Dalprop FOLD F5 folding 5-inch propellers

Foldable propellers are nothing new. We use them on RC airplanes and consumer-ready drones like DJI Mavic for years. But they were never available for 5-inch mini quads! Until now that is, since just today I got a package from Foxeer with 2 (2 and a half) sets of brand new Dalprop FOLD 5.1″ folding propellers for multirotor FPV drones! Yay…

DALprop FOLD F5 foldable 5-inch propellers

DALprop FOLD F5 foldable 5-inch propellers

What to say… They fold indeed. My props are pre-production samples and came not assembled! Double the fun with some puzzles!

DALprop FOLD F5 foldable 5-inch propellers

DALprop FOLD F5 foldable 5-inch propellers

DALprop FOLD F5 foldable 5-inch propellers

Unfortunately, I can not yet test them. It’s raining and the weather forecast says it will be raining for 2 more days. But after that, nothing will stop me from testing them on my favorite flying spot!

How much does a propeller weight? Mass vs. moment of inertia

How often, when you watched or read a brushless motor review you’ve heard a sentence like “this motor will not have any problem spinning a heavy propeller” or “this motor is designed for light propellers”. Or “this is a very light propeller”. But what does that really mean?

Thanks to our good friend Sir Isaac Newton we know that

F = ma

Where F is the force, a is acceleration and m is the mass of an object. In this case, mass is the unit of inertia. This is all true for propellers if you want to throw them in linear motion. But propellers rotate and that changes a few things. Instead of mass we are interested in the moment of inertia and mass distribution around the rotation point.

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

Hand on: DAL (DALprop) TJ5045 propellers

After moving to new, 4S powered, mini-quad based on Reptile X4R 220, EMAX RS2205 2300KV and FVT Littlebee 20A, I’ve discovered that I’m missing some power. DALprop 5040 and DALprop T5040 I’ve been using on 3S did not delivered enough power. So, I’ve gave DALprop TJ5045 a try.

According to specs, they should be most efficient from all DAL 5045 family. Well, efficiency will be determined, one thing is sure: they surely give much more thrust and pitch speed comparing to T5040.

Dalprop TJ5045 top

Dalprop TJ5045

Thrust and speed improved a lot. ATM, hover is at about 32% of throttle and climb rate is impressive. I love it! They also seem to be little quieter that T5040.

Dalprop TJ5045 on Reptile X4R 220

They are also durable. Maybe I’m not crashing as often as before, but when I do, it’s much more spectacular. Today I had two of those spectacular crashes and all propellers survived. Nice.

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!

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.

Quick Review: EMAX GT2218/08 1100KV motors

Since I was lacking some power in my Reptile 500 quadcopter, I was considering switching my Turnigy MT2213 935KV motors to something more powerful. Last previous weekend kind of forced me to make that switch: I destroyed one motor while trying to replace bearings. Being forced with lack of motors I’ve decided to stay with 3S LiPo, AfroESC and 10″ APC propellers and buy motors that would deliver more power while being compatible with rest of my setup. So I have chosen EMAX GT2218/09 1100KV.

EMAX GT2218/08 1100KV

Why them? Mainly because they were meeting my requirements and being actually available and within reasonable price.


  • Weight: 80g,
  • KV: 1100,
  • Max power: 312W,
  • Max thrust:
    • 1380g on APC 11×3.8,
    • 1290 on APC 10×4.7
  • With long shaft at the bottom, so can be mounted in front and behind an firewall,
  • GT series (Grand Turbo, woot woot) for “hi-tec” and “pro” models (such a nice name…),
  • Black (!),
  • Mounting holes: 16x19mm.

Continue reading “Quick Review: EMAX GT2218/08 1100KV motors” »

Turnigy MT2213-935KV MultiStar Motor & Propeller Combo 10-4.5 Review

Good motor-propeller combo is a key for building stable and reliable multirotor platform. Since many amateur RC builders does not feel qualified enough for choosing motor and propeller separately, many producers offer brushless motors and matching propellers as sets. One of them is Turnigy with their budget, entry level set of 935KV motor and matching 10×45 CW and CCW propellers.

MT2213-935KV motor propeller set

It contains:

  • one MT2213 935KV brushless motor with dual mount for both standard and DJI style sloted propellers with male 3mm “gold” connectors,
  • one CW 10×45 DJI style sloted prop,
  • one CCW 10×45 DJI style sloted prop,
  • 3 female 3mm “gold” connectors,
  • screws

First, the motors. They are rated at 935KV and are suited for both 3S and 4S batteries. Unfortunately, not too high power limit (200W in surge) does not allow to use 10″ props with 4 cell batteries. Manufacturer suggests 10″ prop with 3S and 8″ props with 4S. Too bad, since from my experience, their effective lift limit is around 250g per motor. Going above that value causes multicopter to behave little sluggish due to not enough power on more aggresive maneuvers. One the other hand, my current bulid uses four of those motors and weights 1400g with camera, FPV set and 5000mAh 3S battery. And it flies like a charm. I would not mind to have more power, but it’s fast and agile enough to have a lot of fun. Of course, one can forget about aggressive acrobations, but flips and rolls are doable as long and one remembers about alitude loss.

Very nice feature of those motors is possibility to use both DJI props and standard, not-sloted propellers. Short M6 shaft helps to eliminate extensive vibrations for running propellers. And a drop of anaerobic glue secures shaft’s nut tight enough not to let it unscrew in midflight.

Turnigy MT2213-935KV

Second, the propellers. To be frank, those props are crap. Sorry guys, but that is true. They are not rigid and reliable enough. At about 60% throttle they were going into audible oscillation that even my neighbor that had never any experince with RC recognized as something strange. And he was right, since one of those props actually broke during flip. And I think everybody knows what happens to a quadcopter when one of propellers stops to exists then machine is in the air. Crash. And although it fell into high grass grass that softened the fell, all four propellers were broken after that. So I replaced them with APC 10×4.5MR without any regrets.

To sum things up: motors yes, propellers absolutely not! If you are looking for a good 900~1000KV motor then consider Turnigy MT2213-935KV bought separately. And match them with, for example,  APC 10×4.5MR like I have.

All photos are from HobbyKing.com website