mcpx shutting down midair, in full pitch manovers

[andersn]

Hi, Its a bit hard to pinpoint where the error is, my mcpx recently got a new frame + misc parts, also some nice new kbdd, in addition I changed from dx6i, to jr 11x transmitter.

It could be my engine is gone, but I dont think so, basicly when doing 3d, you really can hear the head loosing rpms, so with hard elevator + pitch, or going max negative + positive, it quite often now just "falls out of the sky", everything shuts down, bat voltage is over 4V when it happens.

should I program max pitch to 10/90 instead of 0/100? as its ofcourse fbl, I dont have any swash mixing to set in tx.

[M3bluegsr]

Check Cut/Broken/loose battery cable (could be held on by only a few strands where it connects to the board). Or loose connections from the board to motor, and board to tail. You can tin them with a soldering iron for a better connection.

[Epoweredrc]

Originally Posted by andersn

Hi, Its a bit hard to pinpoint where the error is, my mcpx recently got a new frame + misc parts, also some nice new kbdd, in addition I changed from dx6i, to jr 11x transmitter.

It could be my engine is gone, but I dont think so, basicly when doing 3d, you really can hear the head loosing rpms, so with hard elevator + pitch, or going max negative + positive, it quite often now just "falls out of the sky", everything shuts down, bat voltage is over 4V when it happens.

should I program max pitch to 10/90 instead of 0/100? as its ofcourse fbl, I dont have any swash mixing to set in tx.

your PC need to be 0-100 if your doing 3D but where is your % of pitch at? I mean like i run 65% on my BL one now, before was about 80% maybe you have that up way to high and your bog the heli bad?
you say kbdd you mean main blades? lot people do not like them as well as stock blades

[Jumna]

I have the same problem, cuts out with quick pitch changes. Going to inverted or FFF OK, but anything like flips or rolls it cuts out, but resets on the ground. I think it must be the overload cutout, but why? I have had kbdd blades for awhile, and it wasn't an issue until a week ago. I've had to resolder the battery wires both at the batt and the board, so should be OK but maybe a frayed wire somewhere midway on the wires or a bad solder joint? Could it be the main/tail/servo motor going bad? Irksome to have it drop out of the sky like that!

[jmisuraca]

That was happening to me. After several days I found my problem.

The wires from the battery to the 3-in-one, where it was soldered to the battery connector was only held on by two or three strands. At point 3 listed below.

So going from the battery:
1. Battery
2. connector on battery
3. connector on wire
4. wires
5. 3-in-one

Fixed the connection / wire. Problem gone!

[andersn]

thanks for all the tips, I will have to go over it again, will also try to bind another mcpx, to my Jr, to see how it performs.

[Holst]

Originally Posted by andersn

thanks for all the tips, I will have to go over it again, will also try to bind another mcpx, to my Jr, to see how it performs.

Its also worth checking your swash and grip bearings, if they are binding up at all then this can cause a significant extra load on the motor.

When my motor was on the way out sustained FFF at max pitch would trip the overcurrent but not instantly.. as the other guys have said loose wires are the first thing to check.

[InFocus]

The mcpx has an 'overcurrent' protection to protect parts and electronics. For example, when you crash the mcpx, you'll notice the blades don't start up again, until you go back to 0 throttle, and start over..

When my main motor was about a year old, it started doing as you described, if you put a lot of demand on the motor, (ie, heavy pitch change etc), it would trip this overcurrent protection and shut down..

Since replacing the motor, I've not had this problem in flight.

[Jumna]

My battery wires are about 0.1 ohm, not bad. I just replaced the main motor two months ago; it would be lame to see it dying already. The tail is wagging a bit more, and that presaged the burn-out of the previous motor. I recently got a solid main shaft, but I doubt that's the trouble. Better check the bearings then.

It's not aerodynamic lift that keeps my helis flying, but money!

