A New Motor Run Electronic Controller with DT and auto surface functions for Free Flight Competition and Sport Models
Introduction: This controller has been designed, developed and fabricated by Dan Kennedy (F5D) with the added assistance of seasoned competitor Peter Tolhurst (E30,E36, BMFA Electric). The functionality includes motor load and motor run time control with VIT, AR, wiggler and DT ability via a single servo and release levers. The controller comes as a 16 character 2 line led progamming unit and a controller with a start switch mounted on a fly lead. Prices as of August 2013 are £25 and £17 respectively. I hardly need to add that you only buy the programming unit once ?
What's in the box?
On the left is the programming unit
(this is not airborne). On the right is the controller (4.3gm) to be mounted in
the airframe complete with start button.
The reverse side of the programming unit showing an 18 pin PICAXE chip mounted on a commercial(?) PCB. Top right is a jack socket which can be connected to a USB port on a PC to download new software to the controller should the occasion demand. This is not something that the end user has to do, just a nice feature provided by the developer with 'future proofing' in mind. I.e software changes are easy.
Herewith a close up of the airborne unit. To the right are three pins in Futaba format for connection to the programming unit for data transfer from the programmer. To the left are 2 rows of 3 pads, one row to take the ESC Futaba connector and one row for a micro servo. Dan would normally fit pins here but in an E36 'Pearl' pylon there is only 19mm of internal space and straight pins with a Futaba plug might not package. So I ordered without pins for a soldered joint. The 'push to make' switch is Maplin or Ebay. A much smaller and lighter PCB mounted switch would be an alternative but would be a disadvantage during launch as the timer starts on button release.
The 'other' side of the airborne unit. Not easy to see (lower centre) is a surface mount LED which blinks data at you .(low voltage, ready to launch and other stuff).
The programming unit, now mounted in a ply/balsa box and plugged to the controller board, in a test set up consisting of :-
Robotbirds 1800kv 20gm outrunner
running an APC SF 8 x 3.8 propeller
The 3 buttons, top to bottom, provide increment, decrement and enter functions. Spot the airborne controller tiny ain't it?
Testing : Plug the programming lead into the controller and connect the battery. The display shows a welcome screen then a supply voltage and then you get
This is the motor power or load. Fiddle about with the + or - buttons and hit enter when you get to where you want. The next screen appears.
This is the motor run time , note increments of 0.1 sec ideal for E30, E36 BMFA Electric and F1Q. Increment or decrement the time until you are happy and hit enter.
The software continues with screen settings for a 5 position servo movement requiring inputs for position and operating time at each position.
When the software settings are complete you get a summary of the data you have just input and hit enter to download it to the controller.
A full description of how to operate
the programmer/controller is given in the attached notes written by the
developer Dan Kennedy.
Power unit testing: This is almost an anti climax. Hit the start button for 2 secs and the motor chimes up . The LED is solid (battery voltage higher than low voltage cut off) . Release the start button and the timer starts. Abort the run with a further press on the start button if you wish. Controller is powered down 2 mins after DT and cannot be restarted until the battery connections are cycled. ESC gives out a 'no signal' squeak helping retrieve.
This is a very grown up controller with almost the same functionality as a Black Magic at a fraction of the cost. It is simple to set up and operate and so far has performed faultlessly with consistent timings of motor and servo. You do not have to tweak pots or set the variables using DIP switches. At the price it is an absolute steal!
This will be going in a 285 sq.in 48 in span Pearl. This was built with a FlytProf digital controller with DT and locked down surfaces but I will build a second fuselage with VIT, AR and DT to compare the flight systems.
If you want to purchase a Dan Kennedy controller please contact me and I will give you his email address. Note if enough guys buy a programmer you can always cadge it to tweak your settings ? Hence it will cost you £17 +pp for a very functional free flight controller which you can programme standing on your head eating a bun.
Ian Middlemiss August 2013
Contact address firstname.lastname@example.org