Charles,

I hope the attached items are helpful.

Dave F.

The drawing is to scale.

Proportioned measurements for Terrier fins:

Fin root length 30.8" (42.2" if swept length is included)
Fin tip length 5.6"
Fin leading edge cuff 1.5"
Fin Tip Trailing edge width 1.8"
Fin root trailing edge width 4.6"
Overall Fin span 59.8"

That's -really- similar to the Malemute fins, scaled from 16" motor diameter to 18". Except the tip chord. The Terrier swept delta fin has a smaller tip chord, and maybe a slightly wider span. I didn't run all the numbers.

Grrr... now I'm contemplating making a proper variant of the Terrier at this scale. That means i have to make a couple more 3.44" tubes. Well, the holidays are coming up and I've got plenty of vacation time.

A Talos with the Terrier-esque fins would be more challenging - I don't have another piece of 5" shipping tube. And probably wouldn't use it if I had. That stuff is -heavy-.

Charles,

Peel the inside layers and use a single layer of lightweight fiberglass cloth on the exterior or use Rick Boyette's "Quasi-Glass" method for reinforcement !

Dave F.

I don't think the hose will add much strength. I'd just give the tube a thin coat of resin and not go through the hassle of funny looks in the lingerie dept.

In my case, I 3D printed a 'sleeve' to go over the cardboard to expand the diameter to scale. I'm not worried about the strength.

I -should- have peeled the inside diameter. And would, If I did it again. I think I've epoxied the centering rings in place. If I haven't, then maybe I'll do the peel job. Otherwise I'll resign myself to 6 grain 38mm motors and a pound of nose weight.

That was Rick's initial approach . . . Later, for HPR, he started using "Drain Sleeve" material.

I have a PDF of that, but it is too large to upload . . . Let me see what I can come up with !

Dave F.

Rick Boyette's "Quasi-Glass" method . . .

The first 9 images show the HPR "Drain Sleeve" method . . . The last 2 images show the "Pantyhose Method".

"Drain Sleeve" . . .

https://www.lowes.com/pl/Drain-slee...ment=4294801513

Dave F.

More Terrier combinations

Chris,

That data is very interesting . . .

Are there any photo's of them available ?

Dave F.