By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Getting The Dihedral Right On A Vic Smeed Tomboy.

All Topics | Latest Posts

Search for:  in Thread Title in  
David Davis10/08/2020 07:11:20
avatar
3833 forum posts
741 photos

I have told this story many times so apologies to those who already know this. It was my Uncle Geoff who taught me how to build model aircraft. He died young of cancer in 1961 but before he died he gave me all of his models including a Tomboy and the fuselage of a double size Tomboy. He had drawn up plans for a double size Tomboy, being a draftsman by trade, but over the years the wing plans have gone missing.

Thirty years later, after the sex 'n' drugs 'n' rock 'n' roll years, I completed his double size Tomboy, finished in the same colours as his 36" version. Picture of the model, barely powered by a PAW 19, with my much younger self below.

double sized tomboy.jpg

Unfortunately the years had not been kind to either to Geoff's balsa wood or to his glue joints so I built a second fuselage with all of the joints glued together with cyano and I fitted a Merco 35 in place of the PAW. This cured the lack of power but being a novice pilot in those days I somehow got the model into a spiral dive and when it hit the ground I was left with a big bag of balsa kindling!

I built a third fuselage but was hardly any better as a pilot when I crashed it into a tree and broke the fuselage.The wing and tailplane were not damaged so I put them in a big cardboard box and brought them with me when I retired to France. During the lockdown I built a fourth fuselage but given its very light construction, I decided to fit an electric motor. Pictures of the fuselage in the course of construction below. Note the immaculately tidy work bench!

fuselage taking shape (3).jpg

fuselage taking shape (1).jpg

I have examined the wings which I built in two halves joined together with steel rods to make transport easier and have found that the dihedral is lower on one wing than the other.

As I no longer have Geoff's wing plan, can anybody tell me what the dihedral measurement should be on a 36" Vic Smeed Tomboy? I will then adjust my wings accordingly.

Incidentally, while electric flight is not my major interest, I found that it was good fun to run up the motor on a variety of props to see what current it was drawing. Depending upon the propeller it drew between 30 and 40 amps on a 3S LiPo which should be enough for a model of this type and an anticipated weight of between five and six pounds. (2.5kgs - 2.7kgs.)

ammeter reading (1).jpg

ammeter reading (2).jpg

EarlyBird10/08/2020 07:33:21
335 forum posts
258 photos

Three and a half inches on each tip according to this

Tomboy plan

Hope this helps.

Steve

David Davis10/08/2020 07:38:01
avatar
3833 forum posts
741 photos

Thanks Steve, I'll work on seven inches for my model then.

brokenenglish10/08/2020 08:02:11
avatar
592 forum posts
30 photos

And the dihedral brace from the original plan should obviously still give the correct angle.

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
CML
electricwingman 2017
Slec
Sussex Model Centre
Sarik
Advertise With Us
Latest "For Sale" Ads
NEW POLL - has the pandemic altered your event safety perceptions?
Q: Has the covid pandemic deterred you from attending shows and events in 2021?

 No, I'll be attending just as many as I usually do
 No, but I'll choose my event with greater care
 Yes, I'll attend fewer events going forward
 Yes, I wont attend any where previously I have

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!