jbreptile

Hi guys iam waiting on a new set of wings as well. my wing is soft along the leading edge, this is the latest wings with the two bolts to hold the wing on.

Jeremy_D

Yep we were lucky on that one that it was discovered before flying. As jb has said we are now waiting on the replacement wings from JL. Once they are in we will dissect this wing to see exactly what has gone on in there.

cosmo21

This plane would have been purchased about 4 months ago, it is ovious manufacturing fault. As far as I know my buddy is in contact with JL about now.

MH

LarsHoi

My version is also with 2 bolts.
I have the same problem with my right winghalf. But have been told that it's not a problem.
The left half is hard as a rock, but I'm a bit concerned about the right wing.
Think I'l talk to the dealer again...

Jeremy_D

Hi Lars,

We didn't want to take that chance so I have got a new set coming for jb through Global Jet Club. Once the new ones arrive I'll open up the one with the soft area on the L/E and see what's going on under there.

VF84sluggo

My Feedback: (55)

Mine is also the "new version" with the two wing attach bolts. My jet was also constructed in the July timeframe, give or take a couple of weeks. Hmmmm......

I really don't see a way to get up inside the wing and apply hysol if weak areas are spotted. I'll give my wings a good inspection in any case.

Mark Vandervelden

Hi Guys
Sorry to hear you have "soft" spots on your wing LE especially as the JL Vipers have had a fairly long run of sound airframes that have proven to be structurally sound.
I have taken delivery of two Vipers just two weeks ago, one in Yellow, Green, Silver for my pall, another in Bronze for myself and have given them a good "squeeze and twist" test.
These are both the twin wing fixing bolt version and fortunately just like the ones I've had before there good and stiff with no distortion when stressed. (bent over Knee!)
Having dealt with JL there likely to sort any manufacturing issues out ASAP, you just need to get a dialog going with them and there reps, I'm lucky Jeff here in the UK is good as gold.
Hope your all up and running again soon, I've been stuck indoors over the past two weekend as the weathers not been jet friendly which is very frustrating when my new toys are ready to play with.

VF84sluggo

My Feedback: (55)

I gave my wings a good "feel" today, and I didn't notice anything out of the ordinary. So, short of somehow being able to examine visually all of the wing internal glue joints and fillets, I'm ok with things at this point.

FireFighterFSFD

My Feedback: (1)

Well it looks as if I will be building one of these good looking birds as well. I bought mine through Malcome Kay which is a dealer out of fl for Jet Legend. I will say that he has been very friendly and helpful. I currently have a Wren 54 turbine but hope to soon replace it with something a little bigger and after speaking with Malcome he seems to think that this jet would be a great plane to work with starting out with the smaller engine and later upgrading to the larger. I went with the e-retracts, and will be trying to build this thing as light as possible. I will be using lypos for the batts, no switches, and as clean as possible to keep things neat, light, and functional. I had been a little worried about the 54 in it but at this point I guess I am just going to be hoping for the best and doing what I can to upgrade as soon as possible. I will keep you all posted

essyou35

My Feedback: (11)

FireFighter, here is my .02. Is your mw54 the supersport with 18 lbs thrust or the 14 lb version? Lets be unrealistic and say you got the weight of this viper jet down to say 24 lbs wet.

You'll have a .58 T/W and that is not good odds with the 14 lb turbine. No one I have heard of is using a P60 sized turbine in this jet. I think it will fly but it will be challenge all around. I cannot agree that using that turbine will somehow be "easier" to start with!

With a mw54 MKIII you need the jet to be around 19 lbs wet to have a .75 T/W, and that is what I consider minimal to really fly safely.

If you have the super sport then you should be ok if taking off from concrete.

VF84sluggo

My Feedback: (55)

Hey gang, I have a question about the gear valves: is there any way to make the gear stay up-and-locked?

I ask because when I de-power the jet with the gear up, I hear air pressure being released and the gear drops. I'd like to be able to leave the gear up/locked when breaking down the jet for transportation.

