Update : 20.07.2005
M50 RC model helicopter: week 22 2005.
After haven been looking at the A2-50 RC helicopter announced at E-bay from Wan Trading, a 50 size helicopter with 90% metal parts the pictures looked OK so I decided to make a bet. The price started at 279E and I made e max limit at 350E after 3-4days I got a email from E-bay that I have bought a A2-50 helicopter for 279E, it looks like this new stuff have not yet any interests among RC helicopter pilots.
Before I decided to by it I looked around to find if there was a Chinese factory selling this helicopter and tried to find out if it would be possible to get spare parts. Wan Trading in Germany claimed that he would be able to supply spare parts for it and second I found the factory in China on the internet http://www.eastrcmodel.com
After transferring the payment I just waited few days and the parcel arrived. First I noticed that someone have tried to hide the origin of the helicopter by removing name etc on the parcel.
The first impression, how can they make a helicopter to that price, but after looking more careful at the different parts some of the glamour faded away.
The bottom of the nick servo can be seen behind the left side of the push pull pitch lever, the nick servo should have been mounted on this side but I didn't find the space for it.
I found that the muffler is useless and should not at all have been included it is total empty and will not be any good for the motor or sound. The washout is made with a bad fit and is unstable like a Raptor 50 plastic washout that have been running 100000km, they have made the washout with metal inner part this is bad workman ship waist of good materials with a bad fit like that.
After examine and adjusting on the rotor head I did not find any other complains from a quality point of view after flying more might come.
The main blade are made of wood, and the tail blade of plastic. The frame side and spacers are all made of metal I found plastic on roll control lever, nick parallel lever.
The manual is only illustrations showing the mechanical set up no text, if I was a beginner I would be lost!
Now I have been working hard on the setup, to get +/- 10 deg pitch and +/-5 deg on nick and roll, it is impossible, the space for the washout and swash plate is too small without making any change, in the bottom the swash plate hits the lock ring and in the top the fly bar control lever hits the swash plate.
The swash plate is thicker then the swash plate that I have been working with I tried a swash plate from a Raptor 50, things is much better, first the swash plate is slim line in height and the larger diameter on the two ball links to the mixing lever reduce the swash plate angel for +/-5 deg on nick and roll making my requirements for the adjustment possible. But the original swash plate look great I would like to use it, so I found two 3 *10mm spacer and made two expansion for the ball link to the mixing lever on the swash plate, cut them in the longest possible size .
Now trying out I was close to the goal, I made +10-8 deg on pitch and +/- 5 deg on nick and roll, the next thing I will try to modify is the main shaft lock ring. If I take 0.5mm off each side and take away some material on the edge I get 2 mm more for pitch before the swash plate hits the lock ring, but +10-8 on pitch is fine for the test flight, this modification can wait.
Now after having been working with the adjustment I found that the pitch and the elevator servo arm can hit each other, I cant see other possibilities then to move the elevator servo to the other side of the frame, this will require a push pull arm that is mirrored, so I modifies the original one with a peach of PCB board to get 90 deg in neutral. Moving the servo to the opposite site is easy the frames are look alike the hold for the servo are ready for use from both sides. This might be possible with another kind of servo but with the JR8231 and JR539 I could not make it
As you can see I have used JR 539 servo for the nick, roll and throttle, this is only for a short period I do not like this servo but I have got 4 of them with a 9X radio, now they can be used for testing the M50, if the M50 flies well I will change them to some thing better, example like the pitch servo the JR 8231.
The fiber glass canopy have got some painting, it is black and white from the factory I do not like white helicopters they are not easy to see with the sky as background, I prefer to use signal orange or yellow both with a luminous effect they gives a mush better view with the sky as background.
Looking at some of the parts you could think that the M50 is a Raptor 50, the gear, clutch , main shaft, starter shaft are all looking the same to me, as those I have on my Raptor 50, this is not a bad thing from my point of view, then I just need to have fewer number of spar parts. The tail boom is smaller in diameter then a R50 the M50 boom fits inside the Raptor boom.
The way I have turned the servo mount is wrong but there where no servo mount plate included in the kit this way the base is working as servo mount plate.
I have been examine a lot of screws to see if they have got locktite from the factory and I found it missing places like the main shaft lock ring, all the screws on the frames where locked, this is some kind of frustrating, that you have to disassemble all screws to be sure that they have got locktite.
Now I have taken a contact to the factory to make them change some of the parts in the kit making this a even greater helicopter, the time will show if I have success with this matter, somehow I expect them to solve the problems making the adjustments to the kit and to supply me with the parts that have been changed, now I have finished the development for them just two small thing the longer link ball and the modified main shaft lock ring and of course they have to make a better fit on the washout.
The fly bar paddle are just 18g the red one, the other is a painted Raptor 50 paddle that's wild enough for me at testing..
The cooling fane and throttle arm are made of aluminum nice looking.
Together with the kit is also a hex starter adapter and a worthless muffler. I would like to trade the muffler for 10 servo mount plate in the kit.