[andersn]

I just went over all soldering, all seems to be 100% fine

I did do some tests, its mostly, when going over 90% pitch, I can realy hear the difference in rpms, and its dropping, when "bench testing" (holding heli in hand going full neg, full pos a lot, it didnt trip the overcurent protection, maybe try to cut a pit of the positive pitchrange.

it could be the motor, it "only" has around 100 flights on it, aprox 2months old

[Epoweredrc]

guess could be motor some people do not get as long as others

[Elmosaurus]

Originally Posted by andersn

I just went over all soldering, all seems to be 100% fine

I did do some tests, its mostly, when going over 90% pitch, I can realy hear the difference in rpms, and its dropping, when "bench testing" (holding heli in hand going full neg, full pos a lot, it didnt trip the overcurent protection, maybe try to cut a pit of the positive pitchrange.

it could be the motor, it "only" has around 100 flights on it, aprox 2months old

What are your pitch servo ATV set at?

Blade recommends 75% travel in each direction.

If you are beyond that, you could be biting too large a delta between full positive and full negative.

FWIW, held in hand is not the same as in the air; you don't have the mass of the airframe affecting an inertial load on the rotor disc during the pitch pumps.

E.

[Holst]

Originally Posted by andersn

I just went over all soldering, all seems to be 100% fine

I did do some tests, its mostly, when going over 90% pitch, I can realy hear the difference in rpms, and its dropping, when "bench testing" (holding heli in hand going full neg, full pos a lot, it didnt trip the overcurent protection, maybe try to cut a pit of the positive pitchrange.

it could be the motor, it "only" has around 100 flights on it, aprox 2months old

Try full pitch and move the cyclic stick as well, this will really load up the motor.

[MeatRocket]

I'm interested in the specifics of this, as I'm having the same problem. I'll describe my scenario:

I had a v1 mCPX that I broke the board on. I bought a new v2 board. I installed a MH frame, blade grips & swash at the same time. I noticed the "turn off" while doing wide arching turns or a full pitch up after a tight turn. I figured the motor could be bad. I replaced the main & tail motors & got a new battery.

It still does it! I'm now wondering if it's from added weight of the CF/Aluminum parts (miniscule difference), or if it's a problem with v2 board that have been produced recently. Is your board a recent v2?

[Jumna]

It started dropping out on me for fig 8's! I touched the motor & it's real hot, so maybe that's it, well over 120deg. Blade grips & bearings seem OK. Man, this is like the blade SR & brushed tail motors! Wonder if I killed it doing lots of rainbows?

Meatrocket, you sure it's not a bad wire or solder connection from esc to battery? These wires fray really easily.

[brettskywalker48]

Give the motor a quick spray of wd-40 in the small bent looking openings. Shake off any excess, let it sit in front of an ac vent or fan for a while or hit it with compressed air. It may bring new life to your motor. TEMPORARILY. I have done it to mine several times, with an immediate notice of restored power. I've had my mcpx december & this is my 2nd motor. It keeps responding to my wd40 adrenaline shot so I ll roll with until the 130x shows up at my LHS

[atv223]

Read this. http://www.helifreak.com/showthread.php?t=420784

[MeatRocket]

Originally Posted by Jumna

Meatrocket, you sure it's not a bad wire or solder connection from esc to battery? These wires fray really easily.

This is a brand new board, motors & battery.

[Talesin]

I've had this happen to mine as well; usually after two or three minutes of FFF circuits or stall turns, the tail will start to weathervane badly, and the main rotor just loses lift and stops responding correctly to cyclic commands. Adding positive pitch just makes it worse, and it veers around drunkenly before hitting the ground. No LVC blue flashing LED, it's on solid the whole time. So far it's happened four times (the last four I've taken it out and used it for warming up prior to putting up the 450). Can only assume the motor's finally going bad (as it has well over 300-400 flights on it and no break-in) and just starting to trip overcurrent or cause a brownout. Wires are perfect, though these MH skids are showing wear (the CF snapped on the very first crash... CA to the rescue!).