Review: BuildTak Printing Surface

For last few months I’ve been happily 3D printing PLA on glass. Prints were repeatable, initial adhesion was just fine, ready print was easy to remove after glass cooled down. But I wouldn’t be me if I did not wanted to try something new. So I tried “the ideal 3D printing surface” BuiltTak.

My initial impressions were very positive. Nice mate surface a little similar to fine grain sanding paper. I was a little afraid that adhesion will be even too good and it will be hard to remove the print. But hey, they had to think of it, right? After all, BuildTak is quite expensive after all. (more…)

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Hands on: DALprop T5046 propellers

Last weekend I had an opportunity to spend some time in the air with new DALprop T5046 propellers from Surveilzone.
They are "funny" propellers. On one hand they have some nice features, on the other, they have few flaws that almost disqualifies them in my eyes…

  • Pros
    • Good air "grip"
    • Good efficiency
    • Smooth flight
    • Nice speed
  • Cons
    • Oh man, they are fragile. Each crash equals at least one broken propeller. If you got used to "tough" props from DAL, you will be shocked
    • They are very, very sharp at edges. I've cut my fingers when I was unscrewing shaft nut. You either have to hold them very carefully or wear gloves?
    • Too flimsy. I was afraid that they will bend in flight and cut ESC. I've already lost 2 ESC because of flimsy/bendy propellers and I started to pay attention to "flimsiness"

DALprop T5046

Final conclusion: while they might be an interesting option in terms of performance, they are not prepared for everyday use!

Photo from Surveilzone

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3D Printing: rubber launched glider

3D Printers give almost endless possibilities and 3D printed gliders can be a great weekend project. Last week I’ve printed a small fleet of Monarch XL gliders from Thingieverse. Single glider takes around 45 minutes to print at 50mm/s and few additional minutes to glue all the parts together. Add an hour for a rubber launcher and done. Great fun for a small price. It flies surprisingly well and my daughters loves them.

3d printed glider airplane

3d printed gliders

Flight characteristics improves when dihedral is added. Also elevator can be adjusted, so glider can do loops! Great fun for a very low price!

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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 (more…)

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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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