Metal tail house, metal wheels. The tail blade looks small compared to Raptor 50, oh look another plastic part the pitch control link.
Ups two plastic parts more.
Metal metal metal and more metal.
The test flying is waiting on a OS 50 Hyper motor is in order but not yet arrived. I have been using some time to set up everything so when the motor arrives it is just in place with it and off to the flying fields, but now I must wait. I have also ordered some spar parts for my Raptor 50 et made a boom strike after a autorotation with a little too hard landing in a corn field, the motor just dropped out at a not so nice altitude. I can fly with my Fury 60 but the weather is terrible right now I will find some thing else to do.
Week 23 2005.
I would like to have:
1: Improved washout that have a better tight fit on the main shaft.
2: No muffler, it is worthless. Exchange it with servo mount plate or change some of the plastic arm with metal.
3:Adjustments possibility for +/- 10 deg on pitch and +/-5 on nick and roll. Longer ball link on the swash plate (expanded to max diameter in the swash plate) and/or longer main shaft (-) reduced size of main shaft lock ring. The main shaft is equal to a Raptor 50 changing that would be a minus. The change also make change to the length of the link rod. After test flying I will list the length .
4: Push pull arm on nick that can be used on the left side of the frame, I can't see any reason for not always to mount the nick servo on the left side.
5: Including the hex starter adaptor is for beginners and this kit can't be announced as a beginner kit.
6: A better manual with more details about set up, link length, expected range of pitch nick and roll. The included manual is more a exploded view with numbers etc.
Motor installation. 17.06.2005
I have decided to use a OS 50 Hyper and a MP. Mounting the motor on the base is no problem but I need to make the holes in the chassis wider and to adjust the baring for the starter shaft to make things run smooth. To make things working, the right sequence must be used, loosen the landing gear, put in the motor with out the carburetor , before putting the motor in place mount the carburetor, then take the motor the last step, mount he screws remember to use loctite. Check that the starter shaft is moving free with out using force to turn it (one way baring), if not check if the mounting holes for the motor need to be wider. the next step is to mount the MP, if the motor is mounted too low there is not enough place for the MP. The MP is without treads in the mounting base and there is not room for a locknut, I used a normal nut and plenty of Loctite.
I also added a header tank to the M50, this is not included in the kit.
Test flight: 18.06.2005.
Checking out everything once again. Connecting the pump for fuel and start tanking the M50, after half tank the fuel starts to run into the exhaust, there is some thing wrong with the placement of the pipe for the exhaust pressure connection. I checked that the fuel system works correct running the fuel pump the other way, and it looks ok, no air in the header tank before the main tank is empty. I put as mush fuel in the tank as possible that is 2/3, and decide to fly with that. First the motor is turned with full throttle and no glow, back to idle and add glow and the motor runs the first time. Check out the adjustment for idle hold and cut. Then the time is come to take the M50 in the right element, I take it away from the starter box an slowly add throttle to the motor, it takes to many rpm so I adjust my throttle curve lower and tries again, now it sounds right it is wood main blades they do not like to many rpm. I add more pitch and it is in the air, no trim is needed right now it is flying. After hovering for a while I start moving up and down and finds that the tail is turning on the way up, it looks like the gyro cant hold the tail. After re adjusting the travel on the tail pitch I tries again and it is still moving, it is not 10-20 deg but 90 to 180deg,
I decide to try bigger tail blades, the
originals looks small! I try a pair of Raptor 50 tail blades and they perform
better but the tail still moves on inc. pitch.
After two 2/3 tank of flying I found one broken tail support rod and I have to stop flying for to day.
Now I check out all link, screws etc and find more screws missing and some loose, now I can see where they haven't used logtite . The screws on the two wheels for the belt to the tail, no logtite, one screw for the tail boom no logtite.
The impression of the first flight is ok, it is feeling more alive the my Raptor in Hoover, but I do not like the problems with the tail drifting, I use a 601 gyro in heading hold I suppose that it would keep the tail in place if the hardware is able to.
I will check it out again to morrow
.
I repaired the tail support rod and checked out all screws, already after one
flight some where missing and other where loose. The screws for the guide pulley
for the tail belt have not been mounted with loctite and one where missing and
another where loose. Some thing must be in bad balance. The tank nipple was removed and the connection for the clunk and the muffler connection
was examined, the clunk connection was ok but the
muffler connection
was just a
straight pipe running strait into the tank making it impossible to get more then
half full. I turned the muffler connection inside out so the bended peace was
inside the tank and fitted a peace of fuel tube long enough to hit the inside
top of the tank.
Test flight 19.06.2005.
Now it was possible to make the tank full, after flying 2/3 tank one tail support rod was hanging down from the tail boom, this is getting some kind of boring this tail support rod stuff. I noticed that the helicopter still vibrate so I think I have to find the reason for that.
I did not get any real flight this day just hovering an flying forward and backwards.
Now I took some cold rowing and cyano and reinforced all the plastic rod ends.
