December 30, 2017

Wall mounts for my RC cars

I designed (if you can call it that) and printed simple wall mounts for my RC cars this weekend.

This is how 5 of the prints turned out. My printer needs a lot of love to print. But when it prints it prints well. I had not given it enough love apparently. But when I took the time I got it back to friendly operation again.

And then this was the result. Simple wall mounts to hang the car by the tire. Turned out I actually only needed the middle screw hole.

The mounts in "action" with the cars dangling by the front tire. Haters gonna say it's bad for something in the suspension obviously.

The hanger is available on thingiverse for the ones that would want to print their own:

Final flight of the F-35

Last time I flew it I broke its nose. That was two years ago. After the nose was broken off, it might have been ugly, but it flew well.

And today was the day to fly it for the last time. Since I do not expect to fly this plane any more and it is ugly and taking up precious space, it was time to get rid of it. With a few final flights.

To spice things up I had 4S batteries prepared. ESC and motor is speced at 2-3S.

Away it went. My friend gave it a perfect toss and the power of 4S made it fly perfectly. It was fantastic. For about 10 seconds, then I misjudged the distance to a tree and the plane was converted to garbage.

Collected remains of the F-35

December 17, 2017

Futaba replacement?

Well hello there dear old blog! It's been a while now. I haven't forgotten about you, I just haven't done much on the bench lately.

BUT. I did get myself a radio on the HobbyKing sale maybe a month back. Being a Futaba fanboy, I never expected that I would ever in my life buy a Flysky system. But now I have, I got myself a Turnigy Evolution. I've been looking at alternatives to the bulky Futaba, at least for the leasure flying I do at the office and now that it was on sale I ordered the Evolution at 35€, incluing a receiver.

60€ radio to the left, 600€ radio to the right

Ok. So, there's a small price difference between the 14SG and the Evolution. Don't get me wrong. The 14SG is a flawless radio, at least by the time it was launched. It has never ever glitched in the transmission and the telemetry was a great addition and quite unique in the price range before the Taranis arrived. I really love that radio.

But for flying quads, especially indoors I need two major features.

  • 6 channels
  • Voltage telemetry
And the Evolution has that. Yes, it has telemetry. And the receivers are dirty cheap. And the radio was dirt cheap. In fact, I think I can outfit most of my rotor crafts with receivers for the price of one single Futaba receiver. 

But how bad can it be? I'll get back on that if I have issues with it.

I will not forget to mention there are alternatives to the Evolution out there as well. One of them is the TBS Tango. It's a purpose built radio for quad racing and has some nice features in therms of programming. It is quite expensive, and comes without a transmitter. Which makes it ridicously expensive.

And coming up is a multi protocol radio called iRangeX iRX-IR8M. It looks like a knockoff of the TBS Tango and comes with multiple radio circuits built-in. I won't order one until there are some decent reviews online. My guess is that it will have a bit better gimbals than the Evolution and a poor feature set in the software. It's mostly the form factor, the basic telemetry and the multi protocol feature that will push this product.

October 14, 2017

"Fixed" the z-slop issue on my Fabrikator 2

So. I've finally worked out an extremely simple solution to the Z-slop issues I've had with my Fabrikator II.

The problem with the Z-axis is a combination of two issues with the printer.

  • The Z-backlash prevention mechanism is poorly designed
  • The Z-axis does not run smoothly and has to be forcefully pulled down by the Z-axis rod
The obvious solution would be to address those issues. And I have tried, but can't get the Z-axis to run smoothly enough.

What happens because of this is the there is a 0.2-0.4 mm slop in the Z-axis when it descends and then starts climbing again. This happens when the print starts (home, lift, descend to first position) and whenever a lift is done during the print. As an effect the printer will print 2 or 3 layers at the same height, causing the printer to print badly and the model to be of incorrect height.

So far I've only printed parts in the printer where the effects of this issue is not problematic. Which is quite limiting.

