Emax SimonK 12A ESCs – Mini Review

Hi guys,

In this mini review I’ll tell you what I think of the Emax SimonK 12A ESCs for small quads. They suit perfectly multirotors of ~250mm like the ZMR250.

I. Specifications :

  • Working voltage : 2s ~3s
  • Current : 12A
  • Burst current (10s) : 15A
  • BEC : 5V 1A

One very important thing you need to keep in mind is what you can read on these ESCs’ product page.

Based on SimonK firmware, further optimized to perfect drive performance.

What does it mean? We’re going to see this later.

II. What frame I put them on :

I had wanted to build a new quad (back up quad since I already had a ZMR 250) at a price as low as possible. After some researches, I had found those ESCs that seemed to be perfect. They had SimonK firmware and I could buy 4 of them for 28€ from Ebay.

At first I had used them on a Switchblade 200 but since I wanted to build a more agile and powerful quad, they ended up on a ZMR280. (A QAV280 knock-off)

The ZMR280 with Emax PM1806 2300Kv

The ZMR280 with Emax PM1806 2300Kv

Now I have upgraded my motors to the Multistar Elite 2204 in order to get a more powerful machine.

ZMR280 multistar elite 2204

Multistar Elite 22014 and Gemfan 5030

The latest setup :

  • ZMR280
  • Multistar Elite 2204 2300Kv + 5030 gemfan
  • Emax SimonK ESC 12A
  • 3s 1300mAh ~2200mAh
  • CC3D Flashed with Baseflight
  • Orange RX R620x
  • Flight Time : Between 4 and 5 minutes depending on the battery used. (Almost full throtlle all the time)

III. Pros & Cons :

Since it’s a short review, here are the main Pros & Cons of these ESCs

Pros Cons
+ Cheap – Not really SimonK
+ Work well – Don’t support 4S (out of the box)

CONS : We will start with the cons. Remember what  I told you about the “Based on SimonK firmware […]” thing. Well, that’s because the firmware is NOT SimonK, it’s a modified version.

I was very pissed when I had learned that (as I had just bought 4 more). What is also annoying is that the firmware is different from SimonK, so is the programming process. But still, a guy on Youtube made a great video on how to configure them correctly (or if, like me, you tried to calibrate the motors and you messed up the settings).

Also, they don’t support 4s out the box. BUT, you they work perfectly with 4S batteries as long as you use an external UBEC.

PROS : They’re very cheap and despite the “not SimonK” thing, once set up they work correctly. In terms of flight characteristics, I don’t see much difference with my RCTimer 12A ESCs that have the actual SimonK firmware.

I have had mine for 3 months and after numerous flights and crashes, they still work flawlessly.

IV. Should you buy them?

I’d recommend them if you’re looking for cheap ESCs that work well even though they don’t have the actual SimonK firmware.

Plus, with an external UBEC you can use them with 4S batteries.


Posted in Mini-Reviews.

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