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Old Jun 19, 2012, 10:22 PM
Capt. Z
falcon5's Avatar
United States, NV, Las Vegas
Joined Dec 2004
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I wouldn't give up on it yet.

I say size it up for a single 90mm fan so the inlets are as close to scale as possible but like the guys are saying it doesn't necessarily have to be spot on just real close so it's looks good.

If it's in the 80" or 85" range and anywhere from 14 to 20 pounds it's going to fly great. Modern EDF stuff will fly it fine.

When looking at the T-38 wing area, fuselage lift can be as much as 40% of total lift.

A high power 4500 watt 90mm setup would be pretty sweet on an 80 something inch long 17 pound T-38.

Guys are flying the 98" Skymaster T-38 at 32 pounds and say it fly's beautiful and lands really nice.
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Old Jun 19, 2012, 10:48 PM
awrightbrother's Avatar
Florida
Joined Nov 2007
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Andy
Cost is the other issue. A modern EDF 90 or 100 mm will cost between $300 to $400. The guys want a finished model for $400 to $600. Add kit, ESC, servos, retracts, finish, and we are quickly over their budget.
Fahim
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Old Jun 19, 2012, 11:34 PM
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United States, TX, Grand Prairie
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Quote:
Originally Posted by awrightbrother View Post
Andy
Cost is the other issue. A modern EDF 90 or 100 mm will cost between $300 to $400. The guys want a finished model for $400 to $600. Add kit, ESC, servos, retracts, finish, and we are quickly over their budget.
Fahim
Assuming 70ish sized model with 13-ish lbs AUW

- 100usd 90mm 9-10lbs fan system reliably, safely and easily including...esc\fan\motor(I've been doing this over 2 years)...
- 40usd for 8 corona 4.5kg metal gear 22g servos
- 50usd for set of scaled brushed aluminum oleo with torque arms (same one Andy is using but smaller)
- 36usd for RC lander milled aluminum wheels and brakes on mains and 10usd for ESM 2 piece 6 bolt wheel for front or 60usd if you want ESM 2 piece 6 bolt wheels all the way around and modded brakes.
- 64 for a Set of lander 120 e-tracts or 75 for ESM 20lb retracts
- 20 for LS2
- 50 for servo wires hardware wires and other ish....but that's if you have no supply of this stuff right now...I have an over supply...for me this is beer money.
- 50 for paint..(I'm throwing things in there now)

This can be done, not cost a ton and be a lots of fun
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Last edited by erh7771; Jun 19, 2012 at 11:53 PM.
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Old Jun 19, 2012, 11:44 PM
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United States, TX, Grand Prairie
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Quote:
Originally Posted by falcon5 View Post
I wouldn't give up on it yet.

I say size it up for a single 90mm fan so the inlets are as close to scale as possible but like the guys are saying it doesn't necessarily have to be spot on just real close so it's looks good.

If it's in the 80" or 85" range and anywhere from 14 to 20 pounds it's going to fly great. Modern EDF stuff will fly it fine.

When looking at the T-38 wing area, fuselage lift can be as much as 40% of total lift.

A high power 4500 watt 90mm setup would be pretty sweet on an 80 something inch long 17 pound T-38.

Guys are flying the 98" Skymaster T-38 at 32 pounds and say it fly's beautiful and lands really nice.
Transportation with a 70ish sized plane would be quick and easy....85" we're getting into another vehicle unless there was a way of detaching the nose etc...
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Old Jun 20, 2012, 12:17 AM
Capt. Z
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United States, NV, Las Vegas
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Quote:
Originally Posted by awrightbrother View Post
Andy
Cost is the other issue. A modern EDF 90 or 100 mm will cost between $300 to $400. The guys want a finished model for $400 to $600. Add kit, ESC, servos, retracts, finish, and we are quickly over their budget.
Fahim
Hmmm, how about airframe only. The folks can then set it up as they want. Put whatever fan and retracts, servos and ESC their budget will allow. Some I bet would even make one or two into hand launch pusher prop.

All you would sell would be the airframe,... bare bones foam CNC T-38 airframe.

Just a thought... If not it was still great you looked into it.

