ESC - servos
 

Hey, guys,

I would like to hear an opinion of those who is familiar with the electric RC equipment.

I bought a Mistery 40 ESC with BEC output 5.5V (http://www.hobbyking.com/hobbyking/s...r_(Blue_Series). I am planning to install it on a 450 size helicopter. One of the servos I am going to use has an operating voltage of 5 V.

My question is: will I burn that servo or 0.5 V difference is negligible?

Thank you in advance for your input.

AKM=47

Re: ESC - servos
 

All electronic components have a manufacturing tolerance. All electronic devices have a tolerance.

As components are assembled into a device, there will be a "tolerance stack", of all the components that go into it. Some on the high side, some on the low side. A manufacturer will set the minimums/maximums based on how that device is likely to fail. This can be either an average, high-end weighting or low-end weighting of the tolerance stack.

In the case of setting a 5.0V limit on the servo, the manufacturer set this limit based on a tolerance stack of components that are all on low end. A servo built using components whose tolerance all come in on the high end could probably withstand higher voltage, but there is no way to know for sure.

You can press your luck and try it- if you have one that has all its electronic components on the high end, you can get away with it. If you have one on the low end, it will fail. There is no way to know unless you try. Is it worth the risk? It might be easier to just get another servo that can handle the higher voltage and not worry about it.

Re: ESC - servos
 

Thanks, Max,

After I posted my question, I went through my stuff in the basement, and found a 30A ESC with output voltage of 5 V. So, I think I will go with that one.

AKM

Re: ESC - servos
 

Have some experience with both the Mystery ESC and 450's.

The one Mystery 30A I had, (in a King 2) went poop, dumping full pack voltage into my 149DP and killing it. Got the pack uplugged, put the heli on the build bench and with the receiver out of the picture powered it back up to do a voltmeter test on the ESC leads. Just as the reading showed the output voltage the ESC literally exploded in front of me, chucking components across the table.

The burn scars are still there, a testament to my commitment to NEVER buy anything Mystery again.

To confirm that opinion, some Mystery 9g servos I accidentally bought along with the ESC, supposedly direct copies of the SG90, were the final proof. Besides the fact they ran backwards the geartrain sounds like a pail of rocks. Tried one anyway and found the servo centering all over the place. Took it apart to see the pot had come loose, the hot glue failing to hold it in place any longer.

As for 450, you should look at no lower capacity than 40A for a heli that size.

Re: ESC - servos
 

I new to the whole rc hobby. But that said I am trying to build a 2 cell Walkera 4#6. The problem is the RX can only handle the voltage of one cell.....5 volts is to much. Is there a device to cut the voltage down to the one cell level for just the RX. Or is there a way to send 2cells to the motor send 1 cell to RX.

Re: ESC - servos
 

Your speed control could have what is called the Battery Eliminator Circuit, (BEC) integral to it, meaning it already cuts the 2S or 3S voltage down to the 4.5-6V you radio system should work with and feeds it to the receiver through the lead you plug into the throttle channel.

Re: ESC - servos
 

I am aware of the BEC but the RX for the Walkera 4#6 can not the 5 volts that most BEC send. I am looking a "voltage divider" ........It think thats what it is called.

Re: ESC - servos
 

You may have to do some searching. The Castle 10A BEC I just sold would only go down to 4.8V and the Maxx Products ACC135 I mounted in the T600 would only go as low as 5V.

Don't know of any production gear that would get you down to the 1S voltage. One other option would be to tie the radio into only 1 of the 2 cells through the balance plug, but have never tried anything like that myself.

Are the rest of the components capable of handling the higher voltage?

Re: ESC - servos
 

Tie the RX in through the balance plug hmmm... where can I find instructions I might what to try this.

I just found this also.

http://www.heli-service-nordost.de/s...nterface(49131)
http://www.heli-service-nordost.de/s...ung%20SAVA.pdf

Thanks you from taking the time to humour a newbie Cougar.
Nate

Re: ESC - servos
 

Sounds like it's custom made for your requirements. Hope you can find one.