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Old Dec 24, 2012, 08:39 PM
Mike
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Any tips on installing the metal pinions on these motors? I'm afraid of bending the shaft when I take a hammer to it.

Is there a plastic pinion sold somewhere?
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Old Dec 24, 2012, 08:43 PM
Heli Crash Survivor
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United States, AR, North Little Rock
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Quote:
Originally Posted by miketre View Post
Any tips on installing the metal pinions on these motors? I'm afraid of bending the shaft when I take a hammer to it.

Is there a plastic pinion sold somewhere?
All the pinions I purchased are slip on & you use red loctite,
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Old Dec 24, 2012, 08:51 PM
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Aren't you supposed to apply heat to the pinion to install?
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Old Dec 24, 2012, 09:45 PM
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only if it doesn't slip fit as it should....otherwise it should fit.
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Old Dec 25, 2012, 12:38 AM
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Joined Aug 2009
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I've read that excessive heat permanently damages magnets.

Metals shrink when cold, and expand when hot; therefore instead of heating the Pinion, maybe the same difference could be accomplished by freezing the Motor?

When freezing the Motor doesn't work, I've had success installing tight Pinions on Shafts by carefully pressing them together sandwiched between two blocks of wood and a C-Clamp. One block of wood is about 2 inches thick, and is used as magnetic "insulation" between my metal C-Clamp and back end of magnetic Motor, and the other block of wood has a hole drilled allowing the Pinion to be pressed further on to the Shaft so it can be positioned for proper alignment with the Main Gear. Before tightening the C-Clamp, make certain not to pinch wires, and everything is aligned properly before putting the squeeze to it.

The Pinion hole can be enlarged with a drill bit, and/or the Shaft diameter can be reduced with abrasive as it spins.

I try to avoid using excessive heat with magnetic Motors; therefore, prefer Pinions that are press fitted, and remove them with a Gear Puller.
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Last edited by i812; Dec 25, 2012 at 01:07 AM. Reason: grammar
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Old Dec 25, 2012, 02:36 AM
Deviant
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Originally Posted by Crash Survivor View Post
Ordered one anyway. May be the best indoor combo with the MCP to fly this winter.
Same, was waiting for it for a few months to be back in stock so I grabbed one.
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Old Dec 25, 2012, 04:35 AM
nac
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Melbourne, Australia
Joined Jan 2008
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Hey Guys,

I am selling my kit if anyone is interested.

Walkera Mini CP with Devo 8s transmitter.
2.4G Walkera Devention Mini CP Flybarless Micro Helicopter.
Devo8S TX
extra receiver.
Portable Aluminium Case.
9 x lipo's.
2 x chargers.
Spare parts.
The lot for $250
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Old Dec 25, 2012, 07:53 AM
Deviant
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Originally Posted by nac View Post
Hey Guys,

I am selling my kit if anyone is interested.

Walkera Mini CP with Devo 8s transmitter.
2.4G Walkera Devention Mini CP Flybarless Micro Helicopter.
Devo8S TX
extra receiver.
Portable Aluminium Case.
9 x lipo's.
2 x chargers.
Spare parts.
The lot for $250
Keep the 8S and flash it with Deviation, http://www.deviationtx.com

Unless you get out of the hobby ofc.


By the way this is a good deal.
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Old Dec 25, 2012, 10:22 AM
Mike
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Joined Dec 2010
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Thanks for the tips everyone.
I'm wating for my pinions from overskyrc to arrive. Hopefully, they will be an easy fit on my C05 motor from HK.
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Old Dec 26, 2012, 04:47 PM
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fluctuating rpms

As a newbee I have crashed my MIni a fair bit and am amazed that I only had to replace a boom and rear rotor!

Anyway, this is my problem: motor will now change revs up briefly w/o command change, Mini will hop up, sometimes change direction. Directional change -I guess- would be due to headspeed change, so probably just the one issue: very sudden motor speed change, fraction of a second, but makes it very hard to fly (for me!).

Is this the board? Or is the motor worn out (I use several batteries in a row and would have had it running too hot, I guess).

If it is the board: that means a new Mini is the only option.

If it is the motor, then a new one is needed.

Or an upgrade to brushless! With its own ESC the brushless should take care of this prob for sure? Right? Even if the std motor control on the board is damaged?
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Old Dec 26, 2012, 06:09 PM
Brent 黑雁
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Canada, AB, Ponoka
Joined Jan 2012
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Originally Posted by torsten01 View Post
As a newbee I have crashed my MIni a fair bit and am amazed that I only had to replace a boom and rear rotor!

Anyway, this is my problem: motor will now change revs up briefly w/o command change, Mini will hop up, sometimes change direction. Directional change -I guess- would be due to headspeed change, so probably just the one issue: very sudden motor speed change, fraction of a second, but makes it very hard to fly (for me!).

Is this the board? Or is the motor worn out (I use several batteries in a row and would have had it running too hot, I guess).

If it is the board: that means a new Mini is the only option.

If it is the motor, then a new one is needed.