Randy

P.S. After closer inspection, it seems that the gear is not engaging the up-locks. When fully retracted with 100 psi air, if I bleed the system air pressure down the gear falls out of the wells. From past experience, if the gear is truly "up and locked", the gear will stay up and locked when the jet is depowered and the air pressure bled off.

Malcolm Kay

My Feedback: (11)

Essyou 35,,,, Malcolm Kay here,,,,, just wanted to remind you of the old days when we would fly a thirty pound Tom Cook T33 with a ducted fan producing 11lbs of thrust and then the same plane with the first commercially available turbine the propane powered JPX that produced nine pounds of thrust ,,, on a good day ! Too much emphasis is placed on the amount of turbine power needed to fly a model airplane today, after all a 19000 lb F86 Sabre flew with 4800 lbs of thrust , so that power to weight ratio worked and so it will in a 22lb Viper.....just my 2cents worth,, MK

essyou35

My Feedback: (11)

Yes Malcomn I do understand what you are saying but the poster mentioned something to the efftect of starting with less thrust is a good way to "start".

Full scale sabre pilots were some of the best pilots as we know, taken from the WWII pilots. Also back in the day flyin a 30 lb jet on 11 lbs of thrust required a lot of skill.

I just wanted to make that clear. Of course it can fly, but not easily.

mikedenilin

My Feedback: (67)

Hi Guys,
I really think that a good power range for this Viper is the 80-100N size class turbine. If you want to go really fast, try a 120N.

Just got back from Monster Jam Invitational Jet Rally. We had 4 Vipers at the field, all flying well. 2 VIPERS WITH M100, 1 T12 (Mine), 1 P120.

I think the T-12 is so powerful it's going to make my newly awarded snowboard fly.

Mike

VF84sluggo

My Feedback: (55)

Follow-up on my "up lock" saga:

As a test, I applied pressure, via my Robart hand-pump, directly to the "up" line of one of my main gear. Pumped it hard, to where the gage showed 130+ psi. The main gear retracted nice and firmly, as expected with this pressure. Once I released the fitting and the pressure immediately bled off, the gear could be pulled easily out of the gear well. It was not locked.

So, I removed the main mount. Inspecting the retract unit, there does not appear to be the typical shape of the end of the plunger track that allows the "T" end of the plunger to drop into and "lock" the gear in position...on either end of the track. So, I applied pressure again, and the gear retracted. But, when pressure was removed, the retract could be moved throughout the range of travel. No locking action at all.

Now I'm wondering if my "up/locked" for transportation issue is not with any power being removed, switchology, valves, etc., but instead is a physical design issue with the retract units. Has JL changed the type of retracts used in the jet? There have been other mods that folks have pointed out, like the front wing attach bolts and redesigned engine mount rails.

I'm curious because Rocky says his gear locks up just fine; simply retract the gear, then turn everything off, and that's it. This is what I expected to find this morning, as this is how my L-39, my Intro, and my Nano retracts work. Just retract the gear, turn off the rx and tx, and disassemble as needed for transport.

RC

Jeremy_D

The early ones locked up but from about the second batch onwards they would only lock up with air so when you remove the wing they drop. I kept my wings in the bubble wrap bags they came in so no problem when transporting or storing.

VF84sluggo

My Feedback: (55)

Thanks Jeremy! After I looked closer and did the troubleshooting, it did appear that there was no problem. Everything was working as it should, I just didn't realize it.

Thanks for the info.


Randy

mikedenilin

My Feedback: (67)

If I remember correctly, the purpose of doing so is to make sure that gear will come down when the air pressure drops too much during flight. Mike.

VF84sluggo

My Feedback: (55)

Very good. Thanks, Mike!

