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Old Dec 28, 2012, 09:41 PM
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Originally Posted by pmerritt View Post
for a really new flyer you can probably use up to 45% expo 0% expo will feel WAY to jerky though. I've been flying nearly two years and i still don't care for how sensitive 0% expo makes my bird feel.
I am new to 6 ch CP, but can fly v911 stock (many people use resistor mods on the transmitter to decrease rudder and aileron sensitivity of this heli)

Since the heli is being used in 'beginner mode', it may already have some expo on the receiver, can I try a lower value, like say 20? Should the same expo be used for aileron, elevator and rudder?
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Old Dec 28, 2012, 10:02 PM
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Originally Posted by PurpleShark View Post
4 minutes is with stock. To change the mess you loosen the two screws which hold the motor and move it a little. Don't move it too far, you want a tiny amount of play. I've used a piece of paper between the gear, and then adjusted it a little.
Btw, I'm a beginner myself, only sharing what works for me. I guess other will chime in...
Today I tested the flight time with Tom Z's configuration and got 3:20 mins.
During the test, I just did hovering without moving around.
While Tom Z's configuration is not agile, it roughly gave additional 1 mins flight time, compared with my configuration.

Quote:
Originally Posted by i812 View Post

Some other things that could effect flight times:
  • Mechanical binding anywhere between Motor and Rotor Head
  • Bad LiPo
  • Bad wiring anywhere between LiPo and Motor (most likely broken wire strand(s) from excessive flexing)
  • Bad Motor (most likely metal brushes burnt/melted from excessive current draw when Motor is stalled)
  • Bad RX
I replaced a power cable with new one.
There was a little bit improvement in flight time. (Roughly 30 sec.)

Quote:
Originally Posted by i812 View Post
FWIW, I don't believe the LiPo will be damaged if the Mini is flown until it looses power and start falling out of the sky, provided that when the Mini starts falling it does an emergency "May Day" landing! I've watched the Telemetry Voltage when "May Day" happens, and depending on how fast I was flying, "May Day" occurs when the Telemetry Voltage is anywhere between 3.4 and 3.3 V. Once I let off the sticks, the Telemetry Voltage increases back up to 3.7 V: however, if I try to fly again the Voltage will immediately drop to "May Day" again.

I don't believe I've had any noticeable problems flying LiPo's until "May Day"; in fact I believe the only problems I've ever had with abusing LiPos has been from keeping them fully charged for extended time (more than two weeks) without use.
I agree with you.
While the mini cp starts falling out of the sky, the telemetry indicated 3.3V. So I thought that although I fly the mini until it starts falling down, the lipo will not be damaged.

However, after 10 cycles, the flight time is reduced so much, compared to the first time. Also, even falling out of the sky, only 50~60% of battery capacity is used. So I'm not sure that that my lipos were not damaged. I don't have new batteries or a good charger for discharging test. (My charger supports only 1 A discharge rate maximally.) So I have no way to test my battery status. Only thing that I can do is a capacity check by discharging the battery with 1 A rate using a charger. Capacity is normal.
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Old Dec 28, 2012, 10:05 PM
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Quote:
Originally Posted by harmony View Post
While the mini cp starts falling out of the sky, the telemetry indicated 3.3V. So I thought that although I fly the mini until it starts falling down, the lipo will not be damaged.

However, after 10 cycles, the flight time is reduced so much, compared to the first time. Also, even falling out of the sky, only 50~60% of battery capacity is used. So I'm not sure that that my lipos were not damaged. I don't have new batteries or a good charger for discharging test. (My charger supports only 1 A discharge rate maximally.) So I have no way to test my battery status. Only thing that I can do is a capacity check by discharging the battery with 1 A rate using a charger. Capacity is normal.
What happens to flight time if you turn off telemetry?
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Old Dec 28, 2012, 11:05 PM
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Telemetry doesn't affect flight time, as it's not switchable off on the RX, just on the TX. So if you say "Telemetry off" RX still sends telemetry packets, just the TX chooses to ignores them.


PS: Heads up, fs v1.3 for MiniCP on Walkera's website.
Changelog:
- something about optimization
- solved some fixed id issues

Sorry, can't read proper chinglish.
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Old Dec 28, 2012, 11:19 PM
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Originally Posted by sbstnp View Post
Telemetry doesn't affect flight time, as it's not switchable off on the RX, just on the TX. So if you say "Telemetry off" RX still sends telemetry packets, just the TX chooses to ignores them.


