I was reading in the May issue of RCHeli magazine about John Adams setup with his BCPPs. He has flipped the blade grips upside down to give a smoother collective. (He says, to put them on the leading edge of the blade.) He is Technical Director for Horizon Hobbies/Spektrum. He doesn't go into detail about how to do this, so I had to study the pictures to see what he had done. I had to turn the blade grips over, turn the bell mixer arm 180 degrees, and turn the rotor head frame over. One thing that wasn't obvious from the pictures is that this requires you to change your pitch swash mix from - to +, (or + to - , depending on which way you are originally set up). So, you do have to have a computer Tx. Elevator, auxillary and aileron remain the same.

I did this tonight and had to fly under the lights, and there was virtually no wind. Given these conditions, I wasn't able to fully check it out, but I am certain that my collective is smoother now.

In the article he also mentions that he uses S60 servos that he said are digital. I had doubts about this, after contacting Horizon and a LHS, and looking at them on Horizon's website. There is no mention of them being digital. However, the editor of the magazine, Mike Velez, e-mailed John Adams and confirmed that they are. These are the servos used in the CX2.

There are other cool mods in the article as well.

orlbuzz

i have tried it before, except that i didn't flip the head block over, i just flipped the mixer over but i was connecting the short side to swash and long side to head as a mod for faster cyclic. with this configuration, i find the head to bind very easily with cyclic, if i have to get the bindings out of the 4 corners for reasonable usage, the cyclic rate will have to be really low for some reason, i did had a pic, but deleted it. and i think i posted about it somewhere, but can't find that pic. i can't really find any benifits to this so i just kept the original design with the flipped mixers. maybe flipping the headblock too yeild better results than mine? does ur cylcic bind easily in the corners? how high a rate are you using, what radio?

chopperdudes,

I'm sure you would have to do the complete change as outlined to get the benefit. I didn't see any binding in my preflight checks, everything seemed just as before, but with smoother collective. I don't think John Adams would be using this setup if it caused any problems. I'm using the Dx7 Tx. with an AR6100 Rx. I'm not sure what you mean about "how high a rate are you using". I have -10 to +10 collective, and + & - 6 on ailerons and elevator. I think I have a 7 on exponential, (not very high).

As I said, I had to check it out under lights, so I didn't get much FF in. I'll post again after I get to wring it out a bit.

orlbuzz

well, since i got my blade lying around, i decided to give it a try, still haven't test fly it yet though, still waiting on the dd tail motor. however, my question would be WHY will it make collective smoother? i can't really relate wat's different between trailing edge control and leading edge. force acting on it? etc?.

it's like a wind wane in the wind... holding it upstream towards the wind is very hard to do... like hovering your heli in a tail wind. The heli always wants to whip around so that the tail is down wind. All real heli's that I know of have the pitch links on the leading edge... but honestly I am not sure how much diff it will make in this little heli... there's probably not enough force at work in combination with play. Expirement though, and let us all know what you find out =) I may just have to eat my words and we'll all be switching the pitch links around.

If we could switch the pitch links around for a benifit like that, we could also use hitec 55's with the stock radio, or with computer Tx's and not worry abou tht negative swash =)

chopperdudes,

LMAO, I've been trying to figure that out too! It doesn't CHANGE collective, and it doesn't CHANGE cyclic, so the only reason I can think of is that somehow it tightens up all the linkages. Sorta like pulling a chain rather than pushing it? He didn't go into any depth or detail, like I said, I had to follow the pictures. He was supposed to have his setup posted on the Spektrum website, I haven't seen it yet. I DO notice it most on landing. It is much smoother than ever before.

One thing I discovered tonight is that you now lengthen the pitch links for more negative rather than tighten. I like that, it seems I was always fighting to get enough negative unless I set my swash height just right.

I ordered three of the S60 servos also, even though I don't need them yet. I'll try them when the JR sm 22s I'm using now wear out.