Thanks

Andy
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Old Jun 20, 2012, 01:01 AM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
21,161 Posts
i think a 75 " would fly great even with 85 % inlets .....we have done it before .no need to get hung up on 100% fsa for inlets.the take off roll would be a little longer but once in the air it would fly great. thanks for your effort in this .
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Old Jun 20, 2012, 03:20 AM
wannabe Jet guy
CRCJA's Avatar
Green Valley, AZ
Joined Aug 2004
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T-38

My Air Magic T-38 has a Wingspan of about 40 inches, my first one flew with a BVM fan and BV .91 engine, around 10 lbs of thrust, at a weight of 15lbs, and it would go 150MPH easy. The inlets are not exactly scale, but here is are pictures of both intakes.

The Black one is the Air magic (no longer in production) and the white one is the Bob F.

Ralph
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Old Jun 20, 2012, 07:16 AM
Hey Guys, Watch This.......
mike2663's Avatar
USA, TX, El Paso
Joined Dec 2003
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Quote:
Originally Posted by erh7771 View Post
Assuming 70ish sized model with 13-ish lbs AUW

- 100usd 90mm 9-10lbs fan system reliably, safely and easily including...esc\fan\motor(I've been doing this over 2 years)...
- 40usd for 8 corona 4.5kg metal gear 22g servos
- 50usd for set of scaled brushed aluminum oleo with torque arms (same one Andy is using but smaller)
- 36usd for RC lander milled aluminum wheels and brakes on mains and 10usd for ESM 2 piece 6 bolt wheel for front or 60usd if you want ESM 2 piece 6 bolt wheels all the way around and modded brakes.
- 64 for a Set of lander 120 e-tracts or 75 for ESM 20lb retracts
- 20 for LS2
- 50 for servo wires hardware wires and other ish....but that's if you have no supply of this stuff right now...I have an over supply...for me this is beer money.
- 50 for paint..(I'm throwing things in there now)

This can be done, not cost a ton and be a lots of fun
Sounds about right to me. Also many of us have items "laying around" in this size which makes the 70-75 inch even more appealing.

Mike
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Old Jun 20, 2012, 10:04 AM
Capt. Z
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Another good indicator of interest is 1,200 views in only 5 days.
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Old Jun 20, 2012, 10:11 AM
Hey Guys, Watch This.......
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Yep. I really think this one has a future.

Mike
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Old Jun 20, 2012, 11:10 AM
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I don't think anyone monitoring this thread has a desire to enter the results of this project in scale competition. If the end result is close to looking like a T-38 I think that is good enough.
85% scale would be fine. If one of the members of my club came up and said nice T-38, thats all I ask for.
No one in my club is going to come up and say "ya know those inlets are off by 15% in scale shape and size"! If you tried to make an EXACT scale T-38 I doubt it would be controllable by RC equipment. Just get it close and fly well and call it good. Having said that size does matter.....at 108" in length it is too long for my pickup bed. A 70"-80" length plane is still VERY big say 72"...6 FEET that's a big plane foam or not. Any way that's my 2 cents worth. I can/will support something in that range but 9 feet plus.....too big for me.

al
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Old Jun 20, 2012, 11:29 AM
DFC~ We Do Flyin' Right
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I also would love to see this in a 70-74 inch range (maximum I can fit into my sedan)
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Old Jun 20, 2012, 12:10 PM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
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i like the BF inlets ... the black one is more like a F-20 .also airframe only would be great .....if a guy needs more you can make it avail.
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Old Jun 20, 2012, 01:25 PM
Fly more Foam
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United States, IN, Sellersburg
Joined Jun 2004
995 Posts
I know i kind of started this thread but we all contributed to the interest and desire for finding the means and resources for such a sexy jet. If Fahim from Wowplanes decides to pass on this project as he has recently indicated, what other options can be pooled together for such a sleek jet in the size that we have indicated?.
I know first hand that Fahim's CNC cutting and kits are very good along with the time and skills he devoted to the A10 prototype. The end result for a T38 would be equally as rewarding but he has other irons in the fire at the moment.
The interest in this thread has even suprised me! Hope it does NOT die out with out something coming from the talent and expereince of all the posters.
Sam
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Old Jun 20, 2012, 01:52 PM
awrightbrother's Avatar
Florida
Joined Nov 2007
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OK folks, I have read thru all your comments, and it looks worthwhile to do a 72 incher with the cost analysis posted by erh7771.

But I have one last question. The kit price will be in the $150 range which would put the finished cost around $550, that meets the $400 to $600 finished cost you were hoping for. How many of you are still interested?

Fahim
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