Gilbert SkyFlash - Start to finish

balogh wrote:This is an awesome restoration, Bob, like always.....what size of Gilbert engine is that?

Thanks Andras, it's an .11

Bob

Just found something on the Gilbert .7 0nd .11 engines, not quite well readable stuff, but interesting...the .11 is more than twice the size of the COX 049 product engines, and probably of higher performance too, so I assume this Gilbert plane should be a bit heavier than the COX RTF C/L planes?

http://www.sceptreflight.com/Model%20Engine%20Tests/Gilbert%207%20&11.html

Bob, you had my curiosity going when you showed the unopened box a couple weeks ago. That appears to be one of the cleanest Skyhawks around (or, wrong box? Was the Skyflash the .11 version and the Skyhawk the .074 version?) After your clean-up, it looks brand new!

Andras, Bob answered your question in:

ttps://www.coxengineforum.com/t16249-bob-s-gilbert-skyflash-bob-s-extra-11-runs-on-a-test-stand#210383

rsv1cox on Apr 23, 2022 wrote:

getback wrote:It will bee interesting to see how good the airfoil is to keep that Gilbert in the air

You got me wondering Eric.  Yeah it's no lightweight. [...]

Note: Bob's Skyflash w/Gilbert .11 weighs 20.75 oz. - GG

Note: Bob's Cox PT-19 w/Cox .049 weighs 9.42 oz. - GG

As you see, the Gilbert weighs double the weight of the PT-19. However, it does have more wing area, too. Really don't know how much, but my guess would be around 150 sq. inches. The PT-19, my guess again, but probably around 100 sq. inches. I base this on balsa models, .049 versus those that use a mild glow .09 of the late 1940's, early 1950's.

Plus, the wing is not a simple single highly under-cambered die injected sheet of plastic but either semi-symmetrical or symmetrical with a bottom side. The heavier weight along with airfoil is more neutral with wind direction, so it would be easier to control. The highly under-cambered wings tend to lift into the wind, sag with the wing because of changing lift, requiring constant correction, which for the beginner might prove too challenging until they get the hang of it. This is why that the RTF's entered one-shot flights IMO (been there done that! ), which left me with a donor postage stamp engine 190 for use on a balsa plane, (of which if I spent the same amount of money, could have bought a couple .049 kits, a new engine, props and finishing materials!).

Also, Kim ran the two Gilbert 11's I sent him and posted about them here.

Bob

rsv1cox wrote:Also, Kim ran the two Gilbert 11's I sent him and posted about them here.

I quoted Kim in my reply:

CEF: Bob's Gilbert Skyflash Bob's Extra .11 Runs on a Test Stand, Post# 210610

Based on his and other sources, seems the Gilbert .11 runs best on a 6x4 or APC 7x3 or 7x4 prop. These appear to allow it to wind up to its max HP RPM in the air.

Kim wrote:Once I return from S.M.A.L.L. 2022, I want to have a "Vintage Plastic Day" on the ramp at Cairo's little airport.  Gonna have Bob's Skyflash and several others our for a day of circle turning

Cairo, Missouri (small town of 300 people)?

Had to open up the box again, tight fit cerial box corner reenforsements take up space. Forgot to include the decals and diagrams that came with it.  Also added a Wen Mac handle and lines.  



Used up the last of my wide cellophane for the windows.  

More cleanup pictures





Anyone have an explaination for the horizontal/vertical leadout holes? The Gilbert designers had some interesting ideas for this model not limited to this configuration.

I have no idea but, Maybe to allow a little wiggle room to find its groove?…. Back one for yaw and front for roll?…. Wild guess…

I was thinking that it might have something to do with that strange spring loaded bell crank pictured above. Got to be some explaination when just a couple of holes would do.

Kim wrote:

GallopingGhostler wrote:

Kim wrote:Once I return from S.M.A.L.L. 2022, I want to have a "Vintage Plastic Day" on the ramp at Cairo's little airport.  Gonna have Bob's Skyflash and several others our for a day of circle turning

Cairo, Missouri (small town of 300 people)?

Nope...Cairo, Illinois...'bout 45 minutes across the bridge from Cape Girardeau!

Cairo, at the confluence of the Ohio and Mississippi Rivers, was positioned to become what St. Louis is today -- the gateway to the West.  However, it's almost a ghost town today.  With your interest in historical events, you might find some research into the town interesting.
BTW, I live about 60 minutes from Cairo, but on the other side of the river from Kim.

Not to stray too far from Bob's latest restoration, as usual, it is another superb job!!