After a bit of googling gcode I realized I can solve the issue at the print start with only a bit of fiddling with the pre start gcode snippet. By default in Cura it looks something like this:

G28 ;Home
G1 Z15.0 F6000 ;Move the platform down 15mm
;Prime the extruder
G92 E0
G1 F200 E3
G92 E0

One of the important parts to notice here is the "move down" which on this printer is actually a "lift" part. It is when the printer comes down from this movement and starts moving up again that the problem will occur and the printer will put down multiple layers at the same height. So we can remove that line.

But the homing process will still have the same problem. The last movement of the homeing process is the Z-axis descending until the endstop swith is triggered. After this, the first 0.2-0.4mm of any up movement by the Z-axis stepper and rod will not result in movement of the print head. To counter this the entire build must offset to move the entire model up and prevent this initial slop.

This turned out easier than I expected. By using the G92 an axis position can be adjusted. This will introduce the offset needed and will effectively cause an initial lift of the given value. So I added this command as the last initial command before the print. The resulting Start Gcode now looks like this.

G28 ;Home
;G1 Z15.0 F6000 ;Move the platform down 15mm
;Prime the extruder
G92 E0
G1 F200 E3
G92 E0
;Set the Z-position with offset to counter fab2 z-backlash issue
G92 Z-0.2

This will cause my prints to turn out good and not need any further adjustments. The solution has two drawbacks.

  • The initial movement of the print head will traverse the bed at 0 height. This can cause issues, but might also wipe the nozzle. Which is not always a good thing if it happens at a less preferable location.
  • The print cannot contain any lifts. Prints that would benefit from lifts can still not be printer with this printer.
So. This solves my issue short term. But I should probably try to solve the mechanical issues as well to avoid this hack.

October 2, 2017

3 printers, 3 failures

I have 3 3D printers. I don't know how I ended up with 3 but here I am. I have 3 cheap 3D printers. And it annoys me. Cheap DIY printers are really good for learning. And I have learned a lot. But they are not good for every day 3D printer when you just want them to work.

Yesterday I was sketching a few parts for the kit of BRIO MEC that my children are playing with. I wanted to print a few simple pieces which do not exist in the kit and I think should be there to make a few new construction possibilities.

So I fired up my 3 printers to print 3 pieces at the same time. And I got 3 failed prints.

To the left is a piece from the Mini Fabrikator 1, which also goes under the name TinyBoy. What happened here is the build plate is sticking to the guide bars, and the belt skips. I had this problem in the beginning so it is not new. But it will need some work to clean it up.

In the middle is a piece from the Malyan M150. It is not visible, but the piece is warped. Not really the printers fault, this PLA material warps and I don't know why. Aside from the material issue here, what annoys me most about the M150 is that the bed is unleveling "itself" with time and I have to spend to adjusting it regularly. Not something you have time for every time.

To the right is a piece from the Fabrikator Mini 2. The main issue with this piece is that it is missing its first 0.5mm. Simply because the Z-axis anti backlash is flawed in design and the X-axis gantry is not running smoothly on the guide bars.

After this I will really start considering getting a better printer and selling/giving away some of the others that are to unreliable.

September 28, 2017

Bad day in the HGLRC factory

Zero fucks was given on that very day in the packaging department.

It's not even remotely difficult to put the board correctly in the box. Must have had a terrible day at work.

The board looks really great at first glance. Nice soldering and it is cleaned, which is not always the case with that china stuff.

September 19, 2017

FPV150 got 3 flights

The FPV150 was flying fantastically after the upgrade. But after about 5 minutes one of the ESCs started cutting out. I wasn't running low on voltage or anything and it seemed strange.

Anyway, to make a very long story short, it turns out it is probably faulty. I cannot connect to it with blheli configurator and I actually found in my old blog post that I had this problem with another ESC while building the first FPV150.

