Upscale BSG Colonial Viper RC Rocket glider

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aerostadt

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I am making some progress on the 4" Viper as described in post#1, but I nowhere near as fast as Frank in building. I still need some parts to come in. So far the weight is not bad, only 23.3 oz for the parts shown in the photo's. The turbo tubes have not been glued in, yet. I am currently planning to use the Estes 4" MDRM tube at the top in order to avoid sanding the nose cone. The coupler for the BT-101 fits both the BT-101 and the Estes tube. The MDRM tube weighs a little bit more, but I plan to use the G40 motor, which requires a little bit more nose weight. I got all the measurements from Frank's photo's. I feel good about the measurements, because I get a total length of 42.65" versus Frank's total length of 43".

I found that my old can of 3M spray adhesive is very tricky for attaching 6 mm depron. I need to spray very light or it will melt the depron. Also, the can says wait for the adhesive to get tacky. I have found no such problem. It is immediately tacky. In fact my depron sheets have got to be aligned as close as possible, because once they go together there is not possibility to make corrections. The depron parts are stuck.
 

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burkefj

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Looks good, I think you will be maybe an ounce or two heavier than mine which also flies on G-40's. I'm at 28.6 ounces painted with decals with servos and receiver and wiring(1.75 ounces) and 2.25 ounces nose weight, so that gives me a dry weight of 24.6 ounces painted with decals but no nose weight and radio equipment, glue will add 2 ounces at least to your weight, but at this size it probably won't matter much.
 

aerostadt

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I see that Estes blocks the open nose cone on their viper and that you do the same with a foam filler on the 2.6" viper. I assume that you put a foam filler on the 4" version. I think you said so somewhere. I am little bit surprised that everyone does this. Obviously, it works, so it is hard to argue with success.
 

burkefj

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Yes I blocked the 4-inch version off as well, from my experience making the Mach 2 kits which were similar to the old centuri mach 10, the open tube was very draggy, if you consider surface friction the more surface area you have the more drag and so if you've got surface inside and outside the tube it's more draggy then if you block it off

I see that Estes blocks the open nose cone on their viper and that you do the same with a foam filler on the 2.6" viper. I assume that you put a foam filler on the 4" version. I think you said so somewhere. I am little bit surprised that everyone does this. Obviously, it works, so it is hard to argue with success.
 

aerostadt

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Attached are the latest photo's of my 4" tube diameter BSG Colonial Viper based on Frank's information in this thread. Decals are from Sticker Shock. The total weight without a motor is 30.45 oz and with a G40-7 the weight is 34.90 oz, which compares with the weights in the first post of this thread. I am assuming that the c.g. should be about 15" from the aft end, which is about a factor of 1.5 applied to the c.g. for Frank's commercially available 2.6" diameter Viper.
 

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burkefj

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CG is 15 7/8 of an inch forward from the rear end of the body tube.

Attached are the latest photo's of my 4" tube diameter BSG Colonial Viper based on Frank's information in this thread. Decals are from Sticker Shock. The total weight without a motor is 30.45 oz and with a G40-7 the weight is 34.90 oz, which compares with the weights in the first post of this thread. I am assuming that the c.g. should be about 15" from the aft end, which is about a factor of 1.5 applied to the c.g. for Frank's commercially available 2.6" diameter Viper.
 

BABAR

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CG is 15 7/8 of an inch forward from the rear end of the body tube.
Beautiful design.

Gotta wonder, when it is that big does 1/8” make that much difference?
 

burkefj

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Well Bob was thinking it was 15 in so 7/8 of an inch would make a difference, if you're asking why I didn't just round it up to 16 I'm just reporting what I use that worked.

Beautiful design.

Gotta wonder, when it is that big does 1/8” make that much difference?
 

aerostadt

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Well Bob was thinking it was 15 in so 7/8 of an inch would make a difference, if you're asking why I didn't just round it up to 16 I'm just reporting what I use that worked.
Frank, while we are on this subject, I have a question. I was looking at my Viper C.G. last night with the G40 motor in place. The motor sticks out about 3/4" from the aft end. I think that I can get the quoted C.G. to work, if I can get the 3.7V battery far enough forward. I have some of those heavier 7.4V batteries in my inventory along with the necessary BEC. Should I use the 7.4V battery instead?
 

burkefj

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I have my battery mounted on velcro at the very front of the nose cone I can reach my arm in all the way to the end, do whatever you can do to meet the CG. If you need to use the bigger battery to make it work then that's fine.