I figured out last night that someone wanting to use the Hitec HS 55 servos could do this mod, and not have to reverse the wiring! This mod reverses the swash mixing.

Added Link to last nights Post: http://www.rcuniverse.com/forum/m_56...tm.htm#5665663

Let us know how it works for you.

orlbuzz

well, because there's a mixer, if the blade is at a positive angle, the leading edge will have the tendency to go downward due to the wind pressure on the trailing edge. so right now after the change, if the leading edge trys to go downward, it'll pull on the head and push on the swash because there's a mixer. and if it's negative pitch it's the other way round...

so the force exerted upright in this new configuration is basically the same as the force exerted inverted in the stock configuration? oh well, i might still need mabye a few days to try this out. where can i find the info on this though? where did you get the pics and infos?

mrasmm,

Now that makes sense! Thank You.

orlbuzz

chopperdudes,

It's in RCHeli magazine, May issue. It's about John Adams setup.

Not much info, I figured it out from the pictures.

orlbuzz

yeah, no prob =) you're exactly right like pushing a chain instead of pulling it. If there were some flex in the blade grips or in the tortional element on the blades (like in bigger heli's) I think it would make more of a difference. The only real thing it can act on is the mixer arms... and I don't really know how much of a difference it would make, but we'll wait and find out I guess =)

chopperdudes it's pretty much like your cyclic mod like you were saying, but you leave the links how they are setup instead of swapping the lower links with the upper links.

I still have to wonder why e-flite made the swash reverse... it doesn't make a whole lot of sense to me unless they had existing servos and wanted to make them work with the heli. Anyone else have any ideas why they would make the swash reverse?

thx. i just notice another problem, or rather, inconvinience. because now the blade grips are upside down now, you'd have to bolt the blades on from the bottom, with the head attached, this can be somewhat inconvinient.

lol, yeah... that is the problem... I still wonder why eflite designed this heli with the reverse swash.

HOT OFF THE PRESS, i just got my blade in the air again tonight, nothing more than some hovering in the living room and some punch outs...

DON'T DOUBT IT!!!!! IT WORKS!!! BOTH OF THE MODS!!! PERIOD, END OF STATEMENT!!! i confirmed this tonight. ran my 7chp at 100% gain without stock gyro mix, tail wags CRAZZZYYY. then turned up the stock gyro gain... tail holds like a champ. i used to have to use revo mix for hard collective punches, now it holds VERY well. still a teeny tiny drift still during full power punch outs. don't question it, YOU DON'T NEED TO KNOW WHY, IT JUST WORKS, THE END. I'll still have to give it a good workout when weather permits... but, first impressions are very good.

chopperdudes,

You say both of the mods work. Obviously you talk about using the 3n1 gain with the HH gyro mod.

Do you mean by "both" that the other mod you did is the leading edge input mod? (Flipping the blades over)
If so, I would like your opinion of that too.

I bought some S60 servos and will try them when my JR sm22 servos go bad, or before.

orlbuzz

hmm... i seem to have my share of bad lucks lately... basically flight=crash. i test flew it today after school with the grips flipped, brought it out, it was very windy, but i decided to go for it. hovered a bit, and rolled it over, immediately i heard clicking sounds, climbed, roll back, and the tail was spinning (not the ones taht's out of control)(moderately). so i was able to control it while the wind's blowing it down the field, then it became so small that i just decided to hit throttle hold at about 1 foot. i dunno why, but maybe because the bl motor is soooo much free'er, it kinda auto'ed to the ground without damage. a later diagnose was a popped link. further inspection of the head showed that because i also did the cyclic mod (connecting teh short side of the mixer to the swash), i was getting bindings at extreme collective from the balls and links. just hovering yeild good results, however, i changed it back to the stock formation with my cyclic mod.