So I set out to order a new device. It turned out harder to find than I expected. I couldn't find one identical. Instead I ordered two ESCs from hobbyking with similar specs. I was quite surprised hobbyking didn't carry more variants of this small ESC. Any way, I got a Kingkong and a Multistar. Once upon a time I promised myself never ever to get a multistar again. They used to be real crap. But hey it's revision 16. Sixteen! Did they get it right this time?

I guess I'll find out in a few weeks once I get those props spinning again!

September 12, 2017

FPV150 revisited

Today I finally spent some time one the FPV150 I built a year and half ago. I was quite satisfied with the machine except for a few issues. First off, it sometimes does strange things while flying, like tilting and pitched. Second, the flight controller is mounted so badly it must be unscrewed to connect the USB wire. And the flight controller; well it's a CC3D.

I have noticed the stream of all-in-one flight controllers integrating more and more functions in one single unit. First off was the PDB, but then voltage sensors, current sensors and OSD chips have been added. Even video transmitter on the most recent ones. I got myself the "HGLRC" F3 V3.1. It is essentially some form of Seriously Pro racing F3 clone. I regret not getting the version with video transmitter while I was at it.

I started with a weigh-in. Always interesting to see how this effects the weight. I'll be ripping out three parts and putting only one back in to replace them.


Ok. Now let's open her up. I remember it was quite hard to get it together with all the wiring and boards crammed into the the body.


I remembered correctly. Inside I found a CC3D board in a small form factor, a "super simple" OSD board, a orangerx receiver of some kind. I had used the PDB that came with the Diatone frame. And a noname video transmitter. So I ripped out everything but the transmitter that I left on the top plate of the frame.


Left was only the motors and the OSD. After this image was taken, I also de soldered the ESC leads and removed the camera "assembly". Then I started putting her back together again. First off soldering the ESCs to the PDB. Well, the PDB means the flight controller in this case.


I picked this particular board because i got the feeling that they had made many iterations and improvements on it. This can always be fake and a noname product from China can be utter crap no matter what facade they try to put up. But I think they've gotten quite far with this one. It is made to be fitted in a racing multirotor craft of course, and as such has the wire leads for the ESC just like the motor layout in clean/beta flight. Only this detail is fantastic alone compared to board from the history of FPV racing. It also has easily accessible solder pads for the receiver, instead of trying to put together one of those microscopic connectors for the receiver.


And this is what it looks like with almost everything wired up. Neat compared to what it looked like a few hours back.

I put everything together. No big deal. I kept the buzzer connected to a PWM output on the receiver. This is simply because I've had very little luck with buzzers connected to the flight controller so far. So I'd rather not. After everything was assembled I weighed it again. I was only 2 grams down. Well, I checked the weight of the parts I removed and the weight of the flight controller and it was essentially the same. The 2 grams is probably due to a bit less wiring. Maybe the capacitor that I forgot to solder back on.

After putting everything together I realized there is a big hole on the bottom of the quad, exposing the flight controller. The PDB covered this hole before. 


So I printed a piece of plastic to cover it up.


Setting up betaflight took me probably 2 hours in total. Almost as much time as the build itself. It is simply because I ran into a few issues with the setup and the work went completely without hickups for once.
I had a big problem with the board not arming as expected and I had to do a few things to get it sorted.
  • Upgrading the firmware. Because at some point betaflight stopped displaying receiver signals in the GUI. Maybe betaflight updated in the background and I needed to put in a new firmware. I don't know why.
  • Lower the refresh rates in the PID. The board reported 7% load but the LED indicated overload. I have no idea why.
  • Set the min_check manually. When upgrading the firmware I used the "diff" command as recommended to store my setup. For some reason diff exported a min_check = 0. I don't really know why.
Feels like flight controller setup routine. I have no idea why, but I had to fix 3 things and now it works. I just hope it stays that way!

Footnote 1: I weighed my JJPRO 130 as well to see the difference. At 195 grams I understand why it barely flies. It is too heavy for flying with only 3-inch propellers. It was a big disappointment as it was a drop-in replacement for the FPV150 that I never took the time to fix.

