New Products Flash Sale
Thread Tools
Old Dec 25, 2012, 06:10 PM
chevronflyer is offline
Find More Posts by chevronflyer
"Takeoffs are optional"
chevronflyer's Avatar
United States, FL, Middleburg
Joined Feb 2007
657 Posts
t-rex 500 3gx question

I bought a used 500cf that has been converted to 3gx flybarless.

I have about a dozen flights on it so far but today i noticed something strange. the motor rpm started to surge. It was fluxuating 200 rpm or so up and down. it did that for two flights. On the third flight in normal throttle mode (non idle up) i lifted off into a hover, then as i went up with the power and collective the motor made a funny noise like it couldnt decide which way to run and i lost all head speed and she came down hard enough to break a gear.

when i strapped it to the bench and powered it up again to troubleshoot, i can throttle up slow and its all ok, but if i throttle up fast or go into idle up the motor stutters like it has a switching rate problem from the esc or something.

i have had a similar issue with an electric plane where i throttled up fast and it would stutter but slow it was fine, i changed out the crappy esc for a castle and problem went away.

I am using the align esc and motor in this heli, can i assume it is the esc in this scenerio as well, swap it for a castle ice 75 and problem solved?

anyone experience the same issue?
chevronflyer is offline Find More Posts by chevronflyer
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 26, 2012, 06:38 AM
abenn is offline
Find More Posts by abenn
Registered User
Letchworth, Great Britain (UK)
Joined Jul 2004
13,096 Posts
Not the same, but a similar issue with my 500. After a couple of years with the Align BL70G ESC (not the original) it started sort of stuttering from time to time. It was enough to cause the tail to flick about 3" sideways, then back, due to the momentary sudden loss of power, but first of all I thought it was a gyro or servo issue, and replaced them.

Then I realised the motor noise stopped momentarily every time this happened, so I put my original Align BL60G ESC back on, and it's been fine ever since.
abenn is offline Find More Posts by abenn
Reply With Quote

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold FBL T-rex 500, can sell 3GX seperate helifrek Aircraft - Electric - Helis (FS/W) 7 Jun 05, 2015 11:20 PM
Question How good is the Align T-Rex 500 Efl Pro 3Gx? Wa7sh Electric Heli Talk 7 Jul 24, 2012 09:29 PM
Off Site Align 3gx tool kit t-rex 450/500/600/700 helifreak592 Aircraft - Electric - Helis (FS/W) 0 Jun 03, 2012 03:18 AM
Sold Align t-rex 450 / 500 pro 3gx tool hz025 , het80001 helifreak592 Aircraft - Electric - Helis (FS/W) 0 Apr 11, 2012 09:37 PM
Sold Align t-rex 450/500/600/700 pro 3gx tool kit helifreak592 Aircraft - Electric - Helis (FS/W) 2 Mar 07, 2012 10:05 PM