esc

The new “Favorite” FVT LittleBee 20a arrived into the HacksMods lab. So it’s time to take some clear shots of them and compare with the Flyduino KISS ESC. Which is still one of the highest performing multirotor electronic speed controller. The small size and light weight are great for putting on racing quads. Or burying inside heavier aerial photography equipped quadcopters, or “drones” as the media likes to call it.

In the USA, the Little Bee 20a are known as the MRM Zeus 20. Brian (punkindrublik on RCGroups) of  MultiRotorMania help finance and brought these new ESC to market. So they secured the rights as the sole distributor in the USA. However, the ESC should soon be available from some of your favorite multi rotor online stores.

Continuing in the same small by mighty form factor that the Flyduino KISS ESC brought to market, the FVT LittleBee 20 are about the same size. 12.5mm x 23mm x 3mm. Versus the KISS (v1.1) 12mm x 24mm x 3.81mm

What makes these new FVT LittleBee the current popular ESC is that recent test are showing them to perform similar to the KISS ESC. (Here’s one by QuadMcFly) This is in part due to the use of the SilLab F330 MCU. Which has a faster clock speed than the popular ATMEL chip used on most competing ESC. Add to that dedicated FET drivers and it’s performing quite well. This is what BLHeli creator Steffen has to say about it:

Then there is a very promising little ESC, the FVT Littlebee 20A:

This ESC has a good design with fast dedicated driver chips, which gives excellent freewheeling and exceptional braking.

Initial stress testing on 4S with a Cobra 2208/2000 with 6×4.5 prop, doing repetitive immediate accelerations from low rpm to full throttle went well.
During the initial acceleration, this setup pulls about 100A, so it’s a tough test for a small ESC (and can break other small ESCs).
Hopefully this indicates that the ESC will prove to be a reliable performer.

And so far, this is the closest performer to KISS that I have seen in this size.

Very clean layout and manufacturing placement of components on the PCB. Definitely KISS quality for sure. It seems like they used higher temp lead free solder. My Metcal MX500 soldering station usually makes quick work with lead free solder. But I admit, it took a split second longer with the solder joints on these Little Bee 20. This may be to prevent overheated MOSFET from desoldering itself like what appears the DYS SN20a are doing in some of the recent batches. Also, keep in mind that having to flow the solder at a higher temp usually slows down the manufacturing process. This, along with how clean the ESC looks and components are laid out…continue to signify a high level of quality control. So kudos to Favorite and MultiRotorMania.

Weight of the FVT LittleBee 20a as it came out of the package is 6.73g.

Weight of the FVT LittleBee 20a without heatshrink and wires is 2.12g. I know some of you guys want to know things like this. I know as a hobbyist, I do. So very similar to the KISS 18a which I weighed here. And about .70 grams heavier than the ZTW Spider 18a Opto Lite.

Signal wire polarity in case someone needs this info in the future. (That’s would usually be me.)

I have a few new frames I’d like to use these LittleBee on. Can’t wait to see them fly.

Some of my favorite places to buy from that carries these FVT LittleBee/MRM Zeus 20:
USA
MultiRotorMania: MRM Zeus 20 Amp ESC
BangGood: FVT LittleBee 20 Amp ESC

Australia
ImpulseRC: FVT LITTLEBEE 20A ESC
BoltRC: Little Bee 20A ESC

China
BangGood: FVT LittleBee 20 Amp ESC
MyRCMart: RCX 20A (Little Bee) Mini BLHeli Multirotor ESC

Europe
MultirotorParts: Favourite Littlebee 20A
Supreme FPV: Littlebee 20a esc 2-4s

More info can be found on RC Groups discussion thread:
Little Bee and MRM Zeus 20AMP ESC’s

With DYS/RCTimer SN20a and BL20a possibly having a bad manufacturing batch. Plus, you lose about 10% thrust versus competiting ESC. One of the new ESC some of us have started buying instead are the ZTW Spider 18a Opto Lite as some retailers are calling them. Performance seems good so far. We’ll learn how their fare in crashes and general abuse as more and more people use them and report back.

The BLHeli firmware to use are BS12a or BS20a. either hex will work fine according to sskaug (Steffen), BLHeli creator.

Mine came with the SimonK bootloader. And I was able to use my USBASP to flash BLHeli bootloader on there. Here are the ISP pad locations for your reference:

Weight as they come out of the package. I took off the heatshrink and it was about .2g lighter.

Heatshrink is thin, clear and shiny. Same types they use on many battery packs.

Weight of the naked ESC.

Here’s a shot of the ZTW Spider Lite on the far right. Next to it is the new KISS 30a. And to the far left, is the KISS 18a.

Picture of the MOSFETs and a peek at the soldering. I don’t see any left over solder splashes/balls.

KISS 18a on the left. ZTW Spider 18a Lite on the right side.

Side by side with the KISS 18a v1.1. Which is simply about 1mm longer than KISS 18a v1.0. You can see that the ZTW Spider 18a is slight shorter. And also thinner.

A look at the opposite side.

Here’s the Spider 18a Lite mounted in the lower plate of the Aura 250 FPV quad.

And a couple of closing shots of the Aura 250.

I modified the top plate so I can slide in a 4S 1400mAh lipo pack.
The links below are my favorite places to buy:

USA 

Readytoflyquad: 18a Spider Lite Series ESC
MassiveRC: MassiveRC OneShot125 18a ESC

China
BangGood : ZTW Spider Series 18A Lite

I got the new RCTimer SN20a ESC in today. These are the new crop of ultralight and small ESC, using the latest MOSFET tech. It all started with Flyduino’s KISS ESC.

The first thing I did was desolder all the wires. Then gave it a quick inspection. Follow by some photographs of them sidebyside with the KISS 12A ESC v1 I have.

