wannabejess

I have a Parkflyers Cessna 182.

I replaced the original speed 480 (due to a crash) with a new speed 480 sold to me from ParkFlyers.

I had to solder the new motor onto the power leads (no problem).

Now when I push the throttle all the way on the motor shuts down. if I throttle back to 75%, I get three beeps (just like when I first connect the battery) and it will start spinning again.

Problem is 75% is not enough to hand launch the plane and keep it in the air. also poor performance too!

AnY ideas? I have written to Parkflyers to get their take on this but I haven't heard from them in a week. I will be trying to call them also.

Sir Raleigh

Are you using Lipo or NiMH batteries?
What voltage or number of cells?

Are you sure it's fully charged?

Is the LVC programmed properly for the battery you're using? If it's set for Lipo with a 3 volt per cell cutoff and you're using NiMH batteries the LVC will cut the motor long before it should.

wannabejess

Everything is identical to its original set up. Only the motor has changed.

I am using the stock 9.6 Volt 1000 mah Nihm High Power Battery Packs that came with the plane they were fully charged before trying them out.

I am not sure what the LVC is?

As far as I know the ESC is not programable adnI dont have any programmer for it. But as I stated it should be exactly the same set up I was flying earlier this year. I only replaced the Motor with the exact replacment part from for the same vendor.

I wish I still had the old motor as I think there may have been a difference. I saw as resistor connected between both power leads. Both old and new motors have a resistor between each lead and the motor case but the old motor had one between the leads as well

wannabejess

whoops I was wrong I am using a 1000 Mah Nihm 7.2 volt battery pack that came with the plane.

jdetray

Those components on the motors are almost certainly capacitors, not resistors, but they should not be related to your problem anyway.

It sounds like the LVC is kicking in for some reason, but I don't know why, unless the replacement motor is drawing more current than the old one. Poor (high resistance) connections to the new motor is another possibility.

- Jeff

wannabejess

Thanks Jeff. I could always re-solder the connections and try again. What is the LVC?

Sir Raleigh

LVC stands for "Low Voltage Cutoff". It's a circuit that cuts the motor off when the battery reaches a certain voltage so the battery will still have enough capacity left to power the receiver and servos so you can still land safely. For a NiMH battery that's usually when the battery voltage reaches 1.0 volts per cell (in your case that would be about 7.0 volts for your 7.2 volt battery pack).

One thing you might want to consider getting, if you don't have one already, is a wattmeter. This is a device you connect in series with the battery and ESC which will tell you numerous things including your battery voltage at any given time, the amount of current your motor is pulling at that moment, which if you had one right now we could almost certainly tell you where the problem is.

wannabejess

Could I use a VOM as a watt meter?

Maybe I should fully discharge my packs and then bring them back up to full charge. (Cycle them) It has been a while since I last flew due to a crash and waiting for parts.
I had them on the charger prior to flying for hours but maybe They weren't fully charged.

Teh theory being that they have enough to run at 75% but at 100% throttle they drop teh votage enough to trigger the LVC.

Sir Raleigh

if the packs have not been used for a while cycling them is advised.

Glacier Girl

My Feedback: (4)

Something else to throw in the mix. Are you sure the motors have the same kv rating?

Could be the new one is a higher kv then the old, this with all else being the same, could cause a higher amp draw, and the esc is cutting out due to over limits on it's ability, or the pack is dropping off due to the higher load.


Just in case, kv in layman's terms is like rpm in engines, it how many revolutions per minute, with one volt power.