Author Topic: Why did my electric motor run start running backwards? (Read 4242 times)

Rosie Rosenau · « **on:** January 15, 2015, 02:07:00 PM »

Just a simple question. I have been flying today and put another battery for the next flight and she started running backwards? My 3 wires are still the same. I even did swap them and she still ran backwards. So I put them back to normal. Tried again and she ran correct. Stopped the run and restarted and again the short spin up was reverse as was the main run. So I discontinued my flying today and went home.

My guess is either my ESC is going bad or maybe my Timer is bad or my battery reads 99% on its charge?

So what did I break? Runs fine one flight next flight it is reversed?

Thanks in advance Team
Tally ho
Rosie

Tim Wescott · « **Reply #1 on:** January 15, 2015, 02:13:46 PM »

Quote from: Rosie Rosenau on January 15, 2015, 02:07:00 PM

Just a simple question. I have been flying today and put another battery for the next flight and she started running backwards? My 3 wires are still the same. I even did swap them and she still ran backwards. So I put them back to normal. Tried again and she ran correct. Stopped the run and restarted and again the short spin up was reverse as was the main run. So I discontinued my flying today and went home.

My guess is either my ESC is going bad or maybe my Timer is bad or my battery reads 99% on its charge?

So what did I break? Runs fine one flight next flight it is reversed?

Castle ESC? Or Honest Chen's?

ESCs are run by software, and you can't trust those embedded programmers for spit.

Rosie Rosenau · « **Reply #2 on:** January 15, 2015, 03:17:16 PM »

It is from Brodak so it is an Arrowind. Any ideas on how fix it?

Paul Walker · « **Reply #3 on:** January 15, 2015, 07:42:46 PM »

When I ran Castle ESC's and a Hubin timer it sometimes would run backwards in the 1 or 2 second burst when the start button was depressed. It always ran in the proper direction after the delay period. Kind of made me nervous but never became a problem.

Is that when yours runs backwards?

John Cralley · « **Reply #4 on:** January 15, 2015, 08:12:58 PM »

Most likely this would be the ESC! I have no idea how or even of it can be fixed. I would suppose it could be the timer if it was sending variable frequency as well as variable pulse width output. Try a different ESC and/or a different timer to determine which is faulty.

Wiser heads may explain this - Tim??

Tim Wescott · « **Reply #5 on:** January 16, 2015, 12:01:52 AM »

Quote from: John Cralley on January 15, 2015, 08:12:58 PM

Most likely this would be the ESC! I have no idea how or even of it can be fixed. I would suppose it could be the timer if it was sending variable frequency as well as variable pulse width output. Try a different ESC and/or a different timer to determine which is faulty.

Wiser heads may explain this - Tim??

I'd like to say that it couldn't be the timer, because any sensibly-designed ESC would refuse to go backwards no matter what. Unfortunately, that leaves open the door for a timer that has nonsense in its design, and after 25 years in industry fixing software screwups (some, alas, my own), all I can do is say it can't be ruled out.

If it didn't do it before, and it does now, there's probably a hardware issue with the ESC. There's a chance that the timer is broken and talking to a design flaw in the ESC. In that case, changing ESC's would result in the same behavior while changing timers would fix it.

I suspect that the backwards running that Paul has seen is just a startup thing -- while I fly slime for CL, I fly mostly electric for RC and I've never seen my, or anyone else's, electric motor run backwards past the first second or so when the ESC is fumbling around trying to figure out how the motor is positioned.

John Rist · « **Reply #6 on:** January 16, 2015, 07:26:50 AM »

Unless I am missing something it can not be the timer. The interface between the the timer and the ESC is a 3 wire connection. They are +V, ground, and signal. The signal lead outputs a 1 1/2 ms pulse that varies by a 1/2 ms. This pulse occurs around 60 times a second. As this pulse varies from 1 ms to 2 ms the ESC takes this information and regulates the RPMs of the motor. Some timers (KR timers) have a third wire that attaches to one of the motor leads. It is used to allow the KR timer to set RPMs at a constant level. So unless I am missing something it can not be the timer.

Rosie Rosenau · « **Reply #7 on:** January 16, 2015, 10:53:45 AM »

Well alright there Team. Thank you all so much. I will start by installing a freshly charged battery and do a run. If it runs backwards I will switch out the timer. If it still runs backwards I will swap out the ESC.

As to the time it ran backwards. Yes I mean the burst and then the full speed timed run also ran backwards. We have NO wind today Herr in Yelm , Washington so I really want to go fly again.

I will give an update on the changes I noted above.

Thanks guys. It is such a relief to finally have a source of friends that know what they are talking about. This goes for all of the Stunthanger teammates. My history has mainly been Cox or Norvell or Fox or OK Cub. Yup all gas. It is so nice to finally have electric that works.

Our previous electric powered glider was from Cox and that was in the late 1980s. Needless to say. It was just a powered crash... Such a disappointment back then. So much so it took this long to try electric flight again!

Tally ho
Rosie

Tim Wescott · « **Reply #8 on:** January 16, 2015, 11:16:34 AM »

Quote from: John Rist on January 16, 2015, 07:26:50 AM

Unless I am missing something it can not be the timer.

I was borrowing trouble when I said it could be the timer. It'd have to be some bizarre problem in the timer and some bizarre problem in the ESC together. When you deal with thousands of problems, though, you learn that some of the worst ones are the "oh, it simply cannot be that" ones.

It's far more likely that the ESC has developed an electrical problem, probably in how it measures voltages on the motor windings (which is how it knows how the motor is rotated, which is how it makes it turn appropriately).