September 9, 2017

i2c controlled RGBW LED strip controller

This is part of a internet connected playhouse that I have been planning and building ever so slowly during the summer. The system will eventually consist of a internet connected device (ESP32), battery, solar panel and charger and some lighting installations in the childrens playhouse.

On the porch, I'm planning to install LED strips along the sides to fill the porch with light of selectable color (or even with special effects). It will be controllable both over the internet as well as using a wall switch. Part of the challenge here is to connect the device to the internet, or via something to the internet.

I chose to build a separate device for this purpose instead of integrating it in the main controller. This device will only drive the LED while controlled over the i2c bus from the main controller. There are many many guides on building your own LED controller but I have yet to see one about i2c.

Anyway. I started out with adafruit article on the matter. They make great simple articles and being not so skilled in electronics I was mainly looking for some ideas on which transistor to use for the task. I managed to get the transistor recommended by adafruit from ebay. Ebay is like the only simple source for buying electronic components in small quantities. I read the specs in the FET in question (IRLB8721) and I must say it is massively over dimensioned for my requirements. But I guess it will do.

i2c rgb controller, first setup
Early stage of the RGB LED controller.

As always I started with a first build on the breadboard just to see it working. I also did most of the programming at this point. On the picture is a second arduino sending a sequence of RGB commands to the controller for testing purposes. Worked well and turned out quite simple.

i2c RGB controller
LED controller, disconnected because the light messed to much with my camera.

Next step was to make the controller more compact by building it on a experimental board. This is probably about as good as it gets with my skills and tools. I've moved from a Arduino Nano to an Arduino Pro Mini. It's a bit smaller, mainly because it does not have a USB connector. Instead you need a USB UART/ISP (often incorrectly called an FTDI). Might seem scary, but once you've tried it it is not that bad.

I also had to add a buck converter as the strip I'm using is powered by 12 volt. I added a screw connector for the 12V power and JST-XH connectors for both the LED itself and the i2c connection. I've made a simple i2c bus connection hub previously to connect the devices in the playhouse together.

It all turned out quite good. The only main problem I had is that I cut off the LED strip to solder the wire to the newly cut end. This did not work out well since the light cutting and soldering seems to have damaged the printed copper surface of the strip. This turned into an intermittent lightmare (pun intended, I'm a dad, it's ok!).

September 7, 2017

Problems with mini buck converters

I've been using them for years and put them in so many builds I can't remember. I'm talking about the adjustable mini buck converter (banggood, ebay) . Dirt cheap, small and does the job!

Or do they? Well today I had my first failing unit. I was a bit surprised. I've never tested them before installing and had it half soldered for setting up the voltage correctly. But it didn't work, the converter put out nothing. And yes, I did measure and test and what not.

So I went through the hassle of pulling out the drawer and picking up another one. So this one works, but it tried its best to fool me at first.

So. Negative and positive input right. And negative and negative output? Turns out the last batch I bought all look like this. But except for the silk-screen they are all the same. And of course the output positive is on the same side as the input positive. And the negative is just ground so you might not even want to connect it if you have common ground elsewhere.

August 23, 2017

Mini Fabrikator / Tiny boy base with Raspberry Pi mount

I finally got a work-in-progress projekt finished today and it is well worth taking the time and writing a post on what's on the bench for once.

This time, I made a new base for my mini fabrikator. I had it hooked up the the computer until lately, but it had to move away from that location and I took the opportunity to fit it with a Raspberry to run it with Octoprint. The RPi does not fit well on the sides of the printer so I had to make feets with a bottom where I could mount it. 3D designs can be found on thingiverse.

I made a rather simple grid connecting to the feet of the printer.

Raspberry Pi bottom for Tiny boy
Tinyboy feet with Raspberry Pi. Powered with a 2 cell lipo.

I was unsure if the 5V regulator of the printer controller board would be capable of powering the RPi as well. Instead, I used my favorite adjustable buck converter. This is connected to the 12V power input of the printer.

