mnwizard
04-08-2008, 12:54 AM
As I’m a retired old fart, I probably have more time to putz around with my helis than a lot of the guys on this forum. So I decided to spend a chunk of this spare time on thoroughly testing as many of the CNC parts as I could.
By the way, CNC stands for Computer Numeric Control. It’s not a brand name or a trademark, it simply means that the part is milled by a computer-controlled machine. Specifically a controller that uses G-code instructions, but that’s a whole ‘nother story.
Over the last couple of weeks I’ve taken 2 brand new Lama 2 V3 helis and added upgrade parts to them one upgrade at a time. When I was completely finished with the first one, I started all over on the second one. This way I could tell if a result was just a fluke or if the result was repeatable on another heli. I love to tinker with the helis as much as I love to fly them, so this has been great fun for me. I hope some of the things I found will help other guys on the forum.
BOX STOCK:
http://i28.tinypic.com/2vvus74.jpg
Both Lamas flew beautifully right out of the box. I’ve been flying for a while so I didn’t have to learn how to fly them and you should take that into account when reading this. I was able to take off and hover both Lamas using only the throttle. I don’t know if they really test fly Lamas at the factory, but these 2 were perfectly balanced and setup. I don’t know if my older Lamas were like this because I didn’t know how to fly when I first bought them and I’m not sure what was the helis fault and what was pilot error back then. I did take a fella who has never had any RC experience, instructed him in the use of the throttle and he was also able to lift and hover using only the throttle. I should point out that all the flying involved in this post was done in a large gymnasium so there were no air currents to toss the Lamas around like there would be in a room in the house.
XTREME BLADES: These are the labels from the blades I used –
http://i30.tinypic.com/2iqd36d.jpg
The Xtreme blades are much harder to break than the stock ones, which is why most people buy them, however they do have an effect on the flight characteristics of the Lamas. The stock Lamas have very “soft” flight controls. That is, it takes a fairly large control movement held for a moment or two to affect the Lama flight. This is good for learning as it makes the heli very stable and requires deliberate action to move it from a hover. With the Xtreme blades the flight controls are a little “harder” – they don’t require as great a movement and the heli responds to the movement noticeably quicker. They are also a little quieter than the stock blades. The Xtreme blades are “plug and play”, you can put them on in place of the stock blades and fly immediately without having to reset anything. If you are a brand new noob, you may have trouble with the increased responsiveness of the Xtreme blades. Pilots with a little experience will probably prefer the Xtreme blades.
CNC BLADE HOLDERS: I have tried them all including the red ones, dark purple ones, light purple ones and the expensive Xtreme ones. They are all trouble except for these –
http://i28.tinypic.com/34982a9.jpg
Except for the Xtreme Production holders in the above picture, they all were difficult to assemble and true up. Over the course of an hour or so of flight time the mount for the ball for the flybar link either rotated up or broke. Locktite did not prevent the rotation of the mount. See this link for pictures of the failures.
http://www.heliguy.com/Forum/cnc-upper-blade-holder-problems-t16677,highlight,cnc.html (http://<a href="http://www.heliguy.com/Forum/cnc-upper-blade-holder-problems-t16677,highlight,cnc.html" target="_blank"><font size="3"><font color="#000000">http://www.heliguy.com/Forum/cnc-upper-blade-holder-problems-t16677,highlight,cnc.html</font></font></a>)
The Xtreme blade holders worked perfectly and I had no problems. They are not “plug and play” though. The length of the flybar link will have to be adjusted and the swash plate will need to be leveled. With these adjustments made, there were no flight control problems and the Xtreme blade holders had no discernable effect on the Lama’s flight characteristics. They didn’t make it fly better and they didn’t make it fly worse. The only reason to add them to your Lama is because they look much better than the stock ones. (Unless you're flying outside, more about this below)
UPGRADE INNER SHAFT: Tried them all, and again, except for the Xtreme one pictured here, they were all troublesome.
http://i30.tinypic.com/2h695wn.jpg
The Xtreme inner shaft fit perfectly. However it is not “plug and play” as the length of the flybar link will need to be adjusted. The Xtreme inner shaft is longer between the posts for the blade holders and the bottom of the head.
http://i26.tinypic.com/w19qmr.jpg
This moves the top blades up about 5mm and may help to prevent blades strikes during large control movements. Other than possibly preventing some blade strikes it had no discernable effect on the Lama’s flight characteristics. It is handy though, as it prevents the flybar from popping off and disappearing during a “hard landing”.