PS: Heads up, fs v1.3 for MiniCP on Walkera's website.
Changelog:
- something about optimization
- solved some fixed id issues

Sorry, can't read proper chinglish.
Ok makes sense. Thought I read a thread where it made a difference
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Old Dec 28, 2012, 11:27 PM
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Originally Posted by j35u5fr34k View Post
Ok makes sense. Thought I read a thread where it made a difference
I use deviation for my devo 8S.
There was no difference between telemetry on and off for my mini cp.
But, as you mentioned, Tom Z reported that there was a big difference between on and off.

Quote:
Originally Posted by Tom Z View Post
Telemetry:

I have found out that using the telemetry eats up the battery time.
I went from 5 full minutes of flight time on my Master CP with telemetry
inhibited in the TX to 1:25 minutes flight time with the telemetry enabled.
I found the same thing with my Mini CP, 1:25 minutes flight time with the telemetry enabled and
3 minutes flight time with the telemetry inhibited.
My friends Mini CP had the same results as I did with telemetry inhibited and enabled.
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Old Dec 28, 2012, 11:46 PM
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Originally Posted by harmony View Post
I use deviation for my devo 8S.
There was no difference between telemetry on and off for my mini cp.
But, as you mentioned, Tom Z reported that there was a big difference between on and off.
Same for me, no change in flight times.
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Old Dec 29, 2012, 12:53 AM
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Quote:
Originally Posted by harmony View Post
Today I tested the flight time with Tom Z's configuration and got 3:20 mins.
During the test, I just did hovering without moving around.
While Tom Z's configuration is not agile, it roughly gave additional 1 mins flight time, compared with my configuration.



I replaced a power cable with new one.
There was a little bit improvement in flight time. (Roughly 30 sec.)



I agree with you.
While the mini cp starts falling out of the sky, the telemetry indicated 3.3V. So I thought that although I fly the mini until it starts falling down, the lipo will not be damaged.

However, after 10 cycles, the flight time is reduced so much, compared to the first time. Also, even falling out of the sky, only 50~60% of battery capacity is used. So I'm not sure that that my lipos were not damaged. I don't have new batteries or a good charger for discharging test. (My charger supports only 1 A discharge rate maximally.) So I have no way to test my battery status. Only thing that I can do is a capacity check by discharging the battery with 1 A rate using a charger. Capacity is normal.
If the Mini falls out of the sky when the Telemetry Voltage is 3.3 V, then I doubt there is anything electrically wrong between the RX and Motor; however, if the LiPo did not deliver it's expected mAh capacity, then that is probably an indication that there is something wrong between the LiPo and RX. If you've already replaced the power wiring between the LiPo connector and RX, then I'd suspect broken wire stands between actual LiPo and LiPo Connetor, and most likely at the back end of the Connector since that is where it is flexed the most during handling.

I tried explaining the electrical symptoms of broken wire strands a couple weeks ago in a long post:

http://www.rcgroups.com/forums/showp...postcount=4481

One of the nice features of having Telemetry Voltage is being able to use it to help indicate if the wiring between the LiPo and RX has broken strands. If the LiPo wiring to the RX has broken strands, at full LiPo charge, when the Rotor is not spinning the Telemetry Voltage will indicate 4.2 V; however, when the Rotor is spinning the Telemetry Voltage will indicate something less than normal "full charge" in-flight Voltage (the reason is because broken wire strands equals increased electrical resistance, and increased electrical resistance results with increase Voltage drop across the resistance, and the greater the current the greater the Voltage drop per given resistance. To use Telemetry Voltage as an indication of broken wire strands between LiPo and RX, you'll first need to know what "full charge" in-flight Telemetry Voltage is for your style of flying, then use that Voltage as a benchmark for future comparison.

Also, you should be aware that the colder the LiPo is the less flight time it will deliver. A stock LiPo that provides about 4:30 min of normal Mode slow flight time at 70* F, will only provide about 2 min at 45* F, and once the temperature resumes to 70* will provide 4:30 min again.

If you need to replace the LiPo Connector, here is a post that provides a few different Connector replacement options:

http://www.rcgroups.com/forums/showp...postcount=4489

I think broken wire stands are probably the most common electrical problems with the micro Walkeras.

BTW, every Mini newbie should be aware of these Mods:

Quote:
Originally Posted by i812 View Post
Below are some mods many people believe should be done to the Mini CP as soon as possible:
  • Servo Saver mod - Bytemuncher's RCG Blog has detailed info. Indoorheli has reported not fully tightening the Main Shaft Collar Screw also prevents stripping Servo Gears.