well, i charged the batt up again and went for another flight. the wind died down abit. so i went out. a roll to inverted showed that i need to increase the gain on the stock gyro just abit more as i was getting abit of wagging inverted with the wind. all was going well until i went inverted and did a backflip to upright, i had this move under my belt. but because i didn't fly for so long, i gave myself abit of altitude. all was well... until my cyclic thumb slid off the stick for no apparant reason at all. i quickly got back to the stick and managed to save the heli, however, as i calmed it down abit, i want to climb back up to a save altitude... and i gave it neg pitch, down it goes... need a new center hub and paddle control frame.

well, i didn't like the 'flip the blade grips' mod mainly because i did the cyclic mod, i did noticed a very little more smoothness in collective, but was not working well with my setup so i changed it back to stock seeing no original problem. i really liked the gyro mod because i can now dail my telebee/zoom hh gyro up to 100% without wag. and the tail holds exceptionally well without the use of revo, i used to use revo even with a hh gyro due to kicking still with full collective. but now i don't.

i got the parts, rebuilding it, hope my next flight goes better. =]

chopperdudes,

Sorry about your crash. It sounds like you have really progressed fast, though.

So you had your own cyclic mod and the blade flip mod at the same time? I don't see why that would make a difference as the bell mixer arm is centered on the rotor blade, but I'll take your word for it.

I'm really happy with the blade flip/leading edge mod. I can definitely tell the difference.

I'm glad to hear of the gyro improvement. A friend on this forum wants to try that. I am running all separates, so I can't.

orlbuzz

ya, i think if i have try different orientations of the mixer and the links and stuff, it might work, but i just don't really want the hassel as the batt's ready and i dunno if it's gonna work. i know that stock formation with the cyclic mod will work, so ya. i really like the gyro mod, and tell ur friend that it'll work from hovering to 3D.

How is the 3-in-1 unit and the G90 gyro wired together????

the manual goes through all of that starting on page 40

http://www.horizonhobby.com/ProdInfo...Pro_Manual.pdf

orlbuzz,

have you got the S60's to work?

Well, curiousity got the best of me and seeing how one of my servos stripped, I went and bought a set of the S60's. They fit great, plug and play......

except for the front ELE servo.

The servo arm hits the motor. Looking closer I noticed S60 arm sticks out a little more. wondering if anyone knows how to position these servos in the stock blade cp pro frame.

My reply to lookyj in PM:

lookyj,

I haven't installed the S60's yet. I'm using JR sm22's and they are working well. I did buy some S60's because I got a great price on them. I just woke up here on the East coast, but I will look at them later and see if I can figure anything out. I need to know too, as I would like to try them when my JR's go out.

John Adams was supposed to have more description posted on the Spektrum website, but it hasn't been posted yet.

I'll get back with you.

orlbuzz


Some of the guys were enlarging the slot in the frame to use the JRsm22 servos. I went the other way and ground the tabs down on the servos so they would fit in. (I didn't want to modify the frame so that I couldn't use S75's if I wanted to go back to them.) Maybe that would work for you.

I see that you are using the stock brushed motor. John Adams (and I ) are using the BL motor. I haven't compared the diameter of the motors yet. Maybe that allows more room.

orlbuzz

yes, bl motor is smaller in diameter.

yep that's the issue.... the S60's don't work with the stock motor, unless you modify either the frame or servo case. I just swapped out my S75's from my BL CP Pro and put the S60's in. Haven't spooled it up, but they fit!

lookyj,

Be sure to let us know how you like them! Yay or Nay!

Glad you had a BL heli to put them in.

orlbuzz

hi all, i just finished test flying my "john adams" edition cp & it went ok for the most part. i kept turning the rate gain up until i hit ~50%, then the wag went away (i noticed some harmonics in the wag as i got close to 50%). unfortunately i had almost no right yaw; this was probably due to the old abused gws motor i installed. until i get another cn12-rxc motor, i'm limited to low hovering. 50% gain seemed high, but it could've been due to the old motor.

good to hear the sm-22's are still going strong orlbuzz. mine are too.