Build Log The Modified LAMA 400D. CF blades Page 6

[KCV6]

Hey Sven,

Was thinking more along the lines of "Airy" blades, never used them before but they seem to be popular. I should just lay up my own CF ones, I havn't done any CF work for a while but I still have a few metres of weave and some R180 kicking around.

Cheers.. Mark

[kodak_jack]

Originally Posted by erdnuckel2

The ones on the Lama 400D are the tuffest ones on the market right now (and the only {CoAx}-blades in this size anyway - or why else would I have started cutting them down to fit my Esky Big Lama?

Only thing that would resemble what you are talking about (IMHO anyway) would be someone finally coming out with "real" carbon fiber blades ....

Sven

Sven, are you saying the Lama 400 is even bigger than the Big Lama from Esky?

[erdnuckel2]

Originally Posted by kodak_jack

Sven, are you saying the Lama 400 is even bigger than the Big Lama from Esky?

Yes Jack, it is ... actually significantly!

Edit:
It is almost the size of a Blade400 or Belt CP - just the rotor is quite a bit smaller in diameter.

[erdnuckel2]

Originally Posted by KCV6

Hey Sven,

Was thinking more along the lines of "Airy" blades, never used them before but they seem to be popular. I should just lay up my own CF ones, I havn't done any CF work for a while but I still have a few metres of weave and some R180 kicking around.

Cheers.. Mark

Airy blades seem to be popular, you are right - but they only cut it for the smaller birds - if you dig deeper Mark, you will see that ALL the blades made by aftermarket companies for the size of the Esky Big Lama are tooo flexible - now imagine they have to be even bigger for the Lama400. ( )

What you are suggesting (and probably will be doing soon - something for what I kinda envy you for being able to do) is the ONLY feasible thing in my eyes ... if you know hhow to, make your own CF blades!!

Regards,
Sven

[KCV6]

Originally Posted by erdnuckel2

What you are suggesting (and probably will be doing soon - something for what I kinda envy you for being able to do) is the ONLY feasible thing in my eyes ... if you know hhow to, make your own CF blades!!

A perk of being in the Aerospace Industry More so from the point of view of getting stuff at trade and having some good equipment available so long as I don't interfere with Safety health and environment or any current workload. It use to be a lot simpler.

Hard part will be coming up with a consistent "blank" to CF over, otherwise you are limited to a pressure moulded lamination purely of laid up CF to a thickness which is no where near as strong, although I must admit I am tempted to try this approach first.

Cheers.. Mark

[erdnuckel2]

Originally Posted by KCV6

...

Hard part will be coming up with a consistent "blank" to CF over, otherwise you are limited to a pressure moulded lamination purely of laid up CF to a thickness which is no where near as strong, although I must admit I am tempted to try this approach first.

Cheers.. Mark

That is exactly how a guy who posted his "How to ... build your own helicopter blades" guide did it for the smaller L3/L4 - layers of CF - that's it. But of course the smaller birds are a lot lighter and you need a lot less strength and resilience (besides a few other things ) from the blade ...

[KCV6]

Guess I'll take an A and B into work and do some ProE 3d modeling and see if I can get 2 aluminium dies cut on the 3 axis. There is probably enough curvature in the blade so they won't flex, but they won't be as strong.

Yep, with cam and 2200mAh pack (and all the paint. LOL) my 400 comes in at 722.1 grams.... definately hefty, spot on 640 grams without cam or blades

Mark

[kodak_jack]

Originally Posted by KCV6

Guess I'll take an A and B into work and do some ProE 3d modeling and see if I can get 2 aluminium dies cut on the 3 axis. There is probably enough curvature in the blade so they won't flex, but they won't be as strong.

Yep, with cam and 2200mAh pack (and all the paint. LOL) my 400 comes in at 722.1 grams.... definately hefty, spot on 640 grams without cam or blades

Mark

If you go through all the trouble of making dies, you might as well go into business!!! Do you work with composites at work? I thought Uncle Sam was the only one watching from up there?

