blainer48

My Feedback: (30)

Ok, I am stumped so I am going to ask the masses for some advice. I have a version 1 Jet Legend L-39 that I seem to be having issues getting it balanced. I'm not sure if the CG is that sensitive or what is going on. I went out the other day and could not get the nose wheel to come up. So, seems nose heavy. So, I took it down stairs and moved some stuff around and it seems to either go from one way to the other. The slightest thing can change it from nose heavy to tail heavy. So, I am stumped. If anyone can help me with what the CG is, I would greatly appreciate it.

Jason

Len Todd

Fly it, trim it, roll to the inverted. If it goes up on its own it is tail heavy. If it goes down on its own it is nose heavy.

Jason R.

Also you can check the aircraft incidence, as a friend of mine has one and we noticed when power was put on for take off there would be alot of down pressure put on nosewheel which was quite noticeable as to why it was difficult to rotate. He stiffened nose leg to so it did not sag as much on power up. He ended up putting a slightly longer nose leg in to keep a more neutral incidence. He had it literally jumping into air because of the incidence with power being too negative.

Jason

jeff sewell

My Feedback: (1)

6.25" from leading edge at the root - Still slightly nose heavy at that but mine flew very well.

Jeff

E.N.T.

My Feedback: (1)

That's where my CG is located. 6.25 from leading edge.

hmarmaizmd717

blainer48

My Feedback: (30)

I noticed that as well with the nose wheel. When I applied power it seemed to drop the nose. What did he do to tighten the nose strut up. I've heard of guys putting stiffer springs, etc.. Thanks for the info so far.

Jason

Jason R.

You can put stiffer springs in or use some tygon tubing inside existing spring, this also works.

Jason

blainer48

My Feedback: (30)

Do you get the springs from like a hardware store or does the strut take a specific type of spring?

Jason

Jason R.

You would need to take existing spring out to get the correct diameter, but yes most good hardware stores stock springs. Also Bolt specialists also stock springs if you have no luck at hardware store. If you have the tools you could turn up a couple small sleeves to fit inside strut to tighten spring and therefore do the same job.

Regards,
Jason

blainer48

My Feedback: (30)

So here's my next question. Was this design terrible about aileron slop? I have tried just about everything I can to get the slop out of the ailerons and it doesn't seem to be helping. I switched out servos and so forth but there is still enough slop to make a person second guess flutter. Any ideas or is that just the nature of the beast with this version.

Jason

Jason R.

The L39 i helped with, we ended up replacing aileron hinges with robart and using epoxy to hold them all in. A couple were a little loose but it was fixed once epoxy was used.