SATRAN - Satellite Tracking Antenna

3D-printed, wifi-enabled and android controlled antenna rotator.

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A compact satellite antenna azimuth/elevation rotator with android app. Available from my website as an affordable kit, but it's also possible to 3D-print most parts yourself!

This is a continuation of an old project of mine, when I built a simple satellite antenna tracker with an android app that calculates the position of any satellite using its "kepler elements", and controlling the Az-El antenna rotator to track it across the sky. During a few late nights together with two other ham operators, we built a crappy but functional prototype from spare parts. Now some years later, I decided to redesign it from the ground up as an affordable and easy to use kit.


The onboard microprocessor is an ESP8266 NodeMCU board with wifi-capability that can be controlled manually in a web-interface or automatically through an android app.

Motion happens with the help of two Nema17 stepper motors, and the rotator has a platform that allows for many different kinds of antennas or a small satellite dish.

Now available from my website!

Kits are soon back in stock on my website and the open source STL-files for 3D-printing are also available there for download.

If you have any request or feedback, please let me know! 

/  Daniel

  • The workshop is growing

    Daniel Nikolajsen04/01/2021 at 14:55 0 comments

    Since I am looking to build an injection molding machine to speed up production, I will also need a CNC mill to prepare the molds. I have this simple engraving machine that I built many years ago, and now its finally getting a complete overhaul. 

    First of I am rewiring all the crappy cables or "birds nest" that I call it. Since I built the machine when I was in school I didnt have cash to buy proper cables and connectors, but used anything I could find.

    The machine used to rely on an old Win XP machine with a parallell port that crashed completely some time ago. Now I have bought a USB controller board (the red one in the pic) so I can use it with my newer 32-bit Win7 computer instead. The former computer got cut open and I am rebuilding its case to house all the electronics for the new machine. 

    Later I will replace some of the mechanics to make it more sturdy. The goal is for it to be strong enough to mill aluminium. 

  • Testing, 1, 2, 3...50

    Daniel Nikolajsen03/31/2021 at 16:58 0 comments

    Every single board I make is compiled, hooked up to motors and tested before I ship it off to eager customers around the globe. And today was "test day", with 50 boards getting their firmware. 

    I still havent gotten the last damn screws in the mail so I can sell some more kits, but hopefully tomorrow. Today I found suppliers closer to home, so the next batch will hopefully only take 3 weeks instead of 7.

  • The small factory

    Daniel Nikolajsen03/28/2021 at 14:05 0 comments

    One just isnt enough. At the moment I have two printers making noise in my office almost continuously. But the next few months I probably need to invest in building some sort of injection molding machine, which in turn actually requires another 3D-printer - SLA resin printer - for making the molds. But thats OK, I love 3D-printing almost as much as pizza, which is a lot!

  • That's quality!

    Daniel Nikolajsen03/25/2021 at 14:23 0 comments

    I was a bit relucant to spend 60 bucks on a JST crimping tool, but damn it was worth every penny! 

    Not the fastest way to produce the cables, because it is "single action" you need to crimp twice for each little connector. But quality takes time, and I am not in it to mass-produce anyways. I am more than happy building top notch rotators that people can enjoy for years to come.

    Now I'm only waiting for a batch of screws to arrive, hopefully next week. Then I can open the shop again and take some orders, always nice when your hard work pays off. And I'm sure you are eager also to get your hands on one of the kits!

  • Stepper motor times a hundred

    Daniel Nikolajsen03/24/2021 at 13:45 0 comments

    Its not everyday that you order a hundred stepper motors, but thats exactly what I did two weeks ago. And now they are here! 

    The motors have been one of the biggest issues in scaling up production, since there arent any great producers here in Europe. But after a lot of searching I found a supplier in the far east that can handle the volumes and has a reasonable pricing, but most importantly - can deliver in weeks and not months. 

    A big shipment of screws are now the last parts that I am waiting for before I can start to sell the next fresh batch of Satrans. Hopefully they'll arrive this week *fingers crossed*

  • It's crimpin time!

    Daniel Nikolajsen03/23/2021 at 13:54 0 comments

    Whats worst? Crimping micro JST connectors, or pulling out your fingernails with a pair of pliers? Probably the connectors...

    Since I wanted a more professional way of connecting the DC power cable to the control boards, there werent too many options. I bought the quality looking crimp tool to the left for less than 20 bucks, which felt like a reasonable investment. But a few hours later I came to one conclusion... that it's complete and utter crap!

