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JET LEGEND VIPER BUILD THREAD

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JET LEGEND VIPER BUILD THREAD

Old 08-14-2015, 06:17 PM
  #1551  
Jason R.
 
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I maybe fly half the flight around half throttle the rest is mostly 3/4 to full. Even when have done majority flight 3/4 to full still land with 1/3 of a tank.

Jason

Last edited by Jason R.; 08-14-2015 at 06:19 PM. Reason: wrong quote
Old 08-14-2015, 08:55 PM
  #1552  
M3Baker
 
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Originally Posted by mikedenilin
My typical flying time is 7:30 and got about 1/3 tank left on one tank. I fly with a T12 turbine. Unfortunately, I ended it earlier when I had a mid-air with another Viper. It's such as great flyer, we both are going to get another vipers. Mike
Oh Mike, sorry to hear that.
Old 08-14-2015, 09:59 PM
  #1553  
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Thank you for your condolences. After logging over 51 hours of flying time, I am feeling sad, but also happy to see it go in a spectacular way. Mike
Old 08-16-2015, 01:26 PM
  #1554  
Jon Mead
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I finally managed to maiden my new Viperjet today, after spending far too long completing the installation. However, it was well worth the wait, as the plane flew beautifully. I have followed much of the advice found within this thread and used JetLegend smoke tanks and a single front tank to help reduce the C of G shift through the flight. The power comes from a Jets Munt M100XBL and after 7 minutes the rear tanks were just about empty and the front tank completely full. Servos are Savox 1256TG with a Hitec 645 for the nose wheel steering.

This is the second one in our club and based on the comments this afternoon, there may soon be one or two more! Many thanks to Jeff Sewell at Zedjet for the excellent support and service.

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Old 08-16-2015, 05:25 PM
  #1555  
advent996
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Jon,

Congratulations on your maiden !!!! I too completed the maiden of my Viperjet today. The flight overall was very successful with minimal initial trimming required. I have been following this thread as well and went with the two saddle tank, one main tank configuration. I am running a Jetcat P80se with a timer setting of 7.5 minutes. At the end of the flight I too had just barely gotten into the main tank. Back to the take off... The jet tracked very well and came up to speed nicely. The bad news was that it snapped to the right shortly after rotating. The good news was that I was able to catch it and continue on with my flight. I have heard of at least one other who had also experienced this hard snap shortly following rotation. Servos are JR8411, Spektrum AR12120 receiver with all recommended throws on control services. CG is 35mm aft of center wing tube. The jet was a pleasure to fly after catching the snap and settled in nicely. Landing was extremely stable with 1/4" of crow.

Any thoughts on the snap ???

Thx,

Bill
Old 08-16-2015, 10:02 PM
  #1556  
Jason R.
 
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Congrats on the maidens Bill and Jon. Unsure about the snap, possibly a little slow on rotation.

Jason
Old 08-17-2015, 07:52 AM
  #1557  
advent996
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After re reading the thread it appears AOA noted on pages 29 & 30 may be the cause for my exciting take off. Something for me to look at ...

Bill
Old 08-17-2015, 11:12 AM
  #1558  
rcjets12
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Originally Posted by FenderBean
Mike that's on par with Jose and Pauls, that's a really good flying time. I'm hoping the new project will have the same flight time.
With my Viper with throttle management I can fly for 10 min and still have about 20oz left in the front tank. I'm using the rabbit sp. I have about 104oz
Old 08-17-2015, 12:33 PM
  #1559  
Jon Mead
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Originally Posted by advent996
Jon,

Congratulations on your maiden !!!! I too completed the maiden of my Viperjet today. The flight overall was very successful with minimal initial trimming required. I have been following this thread as well and went with the two saddle tank, one main tank configuration. I am running a Jetcat P80se with a timer setting of 7.5 minutes. At the end of the flight I too had just barely gotten into the main tank. Back to the take off... The jet tracked very well and came up to speed nicely. The bad news was that it snapped to the right shortly after rotating. The good news was that I was able to catch it and continue on with my flight. I have heard of at least one other who had also experienced this hard snap shortly following rotation. Servos are JR8411, Spektrum AR12120 receiver with all recommended throws on control services. CG is 35mm aft of center wing tube. The jet was a pleasure to fly after catching the snap and settled in nicely. Landing was extremely stable with 1/4" of crow.

Any thoughts on the snap ???

Thx,

Bill
Many thanks Bill, I was absolutely delighted with how well the plane flew. My first take off was with no flap, and the the rotation point was probably around 100 feet. The second was with half flap, and the plane rotated after a much shorter run, to the point where it surprised me a little. However, with the M100, there seemed to be enough power to keep the model accelerating into the climb, but I could see how the model might be sensitive in the roll axis at slow speed through an early rotation. I flew again today, and was ready to reduce the climb out angle and let the model accelerate away.
Old 08-17-2015, 05:13 PM
  #1560  
gsmarino2000
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I've never had an outright stall on takeoff, but I did pull too abruptly on the elevator on a couple of my early takeoffs and got the mushy wing wag meaning it was on the edge. I have since refined my technique and get very professional takeoffs. Just pull gently. I also experienced a snap (meaning an accelerated stall wanting to spin) once in this plane. No problem recovering but would have been dicey if I wasn't a couple of mistakes high. The plane handles so nicely, it's easy to forget that it isn't a trainer.

