Model weight

Stuka Stunt Main Forum · 6 of 6 known posts recovered

timme6 · Jul 09, 2001 09:05 AM

LAST EDITED ON Jul-09-01 AT 09:19 AM (EST)

I picked up a scale at the flea market over the weekend.
Weighed the recently completed Akromaster and the covered and clear doped Jr Flite Streak. Now keep in mind, that 20 years ago,
when I did most of my modelling, we didn't weigh anything.
We built and flew our plane without expectations of longevity, and weight was compensated for with more power.
So now I know better, and I've learned a lot from this board and others. Here's the question. The Akromaster weighs in at 23 oz, ready to fly, and the Jt Streak so far is 8 oz (airframe, covering and clear dope only). How are these weights?
Just for reference, my 20 year old Ringmaster with Fox 35, weighs 30 oz.

The Kiwi · Jul 09, 2001 10:04 AM

#1 source

>Weighed the recently completed Akromaster and the
>covered and clear doped Jr Flite Streak. Now keep
>in mind, that 20 years ago, when I did most of my
>modelling, we didn't weigh anything.
>
My bunch was using scales before then to help choose among batches of combat planes for the lightest, which we expected to be the one we could get the tightest turns from. Before that, we'd been hearing about 16-18 Ounce Fast Combats (including engines), but never knew too well what ours weighed. There was a USPO substation with a scale in it I took some stunters onto at times before then, however.

>We built and flew our plane without expectations of longevity,
>and weight was compensated for with more power.

Wish I could tell you about that Akromaster, but the only thing on hand at all similar is a Ringmaster Jr. that weighs 16 Oz with wheels, tank, and Fox 15.

>So now I know better, and I've learned a lot from this board and
>others. Here's the question. The Akromaster weighs in at 23 oz,
>ready to fly, and the Jt Streak so far is 8 oz (airframe,
>covering and clear dope only). How are these weights?

The Jr. Streak seems to be doing OK, at least.

>Just for reference, my 20 year old Ringmaster with Fox 35,
>weighs 30 oz.

By the same token, I've seen claims that Ringmasters have been scratch- built to weigh in the 24 Ounce bracket, as well as some admissions of modellers about having owned 35 Ounce kit-based Rings. I had a Shoestring that weighed 26 with a Fox .19, and several fullsize (both from kits and scratchbuilt) Streaks that weighed 21-22 Ounces with 36X's attached (most were in the 24-28 range).

timme6 · Jul 09, 2001 11:50 AM

#3 source

My old Ringmaster was a Sterling kit and has had some repairs done on it as well. One wing is covered in acetate sheeting and the reattached wing is covered in silkspan. It's quite the "Frankenstein" plane.
The Akromaster and Jr Streak are covered with Skyloft. I think that may have added to the weight somewhat. The material is very strong, but very pourous...porous....uh, has a lot of holes in it. So it takes more dope to fill it than silkspan would require.
Five coats of clear on the Akromaster. So far only three on the Streak.
in the future, I will have to try the polyspan that you recommended.
Thanks,
Tim

captcurt · Jul 09, 2001 11:35 AM

#2 source

I just flew my Akromaster again this weekend. Fox .15 slant. APC 8-4. will easily fly the entire beginner pattern.. It just doesnt like sharp corners--the Fox burps every time. Nothing I done has made it go away.

I believe it is at about 22 oz now with the epoxy/glass repairs!

I'll re-check it this evening. I flew it yesterday with great tension on 60' .015" lines. I wanted a speed check. It was ok even in the wind but I will refit it with proper .012 x about 58'

Cant tell you about the Jr flight streak but that sounds good to me.

timme6 · Jul 09, 2001 11:53 AM

#4 source

My Akromaster has an Enya 19 on it, so I guess the weight will be o.k. I was going o use 52' lines, but after reading your message I may try the usual 60'. Maybe 52's for the first flight and we'll see how it goes. Then move to 60's if needed.
Thanks
Tim

Steve Helmick · Jul 09, 2001 07:34 PM

#5 source

I am always suspicious of scales. Check its accuracy before you do anything. It may have some kind of adjustability, or not. If you look around at sport stunt and stunters, there is a fair correlation between displacement in Cu.In. and weight in Oz. For a .15 engine, 15 oz is good, .35 engine, 35 oz, .60 engine, 60 oz. Smaller models are more of a challenge to meet this rule of thumb. Clear dope weighs a LOT less and saves $$$. Steve