    First I abandoned the plan completely and thought of replacing the JST XH connectors with really small screw terminals instead, but that bugged me for days. So I emptied the savings account and went out and got the one to the right. A japanese-made quality tool for 60 USD, called Engineer PA-09. Hopefully it will pay off in the long run, but its probably the most expensive "pliers" I will buy for years to come. 

  • Considering injection molding

    Daniel Nikolajsen03/22/2021 at 11:03 0 comments

    When scaling up production, 3D-printing quickly becomes a bad alternative. I have two in the shop working constantly, but because of the long time it takes to make the parts for a single Satran - the satellite tracking antenna rotator - I can only produce around 10 full kits each month. 

    Its possible to buy another printer or two, but I can do better stuff with my time than to babysit the printers all day. Also the quality of FDM-prints can be quite low, with all the layers showing. But its great when I make tweaks to the design, with almost zero time until I can start producing it.

    The professional way of making plastic parts are called "injection molding", which requires very expensive molds. I got a quote here in Sweden for almost $10k for a single mold, and my design uses more than ten different parts. There are some cheaper producers out there but its still a minimum $2k per part. Hence not an option.

    But what if.... I could make it the DIY way?

    A surf around the web revealed an exciting new way of making molds with an SLA 3D-printer. The surface finish probably wont be 100% factory-perfect, but it would still be a lot better than 3D-prints, and would bring the production time for some parts down from 6 hours to a few minutes. Also it would combine the possibility of rapid prototyping with the ability to produce tens or hundreds of parts in no-time.

    All I need besides an SLA-printer is some heater element, a little metal work and a hydraulic log splitter... perhaps I should give it a try? 

  • Suck up all the fumes

    Daniel Nikolajsen03/20/2021 at 15:21 0 comments

    When you have 50 circuit boards to solder in a row, the fumes can get quite annoying and unhealthy. Thats why I built this very simple but efficient solder fume extractor. 

    An old computer fan, a 3D-printed housing and two layers of an active carbon filter stolen from a kitchen fan. Removes pretty much all the smoke and smell and cost me more or less nothing. A very good investment in my health and sanity.

  • Getting organized

    Daniel Nikolajsen03/19/2021 at 08:12 0 comments

    Building a prototype is a whole different arena than mass production. Thanks to the large interest from all over the world, I am scaling up this production run, so keeping all the parts in a big box just wont do it anymore. 

    Since every single part is needed before I can start to ship every kit, inventory management is something I am slowly developing, using classic lean management techniques. There are lots of bottlenecks to solve still, but being able to produce five times as much in the same time frame is a big accomplishment for me. Hopefully you have the patience to wait a little bit longer before I can meet the demand. 

    Getting the product in the hands of amazing satellite enthusiasts and ham radio operators is my main priority. And I am loving every second of it...

  • Small adjustments, big impact

    Daniel Nikolajsen03/10/2021 at 06:16 0 comments

    The new batch of PCBs arrived a week ago and I've started soldering all the components. This time the goal is to put up 50 kits for sale on the site, which means a lot of work but also lots of fun.

    I updated the board to v.1.1 but there arent any big changes. The major change is nothing more than a bigger capacitor of 200uF instead of 100.  It seemed that the smaller cap could give an unstable current or voltage spikes from the stepper drivers, that resonated in the stepper motors sometimes giving of an audible noise.

    Also the text is a bit different, with the new website address and also the copper tracks for the power is wider to make sure it can handle all the power, but maybe this also had something to do with the strange whining sound. All in all, they work perfectly now.

View all 32 project logs

Enjoy this project?



ahsima1 wrote 02/26/2021 at 18:06 point


The STL files for the "Top plate" and "Turret base" seem to be different from the pictures. Looks like they lack the groves for ball bearings. Can you confirm those are indeed the right files, or if they aren't, upload the right files.

  Are you sure? yes | no

Daniel Nikolajsen wrote 02/28/2021 at 09:22 point

They are the right ones. the BOM was an old one but is updated now. The continuous ball bearing grooves didnt work, the balls stacked up against each other and made too much friction. In the current version there are only 8 balls on each layer, evenly spaced.

  Are you sure? yes | no

Mihai S wrote 02/12/2021 at 19:25 point

HI, for the past 3 weeks I've been printing like crazy different rotors projects, I like your project but where is the firmware? github?

