Loss of power and steering

[topperj]

Hi

When running my Associated RC8e I constantly get problems with steering and throttle response after about 6 - 7 minutes of runnning. :cry:

It comes and goes.

I'm running the Mtroniks G2 Beast ESC and P2 Beast brushless motor 3000kv; 2x2s Reedy 4900 Lipos.

Any ideas why it's happening.

I've added a fan to the motor to help keep it cool.

Help?

[DCM]

What radio you running, and after 6-7 mins, what is the voltage of your two packs combined?

[topperj]

Spektrum DX3.0

Haven't tested the voltage although I did replace Reedy Lipos with some newly charged Lipos and only managed 1 minute until it started happening again.

[Rcrcrus]

I found the same problem the last sunday setting up a d8t with a new savox servo. I remember having the problem in my 1/10 a while ago.
The servo is taking to much power from the reciever and it is sesetting itself. I pluged in a spektrum regulator and it solved the it straight away.

[DCM]

Spektrum DX3.0

Haven't tested the voltage although I did replace Reedy Lipos with some newly charged Lipos and only managed 1 minute until it started happening again.

It sounds like your Spektrum receiver is shutting down, you need to either run a power cap on the receiver or use a receiver pack.

[topperj]

Receiver pack I understand :D

What's a Power Cap :confused:

[topperj]

Just worked out what a Power Cap is. I already have one fitted.

[lgbzone]

I had a similar problem when i put a savox 1256 in my vorza, except it was worse, the MMM only supplies 5.4 volts to the receiver. a power cap in the receiver helped but didn't totally cure it, so i wired a CC BEC to the esc to supply the receiver with a constant 6 volts, now it's sorted.

[Demon]

hey bud,
As has been identified, when the pack starts to lose power under load the esc's BEC cant provide enough juice to your receiver to power your servo's. You can either remedy this by powering them by an external UBEC or a receiver pack... Capacitors only work if you lose power when you are nailing the throttle (and is a sign of the batteries not being able to provide enough current... i.e, too low C rating).

Hope that helps,
Demon

[ch!3f]

hey bud,
As has been identified, when the pack starts to lose power under load the esc's BEC cant provide enough juice to your receiver to power your servo's. You can either remedy this by powering them by an external UBEC or a receiver pack... Capacitors only work if you lose power when you are nailing the throttle (and is a sign of the batteries not being able to provide enough current... i.e, too low C rating).

Hope that helps,
Demon
this is when you esc draws too much power this cuts the power to the reciever nothing to do with the batteries a power cap basicly helps keep the current to the receiver at the same level as to what it needs!ive had this problem and if you need 1 pm me as a i have a few spare 1s £3 posted and there to the same standard as the spektrum 1s.

[Demon]

hey Chi3f, I beleive it has everything to do with the batteries -under load, if the batteries cannot supply sufficient current, you get a voltage drop in the pack and thus insufficient voltage to the servo's if thei are powered by the BEC on the esc. Running a power cap will as you say help as it will discharge when the battery is unable to provide all the juice the system needs (its an extremely low resistance energy source). either way, your best bet is to try a power cap (and be careful there are 2 different locations you can install them, one on the battery input wires (this has the same effect as increasing the burst C rating of the pack) or onto the receiver itself which will help smooth current fluctuations during high demand situations... I personally use both... :thumbsup:

Take care,
Demon

[jasonwipf]

Ya if your running a spectrum receiver that is a known issue. Just rebind it and it goes away. It may come back after awhile and if it does just keep rebinding but ultimately you may need to send it back. I had 2 of my 6 receivers do it and they sent me new ones for free.

[topperj]

Thanks guys.

I fitted a BEC which wasn't strong enough, so then bought a better one (having got some far better advice).

Problem then was first BEC blew my Spektrum Servo so have now fitted a Savox SC1256 in place.

Rebinding has also been complete.

It works when bashing on the street, the big challenge will come when I get it back on the track this weekend.

Who said electric was simply "plug and play"

[lgbzone]

It's not because of the main battery pack powering the esc and motor, it's due to the rubbish bec in the esc, even when the main batteries have hit the cutoff they would have more than enough power to run the receiver and servo.

the specifications of the G2 Beast ESC state the bec output is 1.5 amp, nowhere near enough for reliable use. the bec delivers a certain amount of current to the receiver to power the receiver and servo, if the servo tries to draw more current than the bec can supply, the voltage to the receiver drops and the receiver turns off (once a very low voltage is reached about 3.5).

topperj;

Glad you're having some success.

if your new bec supports adjusting the output voltage, set it to 6 volts, lower could hinder performance, and higher will reduce the life of the servo.

cheers