Flight testing CNC/upgrades for the Lamas

[Hanol]

So I didn't see the definite answer to the question of the extended inner shaft. xTreme gives you 5mm. Some other mods give you 20 or even 30mm. Is there a real significant difference between them in terms of speed, handling and responce to the controls?

P.S. I am new to Lama. I own it for less then a week. But I flew 30 and 60 size fuel powered helies before, so I am comfortable with controls. And I really feel like Lama's controls are too sluggish. However it's a perfect size to fly on my backyard without disurbing neighbors with smoke and noise. I just wish it will be much faster and more responcieve.

[Jack the R]

This forum appears to be dead, so I reposted my question here.

Perhaps we will get an answer.

You can add longer servo control horns to get more tilt on the rotor. I assume this means the turbo shaft is better than shorter extended inner shafts, since you can tilt the rotor more before being at risk of blade slap.

My Lama's stock though, I haven't tried any of this stuff.

[Hanol]

Servo horns was the fitst thing I looked at. Guess what? They are clipped. No more holes left. Probably because of the body clearance. So I ordered another set from WhoIDontRemember.com. If they too big, I will just make holes in the body. Not a big deal. Another thing I did just now, I removed the little brass weights from inside the ends of hiller bar. It made it much more responcive to the the cyclic. Didn't try it outside yet. But one thing I am sure, swashplate has much more available travel then the standard setup. So next thing to try will be longer servo hons, when they arrive.

As for the extended upper rotor shaft, I can't understand any advantage between 5, 8, 20 or 30 mm in terms of aerodynamics, besides that the extendend distance that will prevent the rotor blade clash.

P.S. I think ESKY Hellies and other RTF jobs are designed to fly reaal easy when you open the box. Perhaps they simply derated them on purpuse to get new unexperinced customers in. Just to make it simple.

[Jack the R]

You must have v4 Lama. V3 has the full length servo arms, but the pushrods are in an inner position. Honey Bee appears to have the same servos and arms, but the pushrods are in the outermost position. Very sensitive! Of course it's also a single rotor coptor.

It's possible the lower rotor is less effective, being in the turbulence of the upper rotor, and the higher the upper rotor is raised, the more effective the lower rotor becomes. Have you watched the flight videos of the Lama with Turbo Shaft? The extra length definitely makes a difference. My Lama wouldn't even fly in that much wind, it's been blown down in less wind than that.

Xtreme blades and blade holders will also help.

I'd get the full Turbo kit in a heartbeat if I knew the other components were good as good as Xtreme parts.

[Hanol]

I got the Douphin for the funny reason. My wife liked the way it looks. We have a boat and one of the Douphins is constantly flying over the coast. And she likes the things that are red. So now it sits in our kichen and she doesn't mind. Only because it's red and says Coast Guard on it.

Since my last message I installed the extended inner shaft (+8mm), metal swashplate from e-Sky and extended servo arms. Had to cut holes in the body for the servo arms. Also removed the little brass weights from the stabilizer bar. Now I can handle it outside on a relatively calm day. Not sure what else I can do. Probably make even shorter/ligter flightbar as I have servos at maximum swashplate travel limits.

One thing I noticed is that I have a little more swashplate travel left to the bottom, and it's restricted to the top. I am thinking about drilling the hole in the outer shaft to move the lower grip with swashplate a little bit higher. May be like 1mm or so. I only affarid that I can weaken the structure. Links between the swashplate and blade grip are fixed I wander if I there are ajustble ones I can buy.

[Jack the R]

My gut says the 20 mm extended shaft is better than the 8mm extended shaft.

Do you have the xtreme blade grips and blades?

BTW, the Dauphin is a Lama V4 with a fancy body on it.

[Hanol]

As of other comments I've read, 8mm or 20mm don't make any change in handling besides the preventing the blade clash. Next thing I will do, I will extend the innrer shaft to 20mm. It's easy to do. Just have to grind a piece of 2mm wire (drill rod) to the size and make a collar/spacer.

Grips/blades shouldn't matter much, as long as there is no slop in them. They can improove the precision, but won't change the flight characteristics.

And I got Douphin only because my wife liked the way it looks, so I can have it sitting in the kitchen next to her other decorations.

[Jack the R]

Originally Posted by Hanol

As of other comments I've read, 8mm or 20mm don't make any change in handling besides the preventing the blade clash

Where'd you read that at?

I noticed that Xtreme has both an extended inner shaft and an extra extended inner shaft. Surely there's a reason for it.

Originally Posted by Hanol

Grips/blades shouldn't matter much, as long as there is no slop in them. They can improove the precision, but won't change the flight characteristics.

The original poster said the Xtreme blades and grips improved wind flying, but I haven't tried it.

[Hanol]

Of course, they will improve some flight characterisics, but not drastically. Stiffer blades/grips will impove the roll rate to some degree. But not as much as the servo arms lenght or the flightbar weight/size. Effects of the hight of top rotor is still in question. Besides the blade clash. I wouldn't trust YouTube videos without the real explanation of how and why it works.

I am about to recive the 2mm drill rod stock and make a couple of inner shafts with different lenght and try them out. Will let you know the results.