  Are you sure? yes | no

Daniel Nikolajsen wrote 02/12/2021 at 20:15 point

Shop will open in approx a week where you can buy control board with firmware preinstalled (EU customers only, exports will begin in about a month)

  Are you sure? yes | no

k.jurczok wrote 02/05/2021 at 09:15 point

good luck with adversity. I believe that the failure will be managed quickly :)

  Are you sure? yes | no

k.jurczok wrote 02/01/2021 at 09:57 point


What is maximum load of this rotor?

  Are you sure? yes | no

Daniel Nikolajsen wrote 02/17/2021 at 06:43 point

It's built for smaller antennas, the exact weight limit is still to be tested.

  Are you sure? yes | no

jed wrote 01/27/2021 at 15:47 point

Perhaps you understand this, but your 10 ohm steppers take a higher voltage to get to 1A. The A4988 driver carriers that look like what you are using are good for up to 35V and more voltage equates to quicker ramp time to the correct current. Your 9V is near the 8V MINIMUM for these drivers. Also, remember you can only measure stepper current when they are HOLDING and not turning. If you'd rather use 10 ohm steppers, try 24V.

What a great project! Best of luck!

  Are you sure? yes | no

Daniel Nikolajsen wrote 01/27/2021 at 16:07 point

Exactly I didnt realise first that it was 10ohm motors I had. Since the entire board needs to run on a single power supply it needs to be at 8-10 volt because of the NodeMCU and A4988. Otherwise the controller board needs to be redesigned with extra voltage control, and because of the cramped space in the housing the entire hardware probably would need to be redesigned too. Thx!

  Are you sure? yes | no

Thomas Daniels wrote 01/18/2021 at 16:38 point

Hi, this looks very interesting and affordable. I have a few questions: Will this rotator be strong enough to carry a 2m and a 70 cm XYagi, each about 1,5m long? Is it watertight enough for permanent assembly outside? Can it be controlled by connecting to an IP-address using any browser? (I do not have any androids here). And how much will it be? If I understand correctly, you are still in the development process?

  Are you sure? yes | no

Daniel Nikolajsen wrote 01/22/2021 at 06:17 point

Hi, a double antenna system with such large arrays I think should be too much for this design unfortunately. Also it is not completely weathertight and durable enough to withstand hard wind, so not recommended for prolonged outdoor use.

 But if I get enough response I hope to make a better version (but more expensive) later on made from aluminium, stronger motors etc. The first version thats still in development is made to be a cheap and simple, costing from around 60USD for only the controller board up to perhaps up to 230 USD for a full kit. The first will probably be available for sale early february. 

It can be controlled via IP/browser but since the positioning (calculating the direction) is done in the app, you need some other software to know where to point the rotator. Perhaps Gpredict (win) and others could work.

  Are you sure? yes | no

jcwren wrote 01/18/2021 at 00:15 point

It's an interesting rotator design and is nice and compact. My concern is the amount of load you're putting on the gear train as the antenna changes azimuth. If the antenna is balanced and the antenna is pointing at the horizon, there's no stress. But as the azimuth increases, the load dramatically increases as it's not balanced on the pivot point as it is with a conventional antenna rotator. When the azimuth is 90 degrees, the gear train is supporting the full weight of the antenna and it's increased because it's cantilevered. What are your thoughts about that?

  Are you sure? yes | no

Daniel Nikolajsen wrote 01/18/2021 at 05:39 point

That's correct, it's not perfectly balanced. But the design isn't made for use with any large 2meter yagi antennas that weigh many kilograms, but for smaller types perhaps a 70cm yagi or some compact LPDA type.

Also when the antenna is in zenith (pointing straight up), the entire antenna is offset from the axle but only with a few inches. This means that the torque on the elevation worm gear is actually not that large.

But changing the axle (M8 threaded rod) to a longer one and putting a mount directly on the axle shouldnt be a problem either if you prefer that approach instead. That should also be preferred if you want to have two antennas - one on each side.

  Are you sure? yes | no

Tom wrote 02/03/2021 at 21:31 point

I can't see it struggling to drive something like this:

  Are you sure? yes | no

Daniel Nikolajsen wrote 02/09/2021 at 08:02 point

No Tom, that yagi shouldnt be any problem, also in my video (and on all the boards I'll ship) the stepper drivers are only tuned to around half capacity to be sure not to overheat anything. With tweaking you could probably more than double the torque without any issues.

  Are you sure? yes | no

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