tr6_guy

I recently purchased a used Mega 16-15-3 motor for my LMH Corona 120. The motor went in just fine along with the Align 35A ESC that came with it. I know the Align ESC isn't the best spedd control I could get but I'm told it should work just fine. Anyway, with everything installed and configured as I think it should be I now cannot even get the helicopter off the ground. There just isn't enough power. Until now I was running the original Electro-Fusion 7-Cell brushed motor and I had goobs of power. I'm wondering what could be wrong.

The only ESC setting I question is the timing. It states I can set it for low-timing (2 pole), Medium timing (6 or more poles) or High Timing (more power, less efficiency). I've tried all 3 with no effect.

My configuration is as follows:

Power Source: 7-Cell NIMH battery
Motor: Mega Motors 16-15-3 Brushless
Pinion: 9-Tooth
ESC: Align 35A. Brake Disabled, see comments above for timing info, Helicopter mode 1 (soft start).

Any guesses on what could be wrong here? Everything I've read said I should be prepared for LOTS of power, not so little power that I can't even get off the ground.

beaner

Hey tr6,
I know many people use the Mega motor in the Corona with good results. Is the main rotor turning in the proper direction, CCW as viewed from the top?

Beaner

tr6_guy

Yes, the chooper does generate lift, just not enough to get more than light on the skids. On someone else's suggestion I dremeled a flat spot on the motor shaft on the assumption that perhaps the pinion was slipping. That made no difference.

Is it possible the Align ESC is just the wrong speed control for this application? The specs say it will work with 6-12 cell NIHMs as well as LiPos but all the setup instructions focus on LiPo setup. I assume that's becaiuse the T-Rex comes with LiPos and the Align ESC was made for the T-Rex.

beaner

Are you are using the stock main gear? If so check that the plastic gear is not slipping on the aluminum mounting hub. This happened to my main gear after a crash. I'm not sure if the gear was defective in the first place or the crash caused it to start slipping.

Beaner

beaner

Hey tr6,
May be a good idea to check the whole drive train. Hold the blades and try turning the main gear by hand to confirm that nothing is slipping. Disengage the motor pinion and check that the drive train is turning freely. If the drive train is free and the only change you have made is the motor and ESC. The next thing I would check is if there is enough power available. Do you have a watt meter? The Corona uses about 150 watts to hover.

Good luck,
Beaner

tr6_guy

Checked teh whole drivetrain, things seem fine. This chopper was workign fine before my OEM motor melted itself.

Here's what I've done today:
- Ground a flat spot on the motor shaft in order to ensure it wasn't slipping.
- Verified that I'm using 6/4 for grips
- Tightened the head on the main shaft because there was a little play there.
- Removed the motor to verify that the rest of the drivetrain spins freely.
- Tried every ESC setting, including aircraft mode.
- Brake Disabled, high battery protection, High timing and Heli 1 setting seem to work best (but not well)
- Tried multiple battery packs to make sure the one I was using wasn't malfunctioning

I'm completely at a loss at this point. Wondering if I should just admit defeat and go buy a replacement brushed motor to replace the OEM motor that inexplicably melted itself last week. I hate to spend the $$$ on a new ESC if that's not going to help. Things actually were working pretty well with teh OEM motor before it melted.

Fitz21

My Feedback: (1)

seems like you have tried everything. This might sound novice, but what have you got to lose; i would check my settings in the transmitter for channel 3. sub-trim, or depending on your radio maybe even hovering throttle knob. Its obvious you arent getting enough head speed and maybe something is drawing too many amps like a bad servo would. also i would disconnect all my servos and see if you get enough power. someone else mentioned a wattmeter. you would know for sure then.

Cambo

My Feedback: (2)

Is there anything on the esc that determines the engine is at full power. On my cc35 the esc has a red lcd that determines you are full. Do you have endpoints on your radio. You might be restricting full power.

Listen to the engine
Is it really screaming?
If so than something is slipping.

Culver10

I had a Mega motor spin its' shaft inside the armature, that would be my guess as to your issue. Hold the large pinion and spool up to see if the shaft is spinning inside the motor.

notasme

tr6_guy,

I think we meet at the LHS the other day testing out our motors and speed controllers. I ment to suggest to you that you try a 3s LIpo pack. Or a 8s Nicd. You battery may not be giving the power that you require.

SS2P

Thats for sure. You will need at least a 9 cell for that. Want get nice power, try a 2100 mah lipo . 20C would work the best. Oh yeah and also it ha to be 3 cell.