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Old Nov 24, 2012, 11:56 PM
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MustangAce17's Avatar
Ocala,Florida
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Fred, I could make up a bl 22mm just as easily. I'm tempted to mold one of my plastic models and i wish i still had my nice 1/48 mirage, can't seem to find it
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Old Nov 25, 2012, 08:16 AM
Current project: Electrolyte
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United States, OH, Dayton
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Wow Fred! Your very good at cutting those foam formers with integrated ducting. Seems like a good construction method at this small scale. Watching with interest!
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Old Nov 25, 2012, 09:48 AM
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Originally Posted by MustangAce17 View Post
Fred, I could make up a bl 22mm just as easily. I'm tempted to mold one of my plastic models and i wish i still had my nice 1/48 mirage, can't seem to find it
Thanks for sharing that thought. The molding of a Mirage would be cool, but I think a 22mm system needs to be kept very light. I will guess my airframe is going to push 6g, maybe 7g? And if painted???? With my standard micro gear (2g RX, 2g servos, 1g ESC, 3g battery, and all related wire, rods, etc) it may be too heavy???? Any idea how much a molded airframe might weigh? Of course if depron was heated and formed into a shell that would be something also????????

Got my thinking cap on anyway. I have a 1/48th scale Convair Delta Dart model. That is cool and very similar, yet has some interesting shapes going on. Might have to pull that down again someday and look it over. Thanks again. Any work on that idea please do share.


Fred
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Old Nov 25, 2012, 10:00 AM
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Originally Posted by pdawg View Post
Wow Fred! Your very good at cutting those foam formers with integrated ducting. Seems like a good construction method at this small scale. Watching with interest!
Thanks Bret,

I don't know for sure so some of you guys can chime in, but it seems that by cutting the airframe to have everything intregrated is very light? 3.1g bare foam, and not much more filled and sealed. Wing and fin will add at least 3g. It is not Durobatics, but when I weigh Depron sheets it almost seems heavy?

I want to try a 40mm jet in this fashon (yes 40mm, I;m ashamed) but I put togeteher a custom cut down unit using a Hyperion 5800kv motor that is itching to be used. I would think wieght wouldn't be too much either, and the 3 dimensional shapes really add strength because of all their curves. Will have to do it soon.

Fred

I'll get some progress photos up later.
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Old Nov 26, 2012, 12:21 PM
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Fred, I'd love to have a partial kit, just so happen to have a gp 30mm fan we could snug in there if anything
Had to take this photo after your post. This is why we can not fit a 30mm into this 1/48th scale Mirage. LOL, this gives a good idea how small it really is. That is a super lightweight Air Hogs 30mm EDF BTW. However I'll be posting soon a new rotor I made for the BIM 22mm EDF is giving equal output as the AH 30mm EDF. . .

Fred
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Old Nov 26, 2012, 12:29 PM
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I posted the other night and as promised I took a photo of the 1/48th scale Mirage profile chuck glider I made. It is pretty cool as I weighted it down with coins and a watch battery to check the glide and flight envelope with a proposed final weight of my full fuselage version.

Interesting and educational. The CG range is pretty close to calculations, and I am guessing some reflex might be in order when we get power to it. Depending on how I throw it makes a huge differance on it flying on rails, or doing a steep angled glide like a lawn dart (Lawn dart on rails). However get the CG too far back and it starts to go high alpha and stall about 20 feet out?????

Got to love scratch building!

Fred



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Old Nov 26, 2012, 01:15 PM
Lee Liddle
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Carrollton, Tx
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1/14th or 1/48th? This is the same size as the build right?
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Old Nov 26, 2012, 01:16 PM
Lee Liddle
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That thing is tiny!
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Old Nov 26, 2012, 01:42 PM
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1/14th or 1/48th? This is the same size as the build right?

Opps, my bad, I corrected the typo, 1/48th scale. Most often I have trouble typing and have to edit many mistakes. It has nothing to do with my spelling! LOL.




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That thing is tiny!

Funny it was looking kinda big to me in person, but maybe that is because I'm used to it. LOL


Fred
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Old Nov 26, 2012, 01:55 PM
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The wing was 3.2g as a rough cut blank. Cut a channel to mount the fuselage, sanded some airfoil shape to it, and it came down 1g to 2.2g AUW. This is good because sealing and paint will put the weight back on!

Then for a referance, the roughed fuselage sections were piled on and we have 5.2g. I will do another weigh-in after sealing and sanding. Wish I was OK with ink finishes, but I am not.

Fred
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Old Nov 26, 2012, 02:07 PM
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I got around to drawng up the wing in my Airfoil program, Comp-U-Foil. It calculates the CG, and gives me specifics including wing area. So the results are in we have approximately 24.82 Square Inches of wing area. We will use 25 SqIn for all practical purpose.

This is my caculations if I am correct, then if I end up at 22g (lucky, but heavy), I would have 4.4699 Ounces to SqFt wing loading, not counting the fuselage sections outside the wing. No lightweight, but within reason I think. At this small scale that seems like a lot!

Fred



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Old Nov 26, 2012, 06:45 PM
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After I sealed the wing using Polycrylic and some tinting to give a blackish-gray tint to the foam. This added 0.5g, or less than 25% of the exsiting weight of the wing (ouch), but should keep paint needed to cover to a minimum.

I also printed out a wing planform from Comp-U-Foil and used a sewing pin to poke a hole where my forward CG will be located.

Fred




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Old Nov 27, 2012, 12:53 PM
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I tried to save some weight with the receiver. 2.1g to start, and I removed the white insulation from the antenna, and the orange heat shrink, plus the ID sticker. Replaced with thin clear heatshrink, liquid electrical tape on antenna, and Sharpie plus paint dots to replace ID tag. Saved 0.2g, but I'll take what I can get.

The orange RX 4 channel micro weighs about the same as an AR6300 6 channel from Spectrum. Differance is the AR6300 is $40.00 more, ouch. I have one but I only need 3 channels on this bird so why waste the better RX.

Fred
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Old Nov 27, 2012, 01:11 PM
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Nederland, GE, Wageningen
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Maybe you could lose some more weight by removing the connectors and soldering the servos directly to the board. Might save you another few 0.1 grams.
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Old Nov 27, 2012, 01:25 PM
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Maybe you could lose some more weight by removing the connectors and soldering the servos directly to the board. Might save you another few 0.1 grams.

Thanks and that is a great idea actually. This time I must take that extra weight penalty because I don't order from HK anymore so if I mess it up I am , LOL. What I should do is order one of those .xx miligram RX's from Bob Selman, but that will be when I have some extra money! If I had a $100.00 bill, I'd really lighten this thing up, but I hope a 22mm can push it along, that was my plan to use stuff everyone can afford and find easy.

Fred
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