JET LEGEND VIPER BUILD THREAD
01-08-2015, 07:57 PM
#1301
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I'm sure that some will disagree, but here is how I see it having made the transition to jets and turbines myself over the last year or two. High speed prop planes like a Jackal get you experience with general complexity, retracts and flaps. You probably wouldn't have much difficulty taking off or flying, but landing a turbine jet consistently is a different type of challenge. You have to deal with high wing loading (by comparison) multiple seconds of throttle lag, high residual thrust and lack of propwash over the control surfaces. I find that the throttle lag means I need to be a lot more accurate and consistent when descending and making base and final turns. You could certainly get your waiver on the JL Viperjets (heck, I've seen people do it with a Flash), but personally I would consider this plane too nice to ding up by bouncing it in, knocking the gear out, etc. I'd suggest getting a fiberglass EDF like the Habu 32 or 32X and mastering the landings. The H32 is a lot of fun to fly (it's still one of my favorites) and it flies pretty much like a turbine jet (minus the throttle lag and residual thrust).
Just my 2 cents ...
Greg
Just my 2 cents ...
Greg
The Habu is a great turbine trainer, without the cost.
Put an 8s system in it, it'' go 150 mph, and give you a high wing loading to practice approaches and landings. Then transitionong to a Viper will be easy. The Viper is actually easier to fly.
Matt
01-11-2015, 10:19 AM
#1302
Agree with that. Not only easier to fly, but easier to see too. I have both.
01-11-2015, 05:50 PM
#1303
My Feedback: (28)
I'm sure that some will disagree, but here is how I see it having made the transition to jets and turbines myself over the last year or two. High speed prop planes like a Jackal get you experience with general complexity, retracts and flaps. You probably wouldn't have much difficulty taking off or flying, but landing a turbine jet consistently is a different type of challenge. You have to deal with high wing loading (by comparison) multiple seconds of throttle lag, high residual thrust and lack of propwash over the control surfaces. I find that the throttle lag means I need to be a lot more accurate and consistent when descending and making base and final turns. You could certainly get your waiver on the JL Viperjets (heck, I've seen people do it with a Flash), but personally I would consider this plane too nice to ding up by bouncing it in, knocking the gear out, etc. I'd suggest getting a fiberglass EDF like the Habu 32 or 32X and mastering the landings. The H32 is a lot of fun to fly (it's still one of my favorites) and it flies pretty much like a turbine jet (minus the throttle lag and residual thrust).
Just my 2 cents ...
Greg
Just my 2 cents ...
Greg
Last edited by Desertlakesflying; 01-11-2015 at 05:53 PM.
01-11-2015, 06:15 PM
#1304
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I get your point, and I've dealt with high wing loading, and I also have a firm grasp of turbine lag. Flying Mustangs you learn to land properly the first time, because trying to jump on a throttle with one of those puts you upside down in the dirt. My RedwingRC MXS-R holds energy like crazy. It doesn't land like most 3D planes. I've flown a few EDF's, one being a Habu and one a Nitroplanes (http://www.nitroplanes.com/69a01-green-pro-4s-arf.html) which is very high wing loading and very fast for a foamy. I make it a point to have accurate consistent landings no matter what I am flying. I actually got a group award for the most consistent least bounce landings. Thanks for the input either way....
Greg
Last edited by gsmarino2000; 01-11-2015 at 06:21 PM.
01-12-2015, 08:22 PM
#1305
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It was the H32 the little red one fiberglass and balsa. I've watched about a million videos of these landing both JL and SM. If they land like they do in the probably 30 videos I've watched, I'm sure I can handle it. Seemed like the Sm was a little easier though. Thanks for the input.
01-13-2015, 07:01 AM
#1306
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Hi, anyone knows what kind of sticky grease inside the struts ? I cleaned mine, I have tried from oil to marine grease and I Cant get that nice damping effect.
01-13-2015, 07:36 AM
#1308
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Hello, this was my 2nd Jet landing ever https://www.youtube.com/watch?v=rdCrEpH4D58
Help please!!
Help please!!
Last edited by javier161; 01-13-2015 at 12:39 PM.
01-13-2015, 06:21 PM
#1309
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Hello, this was my 2nd Jet landing ever https://www.youtube.com/watch?v=rdCrEpH4D58
Help please!!
Help please!!
Greg
01-14-2015, 10:13 AM
#1313
My Feedback: (11)
Javier:
You have a bad approach because you have to come in high over the trees. they are scaring you. You need to cut it a bit closer to the trees. Since you will be diving towards the runway, your final turn should be all nose down and power off. Just got to watch the final turn so you don't get too slow. once done right it will high alpha flare and hold it for a couple seconds before touching down.
So it goes like this, 1/2 throttle or less from last leg before final 180 turn. You should be at the tree level. as you approach the trees climb a bit over them and power off. make your turn as a dive. Keep your nose down all the way in, flaring on touch down. If you are getting slow a slight bump on the throttle will give it speed pretty quickly. You will be at idle all the way in if set up right.
You have trees in your way and you have a short runway. Not every landing will be perfect. I have the same setup and I can grease 9/10 landings but I still break my flex plates every so often and its simply put, I messed up.
