High voltage

[Greg Jackson]

I have been running my E5 with the components listed in my signature for a little over a year now and it has been great. But I'm sure the BEC is set to 6 or around that.  If I adjusted that to 8.4v for a high voltage set up, would I have better run times (longer flight, cooler temps), noticeably higher performance, and would I need to change settings such as gain? I'm happy how it is flying now and do not have a pressing need to change it, but just wanted to know.  If the risks are greater it isn't worth it to me.

[flyalan]

I have never run the BLS 255/256's on anything lower than 7.4V.  They will definitely be quicker on 7.4 or 8.2.  Are you having overheating problems with them now?  If not other than the actual servo speed there would be no difference.  Upping the voltage will likely make the E5 a bit more responsive.  You may need to tweak agility setting as a result.

Cheers

Alan

[Greg Jackson]

Awesome. I turned up the agility setting a month ago, maybe turn it down a little until i see what it feels like on a higher voltage. 

[curmudgeon]

According to Thomas (the MKS guy), running HV servos continuously at 8.4V tends to shorten the servos' useful life.  He explained to me that running the HV servos on a 2S LiPo is OK because the LiPo's voltage drops and does not stay at 8.4V.  He recommended that I set the BEC to output less than 8.4V.

[Greg Jackson]

Great, I will set it at 7.4 to be safe.  I will laugh if I see I already did this, but I'm pretty sure I bumped it up from 5.5 to 6 last summer.

[Greg Jackson]

This must be a joke.  I checked my BEC and I did have it set to 7.5 so I am good with that.  But I decided to check on any updates and there were for the Ice 120HV.  Took care of that and then went through my settings.  I remembered lowering the HS a little after the 3D flight school.  My max headspeed in IU2 was 2100!!!  A lot of times I flew in IU1 so that was probably around 2000.  I couldn't believe it.  Then I remembered wanting to work on some technique with lower headspeeds to become smoother.  But I didn't think I went that low.  Bumped things up to have a max headspeed of 2350.  Can't wait to fly tomorrow after having really low headspeeds for 4 months!!!  I have a new build I'm starting next week so it will be nice feeling the the difference with the E5, it will be like a new heli because I upped the agility a few weeks ago.  So more agility with the increased headspeeds should wake up the bird. I knew I saw a slight wag, thought it was the wind but it was from having the headspeed so low with gain settings from the higher HS. Can't believe I was flying like that!

[chrismechanic]

hi inner3,
             what size motor pinion are you running?
im getting 2100 gov max on my setup with ice 100 at 93% throttle on a 12t pinion.
chris.

[Greg Jackson]

I am running the stock recommended pinion, didn't want to change the gearing for the tail.  You can safely get castle readings up to 108%, even though it will say that is too fast for proper governing.  I have 2350 HS with a reading of 106% I believe running a flat 100 throttle curve in the transmitter.  Then for IU1 I think I have it at 2215. 

[chrismechanic]

Thanks inner3,
                         I didn't know you could do that, I'll have to try it.
Chris.

[Greg Jackson]

Also lowered my timing (efficiency) a couple of notches, will see what it's like tomorrow or Monday.  It is working well on another heli and my motor is cooler and flight times are longer. 

[chrismechanic]

id like to hear back on that one inner3.
thanks,
chris

[Greg Jackson]

The heli flew like it did before.  I think my flight times might have been longer, need more testing to know for sure, but the motor was a little cooler.  Scorpion motors always seem pretty hot.