I was running an ice 100 on my trex 550 with a bec pro.... now running a 120 on my 570 with an external bec

 

Castle talon 90 works fine on mine built in 20a bec aswell

 

I like the YEP ESC's, but I've had one 80A fail on a 500 (500MX). The 80A should be alright with that motor, but personally I'd use a 100A or higher.

 

I have a YGE 90LV on mine, I think they YEP is a clone of that ESC, I should say my X5 but same basic size, mine might be a touch lighter?

Did the kit really come with a 70A as stock?

 

I have a CC Talon 90 on mine as well. Seems to be holding up fine so far, after many many flights.

 

The specification of the 600mx 510kv motor is as follows (check your kv rating)

●Input voltage 11.1V-50.4V
●Max continuous current:75A/125A(5sec)
●Max output power:3300W/5500W(5sec)
●KV value:510KV

And the Specification for the YEP 80A is

Max Cont Current: 80AMax Burst Current: 100A for 10 seconds
Input Voltage: 2-6 cells li-XX or 6-16 Ni-MH/Ni-Cd batteryBEC: 5.5V/6A Switching BECPWM: 8~16 KHz
Max RPM: 240,000rpm for 2 Poles Brushless Motor
PCB Size: 50x30mmWeight: 70g (including wires)

Based on the above, the maximum burst of the YEP is not enough or right on the limit to supply the 600MX if your pushing the motor to its limits. It is able to manage the continuous current but if you really slammed the hell out of your heli - ie permitting continuous tick tocks, you may exceed the maximum continuous current rating (BURST). If it were me, based on the above - i would buy another speedy.

 

Yes @Geena, I have a Talon in my 550 as well. They seem to run good.

 

The 1220 Kv is even a little more amp hungry...

Specifications:

• Input voltageC11.1V-25.2V 3-6cell Li-Poly

• Max continuous current:90A/150A(5sec)

• Max output power:2000W/3000W(5sec)

• KV value:1220KV

• Dimension: spindle Φ6xΦ45x53mm

• Weight: 280g (prox.)

 

The original ESC in the 550 was the 60A ESC with a bigger heat sink that they called the 70A. The motor was a 600M. Later they changed the motor to the 600MX, however the ESC remained. Then they switched to the Talon 90A with the 600MX, and more recently the 730MX. If you look at the 730MX specs the Talon is underrated, as well, but many are using it without problems.

 

Yeah Align is notorious for using under rated ESC in the super combos...

 

Thanks for everyone's replies. I've decided to go for a 100A. My auto'ing skills aren't good enough to take the risk.