Greg
Old 08-17-2015, 07:16 PM
  #1561  
fredo
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I'm so delighted with the performance of this bird I'm also running K100g. Using one main tank and two saddle for fuel. Flying 1/2 throttle most of the time and full on verticals and fast low passes...boy this thing can move I'm somewhere between 6-8 min mark and when I land those two saddle tanks are empty and the main is still full.
I have a question, has anybody tried knife edge without winglets? I wonder if that would improve KE flight without too much mixing.
I tried KE but have to hold hefty amount of aileron. Any other suggestions?
Old 08-23-2015, 02:04 PM
  #1562  
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Originally Posted by fredo
<SNIP>
I have a question, has anybody tried knife edge without winglets? I wonder if that would improve KE flight without too much mixing.
I tried KE but have to hold hefty amount of aileron. Any other suggestions?
Fredo,

I tried knife edge today with the wingtips off. Might have been a little better, hard to say. Regardless it still has pretty significant roll coupling.

Greg
Old 08-24-2015, 04:03 AM
  #1563  
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New square tank is 2800cc previous two tank set up is 3000cc.
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Old 08-24-2015, 02:04 PM
  #1564  
advent996
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Are they coming with the single tank from the factory or did you replace the two 1500cc tank with the single 2800cc tank???

bill
Old 08-24-2015, 02:23 PM
  #1565  
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Originally Posted by advent996
Are they coming with the single tank from the factory or did you replace the two 1500cc tank with the single 2800cc tank???

bill
Hi Bill,
My viper came from the factory with the single tank It was built July 2015.not sure if they all come this way now or not.Maybe one of the reps on this forum could answer that question.
Regards Greg
Old 08-29-2015, 07:07 PM
  #1566  
fredo
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Thanks gsmarino, I was going to try it myself but found after 8 flights I have a new problem. all 3 of my undercarriages have sagged. They became very soft to compress. I remmember, someone has mentioned this before.
Well, I pulled them apart and all 3 UC's have spring in their oleos. To be more specific, each oleo has two springs in it...that's it. I decided to fill the spring cavity with grease.
I'm not sure how this is going to cure the problem, as when it depresses itself, the grease will eventually stop it from going any further. I have a feeling the springs are just week. Any suggestions?
Old 08-29-2015, 08:31 PM
  #1567  
Jason R.
 
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Hi Fredo, I also have the springs in mine. I found mine were greased up poorly and would be very slow to react, then after thorough clean they were very soft. I put a length of tygon tubing inside the springs and they are perfect now. Rides across the grass just nicely. Jason
Old 08-29-2015, 09:23 PM
  #1568  
fredo
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Thanks Jason, the tubing sounds like a good idea. I wonder if anyone tried to simply replace it with a heavier gauge springs.
Old 08-30-2015, 04:38 AM
  #1569  
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Originally Posted by Jason R.
Hi Fredo, I also have the springs in mine. I found mine were greased up poorly and would be very slow to react, then after thorough clean they were very soft. I put a length of tygon tubing inside the springs and they are perfect now. Rides across the grass just nicely. Jason
Jason did you put grease back in with the tygon?

Greg
Old 08-30-2015, 12:35 PM
  #1570  
gsmarino2000
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The grease fill gives a damping affect - very nice, some of the best performing gear I have had. Mine are now starting to sag some after about 40 flights. I haven't opened them up yet, but I am sure they have springs. I really don't want just springs, though - I want to keep the damping effect.

Greg

Last edited by gsmarino2000; 08-30-2015 at 04:12 PM.
Old 08-31-2015, 01:02 AM
  #1571  
Jason R.
 
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Greg

Yes i did put a good coat of grease back on springs. They have not shown any signs of lag and i have just over 60 flights on it now.

Jason
Old 08-31-2015, 05:06 PM
  #1572  
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Tried to get airborne today off sod farm grass is so thick and dense couldnt get up enough steam.Going to try off club field tommorow i have k100g with new standard tank 94oz and smoke tanks.Club is 600ft short grass would you guys leave smoke tanks empty or fill them and try.Do you think 600 feet will be enough 22lbs thrust.
Old 08-31-2015, 05:51 PM
  #1573  
mikedenilin
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600 ft grass runway is marginal. Leave smoke tank empty. Go full throttle and release the brake. You should get it up put if the grass is long and grounds soft you might have problems to rotate.
Old 08-31-2015, 06:09 PM
  #1574  
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Originally Posted by mikedenilin
600 ft grass runway is marginal. Leave smoke tank empty. Go full throttle and release the brake. You should get it up put if the grass is long and grounds soft you might have problems to rotate.
Ok thank you I will try that if it looks slow i will abort.
Old 08-31-2015, 07:21 PM
  #1575  
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I have noticed with the fuel aft more they rotate much faster. Might be something to think about as well.

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