JET LEGEND VIPER BUILD THREAD
12-11-2012, 02:27 AM
#251
RE: JET LEGEND VIPER BUILD THREAD
CG very important, 35mm behind factory recommended, far too nose heavy with factory cg.
I'll let you know the crow measurement.
I always land with a nice long flattish approach, usually lands at my feet, I decend final line up with zero power from about 100 feet, if I am falling short just a bit of power to keep her floating, so easy.
Now had 43 completely uneventful flights, one or two guys watching this thread will vouch for how well it flies, even Jeff from Zedjet uk was impressed with it.
Using P80SE, more than enough power and I'm getting 11 min flights with a bit of sensible throttle control.
I'll let you know the crow measurement.
I always land with a nice long flattish approach, usually lands at my feet, I decend final line up with zero power from about 100 feet, if I am falling short just a bit of power to keep her floating, so easy.
Now had 43 completely uneventful flights, one or two guys watching this thread will vouch for how well it flies, even Jeff from Zedjet uk was impressed with it.
Using P80SE, more than enough power and I'm getting 11 min flights with a bit of sensible throttle control.
12-12-2012, 01:01 AM
#261
RE: JET LEGEND VIPER BUILD THREAD
Hi Mike,
Link below to the lights I used, they have a very wide angle of view, highly recommended and just the right size for the Viper.
Just add an rc simple switch which I'm sure you have access to!
Pilots are a problem with the factory cockpit, I finished up using one of my partners teddy bears!
Gary.
http://www.braincube-aero.com/index....roducts_id=192
Link below to the lights I used, they have a very wide angle of view, highly recommended and just the right size for the Viper.
Just add an rc simple switch which I'm sure you have access to!
Pilots are a problem with the factory cockpit, I finished up using one of my partners teddy bears!
Gary.
http://www.braincube-aero.com/index....roducts_id=192
12-12-2012, 04:13 AM
#263
RE: JET LEGEND VIPER BUILD THREAD
Jeremy, they are simply y'd to my flap channel, direct from rx. You could use the gear or any spare channel on a tx switch.
As we tend to overpower our jets with two batteries etc. its no problem.
As we tend to overpower our jets with two batteries etc. its no problem.
12-12-2012, 06:31 AM
#264
RE: JET LEGEND VIPER BUILD THREAD
Hi Guys
I too have been running the Braincube LEDs in the Viper andin some other airframes and found them to be very good.
I used one of the white ones on each of the forward facing facet and one green and one red on the outward facing facets.
I also lined the facets with sticky backed alloy foil which helps thorough the light forward and also looks very neat.
I too have been running the Braincube LEDs in the Viper andin some other airframes and found them to be very good.
I used one of the white ones on each of the forward facing facet and one green and one red on the outward facing facets.
I also lined the facets with sticky backed alloy foil which helps thorough the light forward and also looks very neat.
At first I tried them on 4 cell nims at 4.8-5v and they were good but on 6v via a reg are much much better.
At 4.8-5v they draw 200ma each, at 6v they draw 250ma each so that's a full amp with all 4 running.
With that in mind rather than push the RXs Reg and the "lands in the RX"I used a separate 1800ma 2s lipo on its own 6v reg.
Then later tokeep things simple I started using the ECU packvia its balance lead as its one less battery to charge.
Whatever system you use lights bring the Viper to lifeandwith these dull evenings here help no end on the approach!
Happy flying
At 4.8-5v they draw 200ma each, at 6v they draw 250ma each so that's a full amp with all 4 running.
With that in mind rather than push the RXs Reg and the "lands in the RX"I used a separate 1800ma 2s lipo on its own 6v reg.
Then later tokeep things simple I started using the ECU packvia its balance lead as its one less battery to charge.
Whatever system you use lights bring the Viper to lifeandwith these dull evenings here help no end on the approach!
Happy flying
12-12-2012, 06:44 AM
#265
RE: JET LEGEND VIPER BUILD THREAD
Hi Mark,
I've found that now I'm using a couple of 2300 life's after four hard flights I'm using very little power, lights are not on for long and bearing in mind at 1 amp per hour a minute or two doesn't even scratch the batteries.
My L39 draws 2.6 amps with all lights on from the powerbox but tucked away in the nose are two 5000 mah sub c's for weight reasons!
