Problem running 8917's straight off Microbeast?

[vanillagorilla]

I ask this on this forum because many of you run this setup on your 6hv...

After reading this thread: https://www.helifreak.com/showthread.php?t=261762 , I'm concerned that the MB is not sufficient to power my servos @ 7.4v - thoughts??

[John Cook]

I'm running them off Microbeast on 2s setup w/out seperate buss. Only have a couple flights so jury is still out. Eric Brandenburg is running same setup though and he's got 20+ hard flights on them and no issues so far.

[sarpilot]

Subscribed! Just about the same setup as you guys running off 2S RX pack. I'm interested to know what Eric thinks as well as others who have this setup....

[vanillagorilla]

Would it make a difference whether its off of a Rx pack vs BEC?

[sarpilot]

Originally Posted by vanillagorilla

Would it make a difference whether its off of a Rx pack vs BEC?

Not sure but hopefully one of these pros will respond... What initially put me off from BEC was I couldn't find one that would output correct voltage for the 8917's, only like 8.4 or something was the choice above 6 I think on the ones I found....

Then Tim I think it was said it would be ok using that even the servos don't care but I had already bought the receiver pack.... yada

I really like using a governor but the pros are saying just run flat curves so I am kind of disappointed ESC Hobbywing governor is like Align. Guess my first upgrade will be CC ESC etc so I will have castlelink etc....

[skunkworx]

Not really. If your BEC is providing enough current, it will power it equally. I've found that the battery doesn't get any lag compared to a BEC, but I think my servos were just too much for the unit I was trying it on. So far, the only they seem to be happy is to be straight off the battery. To say the least, my servos are abnormally power hungry.

For some background to my claim here, I have run my same servos in my Knight 3D off the RX (FB'd) and on my 6HV with BeastX. In addition to what is on my 6HV, the Knight had to power a 5th servo, a governor, plus a switch-glow unit -- all without a single hitch in any of the flights I ever took it up for. When I switched it over to the 6HV, I never got any funny glitches or brown-outs due to power issues. I fly pretty hard/fast and I have my rates set up to fully tax the entire heli (I can bog the snot out of it if I'm not careful) and I've yet to do anything to it that shuts it down or gets my servos hot.

Admittedly, a 600 class won't draw as much as a 700 class will. I've seen literally dozens of pilots that run the same setup that I have and have had no issues, even on a 700 size machine. There is a lot of speculation about power busses and why things fail, but you also have to consider the fact that it's a mass produced item. It could have failed on the one particular unit that the reporting party had and it raises the doubt that it is sufficient enough to work even though it may just be a freak accident/failure.

For instance; I run a 6100 on my 500 class machine and have done so for years. But if you talk to like 98% of 500 class owners, they all run a 6200 or bigger because they heard that their buddy heard from another guy that his brother crashed because he used a 6100 on his machine. The evidence just isn't there to back up their claims that it's unreliable.

I know for a fact that my (8717) servos draw a LOT harder than most other servos out there because I have yet to find a BEC that has the gumption to keep the servos moving properly under load like running straight off 2S. So if they are pulling that hard and they are functioning 100% with the MBX the way it is designed and set up to run out of the box, I seriously doubt that it is anything to worry about. Maybe that's just me, but I typically tend to become a bit of a mythbuster with my equipment becuase by all conventional knowledge, my machines should light on fire or disintegrate every time they take off.

[vanillagorilla]

Originally Posted by sarpilot

Not sure but hopefully one of these pros will respond... What initially put me off from BEC was I couldn't find one that would output correct voltage for the 8917's, only like 8.4 or something was the choice above 6 I think on the ones I found....
.

I'm still waiting to get the castle link on my Pro BEC, but I'm pretty sure you can select any voltage from 5 to 12 volts at .1 increments....I could be wrong but will know shortly. My plan was to just run the servos at 7.4v

Will it harm anything to do setup/even test hover, with 5.1v (factory voltage setting) on HV servos? Or will it just slow them down a bit?

[John Cook]

Originally Posted by sarpilot

I really like using a governor but the pros are saying just run flat curves so I am kind of disappointed ESC Hobbywing governor is like Align. Guess my first upgrade will be CC ESC etc so I will have castlelink etc....

the hobbywing is a decent esc for the price, and while better escs could have been included in the kit I'm sure, the price would reflect that, and sales I'm guessing wouldn't have compensated. On E helis I don't really see a need to run a governor. Flat throttle curves do a good job of regulating head speed. Govs might make the head speed more consistent, but they also present challenges as well, and seem to me "skippy" and can influence the tail on helis if not setup proper. Maybe the CC gov is alot better now, but the last time I tried it I wasn't impressed. They do have a great soft start though, and plenty of tweaking options in the usb/castle link software. I just worry about the reports of random failures and esc fires . Maybe those are over-reported, but scarey non-the-less.