Frank, while we are on this subject, I have a question. I was looking at my Viper C.G. last night with the G40 motor in place. The motor sticks out about 3/4" from the aft end. I think that I can get the quoted C.G. to work, if I can get the 3.7V battery far enough forward. I have some of those heavier 7.4V batteries in my inventory along with the necessary BEC. Should I use the 7.4V battery instead?
 

aerostadt

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I stopped using the 2-cell 7.4V battery sometime ago. So, I have a 2-cell, BEC, and wiring in my inventory and decided to put it to good use. Balance looks good. Hopefully, this will be my last question. How much up-flap are using for your glide position setting?
 

modeltrains

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Just watched video; impressive glide time and she looks grand in the air. :cool:
 

burkefj

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It's probably about 3/8 to a half an inch up trim for glide.

I stopped using the 2-cell 7.4V battery sometime ago. So, I have a 2-cell, BEC, and wiring in my inventory and decided to put it to good use. Balance looks good. Hopefully, this will be my last question. How much up-flap are using for your glide position setting?
 

aerostadt

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I want to thank Frank for designing and developing this model. My first flight on Saturday (03/27/2021) at the UROC meet was a good one and my wife got some good still photo's. I did have trouble with my end-burner motors (G12 and E6) igniting and after 3 misfires gave up on the Concorde and the Klingon Battle Cruiser. The 2 cell Lipo (Eflite 800mah) in the Viper was essentially dead. (It was fine 2 weeks ago.) So, I replaced it with the one-cell Lipo from the Concorde. (I will think twice about using 2 cell lipo's again. My experience has not been good. One cell lipo's for me have been no problem.) The port grain on the G40 (ejection charge removed) for the Clipper was easy to install the igniter at the pad. There is no grass on the Frank Hunt field, which over 100 years ago was part of the Pony Express trail in the Old West, only sage brush and dirt. The landing damaged the depron covering at the front of Viper, but it will be easy to repair. Flying the Viper was fun and easy to do. I wish I could get it to come back to my feet although it probably landed not too far away from the car for an easy walk.
 

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burkefj

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I want to thank Frank for designing and developing this model. My first flight on Saturday (03/27/2021) at the UROC meet was a good one and my wife got some good still photo's. I did have trouble with my end-burner motors (G12 and E6) igniting and after 3 misfires gave up on the Concorde and the Klingon Battle Cruiser. The 2 cell Lipo (Eflite 800mah) in the Viper was essentially dead. (It was fine 2 weeks ago.) So, I replaced it with the one-cell Lipo from the Concorde. (I will think twice about using 2 cell lipo's again. My experience has not been good. One cell lipo's for me have been no problem.) The port grain on the G40 (ejection charge removed) for the Clipper was easy to install the igniter at the pad. There is no grass on the Frank Hunt field, which over 100 years ago was part of the Pony Express trail in the Old West, only sage brush and dirt. The landing damaged the depron covering at the front of Viper, but it will be easy to repair. Flying the Viper was fun and easy to do. I wish I could get it to come back to my feet although it probably landed not too far away from the car for an easy walk.
Right on, it glides better than you would think right?
Congrats
 

Ez2cDave

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Frank,

That looks great . . . No "Felgercarb" there !

Dave F.
 
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Ez2cDave

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Dave,
What is "Felgercarb" ?

I take it that you have never watched "Battlestar Galactica" . . . ( Original TV Series ) ?

"Felgercarb" is an expression used on the TV show, as a "substitute" for "BS / Bovine Excrement" . . .

"Frack" is another one . . . Guess what that means . . . LOL !

Dave F.
 
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BRS Hobbies

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It's very impressive and looks to fly as good as it looks. Awesome job!
 
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