Out of curiosity I also added a volt meter to monitor the input voltage of the printer to see if the power supply is powerful enough for the printer. The voltmeter is placed in a simple shell (see the thingiverse page).

In addition to the electronic components and the Raspberry Pi I also used 14 M3x14mm socket button head screws and nuts to put the things together. Using M3 screws is it necessary to do some drilling in the Raspberry Pi and use nylon nuts.

Raspberry Pi powered by the printer, with voltage meter.

July 5, 2017

ZMR250 Mods

As I mentioned before I got a ZMR250 together with the new googles I bought.

Since the build has a few flaws I have spent some time addressing them and adding a few upgrades just for fun as well.

First off I went though the solderings and resoldered the worst once. I also upgraded the flight controlled (early version of SP racing F3). I have also added a battery voltage sensing cable to the FC as well as a buzzer that is triggered from a radio channel. Later it turned out the buzzer I use is of inferior quality and it has given up on beeping. What is really lacking in terms of electronics now is an OSD.

The most fun stuff I've been doing is however is designing a few parts the I 3D printed for the frame.

First off is the camera holder. There was already a great design on thingiverse for the ZMR250 but for some reason my camera did not fit well so I made a derivative with a few small changes.

Foxeer camera holder

I did crash a few times, mainly grass cutting, during the first flight and I got a lot of grass and dirt in the frame. So I made some side covers to mitigate this.
Side covers.

New this season is a long awaited upgrade in terms of action camera and I have gotten a mobius mini to replace my old mobius that I have used for years. I designed a super-simple mount for it, prints well and works well. Looks well? Maybe not so much.

Mobius mini mount on the ZMR250.

I also made a holder the the video antenna. The hole arrangement with the transmitter (which is a bulky old Immersion) is not fantastic and I was unable to use the existing hole in the frame. The antenna mount protudes and holds both the antenna and power leads in place.

I have also made my own motor guards. I spent a lot of time and not so fantastic printing time on those but finally got a working design in the end.

ZMR250 with all the 3D-printed mods.

June 21, 2017

Micro-build? Custom color switch nuts

It's good to have a backlog of micro activities for those days when you have an urge to get something done but don't have time to start up anything complicated.

Today was one of those days. So I took the time to pimp my transmitters with colored nuts on the switches. Gives them a discrete personal touch. Purple is my sons favourite color and the choice was easy.

Custom colored nuts on the T14SG.

June 16, 2017

X210 First FPV flight

I finally took the time to take the X210 for a spin. I still haven't gotten the camera to work well in low light as in the evening. But now the evenings are bright enough that I can fly after putting the children to bed.

I felt a bit rusty at first but then the feeling started coming back to me.

May 30, 2017

JJPRO P130 Battler, first flight

I ordered the P130 a few months back when a few coupon deals came together and gave me a nice price on this piece. I just couldn't resist. I've built a small brushless quad a year back before the Chineese started pumping them out and I wanted to see where they were at.

After a long wait, as usual, and a few days on the shelf yesterday was the day I put the thing together. I had to figure a few things out with the connector that needed some reconfiguration to get SBUS going and I also made an antenna holder as I could find any suitable way to attach them and keep them away from the propellers.

I won't waste much time on the details here and skip directly to the test flight.

My first in a long time, family life cuts into the hobby budget from many dimensions. But I still got it. But this quad does not. It flies like crap. The power setup should be powerful enough but it is probably the propellers that limits it. If I push it even the slightest the rear left motor/prop hits the limit and the quad tilts or even flips.

So. Don't buy this, there should be better options out there!

May 24, 2017

Turnigy Fabrikator V2; first impressions

I ordered the Fabrikator v2 fairly quickly after its release. I have a v1 and I really like it but it has its flaws and I've been expecting a v2 which adresses some of those. To quickly summarize the promised features of the v2.