Or an upgrade to brushless! With its own ESC the brushless should take care of this prob for sure? Right? Even if the std motor control on the board is damaged?
Does the main gear move up and down? If so, either the main gear is pushed partly down the main shaft or the lock collar just below the swash plate has moved up. Whichever the case, is causes erratic pitch and will seem like the motor is changing speed rapidly.
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Old Dec 26, 2012, 06:25 PM
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I bought one mini cp with devo 8S a few days ago.
Everything is fine except that flight time is too short.
The flight time is 2 min with the original battery.
Hobbyking 300mAh lipo gives me 2:30 ~ 3 min.
I just did a hovering for the flight test.
The mini cp is without any MOD.
Telemetry function was off.
I downloaded a setting from walkera website.

I have searched getting answers for that, but I could not.
Some people says that 2 min flying is normal.
However, others say that they can fly more than 4 mins using stock battery.
What is true?

The followings are my experiments.

1) stock battery
flight time: 2 mins
Used: 120mAh
120mAh remains still. Is it normal???

2) hobbyking 300mAh battery
flight time: 2:30 ~ 3 mins (telemetry off)
Used: 150 ~ 180mAh

3) hobbyking battery teset
- discharge rate: 1A (This is the best configuration that my charge can support)
- discharged: 295mAh --> It seems that battery is normal.

4) telemetry on
- telemetry indicates 4.0~4.1V
- When starting hovering, the voltage goes to 3.7V.
- When a battery voltage becomes 3.3V, the battery cannot lift a mini cp.

From experiments, 50 mAh is used for 1 min flying.
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Last edited by harmony; Dec 26, 2012 at 06:31 PM.
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Old Dec 26, 2012, 06:48 PM
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Quote:
Originally Posted by harmony View Post
I bought one mini cp with devo 8S a few days ago.
Everything is fine except that flight time is too short.
The flight time is 2 min with the original battery.
Hobbyking 300mAh lipo gives me 2:30 ~ 3 min.
I just did a hovering for the flight test.
The mini cp is without any MOD.
Telemetry function was off.
I downloaded a setting from walkera website.

I have searched getting answers for that, but I could not.
Some people says that 2 min flying is normal.
However, others say that they can fly more than 4 mins using stock battery.
What is true?

The followings are my experiments.

1) stock battery
flight time: 2 mins
Used: 120mAh
120mAh remains still. Is it normal???

2) hobbyking 300mAh battery
flight time: 2:30 ~ 3 mins (telemetry off)
Used: 150 ~ 180mAh

3) hobbyking battery teset
- discharge rate: 1A (This is the best configuration that my charge can support)
- discharged: 295mAh --> It seems that battery is normal.

4) telemetry on
- telemetry indicates 4.0~4.1V
- When starting hovering, the voltage goes to 3.7V.
- When a battery voltage becomes 3.3V, the battery cannot lift a mini cp.

From experiments, 50 mAh is used for 1 min flying.
You should never push your batteries lower than 3.7 V on the fear of damaging and severely shortening their lifespan

From what I understand, brushed motors works better when near 100%. If your throttle and pitch curve are at their defaults and you are only hovering (40%~60% stick) then i think 2 mins is around right.

I dunno why but I dont trust my telemetry very much
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Old Dec 26, 2012, 08:04 PM
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Originally Posted by BThirsk View Post
Does the main gear move up and down? If so, either the main gear is pushed partly down the main shaft or the lock collar just below the swash plate has moved up. Whichever the case, is causes erratic pitch and will seem like the motor is changing speed rapidly.
Good idea, but not the problem. The collar was a little loose and I tightened it. End of main shaft flush with bottom of main gear. Everything turns freely. Here the result:

heli is stationary with just enough throttle to be light on skids, but NO movement fwd/back, l/r or up. Then -after a few seconds- heli jumps up (without ANY change on sticks) by 3 feet and shoots off to 2 o'clock.

I understand the change in direction as gyro gets confused when skid is on ground and will overcompensate when heli lifts. BUT what remains is a sudden change in RPM and the jump (problem here: difficult to identify whether the motor changes rpm or the swashplate changes and that leads to rpm change).

If the rpm change was caused by a faulty servo that changes pitch in the blades then the heli would jump too. You got me thinking here. I eyeballed the servos and carefully pushed the rods up and down. Nothing loose, nothing feels funny.

So we have -in my opinion- four possible causes here:

the esc on the main board (would a brushless conversion fix this?)
the mainboard controlling the servos (new main board)
the motor itself (that is not very likely, is it?)
the servo controlling lift (would I not feel broken servo gears by gently pushing the rods up/down?)

Any idea where to look next?? And my apologies the number of ? in this post!
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Old Dec 26, 2012, 08:11 PM
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Quote:
Originally Posted by DantHimself View Post
You should never push your batteries lower than 3.7 V on the fear of damaging and severely shortening their lifespan
As far as I know, that is true only if there is no load for the battery.
When a motor runs, the voltage is dropped much.
(Please check the discharge graph for turnigy 160mAh 30C.
http://www.hobbyking.com/hobbyking/s...X100929X44.jpg)
As in the figure, the voltage decreases around 3.3~3.4V during discharge.
However, if the discharge stops (means no load), the voltage should goes up.
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