I still find some loose screws the screw on the nick push pull control lever was on its way out, more loctite.
Test flight 23.06.2005
First attempt terminated the test flight, the cooling fan went loose, this is always a problem.
Now I had to take out the motor and this gave me the opportunity to balance
the cooling fan, and it was a good idea, I had to remove some material before
the fan was in balance
.
Test flight 25.06.2005.
To day I got some flying. First I tried it out with the wood blades, made loops rool's and and it performed ok, I observed that the loops always had a tendency to kip to the left side just like some thing is different when it is upside down, I tried to make some adjustment and trimming but the problem looks the same.
After flying with the M50 I took my Raptor 50 to compare the two. I still feel that the "plastic" Raptor is performing better, the only difference on the two is the REVLog mounted on the Raptor.
My conclusion now must be that this M50 have to be cheap and the buyer have to be experienced and then the chain is broken because I look at the M50 as a beginner helicopter. If the M50 was without all these small errors it might be a good helicopter. I do not know if the kit I have got from Germany dealer is an prototype or a production model, I have tried to communicate with China telling about my experience with the M50 first they where interested, they thought I was a potential buyer, but afterwards I haven't heart from them, I have e-mailed a early version of this review to them an after that I haven't heard a thing.
Before I am flying again I will change the washout to a Raptor 50 and at the same time I will change to a Raptor 50 swash plate or/and modify the main shaft lock ring to make the M50 making +/- 10 deg on pitch. The origin tail blade are to small use 95mm this will give the best results. With all these modification you can wonder what is left from the original kit!
Test flight 18.07.2005.
I have got some response from China saying that I have put it wrong together, this is after they have been looking at my pictures, I think they do not understand what I am writing, they send me the same pictures that I already have seen from Germany it does not help me.
I have change the washout to a Raptor 50 part from HT, it is of aluminum and is fitting much better then the origin. Flying is also mush better now, it is not so unstable and the response is ok. I am flying with Raptor 50 tail blade but I have big problems with the tail it is going its own ways, this is terrible the raptor 50 tail blade should be big enough, looking at the gear the same ratio is on the Raptor 50.
I also tried the origin paddles they are ok but you do not get a more stable helicopter out of it.
Test flight 22.07.2005.
I have been fighting with the M50 to make the tale more stable, from hover and full pitch the M50 makes almost a 360 turn and that is with the bigger Raptor 50 tail blades, so to day a have lend a par of Raptor 90 95mm tail blades, but I still have problems with the tail, flying backwards it will turn 180 deg sooner or later, now I do not know what to do, putting even larger tail blades on will make problems, the 95mm are already almost as long as the horizontal fin. This is getting a little bit boring, the hely is flying OK but there is still a way to go before you can compare it with a plastic Raptor 50. After finishing the first tank I notice a broken tail support rod.
Conclusion.
I have not tried out the supply of spare parts and I will definitely not by new tail support rods from them if they are the same poor quality, use the Raptor 50 V2 supports rods instead.
What can I say else then "BY a RAPTOR 50" or some thing else then a M50 the price compared to what you get is not in balance and you will get a lot of things to fix and still you do not have a perfect 50 helicopter.
The next step will be that I take the main rotor and use it on my Raptor 50 and afterwards I will use the rest as spare parts on my Raptor 50, 272€ for a main and tail metal head and some additional spare parts is not so bad ,but by a HT main rotor head I think it is better and cheaper. I can't stop thinking what if I have purchased it to the normal price listed 429€ then I think I would feel pissed off. The price in China is 250$ but then you have to arrange transport and tax and other stuff.
NEW 20.07.2005.
Test flight 19.07.2005. I decided to give the M50 the last chance, I have checked all the gyro 601 settings and adjusted all the tail components to be 100% sure that all things are right. I have not changed any thing and the M50 comes assembled, checking the drawings and the hardware it looks right except that the drawing shows that the main rotor should turn the opposite way, a little confusing but other pictures shows that the rotor is running the way it is. With this not right documentation in mind I flew one tank and I still had problems with the tail, now I examined the tail pitch position in neutral and found is close to the end point, this could be another mistake what if the tail rotate the other way then the neutral position would be more in the middle, I changed the drive belt and the blades, switched the gyro and the transmitter reversing the servo . At the same time I switched the tail blades to Raptor 50, they should be big enough, made a test flight and now it looks like the gyro could hold the tail, I lowered the rpm in hover and still the tail was stable like a rock, I tried many different things and found the tail as stable as a Raptor 50 maybe even more, I could now hear this whistle sound when the tail rotor is working hard. Now the performance is some thing worth flying with, but is was a long way to go.
What more can I say then, don't trust any one, don't accept pictures, drawings or any thing to be correct, they could be mirrored or wrong, this is a bad example how wrong everything can be, the assembling is wrong, the drawings is wrong and the pictures are mirrored, ok they make it on the other side of the globe but that is not a excuse, even that the gravity is working the opposite way, have you sort about that. Now I have decided to use the M50 for a while, and time will show what the next step will be.