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Old Jun 10, 2012, 06:47 PM
Lee Liddle
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Carrollton, Tx
Joined Dec 2006
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Quote:
Originally Posted by ysolomon View Post
Yesterday I maidened a much smaller, 8lb ProJet A-10. I did what I thought were high speed taxi passes, and had the same feeling as you do now. When I finally decided to take off, it used the entire runway. I finally forced it into the air at the end of the runway. A combination of forward CG and elevator trim. Once in the air, with enough (a lot!) of trim-- and she flew beautifully, at about 2/3 throttle.
I agree that the CG could be an issue. My gut is that the jet will rotate and lift off at a much slower speed than what we are use to seeing. (The scale effect will be strong in this one ) If the CG is too far forward it just won't rotate, and without rotation it won't have the lift needed to fly. Don't forget to include the fuselage and stab areas in the CG calculations. Otherwise it will be nose heavy for sure.

PS... The video was still very cool! !
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Old Jun 10, 2012, 06:54 PM
Registered User
Joined Jan 2010
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Quote:
Originally Posted by Knife Liddle View Post
There is more EDF power available. Put a couple of 5kw JetFan 90mm`s in that baby. It`ll fly.
More like two 127mm Ramtec's for that wing loading, Joe.
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Old Jun 10, 2012, 06:55 PM
Lee Liddle
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Carrollton, Tx
Joined Dec 2006
8,266 Posts
More Power Baby! !
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Old Jun 10, 2012, 07:15 PM
DELTAS RULE
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tehachapi, CA
Joined Jan 2006
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theres already minimal fsa for 100 mm fans much less two 127's. i did the math because i was originally going to go with a single fan and theres barely enough fsa for one 127mm

Quote:
Originally Posted by jofro View Post
More like two 127mm Ramtec's for that wing loading, Joe.
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Old Jun 10, 2012, 07:42 PM
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A10pilot's Avatar
United States, TX, Schertz
Joined Mar 2006
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Nut:

What do you think the 100% FSA is for the Stumax 110's? What is the intake area for one of the intakes for this size T-38?

Ed
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Old Jun 10, 2012, 07:46 PM
Lee Liddle
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Carrollton, Tx
Joined Dec 2006
8,266 Posts
Quote:
Originally Posted by corsair nut View Post
theres already minimal fsa for 100 mm fans much less two 127's. i did the math because i was originally going to go with a single fan and theres barely enough fsa for one 127mm
Well, there ya go, huh.
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Old Jun 10, 2012, 08:04 PM
DELTAS RULE
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tehachapi, CA
Joined Jan 2006
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andy is using 100 mm stus
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Old Jun 10, 2012, 08:04 PM
DELTAS RULE
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tehachapi, CA
Joined Jan 2006
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i think thetes only about 15-16 sq in between both inlets...those are some tiny ducts
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Old Jun 10, 2012, 08:28 PM
Do it Right, the first time!
CoolerByTheLake's Avatar
United States, MN, Hermantown
Joined Dec 2008
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Just checked the StuMax 100-45. 62.64sqcm or 9.7092sqin FSA

http://www.espritmodel.com/edf-stuma...het-motor.aspx
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Old Jun 10, 2012, 08:29 PM
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USA, NC, Greensboro
Joined Mar 2002
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The force is strong with this one....
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Old Jun 10, 2012, 08:37 PM
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United States, NV, Reno
Joined Mar 2000
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If you have the opportunity and light winds, would you be able to test your acceleration on the taxiway at TPH? Of course I'm not saying to do massive high speed runs or to try to fly it there with the narrow pavement strip. The threat is a narrow strip of pavement and rough side terrain and taxiway lights- not good for high speed runs if you get into a Tokyo Drift scenario. Acceleration only tests however may give you some insight as to weather to push for a liftoff or not on a bigger dry lake bed. If those narrow tires are adding a lot of rolling drag on the playa you'll see it right away on the taxiway.

All earlier kidding aside, I also favor a "yellow light" strategy at this point (not that I have a say on anything, just what my own experience tells me). Extend the "internal pressure" expected "fly by date" and be real methodical at this point. You have nothing to lose but a few extra days of deliberation at this point by being conservative.
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Old Jun 10, 2012, 09:03 PM
DELTAS RULE
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tehachapi, CA
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andy what about those other tires you tried? they may look funny but might work better beeing wider on the lakebed
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Old Jun 10, 2012, 09:04 PM
Do it Right, the first time!
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United States, MN, Hermantown
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+1 on that. As much as all of here would love to see it fly, there's not one of us who wants it to crash either. Take the time it takes to be sure and safe.
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Old Jun 10, 2012, 09:12 PM
Yank Pilot
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United States, CO, Hotchkiss
Joined Oct 2006
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More batteries? Hotter motors?
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Old Jun 10, 2012, 09:21 PM
Another one on the way...
ysolomon's Avatar
Plano, Texas
Joined Feb 2009
2,399 Posts
Quote:
Originally Posted by CoolerByTheLake View Post
Just checked the StuMax 100-45. 62.64sqcm or 9.7092sqin FSA

http://www.espritmodel.com/edf-stuma...het-motor.aspx
At 9.7 x 2, and I'm guessing you want inlets to be some 120-125% of the FSA. That would be 23-24 sq in. I would be nervous flying with what you have. I know that "cheater holes" sound terrible, but starving those fans is worse...
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