  • RX Saver Mod - Attach a somewhat stiff support from bottom of Battery Tray so it extends inside the bottom of the Canopy and helps keep the Canopy from easily sliding upwards when it is hit from the bottom. Marioinc posted details. I think if this mod (or any other mod that keeps the bottom of the Canopy from easily pivoting upward) is performed, then there might not be a need to do the RX Coil Saver mod.

  • Canopy Saver Mod - Apply a strip of tape along the entire bottom edge of the Canopy. The Canopy is very durable; however, it easily splits starting from the bottom edge, and then over time the split travels towards the nose. Hopefully taping the entire bottom edge of the Canopy will prevent splits from starting.

  • RX Coil Saver mod - Apply adhesive (Hot Glue, X2 White Gorilla Glue, CA, etc.) to Coil at front lower right corner of RX board, so Coil doesn't break when Canopy is taken off (in a crash?). If the Coil lead(s) has broken from the PWB and the lead(s) is too short to re-solder to the PWB, it can be carefully unwound as required (one of the Coil's leads easily unwinds one loop at a time from the outside inwards; however the other lead has its end exposed but immediately get buried under all the windings - if that lead is too short, probably the other lead will need to be completely unwound, so the coil can be rewound with long enough leads at each end), rewind as necessary (depending on which Coil wire lead broke from PWB), and re-solder as required. I think the Coil can be replaced for about $0.35 + $2.80 shipping from DigiKey.com; however, we should get one and verify it works before publicizing the Part Number.

  • RX Antenna end - Keep it as vertical as possible - this will keep its exposed bare tip from electrically shorting against the Motor or RX circuitry, and have the Antenna positioned for best signal reception. Some people feel safer insulating (Liquid Electrical Tape, X2 White Gorilla Glue, Hot Glue, Heatshrink, etc.) the exposed wire at the tip of Antenna.

After the Servo Holder's - Canopy Holder Rod breaks from a strong crash, Hot Glue a 38 mm (1.5 inch) length of 1 mm CF Rod centered across the back of the Servo Holder above the Servo Holder Guide Pin and Screw Head. If at a later time the Servo Holder needs to be removed, the Hot Glue and Canopy Holder Rod can be removed as required.
Finally, Tom Z created a " ... Mini ... Review ..." thread that has alot of useful Mini info in the first few posts.
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Old Dec 29, 2012, 09:54 AM
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First of all, thank all you guys for your valuable advice, specially i812.
The short flight problem is almost resolved now.
Using the stock battery, I got about 4:00~4:30 flight time with very very gentle flying.
Also 80% of battery capacity can be used for flying.

There were two problems.
1) Bad strands
After replacing a power wire between a receiver and a lipo, the flight time was improved.

2) Main rotor sticker
Some parts of sticker on a main rotor came off.
It made high resistance when the main rotor is rotating.
After detaching it, it seems that everything is fine.
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Old Dec 30, 2012, 10:01 AM
...if you take the time
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Quote:
Originally Posted by sbstnp View Post
PS: Heads up, fs v1.3 for MiniCP on Walkera's website.
Changelog:
- something about optimization
- solved some fixed id issues

Sorry, can't read proper chinglish.
Anyone tried the new firmware yet?
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Old Dec 30, 2012, 11:29 AM
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Does anyone have a good beginner setup for devo 7e ?
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Old Dec 30, 2012, 12:11 PM
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What should the pitch be at mid-throttle for normal flight?

Zero degrees or 5 degrees?
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Old Dec 30, 2012, 12:27 PM
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Originally Posted by Lentar View Post
Zero degrees or 5 degrees?
Go for zero, it will teach you good habits if you ever wanna go inverted. Or learn 3d.
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Old Dec 30, 2012, 12:29 PM
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Originally Posted by cadrobbi View Post
Does anyone have a good beginner setup for devo 7e ?
Make it yourself, it's not hard.

Set D/R to around 60-65% and Expo to around 20. Limit Pitch travel adjust to 55 (max is 60) both up and down. Keep THR curve linear at first.

There is a thread here by Tom Z that has some very nice instructions, but I don't have a link handy, try to search.
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Old Dec 30, 2012, 12:30 PM
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Originally Posted by PurpleShark View Post
Anyone tried the new firmware yet?
I will but my Mini is in pieces right now waiting for a frame replacement and I have no reason to hurry it's freezing and snow outside and I don't fly it in the house. probably next week after I rebuild it will try the new FW.
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