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Tiny Trainer power plant problems

#1
Greetings,

My sons (10 and 12) are new to RC flying. We bought a Tiny Trainer 'get started package' and had a blast building the plane. Unfortunately, we're having trouble getting the motor to work. We've successfully bound the transmitter (Spektrum DXe) and both rudder and elevator are responding great.

It appears that we've correctly calibrated the throttle but the motor does not respond to the transmitter's commands. When the throttle is pushed forward, the motor rotates slowly making a "chattering" sound. Only once or twice did the motor actually spin all the way to full. Once throttled all the way back, the motor no longer spins freely when pushed forward again. We tried re-calibrating numerous times with no success.

I checked the bullet connections between the motor and ESC and found that this intermittently/ rarely and temporarily fixes the problem. If the throttle is cut all the way and pushed forward the problem re-appears and the motor spins slowly and "chatters".

Also, it seems strange that when the transmitter is switched off (and the throttle is down) the motor begins it's chattering/ slow spining until the battery is disconnected.

Could it be that some of the parts we received were defective or are we doing something wrong during our setup?

Many thanks,

0snapp
 
#2
I've only seen this when I had a bad motor/ESC connection. Normally, if you have spare parts, you would swap a motor or an ESC and see which was the problem.

Mike
 
#3
My very first build did exactly the same, when I calibrated the ESC correctly it worked fine. Go through the calibration procedure again, I didn't do something the right the first time I did it.
 
#4
0snapp,

I am sorry to hear it didn't go smoothly, especially as a project with kids. I've learned alot more about RC scratch building then I would have just flying models I bought in the store. Most of that was from coming to the forum when things didn't work to find out what I was missing.

I second the comment on retrying the calibration. Based on all the things I have done wrong, all of the above could be a reasonably expected from a miscalibrated ESC. I always have trouble getting the timing right as every ESC is different and I frequently don't get it to calibrate on the first try despite a whole set of beeps from the thing.

If that doesn't work I would post the model # of your receiver, ESC, motor here and either the exact series of steps/beeps you did between starting calibration and ramping up the motor expecting a response OR a video of the calibration/ramp.

If anything was actually defective, I would suspect the ESC before anything else. The one good side is that they are really cheap: https://store.flitetest.com/blheli-series-12amp-esc-xt-30/ FT support would probably replace if it really seems to be the case.
 

JimCR120

Got Lobstah?
Site Moderator
#5
When the throttle is pushed forward, the motor rotates slowly making a "chattering" sound. Only once or twice did the motor actually spin all the way to full. Once throttled all the way back, the motor no longer spins freely when pushed forward again. We tried re-calibrating numerous times with no success.

I checked the bullet connections between the motor and ESC and found that this intermittently/ rarely and temporarily fixes the problem.
On more than one occasion I have ssen this and it has always (in my experience) been a solder joint that needs to be re-soldered. If you're not sure which of the 3 connections is defective, follow this procedure to identify it.

Check the 3 phase wires from the ESC to the motor by briefly testing the motor with just one disconnected. Whenever you disconnect a good wire the motor should do less than with all three connected. Usually with a problem as you describe I will find two sets of wires that, when I disconnect either set, the motor doesn't move. The other wire when disconnected changes nothing. The one that changes nothing is the defective connection. Usually resoldering a loose connector will fix it.

Let us know what you find.
—Jim
 
Last edited:
#6
Onward and upward

Many thanks Jim and friends for the feedback.

Here's the update. I took the plane to a local hobby store after trying and failing to resolve the issue myself. The hobby store staff were very interested in the FT Tiny Trainer and were impressed with the quality of the kit.

After troubleshooting both ESC and motor, we isolated the problem to the motor. We hooked up a new motor to the ESC and the set up worked great. They suggested the connections could be the issue or perhaps the motor was bad. Unfortunately, I am not experienced at electronic repairs and don't own a soldering iron so I opted to purchase a new Lumenier RX1806-13 2500kv motor.

We took the plane to the park today and had fun with short hops and bumpy landings as we familiarized ourselves with the controls. The plane is amazingly stable and well balanced and seems to fly pretty well with the slightly more powerful motor. In true pioneering fashion, the 12 year old broke his first prop after a hard landing. The 10 year old followed suit a few minutes later, crashing nose first from an altitude of about 15 feet. We may need to invest in a 5 gallon bucket of propellers at this point.

I submitted a support request to FT with their online form on Friday. I'm hopeful the'll replace the motor.

Thanks again for the thoughts and feedback.

Fly safe!

0snapp
0snapp Jr
0snapp Jr, Jr
 

JimCR120

Got Lobstah?
Site Moderator
#7
What did you do with the motor? If you saved it, you could fix it when you learn to solder. Eventually you will likely learn. Even if you don't, a motor with only a bad lead still has value.
 
#8
Happy landings

Hi Jim,

The good folks at FT sent me a replacement motor for our Tiny Trainer. Everything works great and we had a fun time flying this weekend.

I've got the old motor in my tool box and look forward to troubleshooting it and perhaps even putting it back in service.

Thanks for your positive feedback!

Best regards,

Tim