The others all needed filing and fitting of the top cap to allow free movement of the stock flybar. The dark purple ones required washers (not supplied with it) to be fitted to take the slop out of the blade holder mounting. It was also too long requiring an extra bearing to be fitted on the top of the outer shaft. The lighter purple ones fit ok but took more fussing to get the stock flybar to fit properly.
UPGRADE SWASH PLATE: I tried the light purple ones, the dark purple ones and the naturally finished ones. I had no trouble with any of them. They all fit and they all were more robust than the stock Lama swash plate. Of course they have to be carefully leveled before flight. They had no discernable effect on the Lama’s flight characteristics, but they do not come apart in flight as the stock Lama ones are known to do.
XTREME MOTORS: These are the motors I tested –
http://i26.tinypic.com/aawvhd.jpg
I actually switched motors back and forth between stock and Xtreme a couple of times to make sure I was actually seeing a difference in flight characteristics caused by the motors. It is apparent that the Xtreme motors are more responsive to throttle input than the stock motors. That is, if you need to put in an additional ¼ inch of throttle to gain altitude from a hover, with the Xtreme motors you would need a much smaller movement of the throttle for the same effect. The difference is subtle and a new pilot may not notice it, but a pilot with a little experience will notice it immediately. In combination with Xtreme blades the Lama is noticeably more responsive than stock, requiring smaller control inputs. The Xtreme motors are noisier than the stock motors. After timing several flights I did not see any difference in flight times between the stock and the Xtreme motors when used without any other upgrades.
FLIGHT TIMES: Over the course of the testing I recorded the length of each flight. I called the flight done when the Lama began to require increased throttle. Though not precise to the second, it’s the way I normally fly and the results of multiple flights with the same parts/setup were surprisingly consistent. It became pretty apparent that the only individual item that noticeably increased flight times was a better battery pack. However even with a better battery pack, flight time fell off rapidly at about the 10 minute mark and I believe that the motors get hot enough by that point that they increase current draw rather quickly. One thing I found interesting is that continuous forward flight results in the longest flights times. I guess that makes sense in that during forward flight the rotor disks produce additional lift and the motors get more airflow so they run a little cooler. The combination that consistently provided the longest flight times was an otherwise stock Lama with Xtreme motors, Xtreme blades and a battery pack with a higher C rating. Adding anything else resulted in either shorter flight times or no consistent change. The longest flight with this combo was 14 minutes, the shortest was 11.
SUMMARY/RECOMMENDATIONS: In reviewing this post I noticed that it may seem like an advertisement for Xtreme brand parts, but that's just the way the testing turned out, I don't work for them, honest!
For a noob just learning to fly, the box stock Lama is the most stable configuration. Adding anything other than stock replacement parts will only throw the setup off or make it more difficult for a noob to control.
Once a noob is able to hover successfully, the first upgrade should be the Xtreme blades. Over the long run they will save money on broken blades. Once used to them, the noob will have more precise control of the Lama.
Any other upgrade is going to change the setup of the stock Lama and require the noob to disassemble the Lama and make adjustments to the setup.
Once able to hover and move around “tail-in” the two upgrades I would recommend at this point would be a CNC swash plate as the stock Lama one is a weak point and an Extreme inner shaft to prevent loss of the flybar.
From here on the upgrades are primarily cosmetic for the indoor flyer. The exception to this applies to flying outdoors in a breeze. Nothing you can do to the Lama will ever make it fly in a wind like a heavier single rotor heli. Flying it in any breeze requires a high level of skill. However adding the extended inner shaft and the Xtreme blade holders will help as they raise the upper blades and make all the blade assemblies more rigid which will reduce “coneing” and thus help reduce blade strikes. Even with these upgrades, you will still need a high level of skill with the Lama to fly in anything other than a whisper of a breeze. The main reason for this is that the upper rotor disk is controlled by the attitude of the flybar and will always create drag in forward flight. This drag fights against the thrust created by the lower rotor (tilted by the cyclic stick). This interaction drastically limits the speed obtainable by the Lama. If the wind speed exceeds the speed the Lama is capable of at the moment, the Lama moves with the wind. If the wind is above a slight breeze and the Lama is sideways to it, the wind will actually tilt the upper rotor disk, regardless of cyclic input, and the infamous “death roll” results.
There are a couple of other things I’ve learned from all this. First, be aware that it is very easy to spend more on upgrades than the Lama cost in the first place. Second, it’s very important find a supplier you can trust and be sure of what you’re buying. It’s easy to get burned, just because the ad says it's for a Lama V3, it doesn't make it true.
Finally, if you don’t really like tinkering with your heli, go with the Xtreme blades and leave everything else stock. You’ll be much happier. Upgrades are like adding hot rod parts to your car. Much of the pleasure is in the doing, and if you don’t really understand the set-up of the modifications you can quickly make it undriveable.
