F-20 From prop to DF Help
11-16-2003, 01:40 PM
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F-20 From prop to DF Help
I have the Direct Connection F-20 kit and want to know if anybody has converted it to ducted fan. If it can be done does anybody make a 3.5" fan unit. I think that I can stuff that size fan in it. If I am waisting my time, please let me know. I like that airframe design and want a DF plane to get my Jet waiver with. I am new to DF and Turbines so bear with me please.
11-16-2003, 02:19 PM
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RE: F-20 From prop to DF Help
A 3.5" fan unit will require 3.5" intake and exhaust ducting, so that's not going to fit without a lot of changes. DF planes are designed around the power plant and ducting.
Also 3.5" fans are powered by engines in the 0.15 to 0.45 cubic inch range. A 0.45 powered 3.5" fan would be operating at 40,000 RPM or more to use the power available from the engine. I don't know of any fans or engines that can operate at 40,000 RPM.
Kress Jets and Toki make 3.5" fans. The Toki fan comes with an 0.18 engine and is good for planes up to about 4 lb. They are not that fast, and are probably not suitable for the turbine waiver flight demostration.
The standard DC F-20 could be OK for the waiver demstration, depending on your TCD. For waiver demonstrations the key features are high wing loading and complication (flaps and/or retracts) as well as speed.
The Jet Hangar F-86 sounds like the sort of plane you want to build. That uses a 5" fan with a 0.46 engine. JHH also have other 0.46 sized DFs. www.jethangar.com Only the JHH home page seems to be working at the moment.
Also 3.5" fans are powered by engines in the 0.15 to 0.45 cubic inch range. A 0.45 powered 3.5" fan would be operating at 40,000 RPM or more to use the power available from the engine. I don't know of any fans or engines that can operate at 40,000 RPM.
Kress Jets and Toki make 3.5" fans. The Toki fan comes with an 0.18 engine and is good for planes up to about 4 lb. They are not that fast, and are probably not suitable for the turbine waiver flight demostration.
The standard DC F-20 could be OK for the waiver demstration, depending on your TCD. For waiver demonstrations the key features are high wing loading and complication (flaps and/or retracts) as well as speed.
The Jet Hangar F-86 sounds like the sort of plane you want to build. That uses a 5" fan with a 0.46 engine. JHH also have other 0.46 sized DFs. www.jethangar.com Only the JHH home page seems to be working at the moment.
11-16-2003, 02:34 PM
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RE: F-20 From prop to DF Help
Thank you for the information. I currently have several P-51 mustangs that I race that run in the 150 to 160mph range with retracts and clipped wings that I was told will work fine for the waiver, but I was looking for the engine thrust lags and other issues that turbine flyers have to deal with. I guess that I will sell this kit and start looking for a DF kit/ARF that fills my needs. Any suggestions for something along the F-20/ T-38 line that won't break the bank??? I don't want a raw fiberglass type kit. Something wood or ARF.
11-16-2003, 07:37 PM
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RE: F-20 From prop to DF Help
ORIGINAL: mahmc1
Thank you for the information. I currently have several P-51 mustangs that I race that run in the 150 to 160mph range with retracts and clipped wings that I was told will work fine for the waiver, but I was looking for the engine thrust lags and other issues that turbine flyers have to deal with. I guess that I will sell this kit and start looking for a DF kit/ARF that fills my needs. Any suggestions for something along the F-20/ T-38 line that won't break the bank??? I don't want a raw fiberglass type kit. Something wood or ARF.
Thank you for the information. I currently have several P-51 mustangs that I race that run in the 150 to 160mph range with retracts and clipped wings that I was told will work fine for the waiver, but I was looking for the engine thrust lags and other issues that turbine flyers have to deal with. I guess that I will sell this kit and start looking for a DF kit/ARF that fills my needs. Any suggestions for something along the F-20/ T-38 line that won't break the bank??? I don't want a raw fiberglass type kit. Something wood or ARF.
I am building a Trim Aircraft Spectre right now. It is very F20 looking (and I believe the did at one point make an F20) but it is a fair bit of building. None of it is difficult though. I don't know what you mean by a "raw fiberglass" kit, but it is a fiberglass fuse, and foam wings sheeted with balsa (you have to sheet it yourself) and the price is quite good, about $500USD or so.
I'm putting a RAM750 in my spectre, and so far it's all going good. Jet Tech is building a custom tank for me, and RTI built a tailpipe, hopefully the pipe will arrive soon. I've got almost all the building done, near ready for fiberglassing and finishing.
11-16-2003, 08:02 PM
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RE: F-20 From prop to DF Help
Jeremy,
By saying "raw" I ment the typical green or clear fiberglass that needs to be sanded, filled, primed, painted. I am not very good at that. I can do small repairs to it but not a whole plane and my repairs are not that great. That is why I am looking for a fiberglass ARF or a wood kit. I may just break down and buy a turn key plane from someone. Sheeting foam core wings is more work than I want to do to. I love to fly, not build. As you can tell, I am a fan of the ARF's. I will build when I am retired (long time from now). I would love to see your project though. Could you post a picture or two? I might have to break down and learn how to paint and fiberglass to get what I want I guess.
Thanks for your input on this.
By saying "raw" I ment the typical green or clear fiberglass that needs to be sanded, filled, primed, painted. I am not very good at that. I can do small repairs to it but not a whole plane and my repairs are not that great. That is why I am looking for a fiberglass ARF or a wood kit. I may just break down and buy a turn key plane from someone. Sheeting foam core wings is more work than I want to do to. I love to fly, not build. As you can tell, I am a fan of the ARF's. I will build when I am retired (long time from now). I would love to see your project though. Could you post a picture or two? I might have to break down and learn how to paint and fiberglass to get what I want I guess.
Thanks for your input on this.
11-16-2003, 11:52 PM
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RE: F-20 From prop to DF Help
If all you want is an aircraft that simulates turbine flying characteristics, some ballast a P-51 racer and throttle delay would go a long way. Set the wing loading to 35 oz. per sq ft. or more.
If your transmitter doesn't have a throttle delay function, Jomar, or one of the other companies that make little electronic RC gizmos, has a servo-slow device intended to slow down retracts using normal servos. You can also set the throttle trim high to simulate residual thrust.
If your transmitter doesn't have a throttle delay function, Jomar, or one of the other companies that make little electronic RC gizmos, has a servo-slow device intended to slow down retracts using normal servos. You can also set the throttle trim high to simulate residual thrust.
11-17-2003, 12:00 AM
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RE: F-20 From prop to DF Help
I have found 2 turn-key DF jets on here.... they were VERY reasonable!
TGA F-15, OS-91, retracts, servos etc. $425-
Yellow A-4, OS-91, retracts, servos etc. $450-
The Byron powered TGA F-15 is a little slow for the waiver but the A-4 hauls-
That is the route I would go- check the Marketplace, many folks are going turbine and selling DF stuff cheap!
You might be able to just do a Patriot/Jett-50 depending on the CD-
Cheers
TGA F-15, OS-91, retracts, servos etc. $425-
Yellow A-4, OS-91, retracts, servos etc. $450-
The Byron powered TGA F-15 is a little slow for the waiver but the A-4 hauls-
That is the route I would go- check the Marketplace, many folks are going turbine and selling DF stuff cheap!
You might be able to just do a Patriot/Jett-50 depending on the CD-
Cheers
11-17-2003, 10:17 PM
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RE: F-20 From prop to DF Help
Razor, I hunted through all 805 aircraft listings and could not find the A-4 you were talking about. Could you send me in the right direction? Several people have told me that the A-4 is the way to go. Thanks for the help