[Rotorjunkie]

The extended inner shaft is to eliminate blade strikes...which can become a problem once you move your links out on the servo arms.

[Hanol]

Originally Posted by Rotorjunkie

The extended inner shaft is to eliminate blade strikes...which can become a problem once you move your links out on the servo arms.

I just insalled new servo arms and moved the links one hole out. I had to cut holes in the fuselage to accomadete them.

There are 2 problems.

First is that upside travel of servos hits the limits of swashplate movement. But there is some free room left on the down travel. This can be compensated by decresing the lenght of links between the swashplate and lower grip assembly or by moving the entire grip assembly a little bit up. However grip assembly hight is fixed by the holes in outer shaft and the links are not adjustible. I may want to drill another hole in the outer shaft a little higher, but I am affraid it will compromize the strenth of it.

Second is that when cyclic is at extreme positions, upper swashplate links are touching the soldering joints on the motors while rotating. They had big blobs of solder there. I resoldered them, but swashplate is still touching them, but very lightly. So I definetely have to move swashplate up a little bit. 1mm will be enough.

Overall, after my modifications I can fly it with some wind that I wasn't able to do before. I have much more control, but heli became very sensitive and unstable. And, BTW, I also removed the little brass weights from the flightbar. Also I have +8 mm inner shaft from Extreme. Not 20 mm. However I am going to make couple more shafts to extend it to +20 and to +30 mm as soon as I get to my friend's lathe to make some spacers. I would rather have the aluminum spacers then the colar with the set screw that is going to get lose anyway.

[Hanol]

I guess not only that. By moving upper rotor up, you also reduce the angular stabilization momentum, as it gets away from the center of gravity. Actually as matter of experimenting I made a couple of shafts and spacers. From +8 to +30mm. With longer shaft it gets less stable and more responcive to cyclyc. Not really a major difference, but it's noticeble. I guess +20mm that you can find in the upgade kits is optimal. I didn't find much difference extending it to 30mm. Didn't try any higher, as it looks silly

[reiffton2ff]

Has anyone tried cnc parts from RCProX? Where does one find Xtreme parts? I was looking to maybe get a Commanche which also uses V4 parts.

Ken

[Jack the R]

I put the 3D pro cnc upgrade kit on my v3 and honestly I wouldn't do it again. It looks pretty but it's so much extra weight, the difference just leaps out at you. I've got a Commanche and the only upgrades it'll get will be the 2.0 cm extended shaft, hardened blades, better motors and better batteries. Maybe an LED kit so I can see it to fly at night

[Lozza]

Great info contained in this post guys , thanks a million, Loz...

[Hanol]

One thing you don't need is rigid aluminum blade grips. They can prevent blade clash, and they look good, but they also add extra weight and they reduce the cyclic responce as they have to drag the whole helicoprer body together with the rotor.

Flexible plastic stock grips give you better response. One thing you may want to do is to add a couple of washers made out of magazine cover paper between the grips and the shaft to reduce the sliding motion of the grips for better blade balance. And always use blades from the same set.

[Lozza]

I've just ordered two replacement Extreme motors, do I need to change my ESC on the Big Lama to match these? Or can I just plug and play?

cheers Loz

[Rusty63]

Hi Loz , You will have too change pinions over from old motors . Id run them in too . Before fitting . Post in lamav3/v4 section . Nice too have another aussie around ,cya . Russell

[scottsheli]

Hi,

I received my Dauphin as a X-mas gift last year. Along with the heli I got a CNC kit from RC711.com. I flew the heli for a couple of months, and when I last crashed it I broke the top set of plastic blade grips. So I went ahead and replaced the swash plate, lower hub, upper hub, grips and the inner shaft with the CNC stuff. I had a hell of a time leveling the swash plate and getting it all to work. I put it all down for the summer. I recently picked it back up and I got it to fly well except for the spinning I posted about earlier. The spinning would be from mild to T.B.E.. A local heli guy worked with me on his own time and we finally came to the conclusion that the factory gave me the wrong cut on one blade grip causing the one blade to drag more. I now have my other plastic grips on top and it flies great.

I want to acknowledge Burt Dumond from the Southern Maine RC Helicopter Assoc. for all his help. Thanks Again Burt!!

Scott

[Rockster]

Some minor mods on my Lama. I bought this one second hand as the guy just couldn't fly it and had given up on the hobby. A shame cause his setup was what killed him. Blades screwed in tight, tracking out from all the CNC blade holders, stiff ball joints etc.

In the pic you might see the two main changes. The ball links from the servo are Trex. MUCH smoother, they allow effortless movement of the swash and are a standard fit i.e. 2mm screws the same as the little brass ones on the alloy swash.

The extended little brass balls were then used to replace the short swash control link balls. This provides 2mm more distance from the centre of the shaft and hence a little bit more movement from the same servo throw (similar to extended servo arms but not as pronounced) and no body trimming.

I also made a shim from brass strip similar in thickness to aluminium foil. About 4mm wide and curled it into a small tube around a 2mm drill. It was then inserted between the top blade holder and the brass locators on the shaft. it took away all the vertical slack in the top blade holder removing much of the vibration.

It now hovers very nicely. Next mod is the turbo shaft to help with outdoors.