

The RSM Thunderbird is smaller than the Veco/Dumas kit.

Bob Palmer himself used the differential flap horns on the T-Bird II ('59 or '60 NATS winner) and also his Skyscraper published in MAN. He discovered on his own that the amount of differential was way too much. Local, late, great Bob Emmett drew plans for the T-Bird II that I've read was the basis for the RSM kit plans. I don't know what Bob E. based those plans on. Perhaps he got a Palmer-built T-Bird II to copy? Anybody know?

From the latest developments of Ted/Brett/David, and others (added area on the outboard flap) it would make me wonder if having more flap travel on the outboard flap might have worked better than the way Mr. Palmer did it. You never know until you try stuff, which is why Paul is so dangerous...he is always experimenting with new ideas. Where the ideas come from seems to be a mystery. Probably has a notepad next to the bed, I'm thinkin'.  Steve

[EddyR]

 My win at the 1989 KOI was a early version Thunderbird. Something happened to my Juno and I had to fly the very old Thunderbird. Fox 35 powered.
EddyR
     
  well I found a picture of the old Thunderbird as used at the KOI

[Dennis Adamisin]

Bob Palmer himself used the differential flap horns on the T-Bird II ('59 or '60 NATS winner) and also his Skyscraper published in MAN. He discovered on his own that the amount of differential was way too much. Local, late, great Bob Emmett drew plans for the T-Bird II that I've read was the basis for the RSM kit plans. I don't know what Bob E. based those plans on. Perhaps he got a Palmer-built T-Bird II to copy? Anybody know?

From the latest developments of Ted/Brett/David, and others (added area on the outboard flap) it would make me wonder if having more flap travel on the outboard flap might have worked better than the way Mr. Palmer did it. You never know until you try stuff, which is why Paul is so dangerous...he is always experimenting with new ideas. Where the ideas come from seems to be a mystery. Probably has a notepad next to the bed, I'm thinkin'.  Steve

In the Skylark article of December 1963, Ed Southwick talked about making his outboard flap larger, He also said he thought differential flaps would work better if they were hooked up in reverse...