The KISS are supposely 12mm by 23mm. I measured with my digital calipers at 12.25mm by 23mm. While the SN20a measured at 11.94mm by 23.33mm.

So they are both roughly the same size. However, keep in mind that the latest KISS v1.1 have larger pads so they gain about 1mm in length. It’s nice to see that the SN20a ESC comes with larger pads by default.

The other pluses for the SN20a is that all the wires come presoldered and the ESC heatshrunk. And best of all, the 20A are less than $12 in qty of 3 or more!!!

Runs BLHeli with dampening and OneShot capabilities.

And near identical in weight as well…

And thanks to Zachary, he pointed me to the pinout someone shared on RCGroups.

Discussion Thread:
RCGroups thread: RCTimer / DYS Mini SN20a esc

For flashing…I suggest getting an Arduino Nano. You can use BLHeli Suite to program it into a 4 interface flashing toolstick. This will allow you to flash SN20a ESC with either SimonK or BLHeli bootloader as well as other things. This makes it the most versatile toolstick…and least expensive too at < $4 shipped from the USA warehouse. I’d grab a 3pack or 5pack just to have extra. For friends or other projects that require the Arduino. ;)
The links below are my favorite places to buy:

USA 

BangGood USA Warehouse: DYS SN20A with BLHeli Mini 20A SimonK ESC OPTO
MassiveRC: SN20A OneShot125 20A ESC

Canada
Armattan (blheli pre-flashed) http://www.armattanminis.ca/armattan-20a-opto-esc/

China
BangGood : Rctimer OPTO mini 20A Brushless ESC SimonK 2-4S for RC Multicopter
RcTimer : http://www.rctimer.com/product-1280.html

**Update 2015-07-28** DYS rep recommend updating to BLHeli 14 to avoid any issue of burnt ESC.

Lovely spring weather means I am antsy to build and fly again. I am planning on using this Hobby King HKing 10a brushless ESC in a 230mm size acro quad. Not sure if it will be able to endure SunnySky 2204 2300kv with 3s lipo but I like the physical size…so I will give it a try anyways.

Anyways, the dimensions on Hobby King is incorrect (23mm x 18mm). Here are the actual values as measured with the digital caliper. The bare ESC as pictured weighs 2.59g.

It arrived with 20guage silicone wires for the main power. And 22gauge silicone wires for the motor leads.

Missing from the photo is the electrolytic capacitor (100uf 16v). I took it off so I can use a tantalum SMD capacitor with the same values. It’s much smaller physically. Hopefully it works out. :)

What I like about this ESC is the fact that it’s BLHeli compatible. Plus, it uses all N-channel MOSFET. And it was reasonably inexpensive at $5.78. Here’s an inexpensive BLHeli programmer, and another another. You will need one of these for flashing the firmware or updating the parameters of the ESC using the BLHeli Suite software. Unless you already have an official SilLabs Toolstick. Then you can follow this guide for modding it for the same function.

This is part 1 of my series on the Blade mSR X Brushless Conversion using Steffen’s BLHeli firmware for the XP 3A ESC. The information in this post is also applicable for those of you doing a brushless conversion on the Blade mCP X and will be flashing the XP 7A and XP 12A ESC. All those ESC, along with the DP 3A and Supermicro 3.5A uses a Silicon Labs based chip, so you will need to do the following modification.

Step 1: Obtain the SiLabs USB Toolstick:

The USB Toolstick can be purchased from Digi-Key or from Silicon Labs themselves. Digi-Key ships it out fast and there was no order minimum.

Step 2: Open the USB Toolstick:

Using a guitar pick or a folded over piece of plastic from toys/food packaging, you can insert between the halves like so and twist to pop the halves apart. Then work around the perimeter to easily open the plastic case to get into PCB board. This prevents any damage to the plastic housing which we will reuse later to reassemble the USB Toolstick.

Wedge a piece of plastic to open up the USB Toolstick

Step 3: Soldering Points – Wiring:

Here’s the solder points you need to be aware of. We will use red, black and white wires to match Steffen’s original post.

• Side A: Here is where to solder the white (C2Data) wire. It also shows the two pins (2 and 4) that will need to be soldered together. (Alternatively, if you need to be able to use the USB Toolstick for other projects, you can simply wire up a switch that when enabled, bridges those two pins.)

The white wire solder point and the two pins you need to solder together.

• Side B: On the reverse side, you can solder a red (C2CLOCK) and black (GND) wires to these two legs.

Solder the red and black wires to these pins.

I run the red and black wires through the holes so all three wires are on one side like so.

SiLabs USB ToolStick all wired up.

Step 4: Drill holes for the connector:

I wanted to add a connector. So I drilled 3 holes into the USB ToolStick’s case. This was easily accomplish by temporarily taping the connector I am using to the case to act as a template. Then used a 1mm drill bit to drill at each point of the connector legs. Simply insert the connector through the Toolstick housing and soldered up the red, black and white wires to it. The connector should be held in tightly if done right. The connector I used came with my XP 3A ESC.

Alternatively, you can simply drill a single hole to pass all three wires through the case. Then solder up a connector to them outside the case.

Here is a photo of the result of this step. I can see the position for the black, red and white wires to help me orient the mating plug that goes to the ESC.

USB ToolStick with connector

Step 5 Final: Reassemble USB ToolStick Case:

Once the wiring is done, it’s easy to snap back on the case you took apart in step 1. Here is a look at the modified USB ToolStick with the connector installed into the case. We are ready to use the modified SiLabs USB Toolstick to flash the ESC with BLHeli firmware. This will be outlined in Part 2 of the mSR X Brushless Conversion series.

SiLabs USB ToolStick modified for BLHeli Flashing.