EMAX SimonK Series 30A ESC – 3 months later

When 3 month ago I was doing “Hands on” review for EMAX SimonK Series 30A ESC I was quite optimistic about them. Well, why should I not be? Quite cheap, decent quality, easy to configure. Did EMAX 30A SimonK Series ESC met expectations I was putting on them?

Simple and short answer is: no, they did not met expectations. Reason is: one of them caught fire during flight causing whole UAV to fell from 30 meters into water.

emax 30A ESC SimonK on fire

emax 30A ESC SimonK Series on fire

As you can see on the pictures above, ESC is completely burned. Both MOSFETs and electronics. How do I know it burned during flight and caused a crash and not the oter way? Thanks to Blackbox logs I have a proof that this single ESC and motor connected to it were gradually losing power before UAV crashed. Since motor and attached propeller survived without a scratch, ESC is the one to blame.

To make things worse, it was not too much load that killed it. Before crash ESCs were running at around 45% throttle. That is around 7A per ESC. Way below promised 30A.

So, final conclusion: no, maybe they are cheap and easy to use, they are not reliable! And that is the critical flaw of those ESC!

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Hands on: Piranha Multitool from Banggood

All RC enthusiasts know this algorithm:

  1. Build
  2. Fly
  3. Crash
  4. Repeat

Sometimes there is “buy” instead of “build”, but rest stays the same. What goes up must comes down and very often there is a need to fix/repair something on a airfield. Basic tools are a must when going flying! I’ve decided I carry too many of them and I must combine some of them into one multitool. So, I’ve purchased a Piranha Multitool from Banggood.

Piranha multitool from Banggood 1

One tool combines:

  • Pliers
  • Wrench
  • Knife
  • 2 screwdrivers

Piranha multitool wrench

Piranha multitool pliers

Whole tool makes a solid impression. It is made from steel and at a first glance it does not looks like it wants to fell apart after first usage. Pliers has a cutter and a safety switch and looks strong.

Wrench also feels solid, but there is no limiter, moving part can fell off. Not highly probable, but possible.

Piranha multitool from knife

Knife looks like the weakest element of whole set. It feels flimsy. I hope I’m wrong.

Conclusion? For ~$12 it looks and feels fine. Hope it will work fine too.

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Hands on: Reptile X4R 220 quadcopter frame

Last week, first parts for my new racing quadcopter started to arrive. One of them, was carbon fiber frame: Reptile X4R 220. Why this one? Like I stated many times: I'm cheap. Plus, I did not wanted to go with another ZMR250 build. This frame was easily available, within budget and good looking. So, few weeks later, here we are…

Reptile X4R 220 frame - parts


  • 220mm motor-to-motor
  • Weight: 120g
  • 4mm carbon fiber arms
  • 2mm carbon fiber bottom plate
  • 1.5mm top plate
  • 35mm aluminium standoffs
  • adjustable camera mount (fits HS1117 and RunCam Swift)
  • integrated power distribution board (PDB) with 5V BEC

Reptile X4R 220 frame - arms and bottom plate

After 2 evenings with this frame, I'm almost finished with a build.


  • overall quality is good
  • everything fits, no need to ream holes, sand or cut anything
  • more nuts and bolts than required

Reptile X4R 220 frame - arms


  • top plate are rather thin. I would prefer 2mm top plate or maybe 2.5mm bottom plate too
  • power distribution board is an structural element of whole frame. If you want to use different PDB (I wanted to use Matek PDB-XT60) you might have a problem. Some improvisation will be required
  • In theory, each arm is kept in place by 3 M3 bolts. In theory… In practice, one of those bolts enters nylon standoff. Not metal nut, but nylon. So, instead of 3 bolts per arm, it is only 2.5 bolts or even less… too bad… Still, whole build is rigid enough…

Reptile X4R 220 frame - all things in place

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Hands on: Matek PDB-XT60

As long as quality is decent, there is nothing better like "el cheapo" electronic components. Just like below $5 Matek PDB-XT60 Power Distribution Board with integrated 5V and 12V BEC. Preparing to build a new 220 racer I just got my Matek PDB from Aliexpress.

Matek PDB-XT60

Matek PDB-XT60

Quality, at a first glance looks good. Laminate nicely cut, soldering of BECs looks good. All pads are yellow (I will not say gold on purpose). According to specs, max current that can go through it is 5*25A. That is strange, since it has connectors for 6 ESC. So, let's assume it is 100A in total, and in a quadcopter configuration, each ESC can draw up to 25A. In case of hexacopter it would be 16A.

Matek PDB-XT60

Matek PDB-XT60

5V BEC is a switching step down with 2A max load, while 12V (0.5A continuous load) line is based on LM7812 linear voltage regulator. And that means the following: it does not makes any sense to use 12V BEC in case of 3S. With 2V dropout voltage of 7812, on 3S it would supply 10.6V on fully charged battery and 8V when LiPo cells are at 3.3V. On the other hand, FPV gear accepts voltage starting from 7V so, if needed, 3S can be used after all.

