That's right, my Mini Protos just got cooler. After the last crash that nearly totalled the old one I decided to do a full rekit and leave the parts that survived for crash parts. This helicopter has been a great deal of fun for the last year, so I went with MKS DS95 cyclic servos this time. Fast Lad guys sell them at bargain price in three piece combo deal.

Installation wise...nothing special. After all that has been said and written, I don't think there's much to talk about. No slop at all, very tight mechanics, beautiful aluminium case that will dissipate any heat without a problem.

I was pleasantly surprised how precise they were, though. Every click in v-bar setup produces tiny step accompanied by...well...no centering noise. V-bar didn't need any swash geometry changes as the swash plate stays level in all collective stick positions.

Initial flight tests went fine and even though there are some strange tail hunting issues now (I know, DS95i needed), these servos bring a whole new level of precision and control :) I'm impressed.

Edit: DS95i installed. This thing feels like a simulator!

About a half year ago, when I first started to seriously think about building a 50 class helicopter, I started thinking about which HV servos to use. When I finally decided for the Fusion 50, Outrage servos seemes like a pretty obvious choice.

Later on, I came across somewhat mysterious Hyperion Atlas DH20 line. At the time, there was literally no information about them coming from the helicopter community. They seemed too cheap to be true. Because I've had great experience with Hyperion Wing, servos designed for wing mounted aileron and flap applications, I decided to give it a shot. They come for around 40 euros, so why the hell not? :-)

The final decision was to use DH20-FTD on cyclic and DH20x-GCD on tail. I plan to run all the electronics on 7.4V off a Western Robotics or Gryphon BEC. DH20-FTD is equipped with titanium gears (first gear is plastic) and should deliver 0.16sec/60 deg of speed, 9.5kg/cm dynamic torque and holding torque of 19kg/cm. DH20x-GCD has carbon poly gears and data sheet promises 0.06/4.5/9.0 respectively. Both servos have coreless motor and double ball bearings inside.

DH20's come tightly packaged in boxes just big enough to carry a servo, manual, set of servo horns and some mounting hardware. You get a sticker in every box too! :)

Servos have very solid feel when handled. Substantial cooling capability of the metal case is obvious, when your servos spend a whole day accumulating winter cold inside of the UPS truck.

Both DH20 and DH20x come equipped with a Futaba connector and splines. Each of my servos had a wheel mounted out of the box. No loctite is used on the titanium ones, so even if you use the original wheels, don't forget to threadlock the top screw.

There was a crack going from a hole on one side of one of the wheels to a hole on the opposite side of it. Given by how tight the packaging is, I wouldn't be too surprised if it cracked during shipping, but manufacturing mistake isn't out of the question. All other wheels and horns are top quality. I used Align D6CF metal servo wheels (blue Futaba ones) anyway, so no big deal.

All servos exhibit very solid holding power when turned by hand and absolutely no slop in the servo mechanism. Centering is spot on.

They fit very nicely in the Fusion 50 frame. When used together with supplied rubber dampeners, cyclic servos require the balls to be mounted facing servo rather than outside in order to keep the bellcrank pushrods parallel with the frame.

The Hyperion Atlas DH20 & DH20x HV servos seem to be a very solid piece of manufacturing work and certainly satisfy my idea of quality on the first look. Favourable price tag makes them a compelling alternative to more expensive high voltage servos on the market. Flight report is coming in a few months when the F50 hits the air.

More Hyperion servos can be found here.

After a couple mild winters it's payback time! Temperatures have dropped under -10°C a month ago and, as it seems, not much of outdoor heli time is going to happen for couple more weeks. Luckily, I have been preparing for the cold days this year :)

I found a couple sites with cool indoor foamy plans I think are worth of sharing, so here you go:

F3P index on RCGroups - notoriously known, but what the hell, I'll link it anyway :)

Aero 3D Brasil F3P thread - some true gems in this one!

Expressfly free shockies

Breeze F3P

Hoaxi II

Challenger 3D

Troll

Knuffel (direct link to PDF plan)

Smove (direct link to PDF plan)

Yak-54

Velox V3

So far I have flown 22 inch scaled down version of the Matchless Yuka and Cirrus F3P. Both of them were equipped with el cheapo stuff coming from HobbyKing:

18-11 2000kv Micro Brushless Outrunner (10g) spinning 6x3 GWS prop

TURNIGY Plush 6A /.8bec/6g Speed Controller

Arrow 4.3g / .8kg / 12sec Micro Servo

and Spektrum AR6110E receiver

Although you could go a bit lighter, I'm very happy with this setup. Costs come close to nothing and these planes still deliver tons of fun.