I think folk get a bit hyper by refusing to use flight batts for anything other than powering the rx and servo's but as I mentioned lights hardly affect the power consumption so why stick more weight in than you need with yet another battery?
Gary.
I've found that now I'm using a couple of 2300 life's after four hard flights I'm using very little power, lights are not on for long and bearing in mind at 1 amp per hour a minute or two doesn't even scratch the batteries.
My L39 draws 2.6 amps with all lights on from the powerbox but tucked away in the nose are two 5000 mah sub c's for weight reasons!
I think folk get a bit hyper by refusing to use flight batts for anything other than powering the rx and servo's but as I mentioned lights hardly affect the power consumption so why stick more weight in than you need with yet another battery?
Gary.
12-12-2012, 07:17 AM
#266
RE: JET LEGEND VIPER BUILD THREAD
Hi Garry
I agree, two large battery packs can easily cope with the lights for hours and hours evan at 2.5+ amps.
What I was worried about is inmid size jets I-we use the Powerbox duel reg switch, they can only just cope with 3amps constant.
Anything close to 3amps constant puts the Powerbox reg well above its recommended max temp, at 2amps constantis its true max, I've tested them at length.
And of course running 1-2 or evan 3amps constant throught the Rx output puts a huge strain on that singel socket andlands within the Rx its self
I agree, two large battery packs can easily cope with the lights for hours and hours evan at 2.5+ amps.
What I was worried about is inmid size jets I-we use the Powerbox duel reg switch, they can only just cope with 3amps constant.
Anything close to 3amps constant puts the Powerbox reg well above its recommended max temp, at 2amps constantis its true max, I've tested them at length.
And of course running 1-2 or evan 3amps constant throught the Rx output puts a huge strain on that singel socket andlands within the Rx its self
The bigger Powerbox setups like the Evolution etc can easily cope with the extra amp draw but they tend to be in the bigger airframes.
That's why at first I used a separate pack in the Viper but soon after started using its ECU pack as at 3.7amp and was more than able to cope.
That's why at first I used a separate pack in the Viper but soon after started using its ECU pack as at 3.7amp and was more than able to cope.
A 6v reg only costs £3 or £4, all I do is fit it with a lead to connect it to the ECUs lipos balance lead after start up, Ive nowfitted a RC switch to keep it simpel .
I'm not saying using a PB Dule Switch wont work it will, but I'm not willing to push one that hard and risk a brown-out or reg to fail, so do everything to avoid it.
I love your Brown-Bronze Viper it looks terrific in the pic at the top, I have now taken delivery of one to eventualy replace my Red one
These Vipers must be good its the first time Ive bought two of the same airframe!
Regards Mark V
Regards Mark V
12-12-2012, 09:31 AM
#268
RE: JET LEGEND VIPER BUILD THREAD
Hi Gary
The Gemini is rated at 2x8amps so your well covered. I believe its actually intended for heles as it got a separate gyro power feed built in.
I use the Gemini in 50cc airframes were the currant draw is fairly high as the engines tend to shake everything to a blurry mess and punish the servos!
The PB Duel Switch is commonly used on jet airframes Viper sized and has been around for years.
Regards Mark v
12-12-2012, 09:47 AM
#269
RE: JET LEGEND VIPER BUILD THREAD
Hi Guys
Ive been getting a constant 9-10 minuets over 50+ flights on the Viper runninga Wren 100 with the Std 3lt tanks.
I often do a touch and go or two at the end of a flight and after all that I'm still coming back with over 1/3 of one tank left!
I had noticed that with one tank empty and the other low she takes off very quickly (and then can go vertical, nice)
last week I thought about putting some smaller tanks in but first I rechecked the CG both full and then empty.
Completely empty the CG is 43mm back from the centre of the wing tube but full its 23mm forward of the tube, that's a shift of 66mm!
It flys safely when completelyempty at 43mm (Ive ran it dry to prove it) and is OK with full tanks but I thought I would try to improve things.
I was hoping to bothreduce thetotal weight by reducing the fuel load and maintain a more constant CG throughout the flight.
I had some 800ml tanks identical to the JL ones and found they fitted a treat under the front of the engine bearers so I gave it a go.
I plumed these in parallel then as a front tank I found a 1350ml Dubro type replacing the twin 1500ml tanks giving a total of 2.95lt.
The CG now when full is now 20mm back from the wing tube and creeps forward as the rear tanks empty to 15mm behind.