So far, so good. Now I wait for the rest of components to arrive. I hope soon…

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Hands on: Emax SimonK Series 30A ESC

You want to know the secret? I’m cheap. I almost never buy expensive stuff. It’s not that I can not afford it and buy cheapest stuff available. In my opinion, both ways are wrong. I buy things that position themselves somewhere in the middle. Not the cheapest, not “the best” and most expensive? Why not the cheapest? Because of very low quality. Why not the best? Because I have to pay a lot a little of additional quality or performance I do not really need. And things in a middle usually provide enough for reasonable price. For me it makes sense…

Thanks to GearBest I’ve received a set of EMAX SimonK Series 30A ESC for a review. They are not the cheapest 30A ESC for multirotors. You can easily buy some no-name for almost half a price. You can also but “the best” for almost twice as much. But are they worth the price? I will try to find out in the next couple of weeks while using them on my 600mm quadcopter.


EMAX SimonK Series 30A ESCs are packed in antistatic bags with a user’s manual in Chinese and English.

EMAX ESC SimonK 30A boxed Continue reading “Hands on: Emax SimonK Series 30A ESC” »

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Quick review: DAL 5040 propellers

My last review of cheap Chinese propellers, Gemfan 5×3 3 leaf, was quite negative. This time it will be much, much better: DAL 5040 (5×4″) fiberglass reinforced propellers. They are cheap, only slightly more expensive than super popular Gemfans 5030. But they beat Gemfans in every aspect. Not only DAL 5040 give more power and pitch speed. They are also much more durable. The internet calls them “indestructible”. No, they are not indestructible, but they are strong enough to survive crashes big enough to break Gemfans 5030.

DAL 5040 (5x4") fiberglass reinforced propellers

So, even if they are slightly more expensive, they last longer and give more power. It is also interesting how they break. It is either in the hub and whole leaf is gone, or they fracture is the middle of a leaf.

DAL 5x4 fiberglass props

DAL 5040 propellers

Bottom line: I like these propellers very much, they are surely worth the price!

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Quick review: Gemfan 5×3 (5030) 3 leaf propellers


This will be very quick review with a simple conclusion: I will never buy Gemfan 5030 3 leaf propellers again. Never. Why? They are cheap, you can buy them for around $3 for 2 pairs from China. But they have few flaws:

  1. Every crash, even gentle means at least one broken propeller,
  2. Quality is low,
  3. Look at this picture: Brokern gemfan 5030 3 leafThis propeller never hit anything in its life. See white stress marks near hub? They appeared during normal flight. This prop would break soon,
  4. At least twice in last 2 months Gemfan 5030 3 leaf broke in flight. In both cases during quite normal flight. No crazy stuff. Simple turn.

So, my verdict is: no, never again. I’m going back to Gemfan 5030 2 leaf version. They are cheaper and offer very similar performance. And I think they are slightly harder to break after all.

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Quick review: Turnigy 2730 1500KV brushless motor

I’ve bought first Turnigy 2730 1500KV brushless motor by accident. I needed something small and cheap for Depron airboat. Then I needed something similar for a Depron airplane. At the end, in 6 months, I owned 3 T2730 1500KV motors. Not all of them survived the experience. One got lost in the middle of a lake with the rest of airboat it powered. Second got burned what I forced it to power too big propeller. Third one still lives and this type is my first choice for anything up too 400g of weight.

Turnigy 2730 brushless outrunner motor Continue reading “Quick review: Turnigy 2730 1500KV brushless motor” »

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Quick review: Eachine PCB Power Distribution Board for ZMR250/QAV250

Building a quadcopter without nice power distribution board always leads to the same result: state of total cable entanglement. It looks ugly, makes maintenance hard and adds unneeded weight. I will not show how my ZMR250 quad looked after I added FPV and OSD into it. Almost all space between top and bottom plate was taken by cables. Nightmare. So, after spending less than $9 I’ve become an owner of Eachine PCB Power Distribution Board w/ OSD Socket Support NAZE32 CC3D OSD For QAV250 Quadcopter from Banggood. This board did not have very good reviews, but offered three things I wanted: sockets for micro MinimOSD, integrated signal lines and low price. So, I gave it a try.

Eachine PCB Power Distribution Board w/ OSD Socket Support NAZE32 CC3D OSD For QAV250 Quadcopter Continue reading “Quick review: Eachine PCB Power Distribution Board for ZMR250/QAV250” »

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Quick Review: FPV 1/4 CMOS HD Color Camera Module 600TVL 120 Degree Wide Angle

Usually I have absolutely nothing against buying cheap stuff from China. OK, maybe quality will not always be as expected, but usually it’s not worth paying extra 100% in price for 10% of extra quality. Usually, with some exceptions. Exception number one are mechanical parts like motors. Exception number two are FPV cameras. And the second one is new one. I’ve put it in place after using FPV 1/4 CMOS HD Color Camera Module 600TVL 120 Degree Wide Angle from Banggood for one month.

FPV 1/4 CMOS HD Color Camera Module 600TVL 120 Degree Wide Angle from Banggood Continue reading “Quick Review: FPV 1/4 CMOS HD Color Camera Module 600TVL 120 Degree Wide Angle” »

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