Originally Posted by Greg Knipp

Chris Jenkins, I have enlarged my Tomboy plans to a 48" version as well for a future endeavor. By enlarging the wood sizes do increase so I was wondering if you
used 1/4" sq. for the fuselage framework or stay with 3/16" sq. as in the original? Wing sprs obviously would be increased proportionally and in those respects I was going to utilize a upper and lower with shear webs. Did you do any other drastic changes?

Thanks....Greg Knipp

Hi Greg....I used 1/4 sq for the main longerons, and then for the cross bracing and diagonal bracing used 3/16 x 1/4.

I used the main spar as per the plan...but did toy with the use of 1/4" spars top and bottom with shear webs...in the end I stuck with the solid main. (I could have saved some weight).

The model comes in at 7oz/Sq ft...which gives a nice floaty model. As mentioned in the thread the only major modification was to make the undercarriage legs plug into two brass tubes in the fuze..with an external cross brace with a saddle clamp to hold the assembly in place. Also the tailplane is bolted on, and the wings two piece. It can pack down into a airline cabin baggage sized box....(with a bit of goodwill !)

The 48" version is a much nicer flying model than the 36" in an electric RC set-up. The 36" with a Mills 0.75 up front and single channel on the rudder is probably the best mode for the 36".

Good luck,

Chris

Thanks Chris!!!! I enlarged mine for the reason you gave as well. I figured it would fly just a bit better as RC assist with electric.

Greg

Originally Posted by Greg Knipp

Thanks Chris!!!! I enlarged mine for the reason you gave as well. I figured it would fly just a bit better as RC assist with electric.

Greg

Godd Luck greg....you wont be disappointed.

By the way...I used 2 degrees side thrust and no down, with the CofG just a little aft of that indicated on the plan.

What did you settle on for elevator width? I figured on 1" would be sufficient.

Hi Chris sorry for the delay, yes I get my mylar from Mike too

I've not had much time to get out and cover the Tomboy, but did a little more today, nearly finished another few hours how

I've got to give this tissue over mylar a ry. I just love the looks of the finished product and apparently it does not add alot of extra weight. Do either of you fellas have a seperate thread on the correct way of applying this type of finish?

Hi Greg, I'm just starting to 36 inch Tomboys, so I will add to this thread and take some pics and show you how its done, it does take some time, but its worth it in the end.

The Mylar adds so mush stengh, stops the model from twisting.


I dont always use tissue and dope, with the Tomboy above I used Mylar, then brushed balsalog all over the Mylar the used Litespan with a iron

The nice thing with the Mylar is you can add your design on top very easy.


Jiffy

took about 5 mins to stip and sand ready for recovering.

Originally Posted by Greg Knipp

I've got to give this tissue over mylar a try. I just love the looks of the finished product and apparently it does not add a lot of extra weight. Do either of you fellas have a seperate thread on the correct way of applying this type of finish?

Here is how I go about it:
First, the film (Doculam in my case, or equivalent) is applied only over the open bays.
Once applied and tightened, I wash it with rubbing alcohol to remove any trace of grease.
After that, I sand it lightly with fine abrasive paper (600 or 800 grit)
Then, I wash it again with white vinegar (this is supposed to mildly etch the film)
When dry, it is ready to receive the tissue which must be doped on wet.
The first coat will blush, but this disappears upon applying the second coat.
As mentioned above, it is easy to decorate afterwards with tissue.
Try it, you'll love it!

Originally Posted by JMP_blackfoot

Here is how I go about it:
First, the film (Doculam in my case, or equivalent) is applied only over the open bays.
Once applied and tightened, I wash it with rubbing alcohol to remove any trace of grease.
After that, I sand it lightly with fine abrasive paper (600 or 800 grit)
Then, I wash it again with white vinegar (this is supposed to mildly etch the film)
When dry, it is ready to receive the tissue which must be doped on wet.
The first coat will blush, but this disappears upon applying the second coat.
As mentioned above, it is easy to decorate afterwards with tissue.
Try it, you'll love it!

Pretty much the same for me, except that I use PolyC rather than dope...mainly because I can't get dope out here, but also because its water based, fuel proof, and produces a finish that cant be distinguished from dope. But I dont use a sandpaper rub on the thinnest mylar.

Cheers
Chris

Heres a few mor pics, nearly finished now, sprayed on coat of dope, and two coats of flair fuel proof, in the airing cupboard drying for seven days, then I need to glue the windows on and put all my links on for the radio

Originally Posted by Jiffy

Heres a few mor pics, nearly finished now, sprayed on coat of dope, and two coats of flair fuel proof, in the airing cupboard drying for seven days, then I need to glue the windows on and put all my links on for the radio

She looks very nice indeed Jiffy.....there is going to be a big factor with this one !

I'm thinking you will find it a much more agreeable model than the 36"...looking forward to the maidens report !

Had the chance to take the 48" Tomboy out yesterday in near perfect conditions for trimming...overcast, cold, and zero wind.

The only trim necessary was a minute degree of down evlevator, and similar amount of left rudder. With the CofG a little further back than shown on the original plan, the glide is flat and long. Alltogether a very well mannered model and really quite a floater in this guise.

Two 25 minute flights recorded (with a pack change inbetween)....a big factor with this model !

Hello, I am just starting an RC build of a Tomboy 48" from a Bob Holman short kit. The dihedral is show on the plans as 4" per wing, which seems a bit excessive. The plans indicate either RC or FF. What seems to be the optimum dihedral for the 48" RC version? Also, I would like to cover it with something transparentish and paint some trim on it. Would Solartex be too heavy? Looking at Polyspan also, but looks to be more of a pain to apply.

Thanks,

Mike

Hi Mike, as others have suggested in this thread I'd go with tissue over mylar as its strong and very light.
I'd also suggest resisting any temptation to alter the design or it wont be a Tomboy.
Rudder-only of course, it really doesnt need an elevator and hardly benefits from one anyway!
Cheers
Phil

Single-Channel Tomboy48 with rear-facing FlyCam (3 min 19 sec)

Single-Channel Tomboy 48" Maiden Flight (5 min 26 sec)