[KCV6]

Not directly working with composites these days, have drifted more into Optoelectronics, however we have in the past, and I use to do replacement CF side covers, brackets and bits for bikes.

I'll have a word to the Plant Manager and see if he would be willing to let me slip some 3 axis time in. If I can get good accurate dies cut the actual CF bit will be the easy part. The CF cloth is actually not badly priced here in Aus as there is no import duty or taxes on it.

Cheers.. Mark

[KCV6]

One thing I'd like to try is limit the amount of movement in the flybar and therefore the upper blades.

I have tried to simulate upper to lower blade strike and fortunately Walkera seem to have spaced the blades far enough appart that this won't happen at full servo extent. The top blades do however seem to move a lot when following the flybar. I would have thought this free movement could be limited to a certain degree which may in turn reduce the efect wind has on the helo.

Feel free to join in and comment.

[erdnuckel2]

Originally Posted by KCV6

One thing I'd like to try is limit the amount of movement in the flybar and therefore the upper blades.

I have tried to simulate upper to lower blade strike and fortunately Walkera seem to have spaced the blades far enough appart that this won't happen at full servo extent. The top blades do however seem to move a lot when following the flybar. I would have thought this free movement could be limited to a certain degree which may in turn reduce the efect wind has on the helo.

Feel free to join in and comment.

Been done for the smaller Lamas in Germany by Skytec (if I understand correctly what you suggest):
They make a rotorhead called "Speed" in which the angle the flybar can have in reference to the rotor axis is limited to a certain maximum degree. (Because of the design of their rotorheads there is practically NO sideways (lef/right) flybar movement possible anyway and with this particular rotor head the up/down movement gets limited.

Sven

[KCV6]

Yep, you do get my drift. I was thinking of machining up a new top retainer with deeper sides so it limits the amount of angle the flybar can pivot. I realize this will probably decrease the stability, or ability of the 400 to correct itself, but it should also limit how "out of control" it gets on abrupt change in direction. My spare flybar has arrived so I will start playing around a bit with length and put some temporary shims on it to limit it's movement to see how it effects the flight performance.

Don't get me wrong the 400 Lamas standard fly very nicely, I just can't help tinkering. LOL

[erdnuckel2]

Originally Posted by KCV6

Yep, you do get my drift. I was thinking of machining up a new top retainer with deeper sides so it limits the amount of angle the flybar can pivot. I realize this will probably decrease the stability, or ability of the 400 to correct itself, but it should also limit how "out of control" it gets on abrupt change in direction. My spare flybar has arrived so I will start playing around a bit with length and put some temporary shims on it to limit it's movement to see how it effects the flight performance.

Don't get me wrong the 400 Lamas standard fly very nicely, I just can't help tinkering. LOL

What is to get wrong about it? The Lama4 flies nicely (even more so if it happens to be of those that come from the factory with the servo horns in the 2nd hole) ... and yet it is the most modded heli on the planet (coax, that is)
Tinkering or ... "tinkeritis" (I think that is the term doctors gave that psychological condition ) is a very useful and admirable trait (in our hobby anyway) and the rc helis would surely not be where they are today if it weren't for the people who suffer from it ...

Regards,
Sven

[KCV6]

Unfortunately Tinkeritis has been known to lead to indebtitis which is sometimes followed by sparebeditis.

Agree wholeheartedly

Cheers

[KCV6]

Put 2 partial 2200mAh packs (about 10 mins worth on each) through it tonight under the back yard floodlight. Mostly hovering with rapid stick inputs to try to unsettle it.

With the shorter tail moving the weight closer to the main shafts and the reduced weight on the flybar it is a lot more responsive and as expected a bit more "stick intensive" to fly. Breeze was all over the place but no more than 5 mph. I will have a crack at shortening the flybar by 1 weight loop each end and limit the flybar pivot by a couple of degrees at a time next. I'm surprised that with all the added weight this thing still has more power than you need. half stick is hover I may have to rig up some more weight just to see how much it can lift.