By the way, CNC stands for Computer Numeric Control. It’s not a brand name or a trademark, it simply means that the part is milled by a computer-controlled machine. Specifically a controller that uses G-code instructions, but that’s a whole ‘nother story.
Over the last couple of weeks I’ve taken 2 brand new Lama 2 V3 helis and added upgrade parts to them one upgrade at a time. When I was completely finished with the first one, I started all over on the second one. This way I could tell if a result was just a fluke or if the result was repeatable on another heli. I love to tinker with the helis as much as I love to fly them, so this has been great fun for me. I hope some of the things I found will help other guys on the forum.
BOX STOCK:
http://i28.tinypic.com/2vvus74.jpg
Both Lamas flew beautifully right out of the box. I’ve been flying for a while so I didn’t have to learn how to fly them and you should take that into account when reading this. I was able to take off and hover both Lamas using only the throttle. I don’t know if they really test fly Lamas at the factory, but these 2 were perfectly balanced and setup. I don’t know if my older Lamas were like this because I didn’t know how to fly when I first bought them and I’m not sure what was the helis fault and what was pilot error back then. I did take a fella who has never had any RC experience, instructed him in the use of the throttle and he was also able to lift and hover using only the throttle. I should point out that all the flying involved in this post was done in a large gymnasium so there were no air currents to toss the Lamas around like there would be in a room in the house.
XTREME BLADES: These are the labels from the blades I used –
http://i30.tinypic.com/2iqd36d.jpg
The Xtreme blades are much harder to break than the stock ones, which is why most people buy them, however they do have an effect on the flight characteristics of the Lamas. The stock Lamas have very “soft” flight controls. That is, it takes a fairly large control movement held for a moment or two to affect the Lama flight. This is good for learning as it makes the heli very stable and requires deliberate action to move it from a hover. With the Xtreme blades the flight controls are a little “harder” – they don’t require as great a movement and the heli responds to the movement noticeably quicker. They are also a little quieter than the stock blades. The Xtreme blades are “plug and play”, you can put them on in place of the stock blades and fly immediately without having to reset anything. If you are a brand new noob, you may have trouble with the increased responsiveness of the Xtreme blades. Pilots with a little experience will probably prefer the Xtreme blades.
CNC BLADE HOLDERS: I have tried them all including the red ones, dark purple ones, light purple ones and the expensive Xtreme ones. They are all trouble except for these –
http://i28.tinypic.com/34982a9.jpg
Except for the Xtreme Production holders in the above picture, they all were difficult to assemble and true up. Over the course of an hour or so of flight time the mount for the ball for the flybar link either rotated up or broke. Locktite did not prevent the rotation of the mount. See this link for pictures of the failures.
http://www.heliguy.com/Forum/cnc-upper-blade-holder-problems-t16677,highlight,cnc.html (http://<a href="http://www.heliguy.com/Forum/cnc-upper-blade-holder-problems-t16677,highlight,cnc.html" target="_blank"><font size="3"><font color="#000000">http://www.heliguy.com/Forum/cnc-upper-blade-holder-problems-t16677,highlight,cnc.html</font></font></a>)
The Xtreme blade holders worked perfectly and I had no problems. They are not “plug and play” though. The length of the flybar link will have to be adjusted and the swash plate will need to be leveled. With these adjustments made, there were no flight control problems and the Xtreme blade holders had no discernable effect on the Lama’s flight characteristics. They didn’t make it fly better and they didn’t make it fly worse. The only reason to add them to your Lama is because they look much better than the stock ones. (Unless you're flying outside, more about this below)
UPGRADE INNER SHAFT: Tried them all, and again, except for the Xtreme one pictured here, they were all troublesome.
http://i30.tinypic.com/2h695wn.jpg
The Xtreme inner shaft fit perfectly. However it is not “plug and play” as the length of the flybar link will need to be adjusted. The Xtreme inner shaft is longer between the posts for the blade holders and the bottom of the head.
http://i26.tinypic.com/w19qmr.jpg
This moves the top blades up about 5mm and may help to prevent blades strikes during large control movements. Other than possibly preventing some blade strikes it had no discernable effect on the Lama’s flight characteristics. It is handy though, as it prevents the flybar from popping off and disappearing during a “hard landing”.
The others all needed filing and fitting of the top cap to allow free movement of the stock flybar. The dark purple ones required washers (not supplied with it) to be fitted to take the slop out of the blade holder mounting. It was also too long requiring an extra bearing to be fitted on the top of the outer shaft. The lighter purple ones fit ok but took more fussing to get the stock flybar to fit properly.