  • Heated print bed
  • SD card and Wifi
  • 100x100 build surface (slightly bigger than v1)

In essence, my first impression is disappointment.
  • It is noisy. Much more than the v1. And makes strange noises at that.
  • Wifi access seems limited to Windows users, I'll get back on that if I figure something out.
  • SD card is unusable without wifi setup, the printer has no screen or nobs.
  • Z-axis seems slower.
  • My specimen has an issue with the z-axis. But I can make it work by pressing the Z-axis down.

First print
It took me a while to figure out what was wrong with the Z-Axis to the printer to start printing anything but a ball of plastic. When it finally started printing I used the recommended "slow" settings. Just like with the v1 the recommended settings is way too fast. By dividing everything by 4 things started working more smoothly.

The first print actually failed miserably after about 5 minutes when the model detached from the print bed.

I have to give some points for the solid build quality of the encasing. It looks good and feels good and this is definitely a printer you can put in your backpack and show off at work or school.

May 22, 2017

Camera holder make for the ZMR250

So I got a ZMR250 "bundled" with the Fatsharks I bought second hand. The nice thing about this frame is that it has been around for some time and there are so many tutorials and printable parts out there to customize the frame as much or as little as you like.

This fine specimen had camera holder made up of essentially a few zip-ties. And it didn't really do the job.

So I printed the simplest camera mount I found on thingiverse. It turned out however that the fit wasn't so fantastic. I got the impression that the form factor of my camera wasn't the same as the maker of the camera holder.

So I made my own mod of it to better suit my needs.

I love how 3D-printing makes things like this really simple!

May 20, 2017

How other people build

I got myself a new pair of goggles. Fatshark attitude v3. A bit of a desperate move, they are pricy even second hand and I would rather buy the Aomway commanders but they never seem to come in stock. And then a month of shipping when they finally arrive. I can't wait that long.

With the goggles I got (at a price as well, but I had to buy it) a ZMR 250 racer. It's well speced and should come handy. When I received it I quickly realized a lot about how people build their quads.

I'm not that meticulous when it comes to building. I never get it perfect, I take a few short cuts and I try to improve every build I do. Good enough for me. But the build you see while at the club are usually impressive. Every detail is often perfect and to no surprise those builders like to show their work.

But you won't see the builds that aren't just as perfect. Here's one of those. I'll just give you a picture of the electronics. You get the point.

May 2, 2017

Inside the Fatshark Aviators

My FPV goggles has started giving up on me, or they more or less have already. There seems to be a malfunction in the power supply causing the goggles to restart every now and then. And that's not a good thing.

I decided to take them apart to see if I could locate the issue. So, I couldn't fix them (I'm not an electronics engineer).

What surprised me most was the very poor quality I found inside. Plastic wiring, dirty circuit boards and broken off plastic parts to make the parts fit inside the shell. And to get the receiver board to fit inside they have actually milled off a part of the RF shield.

Fatshark RF shield, fixed from factory?

Seriously! Where can I find the magic inside those plastic shells that motivated the price of this product?

April 26, 2017

5 minute fix for the wallmounted screen

As I blogged earlier I made a simple flush wall mount for the computer screen in my hobby room. However, the mount is a bit tight to the wall since the power connector is sticking out. Today, I made a simple fix for this, something I should have thought of earlier.

I simple drew and printed four standoffs for the screen mount. This way I can simply give it another cm and a half of space. I intended to make them longer, but I didn't have any screws long enough.


This might be the first real practical application for my 3D printer.

April 25, 2017

Build page for the X210

I finally took the time to document the build of the X210. Read more one build page. I will post more info as soon as I get flying.


April 2, 2017

REVO, Flip32 and raceflight?

This weeks biggest waste of time turns out to be Raceflight. I can't tell if it is the fault of raceflight or my own fault by trying to run it on an unlabeled flight controller.

Anyway. I got an unlabeled Chineese flight controller in the package for my X210 build. Banggood calls it a CC3D REVO F4. There is no such thing, but we already knew that already didn't we?

