weird blade cp pro problem

[shaggybirdman]

my friend has a cpp, and it has a weird problem other than being a POS. full throttle just gets it off the ground. it has about 1/4" movement on the swash at full positive stick. he has killed 2 3 in 1's, and on a brand new one now.

he has done this so far:

originally brought the swash rods into the first hole. he could drive it into the rafters in his basement still at that setting.

got the super landing gear for it.

about a month of trying to hover it started to loose power. got to the point of full positive stick plus full trim, and could only get 12" off the floor. made it easer to learn to hover not having to worry about blade pitch.

adjusted the swash to level (by eye)

killed 2 3 in 1's, and bought a 3rd.

hobby shop told him to adjust the links to the fly bar to get more pitch, but still can't get over 12" off the floor, but doesn't need full trim anymore.

i think it has to be in the radio now. yes he could move the swash rods out further on the servo arms, but originally set all the way in her could hit the rafters. i told him to take it to the hobby shop, and try a brand new radio out of a new cpp. we know the owners like family, so it shouldn't be a problem.

what do we look for? it's really pissing the both of us off to no end. :arggg: all help greatly appreciated. :confused:

[fllyer]

I could be wrong, but it might be time for a new motor (main). They wear out almost as fast as the tail motors.

[Kamikaze_K]

Just what I was gonna say. Sounds like a worn out motor.

[darkchiild]

Most likely the issue is the blade pitch. What is the pitch currently? I believe for the cp pro, you should have 11 degrees throw in either direction in idle up mode according to spec. If it's not that, then the only other thing it could be is the headspeed.

It's possible the bearings are shot in the motor. Try turning it by hand. Is it smoothe? Make any noise? Maybe the brushes in the motor?

Either way, it's pitch or headspeed. Pull out the pitch gauge and find out how he's set up. It's possible he has too much pitch as well so that he's up to 10 degrees when the headspeed is too low.

[shaggybirdman]

i'm going over to his house in a bit. i'll take my pitch gauge with me. we swapped out a motor from a friends heli, but it could be worn out as well. i have a tack also. i'll take that as well.

thanks for the input. i'll let ya all know what i find out when i get home later.

Jerry

[shaggybirdman]

ok here's what i found. one blade had +9.5 or so. the other had +6. that explains some of the lift problem. it still had problems though. full positive only netted 2.5 to 3' off the ground. i tacked the rotor, and got just under 4000 RPM. not sure if that's good or bad. i'd like to get a tack reading of a brand new cpp.

a bell hiller head is oh so nice, and very simple. setting one of them up has gotta be a snap over the trex head. although the upper links are a pain to get off for adjustment. i'll try and get him to get a new motor, but he put the motor from a friends cpp witch he claims only has 5, or 6 flights on. i kind of wonder about that.

anyhow any other thought with this new info?

Jerry

[Skiddz]

4000 RPM on a CP? That's almost twice what they normally run at... I run mine on a brushless setup at around 2100 RPM and for what it is, it flies pretty well.

Looking at the previous posts, it sounds like it could use a full head setup and probably a new motor. My original main motor took a crap the 1st week and I went brushless for the main motor and a direct drive tail rotor.

[darkchiild]

Seems to me if the motor is running the blades at 4000 rpm, the motor probably isn't the issue. What kind of pinion do you have on that to get the head speed up so high? That's ridiculous! There must be some mistake on the measurements. If the pitch is actually around 11 degrees, and the headspeed is 4000 rpm, there's no way that thing isn't a speck in the distance with full throttle.

[shaggybirdman]

hmmmm me thinks i had a brain fart, or a senior moment. i now think the rpm is wrong, so please put you eye balls back in there sockets. i either checked it wrong, or something else. i did the pre check on a florescent light, and got the rpm is said in the directions. i did test it in a basement with ambient lighting. that's probably where i went wrong if the 4000 is what it read. man it sucks getting old.

whatever you do don't get old!!!!!!!

[shaggybirdman]

i have the pitch set at +9.5 both sides. is it possible that the +6 is the factory setting? i won't see it again till the weekend though.

any other thoughts, or ideas to try. i can't pry open his wallet for the cost of a motor :dontknow

[darkchiild]

Doesn't sound like a motor is required. If it has headspeed, and it has pitch it will fly. If the head is set up correctly you should have 11+- degrees of pitch in idle up. Set it up that way, get the headspeed somewhere around 2000, and you should be good to go.

[shaggybirdman]

how do i change the head speed?

[darkchiild]

Assuming you're using the stock radio (which isn't programmable) the only ways to do it are either A: change the size of the main gear or B: change the size of the pinion on the main motor. Less teeth = lower head speed, more teeth = higher head speed. You probably shouldn't need to change the headspeed from stock to get lift though.

[shaggybirdman]

i just wish we could figure it out. he has a b 400 coming for his birthday, but this freaking thing is driving me crazy. yes he is using the stock radio.

[groundparrot]

Let's get on the same page.
Put all the linkages back in thier factory positions.Servos at 90*.Blade pitch at zero in idle up and throttle centered.
Secure the heli and check RPM. 1700 in idle up, full throttle.Full down is easier to sopport than full up.
Let me know what happens and we will see if we can find a solution.

P.S. If I get stumped ,I have 30 birds on my consulting team , a Blade CP that I fly almost daily and an old Hirobo 30 that I still fly ocasionally.

[shaggybirdman]

will do. i believe he has already done that. i'm going over after i eat.

[shaggybirdman]

i checked them before and i think i got around 2200 if memory serves me correct. does the cpp come with an extra pinion? i'll report back when i get home tonight.