If the ESC has a set-up mode where you can reverse motor direction with some stick-fandango at the transmitter, the timer may be reprogramming it. Oh happy thought -- this comes under the head of "bizarre problem", but if it's happening the fix is a different brand or model of ESC, not a different, identical, unit.

Crist Rigotti · « **Reply #9 on:** January 16, 2015, 11:38:55 AM »

I keep thinking if the ESC was made by COX that would be the problem!

Keith Miller · « **Reply #10 on:** January 16, 2015, 12:29:29 PM »

Quote from: Crist Rigotti on January 16, 2015, 11:38:55 AM

I keep thinking if the ESC was made by COX that would be the problem!

Good one!

John Rist · « **Reply #11 on:** January 18, 2015, 02:49:30 PM »

I recommend replacing the timer with a servo tester. Many are listed on eBay. Just search servo tester. I have several - even the cheep ones work. It the problem persists it is the ESC that is bad.

Tim Wescott · « **Reply #12 on:** January 18, 2015, 03:09:48 PM »

Quote from: John Rist on January 18, 2015, 02:49:30 PM

I recommend replacing the timer with a servo tester. Many are listed on eBay. Just search servo tester. I have several - even the cheep ones work. It the problem persists it is the ESC that is bad.

If you also fly RC you can temporarily plug the ESC into a receiver and do it that way.

John Rist · « **Reply #13 on:** January 18, 2015, 07:19:46 PM »

Quote from: Tim Wescott on January 18, 2015, 03:09:48 PM

If you also fly RC you can temporarily plug the ESC into a receiver and do it that way.

If you fly RC you should have a servo tester to set up your servos. the one I like is: http://www.ebay.com/itm/Esky-000537-Servo-Tester-EK2-0939-USA-Seller-/200766708488?pt=Radio_Control_Parts_Accessories&hash=item2ebea0db08 and cost $36. It measures timer output as well as testing a servo.

I also have: http://www.ebay.com/itm/Multi-Servo-Tester-3CH-ECS-Consistency-Master-Checker-Speed-Controler-CCPM-SS-/321463863858?pt=Radio_Control_Parts_Accessories&hash=item4ad8bd4a32 cost $2. It only test a servo (or ESC) but hay it works! the $2 includes shipping!

Horby · « **Reply #14 on:** January 18, 2015, 07:51:48 PM »

Change the esc and move on.

Warren

Rosie Rosenau · « **Reply #15 on:** January 19, 2015, 04:18:37 PM »

AOK team. The I's have it. On payday I will order some more timers? Anyone make one like Brodak FM-0c? ;
I will also buy a lot more 25-30 amp ESC for brush less motors from Hobbyking and then a few 1/2a's from Eric Rule out of RSM distro. He steered me to another LIPO battery source... Hobby king and saved me 750$. Needless to say. I owe him big time and will see to it he is rewarded.
Tally ho
Rosie

Tim Wescott · « **Reply #16 on:** January 19, 2015, 05:16:55 PM »

Quote from: Rosie Rosenau on January 19, 2015, 04:18:37 PM

AOK team. The I's have it. On payday I will order some more timers? Anyone make one like Brodak FM-0c? ;
I will also buy a lot more 25-30 amp ESC for brush less motors from Hobbyking and then a few 1/2a's from Eric Rule out of RSM distro. He steered me to another LIPO battery source... Hobby king and saved me 750$. Needless to say. I owe him big time and will see to it he is rewarded.

For all my blathering about how it might possibly by some long stretch be the timer, that's a 1 in 1000 chance or less, and even then the ESC would still have to be dorked somehow.

Spend your money on another ESC, only get a timer if that doesn't seem to fix the problem.

MikeCoulombe · « **Reply #17 on:** January 19, 2015, 05:49:52 PM »

I once had this sort of thing happen to one of my RC planes.
I turned on the transmitter but didn't select the correct model, so when I plugged in the battery on the plane it ran backwards and since the motor wires are not easily accessed I had to reprogram the esc, after setting the transmitter to the correct model.
Dulux 70amp esc, G60 motor, Airtronics rds8000 2.4ghz.
It only happened once and I have since been careful not to repeat the mistake.
This problem seems to have been caused by a conflicting input from the transmitter through the receiver, scrambling the esc program.
I would still consider the esc as the culprit, just because the problem you describe has not been brought up around here before.
My 2cents.

John Rist · « **Reply #18 on:** January 19, 2015, 08:00:24 PM »

I would go with a KR timer and a Hobby King ESC. Has the advantage of RPM control and burn out protection.

http://www.rsmdistribution.com/index-2.htm Look under Electric Flight Products and scroll down to:

"KRPKG   KR Governor Ver.2 With Switch & Program Stick.
Governor controls, RPM, Start Delay, Flight time & features increased RPM when you enter any maneuver (similar to how a tuned pipe glow system works)
The Governor comes with a soft start included plus it shuts down the entire electrical system in the event of a prop strike.   $49.50"

I have one and it works great. It does require the ability to solder for instillation.   But I would think if you plan to go electric you need to learn how to solder.

Rosie Rosenau · « **Reply #19 on:** January 27, 2015, 09:37:07 PM »

Ya know Eric Rule and his company has such good reviews I called him today and ordered 2 complete .061 competition level complete wet ups. With 10 extra motor shafts... mine tend to get a tad bent... but less often now. Anyone know where a flying circle made of foam or maybe Jello?

MikeCoulombe · « **Reply #20 on:** January 27, 2015, 09:45:49 PM »

One day you will stop bending motor shafts and start thinking about $50 props...