Author Topic: A Size Stunter (Read 2513 times)

Phil J · « **on:** September 01, 2022, 04:34:10 PM »

Greeting,

I have for quite sometime had a couple of New OS 10 FSR engines and I finally decided to relive some of my best childhood memories learning to fly with my Dad's Jr. Nobler. Decided on building a scaled down version of Billy's Juno. It's ready for the finishing process and currently weighs in at 18 ounces with engine and muffler. The CG is good but i am concerned it might wind up being a little "Porky" with a silk span & dope finish for the engine. Can anyone help with what would be an acceptable flying weight. I have had my share of planes that look okay but do not fly or I should say "Stunt" very well hoping this doesn't turn out to be another "Boat Anchor"

Happy Flying,

Phil Juarez

Phil J · « **Reply #1 on:** September 01, 2022, 07:01:06 PM »

It's approx. 302 Sq. In. 40" wing span

Dwayne Donnelly · « **Reply #2 on:** September 01, 2022, 07:04:57 PM »

That is some nice work.

Paul Taylor · « **Reply #3 on:** September 01, 2022, 08:22:47 PM »

I suggest this stuff.

https://www.towerhobbies.com/product/ultracote-parklite-white/HANU0801.html

Steve Berry · « **Reply #4 on:** September 01, 2022, 08:32:50 PM »

I would say top end of 27oz, no more. That would give you a wing loading of around 13oz/sq ft, which while a little heavy, will give a solid feel on the lines and should handle the wind without issue.

Steve

Phil J · « **Reply #5 on:** September 02, 2022, 04:32:48 AM »

I appreciate your input Steve.

Thanks,

John Park · « **Reply #6 on:** September 02, 2022, 08:08:37 AM »

Your engine is probably comparable in power to the OS-Max .15-III I used to fly (with an extra head gasket in an attempt to get a 4-2-4 run) in a succession of own-designs, some of which were quite decent performers. The models were mostly about 350 sq. in. wing area, and I regarded 24 oz. as the absolute maximum weight for a good stunt performance. A 3/4 scale modified Al Rabe Mustunt I, wing area 275 sq. in., weighed 22 1/2 oz. and was too heavy: its wing loading was about 11.8 oz./sq. ft. I think it's accepted that the smaller a model is, the lower its wing loading should be, and I'd regard 10 oz./sq. ft. as the maximum for models of this general size. For a 300 sq. in. model, I'd aim for an all-up weight of 20 oz.

Tim Wescott · « **Reply #7 on:** September 02, 2022, 08:17:06 AM »

Some thoughts, but no guarantees:

Use tissue, and let it show. Before they went out of business I'd have recommended Esaki, but ... Easy Built Models recommends Mt Fuji for people who liked Esaki, and they've got a lot of colors.

To save even more weight, sacrifice some shine and use colored tissue for trim. I've covered a couple of 1/2-A planes this way, and it looks nice in a "not a stunt finish" sort of way
Esaki is great on open bays (like that beautiful wing), but really hard to get right on solid structures, because it's so dense. That density is part of what makes it great stuff -- you don't use much dope -- but you simply cannot paint through it to stick it down. I'd use some "domestic" tissue on the solid bits

Put yourself out on a limb and use tissue over mylar. The freeflight guys use this and love it -- but I haven't seen it in person, they don't get judged for "pretty", and I've heard horror stories from first-time users of the technique
Use lightweight plastic covering . This would certainly give you some shine without much work -- but if you take that road, make sure it's fuel proof. Some of the lightweight coverings use adhesive that dissolves in fuel[/i]

John Rist · « **Reply #8 on:** September 02, 2022, 09:41:40 PM »

Ty tells me that plastic covering can be a problem. Some wing types depend on the covering for rigidness. Plastic coverings have give and allow the wing to flex under load. For these models silk span provides the best support. Just some thing to think about.

Motorman · « **Reply #9 on:** September 02, 2022, 10:51:46 PM »

There's Coverite Micro Lite if you can find it.

Jared Hays · « **Reply #10 on:** September 02, 2022, 11:35:15 PM »

Was this the one at the Topeka Contest a couple weeks ago? If so, crazy cool and top notch craftsmanship... The Mini Stiletto is badass as well if you're the same guy.