FireFighterFSFD

My Feedback: (1)

well I was not trying to kick a hornets nest here so apologies for that. Let me back up and explain where I am at and my plan.
I have been flying for 21 years and flown about every thing in this hobby that was ment to fly and a few that I dont think were really expected to fly . When I had said place to start, I meant that I could get my project started and have it flyable while I prepare for a larger turbine. I have been thinking about just sailing some of the planes I got and getting a better suited engine. The biggest problem I face is not the ability, time, or money, but the wife. I have plenty of stuff to fly as it is and the wife has her hobby that makes this one look like a quarter machine so when I go and dump money on something, for some reason she thinks that means she gets to do the same and my 8 thousand dollar toy just cost me 16. hahaha
A few of you that have called asking when I ordered this thing know exactly what I am talking about.
so far I have done this under the radar of the other half after I sold some other stuff. If I can move the jet I got then I will call it a good day.
Malcolm has been very helful and after talking with him I was sold on the JL line. I guess now I have to just wait on it to get here and get started. I know there has been build thread after build thread on this but I kinda thought I might do one just to do it.

VF84sluggo

My Feedback: (55)

Ok, my gear saga continues...I don't know if I messed something up with all my efforts to get the gear to stay locked "up" when the rx/tx is turned off or what, but here's the deal now:

With air lines hooked up, system pressurized, tx/rx on, when I retract the gear, they retract as expected. But, when I select gear down on the tx, I hear a release of air pressure and the gear kind of flops down out of the wheel wells. They do not lock in place. They can be moved up and down by hand. Pressure is good on the gage. If I push the little blue button on top of the gear down electronic valve, the gear will seat in the down position, and when wiggled by hand, they are locked down. I can cycle the gear up and down, and it's the same thing over and over again: nice, firm retraction, flop down with an audible air release sound, then a push of the blue button on the "down" valve and then an audible seating of the gear in the "down' position.

Any idea what's going on here? The air system is tight, so this is not leak related as far as the air plumbing is concerned.

Thanks,

Randy

mtnflyer14

Sluggo,
I don't have mine yet, probably isn't even on the boat yet, so can't help with troubleshooting, but you are saying that you do not get a 'down and locked' unless you manually push a button on the electronic valve? If so, that is obviously unsatisfactory. I hope someone points an "ah ha" that we are overlooking here.
Regards,
Gus

FireFighterFSFD

My Feedback: (1)

have you tried adjusting your ATV in your radio on the gear channel. It wont help the power off issue but if if it is doing it when turned on it might help.

VF84sluggo

My Feedback: (55)

Yep, ran the ATV to the limits, but this most likely was just a feel-good excercise, since the signal was already being sent to the electronic valves as it was. Increasing the ATV won't make it send more of a signal and make the valve somehow push harder.

Gus, I'm not sure what the deal is now. Each of the gear valves has a little blue button on top that you can press to manually operate the electronic valve. As I was fiddling with the valves, I noticed that pushing the button caused the down-valve to operate and the extra push locked the gear down. I don't recall having this problem when I first started playing with the gear system yesterday. The gear went up and down normally without having to manually press the blue button.

Yesterday I got side-tracked trying to figure out why the gear would not stay up-and-locked after I retracted the gear, and then shut the power off, like I would do at the end of the day as I prepared to disasseble the jet for pack-up. I didn't realize that this is normal for this new-style retract. So, I don't know if I somehow reprogrammed the down-valve as I was "troubleshooting" what in reality was a non-problem. What I noticed was that the gear would drop, even with pressure in the system. Once I turned the rx off, I'd hear a release of air pressure from one or both - couldn't tell which - of the electronic valves and all three gear would flop down out of the "up" position. So, I ended up messing with blue buttons, ATV's, you name it. So, I may have inadvertently done something, because when I resumed my gear testing today I discovered this new issue.

I will say I'm not a fan of the no up-lock retract. With no air pressure, the gear will fall out of the "up" position. Moving the fuselage around and sliding it onto my storage rack with the nose gear hanging out in the breeze is a pain. Same for the wings: the mains fall out of the wells if the wing is not kept upside-down.

Anyway, if I can't figure out what's going on with this electronic retract valve system pretty soon, I may just go with the tried-and-true Robart-pneumatic-valve-hooked-to-a-servo setup, run 3mm air lines, and just be done with this.

RC

noahb

My Feedback: (67)

Sluggo, check your small airlines. You may have a kink in one of them. I had a similar issue with just one gear. Happens the airline had kink and the air pressure would not flow to push the gear down. Ler us know what you find out.