Dalprop Nepal N1 5″ propellers

This weekend, thanks to Foxeer, I had an opportunity to test flight new Dalprop freestyle props: Nepal N1. Although the name is a puzzle for me, I’m pretty sure Dalprop Nepal N1 might make some stirr!

Dalprop Nepal N1

Anyhow, Nepal series is intended for freestyle although I’m pretty sure you can do some relaxed, non-competitive FPV racing with them as well.

  • diameter: 5,1″
  • pitch: 4,35″
  • weight: 3,7g
  • PoPo compatible
  • material: polycarbonate

Dalprop Nepal N1

The most visible feature of Nepal N1 is that they have heavily swept-back blades. The resemblance to Azure Power propellers is obvious, but they are far from being identical. Blade shape and curvature are different.

Dalprop Nepal N1

After flying a few LiPo packs with those propellers, all I can say is that I like for they perform and for sure will use them a lot.

  • The prop wash is very gentle and easy to tune out. The marketing slogan for Nepal N1 is “No prop wash” but it’s only a slogan. Prop wash is there, but it’s not big and simple to avoid
  • Yaw is responsive but not over-responsive like some heavy pitched props
  • They seem like a nice compromise between very gentle and power lacking props like Ethix S3 and the previous generation of Dalprop propellers know as Cyclone.
  • Nepal N1 feel very precise in flight and I was kind of surprised how easily I was able to navigate between trees and fit into small holes
  • I have no idea what exactly they used to make Nepal N1, but they are bloody tough props! After a few at least moderate crashes, there is still not a single scratch on them and I did not have to replace even a single propeller. All are straight and you can see some evidence of being in use only after a close examination. Very durable indeed
  • Powerlooping is easy again as they do not lack power at the high end and I had no problems to travel back far enough to have enough time and space to hit the gate again. Very nice!

Dalprop Nepal N1

Pirx Seven – The ultimate custom 7-inch FPV frame, part 1

Do you know this old saying “If you want something done right, do it yourself”? I do and sometimes I just live according to it. Not always, I’m not crazy, but at least from time to time!

I fly 7-inch FPV drones a lot. To be honest, they are my favorite flying devices. There are a few good 7-inch frames, like TBS Source One for example. There is a difference between good and great tho. I do think that Source One is a good frame, there are a lot of things on it that do not make me very happy tho! The list might not be very long, but it is relevant:

  • props in the view
  • limited space to install split-like hybrid cameras
  • no very convinient place to install VTX
  • it’s not that big inside as one might imagine…

Because of that, and because I think I know how to do it (I’m an engineer) I’ve devided to design and manufacture my of 7-inch FPV drone frame that would fix what I do not like in Source One.

This is how Pirx Seven was born!

Pirx Seven - 7-inch FPV drone frame

  • Dead Cat configuration
  • Plenty of space inside for everything you want! There is even a place in the back to fit the whole 30x30mm stack!
  • Place for Split-like hybrid camera in the front
  • Attachable mounts for antennas, GPS and other accessories
  • Clear, unobstructed view for HD camera like GoPro on the front deck

So far, I was able to mill a prototype unit to test it in flight. So far so good, I really have to say that I like what I designed.

Pirx Seven - 7-inch FPV drone frame

Fully assembled frame weight 205g with steel screws and aluminium standoffs.

Pirx Seven - 7-inch FPV drone frame

What next? Test flight and some changes. The full list consists of 12 points in total and basically means that I will have to redesign almost everything…

If you want to know why the name and what does Pirx stands for, here is the answer. It’s a tribute to Polish writer StanisÅ‚aw Lem and his book Tales of Pirx the Pilot.

Your first 7-inch FPV drone

I love 7-inch FPV drones and during the last year, they were my most used FPV gear. For freestyle, cinematic, cruising and long-range. I currently own 3 7-inch FPV drones and 4th one in the assembly process.
I think of myself as a 7-inch expert. I’ve wasted enough money and equipment to know what works and what does not work well with 7-inch propellers.

TBS Source One 7-inch FPV drone

If you are thinking about building your own 7-inch FPV drone, here are some tips that might save you a lot of time and a lot of money on wrongly chosen equipment.

The Frame

Of course, the frame is the most important part of a build. No matter if you will be building a freestyle or long-range rig, there is one thing that you have to know: Horizontally scaling 5-inch frame by making arms longer is a no-go. Longer arms require more stiffness and they also have to be thicker! The sweet spot is 6mm thick good quality carbon fiber. 5mm thick might work too but forget about 4mm or thinner arms. They will be too flexible and the whole quad will be in a state of a constant wobble!

Alfa Monster 7-inch FPV Frame

If you are looking for 7-inch frame recommendations, here are my choices: Team BlackSheep Source One with 7-inch arms, Alfa Monster and AlfaRC Fighter.

Propellers

Kind of obvious, right? The choice of good 7-inch propellers is not that big as one might imagine. Sure, you can buy some “inventions from 4 years ago for cheap” but believe me, they are not worth it. There are 3 types of modern 7-inch propellers that I find worth looking at in late 2019:

  • DAL T7056C – good for freestyle and thanks to aggressive pitch they are very dynamic. Can be used no longer flight, but this is not where they really shine.
  • HQProp Durable 7x4x3 V1S – a more aggressive version of 7×3.5×3 that in my opinion works much better than original. Slightly more pitch only helps during steady flight. They are rather for cruising than for freestyle.
  • GemFan FLASH 7042 – kind of good propeller, but don’t get me wrong, you should try 7042 only if DAL or HQProp are too heavy for your motors. So if you have 2207 or 2306 you might try FLASH. If you have bigger motors, just go with DAL or HQProp.

Motors

Brotherhobby Avenger V2 2507

Probably the most often made mistake by the “7-inch virgins” are too small motors. Beginners think that putting the same motors that work great with 5-inch propellers on a 7-inch frame is a good idea. OK, maybe sometimes they lower the KV. This will not work. I know. I tried that by myself and only wasted some money and a lot of time and nerves.

What you need are big motors. In a size of 2506-2507. 2208 might work as well and 2508 is rather the max size that makes sense.

On the KV size, the rule of thumb is that on 4S you should aim at 1500-1500KV and on 6S at 1200KV. Those values give a nice compromise between efficiency and raw power. Of course, this is only a rule of thumb and when needed you might choose higher KV. For example, my 7-inch freestyle drone uses 1700KV on 4S motors.

My recommendation is rather simple: for now, there is only one motor that comes is wide enough KV range and it’s called BrotherHobby Avenger v2 2507.

Everything else

For the rest of the equipment, you can choose whatever you want. Any equipment will work and you do not have to match it to the propeller size. My choices are:

FPV drone with a pusher prop | DIY Pentacopter!

Here it is Penta Engine Nitro Incredible Ship – P.E.N.I.S. Or shorter: Willie. OK, let’s be serious for a moment. It is a pentacopter. A normal 5-inch FPV drone based on Martian II frame with the 5th motor attached in the back. When I flip a switch, the 5th motor starts and it flies almost like an airplane. It’s a VTOL. The idea is not mine and a few years ago there was something called Foxtech Screamer 250.

Race Day Quad Mach 1 with EMAX RS2 2306 2400KV

This year my friends and I stared a local FPV drone racing series. Nothing serious, just a couple of guys meeting once in a while and measuring times over the track. 100% amateur thing. After the second race, I’ve realized that I do not have a drone designed for racing: more than 400g without a battery! That is just too heavy for any kind of competitive racing. The solution was simple: I need a good racing machine. Much, much lighter than the current one.

As a result, Mach 1 was born