[sarpilot]

Originally Posted by vanillagorilla

I'm still waiting to get the castle link on my Pro BEC, but I'm pretty sure you can select any voltage from 5 to 12 volts at .1 increments....I could be wrong but will know shortly. My plan was to just run the servos at 7.4v

Will it harm anything to do setup/even test hover, with 5.1v (factory voltage setting) on HV servos? Or will it just slow them down a bit?

Ya Castle you can pretty much do anything with proper gearing.... stock ESC I reserve comment until some flight tests......

[Eric Brandenburg]

I just read through the thread in the link of the OP, here is the score. The Microbeast can run up to 8.5V without issues, and everything is rated for it so no worries there. What they are talking about with HV servo's is the current draw that some servo's can create (8717 or 8917 for example). Under hard flight loads some servo's are capable of drawing near 3A.

The concern is whether or not the microbeast was designed with high current traces in the boards, and whether or not it can withstand long term current flow. In my opinion it's probably just CYA for the beastx guys. I have not heard of any issues where people are frying the boards due to running high powered servo's so I think it is more misleading than helpful. The same was said of the mini Vbar not being able to withstand the current draw of high power servo's in larger airframes, and today that has been proven false with experience.

For more info on this type of subject my friend Carlo (designer of the famed ProBar) found a Spektrum receiver that had the issue in question and would cause things to fail http://rc.runryder.com/helicopter/t5...ghlight=traces

[Eric Brandenburg]

With regard to the battery vs BEC question the bec is much more convenient, however I have never had any heli with a bec that never had the bec go bad, except on something like a 450. Battery all the way, you will never over current it and shut it down.

I have seen a few people complaining on the stock ESC not having a good gov. I'll make a post in the near future detailing how to set the stock esc up with an external governor to have better than Kontronic performance at under Castle pricing.

Having a god governor built into the esc nowadays no longer matters IMO. As long as it is quality and won't burst into flames that is what matters. All you need is a very linear throttle output. Once you get to that point, the cheapest esc wins as they will all perform the same(as good as the gov managing them).

[sarpilot]

Originally Posted by Eric Brandenburg

I just read through the thread in the link of the OP, here is the score. The Microbeast can run up to 8.5V without issues, and everything is rated for it so no worries there. What they are talking about with HV servo's is the current draw that some servo's can create (8717 or 8917 for example). Under hard flight loads some servo's are capable of drawing near 3A.

The concern is whether or not the microbeast was designed with high current traces in the boards, and whether or not it can withstand long term current flow. In my opinion it's probably just CYA for the beastx guys. I have not heard of any issues where people are frying the boards due to running high powered servo's so I think it is more misleading than helpful. The same was said of the mini Vbar not being able to withstand the current draw of high power servo's in larger airframes, and today that has been proven false with experience.

For more info on this type of subject my friend Carlo (designer of the famed ProBar) found a Spektrum receiver that had the issue in question and would cause things to fail http://rc.runryder.com/helicopter/t5...ghlight=traces

Eric is your setup still good off 2S with the 8917's? Wanna start stretching this thing out some but the microbeast board guys have me scared to death... chop wires here, splice wires there, yada. I've got like maybe 40 flights on mine now just circuits straight off 2S with no issues.....

[John Cook]

his is still good. We were just flying yesterday and my 6HV is setup identical to his, cept the nut behind the sticks on mine is pretty loose lol.

[sarpilot]

Originally Posted by John Cook

his is still good. We were just flying yesterday and my 6HV is setup identical to his, cept the nut behind the sticks on mine is pretty loose lol.

TY... they are in panic mode on the MB thread.... Look at some of the wiring diagrams on the "HV setup" thread.... I am like wtf?

I know enough about complicated electronics to electrocute myself.....

[John Cook]

yeah lol

also, even more demanding on the Beast X would be my FBL 3D+.

it's a direct 2S setup to the Beast X unit. I did however use 2 servo leads for power from my battery plus another to the Rx just to share the load ONTO the buss. But once power is on the Buss, then it's all the same IMO. My 3d+ has 8917's on cyclic, Align DS620 on throttle and Outrage 9088 on tail. Plus an ATGv3 gov, but I guess that's through the Futaba RX.

Oh well, I'm not sweating it. Look at Eric spank my 3d+ FBL; taking care of stinky like a 50cent SKANK!!!!
[ame]http://www.youtube.com/watch?v=gKYxTJKWPLE&feature=player_embedded[/ame]

[sarpilot]

As always great flying from Eric... wish I had the nerve to do a takeoff like that...
I'm gonna do the same with mine as I have some servo extensions coming dual bus 2S lipo one feed to the rx one to the beast. I'm gonna post my idea on the mb thread see what they say to that, they are all talking about "bottlenecks" and all that. Hey 2 separate feeds to a common bus how can it "bottleneck"? It either can handle 2S lipo or it cannot. they are all like, do this and stuff and I am but are there any documented failures not doing this seperate cyclic feed job and all you could hear in the backround were crickets.

Like your sig by the way... From Chicago born and raised.....

Best regards,
Tom