You have a bad approach because you have to come in high over the trees. they are scaring you. You need to cut it a bit closer to the trees. Since you will be diving towards the runway, your final turn should be all nose down and power off. Just got to watch the final turn so you don't get too slow. once done right it will high alpha flare and hold it for a couple seconds before touching down.
So it goes like this, 1/2 throttle or less from last leg before final 180 turn. You should be at the tree level. as you approach the trees climb a bit over them and power off. make your turn as a dive. Keep your nose down all the way in, flaring on touch down. If you are getting slow a slight bump on the throttle will give it speed pretty quickly. You will be at idle all the way in if set up right.
You have trees in your way and you have a short runway. Not every landing will be perfect. I have the same setup and I can grease 9/10 landings but I still break my flex plates every so often and its simply put, I messed up.
01-14-2015, 03:08 PM
#1314
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I'm just getting started with my Viper and am planning out the installation. The 5-way air manifold is something I haven't come across before, so I thought I would sketch the air system out to see which fittings were used and where. I ended up drawing it on the computer, so have uploaded the sketch for comment. I bought the Jet Legend electronic valves, as they have the 2mm connectors and everyone says that they are reliable. Am I right in assuming that the connector at the side of the block is for the air inlet and the three connectors on the front are the air outlets to the retracts and brakes? I also ended up with a spare port on the 5-way manifold.
01-15-2015, 08:15 AM
#1315
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Thanks. I will try that this weekend. Do you always use crow? how about flap elevator mix, Mine flyes with more or less 3mm up trim and from there 3mm down for takeoff and 6mm down for landing flap. Yesterday I rechecked CG and was nose heavy, maybe this is why it is coming to fast on aproach. I moved ecu battery from the front to the turbine bay.
Now i lift the model from the opening on the turbine bay and it balance flat, maybe a bit to the nose.
Now i lift the model from the opening on the turbine bay and it balance flat, maybe a bit to the nose.
01-15-2015, 08:24 AM
#1316
My Feedback: (11)
Full flaps and crow. No elevator trim needed on mine with crow. I don't think cg is an issue, you had too much speed and altitude. Here is my maiden. Go to end for 3rd person landing. I came in too high and hot as well. But way slower than you!
Jet Legend Viper Maiden: http://youtu.be/_lV9nCEn2sA
Jet Legend Viper Maiden: http://youtu.be/_lV9nCEn2sA
01-15-2015, 06:06 PM
#1319
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Thanks. I will try that this weekend. Do you always use crow? how about flap elevator mix, Mine flyes with more or less 3mm up trim and from there 3mm down for takeoff and 6mm down for landing flap. Yesterday I rechecked CG and was nose heavy, maybe this is why it is coming to fast on aproach. I moved ecu battery from the front to the turbine bay.
Now i lift the model from the opening on the turbine bay and it balance flat, maybe a bit to the nose.
Now i lift the model from the opening on the turbine bay and it balance flat, maybe a bit to the nose.
01-16-2015, 12:13 PM
#1320
I have not gone with the crow set up on my viper and have 60 mm flap and 5mm down elevator mix for full flap landing. Here is a link to my first take off and landing and it comes in at a good speed in this video but this is fast compared to how slow it lands now. It will always land nose heavy as the fuel is in front of cg. I hardly use the brakes even on a sealed strip as it slows very nicely for short landing roll out.
https://www.youtube.com/watch?v=27E6HyQ1eYo
Jason
https://www.youtube.com/watch?v=27E6HyQ1eYo
Jason
01-18-2015, 04:17 PM
#1323
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Yes, if you are running Kero or Jet A. I was testing my K100G yesterday. If you are running diesel (like I do), the manual parameters for diesel give more flame than I am comfortable with on a plane with a pipe. There are several posts in the turbine section with better diesel settings.
01-18-2015, 04:22 PM
#1324
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If it actually caught on fire, I expect there is something going on besides just the startup and run parameters. It sounds like you had fuel pooled in the engine. Remember that kerosene does not evaporate quickly like gasoline, and due to the combustor design you cannot pour it out the back of the engine. You can always contact Kingtech about this and get their recommendations, either directly or through the RCU Kingtech support forum.
01-19-2015, 03:02 PM
#1325
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First and second attempt to start of the day failed. Third attemped it started a long yellow flame, but never reached idle speed. Tailpipe was orange because of the flames, and then a short started on the servo leads that goes close to the pipe, and made the Sensorswitch overheat and melted. I disconnected power supply promptly but, not sure if futabas r7708sb had any damage of over current; I guess no because maybe the amps where not high enough because current was limited by the power supply to the receiver because JR connector.
I opened them yesterday and there is no sign of over current and they work perfectly, not sure if I need to throw them away.
Im starting a paint Job of the back part of the plane, a new fuse was almost $800 plus $500 of shipping and handling from China to USA.
I opened them yesterday and there is no sign of over current and they work perfectly, not sure if I need to throw them away.
Im starting a paint Job of the back part of the plane, a new fuse was almost $800 plus $500 of shipping and handling from China to USA.
Last edited by javier161; 01-19-2015 at 03:04 PM.