Now from when the rear tanks are empty its going to be about the same as before with one of the std twin tanks full "success"
I have now had a few flights with this setup and it definitely gets off the ground much more quickly so helpful if you fly from grass.
Wile flying and held inverted it now needs less down stick in the early minuets but being semi symmetrical still need a fair bit.
Flight times and overall wieght are the same as before as its only lost 50ml, tanks empty evenly at the rear andare completely dry after a flight.
I think this is a well worth improvement, cant see any real downside unless your using the space at the rear for smoke tanks
If you wanted you could increase the fuel load by 100ml by useing one of the std 1500ml tanks up frontand still get a more constant CG?
Since the weekend I have fitted an evan smaller 1lt tank at the front so itsnow got 2.6lt andis 3/4lb lighter, look how much room there is now
To be safe Iwill reduce my first flight times to 8 mins, I will let you know how it goes after next weekend weather permiting!
To be safe Iwill reduce my first flight times to 8 mins, I will let you know how it goes after next weekend weather permiting!
12-12-2012, 10:03 AM
#270
RE: JET LEGEND VIPER BUILD THREAD
With you now Mark didn't realise you meant the switch!
The reason I asked was because my Gemini uses a lot more power from one batt, I swapped leads to eliminate a duff battery.
Spoke to Emmerich and he said the regulators needed adjusting but it would still work fine
I used the Gemini as it was left over stock from my model shop when I retired.
All the best,
Gary
The reason I asked was because my Gemini uses a lot more power from one batt, I swapped leads to eliminate a duff battery.
Spoke to Emmerich and he said the regulators needed adjusting but it would still work fine
I used the Gemini as it was left over stock from my model shop when I retired.
All the best,
Gary
12-12-2012, 10:29 AM
#271
RE: JET LEGEND VIPER BUILD THREAD
Hi Gary
Until you get it "recalabrated" you could simply swap the baterys leads every flight or so.
Evan if one battery was alowed to get a bit lower than the otherit would just start useing the 2nd one so compleatly safe.
The PB Gemani is a more robust setup and only about £25 more than the PB Duel Senser Switch
Rgards Mark V
Until you get it "recalabrated" you could simply swap the baterys leads every flight or so.
Evan if one battery was alowed to get a bit lower than the otherit would just start useing the 2nd one so compleatly safe.
The PB Gemani is a more robust setup and only about £25 more than the PB Duel Senser Switch
Rgards Mark V
12-12-2012, 12:32 PM
#274
RE: JET LEGEND VIPER BUILD THREAD
Hi
I wondered how long it would take for some one to notice that
.
.As not all the full size Joby's have got tip fins, in fact very few I wanted to see how it flew and looked with out them.
Rather than chop my new Bronze Black one about I thought I would trim my older Red one first and see how it went.
Partly because theres a nice colour change just in the right spot and partly because it already needs the tips touching up.
I have made the new and old tips "plug in" so its easy to go back if it did not work or look right.
When I flew it last week end it was breezy and as we know Vipers can wiggle a litel bit when its bumpy.
With the new tips it didn't wiggle, Ihad tried a small gyro the weekend before to see what would happen, that made no difference at all but this did?
I tried a few tight turns fast and slow and noticed no real difference, the stall was the same as before but vis or orientation was not as good but the light was poor.
To my eye I like the new tips but that's just me, to many a Vipers not a Viper with out them so I guess its like "Marmite" you love it or hate it
Regarding the Gyro, I turned it off for the new tip tests but when it was on It didn't make any real difference with ether tip in normal flight except in the stall tests.
When I managed to get it to fully stall (you have to go very very slow) you could see the gyro kick in on the rudder as it droped its nose and stop any incipient spin start dead!
Of course your supposed to use the rudder to stop it dropping a wing but its instinctive to hit the aileron stick but the gyro beats you too it and its all sorted befor it starts!
To that end a gyros def not needed but certanly dosent hurt any, just stay away from the real cheapys there more likely to cause a problem than cure it.
Conclusoin is I like the new tips
Conclusoin is I like the new tips
Regards Mark
12-12-2012, 12:38 PM
#275
RE: JET LEGEND VIPER BUILD THREAD
Mark can you send me a link to the 6V regulators you are using? And just to be clear, I would connect the lights to the regulator which is powered off the ECU batt and switched on and off via a spare RX channel? Or are they on the whole flight?