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View Full Version : Strange Lama V3 behaviour


JuZ
02-13-2008, 04:45 PM
I've had my Lama V3 for a while now and was getting confident enough with it to start getting the blades clashing during extreme maneuvers! So I bought and fitted the Turbo shaft upgrade kit (http://www.rchelicoptershop.com/catalog/turbo-kit-for-lama-robins22-comanche-p-185.html) which has made it much more responsive and faster in a straight line, no problem there, but now when I try to hover the heli moves in a strange elliptical circle, I've tried to illustrate what I mean with my MS Paint skills :rolling

http://i8.photobucket.com/albums/a20/juz13/Web/OddLama.jpg

That is how it behaves with no stick inputs, I can't trim it out as it's moving forward for half the loop and backward for the other half!

The bearings for the main shaft have a small amount of play, could that cause it?

Hopefully someone will be able to help it's getting rather annoying!!

tz250w
02-13-2008, 06:27 PM
I've had the same problem with my son's V4 after crashes and found that binding links cause the problem. Usually the flybar. What I do is check to make sure the rod ends are all perpendicular to their ball and give them a squirt of silcone spray.

JuZ
02-14-2008, 02:36 AM
Turns out that it's a common problem known as the "toilet bowl" effect, I found a video of someone elses Lama doing the same thing.

http://www.youtube.com/v/JLl5h7VPlx8&rel=1

Apparently it can be caused by the flybar, so I'm going to check mine later on, I'll be back with the results :thumbup:

tz250w
02-14-2008, 04:26 AM
Yup, that's what his does if the flybar linkage and pivot isn't completely friction free. That's where getting the rod ends straight and the silicone spray helped out.

JuZ
02-14-2008, 06:20 AM
I've also read that the metal upgrades can also cause this, so seeing as my flybar is free I'm going to try re fitting my platic topped inner shaft and see what happens.

JuZ
02-15-2008, 07:29 AM
Just a quick update while the batteries are recharging, removing the turbo shaft upgrade and refitting the stock inner shaft totally cured the "toilet bowl effect" so I now have a plastic/metal hybrid with alloy swashplate and lower blade holders and plastic uppers, I have ordered a standard length alloy inner shaft to see if I can have all metal, we shall see......

damyxz
02-15-2008, 10:57 PM
It is caused by the flybar link to the top blades. Be sure that the top blades are perfectly horizontal when the flybar is at horizontal position. a slight deviation will cause this. adjust the link as needed.

JuZ
02-16-2008, 02:12 PM
Read my previous post it was nothing to do with the flybar this time.

damyxz
02-17-2008, 12:57 AM
As I said, adjust the flybar link as told, The metal shaft upgrade might have slight difference in dimension as the plastic part. The horizontal alignment of the upper rotor blade grips and the flybar should be perfectly parallel to each other.

tz250w
02-17-2008, 09:17 AM
As I said, adjust the flybar link as told, The metal shaft upgrade might have slight difference in dimension as the plastic part. The horizontal alignment of the upper rotor blade grips and the flybar should be perfectly parallel to each other.

And I checked my son's, it was off by a turn and a half. After adjusting, I could throttle up, go to the fridge, grab a beer, come back, sit down, burp and still have time to adjust the throttle before it hit the ceiling!

Thanks for the tip. :thumbup:

ct420
02-25-2008, 03:35 AM
I've had my Lama 2 for nearly 3 years now. I've had TB effect more times than I can count. I can tell you for sure that it is nearly always:

1) Most common: Something to do with the flybar (bent, link not adjusted correctly, sticky, etc)

2) Less common: Blades (badly damaged/unbalanced, etc. can sometimes cause TB)


Also, it's not built to fly agressively. The key with the lama is smooth, graceful maneuvers, especially in stock form.

With a shortened flybar, Extreme extended inner shaft, extreme motors, and extreme blades, I can fly mine a lot harder than stock form, but I still can't bang it around too much. It's just not built for it ;)