Phil J · « **Reply #11 on:** September 03, 2022, 04:57:14 AM »

I appreciate the input & suggestions guy's. Clearly I have some things to consider, and some target flying weights to consider.

Hey Jared yes this was the model at the Topeka Contest with the 1/2A Stiletto, I enjoyed our visit.

Happy Flying!

Larry Renger · « **Reply #12 on:** September 03, 2022, 06:14:16 AM »

Go see the SLC over Polyspan thread in the finishing section. Light, tough and pretty.

phil c · « **Reply #13 on:** September 08, 2022, 08:48:02 AM »

Silkspan under SLC works well. But build a simple wing frame, maybe 5 x 10in. to see if it suits.

Phil Cartier- 6249

Phil J · « **Reply #14 on:** April 30, 2023, 03:41:11 PM »

Here are a few pictures of my "A" size ship I posted a few months ago in bare bones, I ended up with an ready to fly weight of 20.5 ounces a little heavier than I was shooting for. As the weather gets better here in the mid west, I hope to get some trimming flights in in the next few weekends provided the wind isn't blowing 20 mph like most days are in this neck of the woods.

Happy Flying,

Tim Wescott · « **Reply #15 on:** April 30, 2023, 03:57:20 PM »

Nice! What did you cover it with?

John Carrodus · « **Reply #16 on:** April 30, 2023, 04:04:23 PM »

Outstanding workmanship.

Phil J · « **Reply #17 on:** April 30, 2023, 05:17:52 PM »

Quote from: Tim Wescott on April 30, 2023, 03:57:20 PM

Nice! What did you cover it with?
Tim,
I wound up covering with silk span & Brodak dope.

wwwarbird · « **Reply #18 on:** April 30, 2023, 06:17:22 PM »

Very, very nice work. i'm so glad to hear it's not an iron on finish, kudos!

M Spencer · « **Reply #19 on:** April 30, 2023, 07:34:56 PM »

Should be a humdinger . Thats under 10 Oz. Sq. foot . Bit light in a gale . Double its better there .

Shouldnt pull you off youre feet though .

Dan McEntee · « **Reply #20 on:** April 30, 2023, 07:35:08 PM »

Yes, a nice looking airplane!! From the color combinations, I have to ask, are or were you in the offset printing business?
Type at you later,
Dan McEntee

Phil J · « **Reply #21 on:** May 01, 2023, 04:19:31 AM »

Hi Dan,
Good guess! Yes I am in the Graphics Industry, as a Graphic Designer. Believe me it comes in handy. My market is primarily decals for the forklift & aerial platforms. Next time you see a Genie or JLG Aerial Lift on a jobsite it's likely that some of decals on it are manufactured by the company I work for.

Dan McEntee · « **Reply #22 on:** May 01, 2023, 07:23:56 AM »

Quote from: Phil J on May 01, 2023, 04:19:31 AM

Hi Dan,
Good guess! Yes I am in the Graphics Industry, as a Graphic Designer. Believe me it comes in handy. My market is primarily decals for the forklift & aerial platforms. Next time you see a Genie or JLG Aerial Lift on a jobsite it's likely that some of decals on it are manufactured by the company I work for.

I have spent quite a bit of time on Genie lifts and other brands. I worked in industrial maintenance for the better part of my career, most of it as a maintenance tech for a large commercial printing plant here in St. Louis working on web presses and large format sheet fed presses for 20 years. I have seen other companies use the red, yellow, blue, and black combinations in their logos and company trucks and such. Most printing companies worked it into their logo or advertising some how. It's an interesting line of work and the offset process is pretty interesting. The only part of it I didn't like is dealing with the ink!!. So it was the trim color layout that was a give away to me. I had a friend at the printing company that collected and restored Cushman Eagle scooters and he had one of each painted in the primary colors! They looked pretty neat parked next to each other.
Type at you later,
Dan McEntee

Phil J · « **Reply #23 on:** May 01, 2023, 07:41:16 AM »

I appreciate the complement Bob! I'm pleased with the way it turned out and ready to get out to the field for some trimming sessions.