I'm starting my build of Nicolas Pietu's Hoaxi II today (22 incher again) and can't wait to see my first indoor bipe in the air :)

Here's how I went about converting my mCP X to brushless. I strongly recommend BL conversion to anyone who wishes to push the flight envelope beyond mild aerobatics.

My conversion takes the more difficult, but also more rewarding path to the final product. If you don't know how to solder, don't feel comfortable doing it on your own or just can't be bothered, check plug-and-play conversions. WOWhobbies carries them among others.

Note: This guide is a revision of my article published in czech language here.

You will need:

- brushless motor, like the powerful but hungry OverSky HP05S or weaker Walkera HM-4G3-Z-39 inrunner

- speed controller - WK-WST-10A-L3 or OverSky XP-12A, both work great

- pinion gear, 8T or 9T, modulus 0.3 with 1.5mm hole

- brushed to brushless signal converter; I used "theSteve" Custom made converter for the Walkera 4#3/a/b helicopter and the Blade MCPx/MSR

- common tools, such as a hobby knife, soldering iron with a very fine tip (you will be soldering onto SMDs and small contact points), pliers, tweezers and some other hardware

First off, think about how would you like your components to be laid out. Cut the wires so that you have just enough to connect them to the right spots.

There are four wires coming out of the converter:

- yellow - signal input; this wire taps into mCP X signal circuit
- white - signal output; this one supplies the conveted signal to the ESC
- red - power lead
- blue - ground

Remove the ESC out of the heat shrink it comes in. Note, where the original servo wire leads are connected and remove them from their solder points. Solder the white converter signal output wire instead of the original servo signal (usually white, yellow, orange). Do not solder red and blue wires yet, read on for reason why and correct spots.

Red and blue power leads are best soldered to the spots seen on the following image. The reason why not to connect them directly into the ESC power circuit is because every time you spool up (especially with powerful motors such as HP05s), the converter goes crazy and quits delivering correct signal to the ESC.

Now connect the yellow wire to a small SMD resistor on the rear side of the main board.

Heavier gauge power ESC leads will be connected to the flight battery. Solder them to the opposite side of original power leads. White is for positive, black ground.

With motor already installed in the modified frame connect motor leads to ESC's output solder points. Carefully check for correct rotation. If motor goes backwards, change the rotation direction by swapping two out of the three motor wires.

Here is how I connected the Walkera HM-4G3-Z-39...

...and later the HP05s.

That's it! Finish the installation by fixing all the components to the helicopter and go fly the thing.

Be careful, being cut by a brushless mCP X hurts! Don't ask how I know :o)

I noticed some strange friction in the movement of throttle stick on my (at that time) brand new DX8 transmitter. It almost got me in trouble when it started to show.

I opened the tx and found that once again Horizon Hobby delivered a very good, but not super perfect transmitter after all. Don't get me wrong, I love my DX8. It's the way they make us all test pilots that disappoints me now and then...

HH made it easier to switch between all four transmitter modes. DX8 has a pair of metal stripes on vertical axis for both sticks. This allows for easier choice of ratchetted or smooth stick movement without major mechanical changes.

Mine were not finished and checked at the factory. I had razor sharp edges, leftovers from processing, facing the plastic arc on both. One of them cut a tiny dent into the plastic already, making it almost impossible to change throttle in certain positions. I had to file them myself and do all the additional quality control you would expect from a world class factory.

I had a discussion about removal of the washout arm pins from Mini Protos some time ago. Here's my method using ball link pliers. You can easily push the pin out of the arm with 1.5mm allen wrench or hex screwdriver this way.

Since I had no real use for my Dremel case and had no mCPx case at the same time, I made this. It fits my laptop bag just right.

Charger and the AC adapter are fixed in place with 3M™ Dual Lock as well as batteries will be, once the CNC battery mount comes from Astroid Designs. There's some place left luckily, so a 6V BEC and a 2S LiPo pack will fit for charging while out in the woods.

I've been thinking of how to give back what I learned and discovered about RC helicopters to the community. All the little hints and tips given to me along the way, the inspiration and ideas. I like forums for what they are, but they often come short when you need to refer back to a post made a couple weeks or months ago.

So this is my way, I guess :)

Fly safe!