ESC and BEC questions

[Bob O]

Looks like I'll be using the Koby 40 with the built-in BEC. 3A continous with 10A burst capability. If it's good enough for David K. and others, it's more than good enough for me.

Looks like it's Ramen noodles for a while.

[GimpyGolden]

Can always use an Rx Cap if you find you have Voltage issues.

[Rob43]

Fromeco DC-UP Mark 2 has worked well for me using 8717's and 8900 on my 7HV. Two seasons thus far, and one avoided crash from it's protection (not BEC failure, but cell connection failure inside of pack). Small (25mmx 69mm), and light weight at 17g. Much more capacitance than many other devices at 1.25 farads (not micro farads). Simply connected to an available port on the receiver bus.

[Bob O]

That gadget looks cool, Rob.

Is this item from Spektrum the same thing?

http://www.horizonhobby.com/products...tor-SPM1600#t2

[Rob43]

Very same type of a safeguard without the fancy little display. However, the capacitance of the Spektrum device looks to be 1700 microfarads if I read the label correctly. The Fromeco device has a 735 times that amount of capacitance. I suspect the Spektrum decvice would protect against brown out and prevent a reset crash. If the BEC stopped working, or intiated a power down sequence, it wouldn't have enough to aid in a safe landing. I don't know enough about the Jive BEC to know what happens when it's overloaded. Presumably it comes back lightning quick, and you'd not know it if using either device. I'd be tempted to try the Spektrum device on a micro sized heli like the Warp. If there is room for the Fromeco on the Warp, it has enough to have a chance at a safe landing in a complete loss of power.

I am about the least knowledgable on such things though. Caviat emptor! Hahahha.

[Luigi_tuga]

Nop.
It's a 4700 cap.
But a cap doesn't accumulates enough power to keep servos working. It's there to filter a power downspike that has a duration of ms and keep the voltage level, wich will keep your rx working.

[GimpyGolden]

I was referring to the one Bob posted. The DCUP is a little big for the amount of real estate on a Warp.

As Luigi states it isn't a fail safe or buffer, just there to smooth out BEC Voltage.
I use them on RC Cars with power hungry servo's like Savox.
Without one I've had BEC shutdowns and cogging on start up due to compromised Throttle signal when Rx browns out.

[Coco66]

The Spektrum specs clearly states "This Voltage Protector is not intended for Aircraft use".

[GimpyGolden]

Can't see why not.
If my 92A+'s give me trouble I'll be using one.

[r1sportbike]

Originally Posted by almostRetired

Is the Kobby 55 overkill for the Warp 360 using MKS DS92A cyclic and MKS DS95i tail?

Would the Koby 40 be a better fit?

Thanks

I have the Koby 40 on my Warp with MKS 92a+ and a MKS 8910a for tail. Everything is very happy.

[Bob O]

Originally Posted by r1sportbike

I have the Koby 40 on my Warp with MKS 92a+ and a MKS 8910a for tail. Everything is very happy.

Oh yeah, that's what I like to hear!

[GimpyGolden]

Me too.

[Rob43]

That will be my setup too. I saw the other post on delivery delay.

[RCNet]

The Koby user manual suggests that you should use a buffer/battery pack in parallel with the BEC.

Do you use (or plan to use) a buffer pack with your Koby, or do you take the E in BEC literally?

[GimpyGolden]

I use a buffer on 700 size for safety, all my other sizes I run and trust the K BEC.
Never an issue, even ran a Logo 500 with an old Jazz 80 BEC (3A)

[Bob O]

Originally Posted by RCNet

The Koby user manual suggests that you should use a buffer/battery pack in parallel with the BEC.

Do you use (or plan to use) a buffer pack with your Koby, or do you take the E in BEC literally?

I don't plan on using a buffer pack. The default BEC voltage is 5.6V, and I'm going to leave it at that based upon the following from the manual:

"For BEC voltages exceeding 5.6V a redundant
receiver current supply should be connected."

and this:

Originally Posted by Caleb White

YGE 40, yes, using internal BEC, 5.5V. Just get a good ESC and have a governor and BEC all in one package.

[Luvmyhelis]

One thing to think about here. I spent hours chatting with Thomas at MKS USA just a few weeks ago, and he emotionally emphasized that with either the MKS Ds95s that I run and the newer 92a that one should run a Bec with a 10 capability. As these servos can easily overcome the safety net these lower than 10a bec's can provide. Even if the bec is rated in bursts up to 10a it is not enough. Also when most bec's fail they allow full voltage through the entire power circuit. So if you are running 6s, guess what?

Lots of guys (including me) have smoked 5.5a bec's running them on expensive esc's. I lost one recently on the bench setting up a new Sk720. I was leveling the swash and it smoked all four of my servos and the esc caught on fire. It also took out my Sk720. Not good.

And for those who claim the Yep, Yge, CC Ice50 or lite bec is good enough? Think again. Even though I got by with it for a year earlier with MksDs95s the esc's seem to be hit and miss on quality on every single production esc in existence. One smokes, and 6 others work fine. Err on the side of caution here!

I also paid the supreme price with another set of new MksDs95s when another one of the listed esc's bec's went up last month. The ensuing fire totaled one of my new prototype one off helis. Which is why I am now here buying a new version to replace it. And replacing 7 expensive MksDs95 servos, plus an Sk720.

Thomas basically said this. One of their biggest issues is seeing lots and lots of smoked servos that are coming back from onboard esc bec failures. In fact, this may be their largest area of servo failures. And, quote: If there is any way possible, please run a separate battery pack for the electronics. If that isn't possible, run a minimum of a separate 10a bec: Unquote. We went on to discuss the issues with doing this in the 450 class with separate batt packs.
Due to his advice I now run a Probec on one of my 450s (inside mounted) and on the new Warp I am going to use a Western Robotics Hercules for it in 12s config. Overkill? Not if you have faced the losses I have this last month!

A year ago if you had asked me about running the built in bec's I would have been on the bandwagon. Not anymore.

[r1sportbike]

Originally Posted by RCNet

The Koby user manual suggests that you should use a buffer/battery pack in parallel with the BEC.

Do you use (or plan to use) a buffer pack with your Koby, or do you take the E in BEC literally?

No buffer pack and no issues. I would never put a buffer pack on a 450.

[OICU812]

You do NOT need a buffer pack on the Koby or Jazz 40,55 etc, you can safely run 6Volts as well ZERO issues. Know that you need program disc to do all the inner expert settings, which honestly you dont need to do or tweak either for a 450. Set for mode 4 and be done with it.

[RCNet]

Thanks for the good feedback and opinions on BECs/buffer packs. As you can see by my signature, I'm still just playing with BnF Micros but seriously considering moving up to something bigger and better. There is just so much to learn/consider, but I do know the Warp is on my short list.