The board comes preflashed with the Raceflight firmware and identifies itself as, in fact, a Revolution board. It's still close to a Revolution, but it doesn't have all the chips on board (like mag and vario I think). The problems began when I realized I couldn't change all the settings in the Raceflight configurator. All options are not there anymore. The port configuration seems broken with missing options like MSP. Something fairly important in my case since I will run the OSD from the FC.

I don't know if it is a problem with Raceflight or the flight controller. I wasted two evenings trying to configure the FC using mainly the CLI (since the configurator is half-broken) and did not succeed. I even broke the firmware once and had to reflash the whole thing and had to start over. Additionally, the firmware takes a minute to boot, which makes the process rather painful.

But I finally figured it out and here's the recipe:

  • This board goes under three names;
    • CC3D REVO F4 (The Chineese favourite)
    • Flip32 F4
    • Airbot F4
  • Raceflight does not work on this board, at least not the latest community binary.
  • Betaflight works with this board. Flash it using the AirbotF4 target. All features are there and you can configure them without the CLI.

Smaller sensor for the X210

I did what I had to do to get a smaller sensor for X210. Even with this one it won't fit fantastically in the frame. But I can make it work this time.

I ripped it from the belly of the F-35. This is a plane that I would very much love to fly once more, but it is to far down on the priority list and thus unlikely. It is now also less one telemetry sensor, not that it matters in the air anyway.

This is the difference between the PRO and the non-PRO version. The size. The PRO is massive. In terms of specifications, it is the same.

March 23, 2017

X210 Build; telemetry sensor

This is part one on the telemetry sensor. I got this sensor second hand and had no idea it was the "PRO" version of the e-fuelgauge which is much bigger than the "normal" one. Obviously, with a size larger than the flight controller, this is a no go on this build.

E-Fuel gauge pro with Realacc X210

I will probably strip the sensor from another model to get a small one to use with this one. I can probably use this larger sensor for a larger model in the future.

March 11, 2017

Realacc X210, first impressions

I went through the contents of the X210 package I got the other day and cleaned up and sanded the edges of the frame pieces. My first impression is that the frame pieces are of fairly good quality for the price. I've seen much worse. I only noticed a few obvious quality imperfections, except for the fact that it was dirty and the edges were sharp.

X210 Camera mount

Above is a detail of the camera holder pieces. They stick down through the top plate and fixates to the bottom plate and contains a swivel point for both the flight camera and polaroid cube style action cam. On the lower plate the insets that fixes the plate to the top plate of the frame is not completely milled. Easy fix, but this is the details that imply the lack of quality control and overuse of worn out tools in cheap Chinese productions/clones. Nothing unexpected really.

Another thing i noticed is the lack of information about the flight controller. The kit I got comes with a flight controller which is completely unlabeled. The product page claims it to be a CC3D REVO F4. Such a product does not exists and the product title itself is not much more that pure clickbait. Banggood themselves actually carry a product by this very name. Checking it out it can potentially be the one I got. The board configuration seems to match up well with a Flip32 F4. The only reason I started digging into this was because I quickly realized I had no idea whatsoever how to hook up this unlabeled board. And in terms of manual or product information, there's not much to go on.

March 10, 2017

Realacc X210 on the build table

After a massive 55 days of transport and no less than 28 days in the air between China and Sweden the next race quad frame finally arrived. Or at least, the tracking information claims it's been flying for 28 days. But now it's here and I can start to plan the build.

Realacc X210

This is the stuff I'm planning to use. I've bought most of the stuff from banggood. I got the Realacc X210 package which comes with a set of racerstar BR2205 motors and 30A racerstar ESCs. It also includes a noname F4 flight controller.

In addition to this I also got a second hand R7003SB receiver and a e-fuelgauge at an online forum. Unfortunately the e-fuelgauge is the PRO version which is very big and it's going to be a challenge to get it to fit in the frame.

