Strange symptoms, simple solution - RCCanada - Canada Radio Controlled Hobby Forum
RCCanada - Canada's Radio Control Hobby Forum
Electric Flight Discuss Electric Flight in Canada

Thread Tools Display Modes
Old 04-11-2012, 07:46 PM   #1
Dave Holmes
RCC Supreme Contributor
Dave Holmes's Avatar
I am: Dave Holmes
Join Date: Mar 2004
Location: Prince Edward County, Ontario (no longer Brampton!)
Radio of choice:
Futaba 72 Mhz
# of RCs: 30+

Feedback: 4 / 100%
Posts: 4,209
Total Props: 10
Strange symptoms, simple solution

       Remove this ad - become a site supporter!
I'm still messing with my PBY Catalina that had me buffaloed in an earlier thread. (

This time, I got to fooling with it on a test stand and the starboard motor was acting really strange. Sometimes it would act like it wanted to start backwards, but most of the time it would kick in properly. However, when I throttled up it would wind up to about 2/3 and then just spin down and stop. At this point the ESC would often go through its beep sequence indicating it was booting up.

I had myself convinced the ESC had gone sour, but to be certain, I swapped the two ESCs; left to right and right to left. Same thing with the 'good' ESC.

OK, it must be the motor, but what the heck, let's go all the way. I pulled the starboard prop, cowling, etc to get at the motor and plugged the ESC directly into the motor, bypassing the extension wires provided by Great Planes.

Voila! Works perfectly!

How can the wires go bad? If they were shorting I would have smoked the ESC for sure, but it was OK. Out with my V.O.M. and sure enough, two of the wires register .4 Ohms resistance. The third was variable but the lowest I got was 54 Ohms. Checking found the female end (at the motor) had a bad solder joint and it had corroded and arced badly. Replaced the connector, put fresh heat shrink on it and now both motors wind up together like they did last year.

The symptoms were really confusing on the surface, but once I kicked into proper troubleshooting mode it was simple enough, and the repair was easy.
Dave Holmes

The older I get, the better I used to be!
Dave Holmes is offline   Quick reply to this message.

Sponsored Links - Subscribe to remove this ad.
Old 04-11-2012, 08:46 PM   #2
RCC Contributor
CdnFlyer's Avatar
I am: Bill s
Join Date: Jan 2004
Location: Hamilton, Ontario
Radio of choice:
Futaba 9CAP
# of RCs: 11

Feedback: 2 / 100%
Posts: 353
Total Props: 2
Re: Strange symptoms, simple solution

Way to go
Bill - Burlington Radio Control Modelers
MAAC - 47841L, IMAA - 31638, WMWA - CAN10
Married 42 years to a great wife who lets me go to the flying field and weekend events
I'm gonna have two more flights, but go home after the next one!!!!!
CdnFlyer is offline   Quick reply to this message.
Old 04-11-2012, 09:53 PM   #3
Level 3 Supporter
★ Site Supporter ★
Cougar429's Avatar
I am: Gary L
Join Date: Aug 2008
Location: Tecumseh, Ontario

Feedback: 72 / 100%
Posts: 5,256
Total Props: 30
Re: Strange symptoms, simple solution

Glad you finally found it. I've found many bad solder joints at the ESC/motor connectors and simply resolder them at the beginning just to be sure.
I know there's money in aviation........I put it there!
Cougar429 is offline   Quick reply to this message.

Quick Reply

Register Now

In order to be able to post messages on the RCCanada - Canada Radio Controlled Hobby Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Member names may only be composed of alpha-numeric characters. (A-Z and 0-9)

!!ATTENTION ADVERTISERS!! If you intend on advertising anything on this forum, whatsoever, you are required to first contact us here . Additionally, we do NOT allow BUSINESS NAMES unless you are an Authorized Vendor. If you own a business, and want to do sales on this site via posting or private message, you will need to follow the rules. Shops, Stores, Distributors, Group Buys without being authorized will see your account terminated.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Your Name
Your first name and last initial is required if you plan on using the forum.
Which city & province you live in. This is mandatory for classified listings.
Radio of choice?
Which radio is your current favorite to use?
Number of RC Vehicles?
How many boats, cars, planes do you own?


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
vBulletin Message

Thread Tools
Display Modes

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Strange servo behavior help / solution found JKovats General RC Aircraft Discussion 24 03-10-2012 04:26 PM
Plane strange with floats KaptainKrunch Float Planes 10 02-22-2010 08:44 PM
Strange charging question Warbird_ace Electronics 18 08-08-2006 07:23 AM
Strange Brew! 4REDave General RC Aircraft Discussion 11 01-29-2005 09:20 PM

All times are GMT -5. The time now is 01:51 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.