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Old Feb 26, 2013, 09:13 AM
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Originally Posted by nerv View Post
hi Anastasios, I'm curious to know how you tested the thrust. did you put the fan hatch and cockpit on when u test the in plane thrust?
Dear Nerv,
I test my L-59 today and the static thrust with the canopy on , is 3.2 to 3.3 kilos.Without the canopy is 3.4 to 3.5 kilos. There is a difference of 200 gr but I believe that when the jet would fly some extra air should be added to the inlet ducts and I would gain some of the lost 200gr. Anyway , 3.3 kilos of thrust are okay for a safe flight.
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Old Feb 26, 2013, 01:09 PM
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United States, CA, San Jose
Joined Jan 2007
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Thanks for the infor Anastasios. 7lb of thrust should move the bird with some authority. Good luck on your maiden and be sure to take some videos.
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Old Feb 26, 2013, 01:40 PM
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Keep in mind what I said in a previous post; too much speed on landing can cause bouncing and an eventual bad landing. Anyone doing a maiden flight should simply trim the bird in flight and then practice low speed flybys as if to land to get some idea of the speed needed for a safe landing. You can save the barrel rolls for the next flight. Don't wait till you are nearly out of battery power to practice your landing approaches.
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Old Feb 26, 2013, 03:37 PM
DominicM
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Fleet, Hampshire, UK.
Joined May 2003
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Sound advice urrl but you do see so many maiden flights where quick trim out and then into aerobatics. Frequently ends in a disastrous landing.

Took the intake tubes out and wrapped the front with carbon tow and cyano. Could only just get them back into the fuselage. Tested and no more collapsing due to the vacuum effect at full throttle. No improvement in power though. Power down to 1.5KW but think that may have been because the lipos were very cold. Going to test on 10S tomorrow to see if it really is a starvation issue. Got any pics of your mods to let in more air Anastasios? Did not understand "cut a round hole at the inlet tubes where they meet".
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Old Feb 26, 2013, 03:40 PM
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Originally Posted by urrl View Post
Keep in mind what I said in a previous post; too much speed on landing can cause bouncing and an eventual bad landing. Anyone doing a maiden flight should simply trim the bird in flight and then practice low speed flybys as if to land to get some idea of the speed needed for a safe landing. You can save the barrel rolls for the next flight. Don't wait till you are nearly out of battery power to practice your landing approaches.
Urrl , I have a Falcon 120 edf and with 2x6cell 5000mAh 40C Lipos I could fly for 2.5 to 3 minutes with very careful throttle settings and after landing my 12 cell Lipos were from 11% to max 18% or remaining power. I could not have the power for a missed approach. 2.5 to 3 minutes of flight is nothing.So I decided to buy the HK L-59 and use my Falcon's Lipos hopping that my flights would be more than 3 minutes. As for my Falcon I had removed my 120mm edf unit and I am going to use my KJ-66 turbine for longer and better flights. I hope that my L-59 would give me more confidence in order to fly later my turbined Falcon.
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Old Feb 26, 2013, 04:01 PM
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Originally Posted by ditchit View Post
Sound advice urrl but you do see so many maiden flights where quick trim out and then into aerobatics. Frequently ends in a disastrous landing.

Took the intake tubes out and wrapped the front with carbon tow and cyano. Could only just get them back into the fuselage. Tested and no more collapsing due to the vacuum effect at full throttle. No improvement in power though. Power down to 1.5KW but think that may have been because the lipos were very cold. Going to test on 10S tomorrow to see if it really is a starvation issue. Got any pics of your mods to let in more air Anastasios? Did not understand "cut a round hole at the inlet tubes where they meet".
Hi Ditchit. Nerv on page 94 report #1398 has a photo that shows an inlet duct of another jet and in the middle of the duck {at the side that meets the edf unit} has a round pipe. The L-59 inlet duct hasn 't ,so I have made a round hole where the photo shows the pipe and the edf unit draw air from the left and the right duct
from outside and from the middle round hole from inside the fuselage from the front retract compatment. So the system draws more air and give me more thrust. Thrust that I need because this model is heavy.
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Old Feb 26, 2013, 05:16 PM
DominicM
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OK. Thanks. Understand now. Having done some research I now know that my HET motor definitely needs 10S for the DS-51. I'm not inclined to add more weight with another 2S5000 pack since I am 3.2kg already. To stay 8S I definitely need the Jetfan 90 or CS12. I'm going to try 10S tomorrow anyway to see what watts I get. Thanks for all the help. I'll get this bird in the air soon-ish ;>)
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Old Feb 26, 2013, 06:22 PM
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United States, CA, San Jose
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I think all you need is the 1680kv motor for your ds-51 with 8cell. Or you can go with 10S 4000 pack to save weight.
I found something very interesting in Hobbyking, there's a "special" lipo that holds 6600mah, 65C, and only weighs 1094gram as 8cell setup or 822g as 6S setup. The capacity to weight racial is just unbelievable on this particular lipo (not to mention the price too).
http://www.hobbyking.com/hobbyking/s...Boat_Pack.html
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Old Feb 27, 2013, 05:02 AM
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United States, FL, Hollywood
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Originally Posted by Anastasios View Post
Urrl , I have a Falcon 120 edf and with 2x6cell 5000mAh 40C Lipos I could fly for 2.5 to 3 minutes with very careful throttle settings and after landing my 12 cell Lipos were from 11% to max 18% or remaining power. I could not have the power for a missed approach. 2.5 to 3 minutes of flight is nothing.So I decided to buy the HK L-59 and use my Falcon's Lipos hopping that my flights would be more than 3 minutes. As for my Falcon I had removed my 120mm edf unit and I am going to use my KJ-66 turbine for longer and better flights. I hope that my L-59 would give me more confidence in order to fly later my turbined Falcon.
I've been going 4 minutes on 6S 5000mah 40C and sometimes 5 minutes including the landing. Ending voltage is usually about 22.2v or so. Guess how old your batteries are is a factor also.
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Old Feb 27, 2013, 02:27 PM
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A couple of flights this morning.
L-59 Two Flights (1 min 15 sec)
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Old Feb 27, 2013, 02:41 PM
DominicM
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Fleet, Hampshire, UK.
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Very nice urrl. Kudos to you, you've really got that jet working well.
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Old Feb 27, 2013, 04:13 PM
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Canada, ON, Newmarket
Joined Nov 2006
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I bought Vettster's L59 off him less the EDF. I plan on using the CS fan with a 1400kv motor on 7S. I will also be adding retracts.
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Old Feb 27, 2013, 04:57 PM
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redcar cleveland uk
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Originally Posted by davecrash View Post
I bought Vettster's L59 off him less the EDF. I plan on using the CS fan with a 1400kv motor on 7S. I will also be adding retracts.
Has trev sold his hawk aswell?.
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Old Feb 27, 2013, 05:00 PM
Fly now crash later
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Canada, ON, Newmarket
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Originally Posted by phily32 View Post
Has trev sold his hawk aswell?.
He sold all of it, Gone to turbines only.
I'm taking bets, He will be back to EDF's by spring.
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Old Feb 28, 2013, 05:58 PM
Fly now crash later
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Canada, ON, Newmarket
Joined Nov 2006
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These electric retracts from HK are a perfect drop in fit. http://www.hobbyking.com/hobbyking/s...dProduct=14838
Trevor removed the nose gear mount so I'm making my own. I'm using these legs. http://www.hobbyking.com/hobbyking/s...Class_Jet.html
I will be angling the nose mount so it will go completely into the fuse when retracted.
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