I terms of FPV I got a new transmitter, even thou I have a few in the drawer already. I wanted one with a display that displays the selected channel. I've grown tired of fiddling with the dip switches which you never understand how to get them right. I got a FT48X. I've never heard of it so we'll so how well it works out. To go with that I got a Foxeer HS1177. I've flow larger Super HAD boardcams since forever but they won't fit in the frames anymore. This camera is essentially the same in a smaller package. To go with it I got a backpack style OSD chip. I also got a Mobius Mini which seems really nice, both in performance and in form factor.

Building is right around the corner, but first off the frame need some cleaning and sanding as the Chinese copies usually comes dirty and with sharp edges.

February 10, 2017

One day build, computer screen wall mount

I did a one-day-build the other day. If Adam Savage can do it so can I! But in contrast with Adam, I usually get 20 minutes of effective work done during a day. Because of this those 20 minutes has to be effective.

I had this planned for a while. I wanted to have a wall mounted computer screen in the Hobby room, mainly to save space by not having it stand on the desktop. I did this before with the old screen that I mounted in the corner for the document reading computer, but this time I wanted to take it one step further by letting it hang on the already installed rails on the walls.

And the day came when I was doing some carpentry in another room so I had all the tools in place and was gonna get the room dirty anyway. And during the hours of carpentry it is easy to squeeze in some side tasks to get most out of those 20 minutes I mentioned.

The design is simple. I had ordered a new screen, with two requirements; cheap and with VESA mounts. I found a Samsung for about 100€ which is perfect for the task.

I then cut a piece of plywood. Old crappy plywood but does the job. 20 minutes does not suffice if I  need to visit the local hardware store, so I used what I had.

Then, just bring out the saw and start cutting it to fit the width of the rails. I also cut out lots in the sides of the bord to prevent it from taking up unnescessary space in the rails. A slot was also needed for the connectors and the mounting for the unused foot.

First round of cutting the plywood board.

The screen had a part of the foot which is fixed to the screen, and cannot be removed. Unless you pry it open and unscrew it that is. So I had to do that, but it wasn't much of a problem.

1 cm thin screen with 3-4cm ugly foot sticking out the back.

Screws to the foot accessible from the inside when the back plane is slightly lifted.

The foot problem has been fixed.

Screen mounted as intended, without the cables...

A bigger problem turned out to be the connectors. That wise-ass at Samsung that designed this 1 cm "thin" screen did not think of putting connectors on the back that does not protrude. So, with the screen comes a power cord and a HDMI cable which will stick out some 4 cm behind the screen. I will solve the issues with the HDMI cable with a angle adapter, but the power cord it a bigger issue. Currently the screen hangs slightly tilted due to the power cord. I'm considering adding standoffs where the screen is screwed to the board to move it about 1cm further from the wall.

January 24, 2017

Document reading computer in the hobbyroom

I've seen this a couple of times, especially in my friends garage and workshops. They have an old computer and screen mounted on the wall of the shop for one single purpose; easy reading of documentation while working in the shop.

This was an idea I had from the beginning with my new hobby room. The room is small and workspace is limited. Placing a laptop or tablet on the workspace would take up space and the tablet is impractical when not standing up. So, maybe a wall-stand for a tablet? Might work but has the drawback that you must touch it to navigate. And, compared to the reuse, would come and a cost.

Instead I have an old screen stowed that I wanted to use for this. To go with this screen I have used a computer I bought as a potential replacement for my boxee. The computer is an Z83 that I purchased a while back. It is a cherry-trail (Atom) based small form factor computer which comes at a reasonable price for the performance. It came with Windows 10 preinstalled but I installed debian on it as I have gotten used to the features Linux gives me. It did however not pass the WAT (Wife Acceptance Test) and was quickly shelved.

The screen I used is an old 1024x768 screen with a VESA mount on the back. I screwed a piece of plywood to the mount to be able to attach the screen to the wall. The setup takes up limited space on the workspace and I can use a cordless mouse to navigate the documentation while working.

Below is a picture with the documentation computer in action. Here with a 14SG manual on display. Yes I know, it is still chaotic on the desktop, but the hobby room is still a work in progress.

Hobby corner with the documentation computer.