UPGRADE SWASH PLATE: I tried the light purple ones, the dark purple ones and the naturally finished ones. I had no trouble with any of them. They all fit and they all were more robust than the stock Lama swash plate. Of course they have to be carefully leveled before flight. They had no discernable effect on the Lama’s flight characteristics, but they do not come apart in flight as the stock Lama ones are known to do.
XTREME MOTORS: These are the motors I tested –
http://i26.tinypic.com/aawvhd.jpg
I actually switched motors back and forth between stock and Xtreme a couple of times to make sure I was actually seeing a difference in flight characteristics caused by the motors. It is apparent that the Xtreme motors are more responsive to throttle input than the stock motors. That is, if you need to put in an additional ¼ inch of throttle to gain altitude from a hover, with the Xtreme motors you would need a much smaller movement of the throttle for the same effect. The difference is subtle and a new pilot may not notice it, but a pilot with a little experience will notice it immediately. In combination with Xtreme blades the Lama is noticeably more responsive than stock, requiring smaller control inputs. The Xtreme motors are noisier than the stock motors. After timing several flights I did not see any difference in flight times between the stock and the Xtreme motors when used without any other upgrades.
FLIGHT TIMES: Over the course of the testing I recorded the length of each flight. I called the flight done when the Lama began to require increased throttle. Though not precise to the second, it’s the way I normally fly and the results of multiple flights with the same parts/setup were surprisingly consistent. It became pretty apparent that the only individual item that noticeably increased flight times was a better battery pack. However even with a better battery pack, flight time fell off rapidly at about the 10 minute mark and I believe that the motors get hot enough by that point that they increase current draw rather quickly. One thing I found interesting is that continuous forward flight results in the longest flights times. I guess that makes sense in that during forward flight the rotor disks produce additional lift and the motors get more airflow so they run a little cooler. The combination that consistently provided the longest flight times was an otherwise stock Lama with Xtreme motors, Xtreme blades and a battery pack with a higher C rating. Adding anything else resulted in either shorter flight times or no consistent change. The longest flight with this combo was 14 minutes, the shortest was 11.
SUMMARY/RECOMMENDATIONS: In reviewing this post I noticed that it may seem like an advertisement for Xtreme brand parts, but that's just the way the testing turned out, I don't work for them, honest!
For a noob just learning to fly, the box stock Lama is the most stable configuration. Adding anything other than stock replacement parts will only throw the setup off or make it more difficult for a noob to control.
Once a noob is able to hover successfully, the first upgrade should be the Xtreme blades. Over the long run they will save money on broken blades. Once used to them, the noob will have more precise control of the Lama.
Any other upgrade is going to change the setup of the stock Lama and require the noob to disassemble the Lama and make adjustments to the setup.
Once able to hover and move around “tail-in” the two upgrades I would recommend at this point would be a CNC swash plate as the stock Lama one is a weak point and an Extreme inner shaft to prevent loss of the flybar.
From here on the upgrades are primarily cosmetic for the indoor flyer. The exception to this applies to flying outdoors in a breeze. Nothing you can do to the Lama will ever make it fly in a wind like a heavier single rotor heli. Flying it in any breeze requires a high level of skill. However adding the extended inner shaft and the Xtreme blade holders will help as they raise the upper blades and make all the blade assemblies more rigid which will reduce “coneing” and thus help reduce blade strikes. Even with these upgrades, you will still need a high level of skill with the Lama to fly in anything other than a whisper of a breeze. The main reason for this is that the upper rotor disk is controlled by the attitude of the flybar and will always create drag in forward flight. This drag fights against the thrust created by the lower rotor (tilted by the cyclic stick). This interaction drastically limits the speed obtainable by the Lama. If the wind speed exceeds the speed the Lama is capable of at the moment, the Lama moves with the wind. If the wind is above a slight breeze and the Lama is sideways to it, the wind will actually tilt the upper rotor disk, regardless of cyclic input, and the infamous “death roll” results.
There are a couple of other things I’ve learned from all this. First, be aware that it is very easy to spend more on upgrades than the Lama cost in the first place. Second, it’s very important find a supplier you can trust and be sure of what you’re buying. It’s easy to get burned, just because the ad says it's for a Lama V3, it doesn't make it true.
Finally, if you don’t really like tinkering with your heli, go with the Xtreme blades and leave everything else stock. You’ll be much happier. Upgrades are like adding hot rod parts to your car. Much of the pleasure is in the doing, and if you don’t really understand the set-up of the modifications you can quickly make it undriveable.