Home The News Buddy Box and Simulators by James Gamble
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Buddy Box and Simulators by James Gamble E-mail
Written by James Gamble   
Wednesday, 06 January 2010 17:27

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At the recent AGM it became apparent that some of our new members and existing ones would like the option to use the buddy box facility which is often incorporated into most transmitter modules.

This sparked an idea to write a small article to help our members and future ones to train and improve on existing skills so as not to suffer some expensive and frustrating consequences on the field.

One option for learning is to have an experienced pilot by your side or stood over you helping with the controls or to brave it yourself, but the latter usually results in something like this


Two safer methods of learning RC are either by using a buddy lead system or a simulator program. Which ever option you choose will not cost you more than a few pounds and certainly will improve confidence and model lifespan.


Buddy box leads are available for most transmitters and likewise interface leads for the PC, but these do not have to be purchased! You can make them very easily.

The Buddy box system

The first thing to do is to find if you transmitter has the facility to allow a connection to be made, and this can be found usually on the back cover or on the side and can take various forms depending on manufacturer.

Below is a link to MFTech which shows as far as I can see virtually all transmitter pinout permutations.


The two connections required are Signal and Ground (in PPM mode).

Sometimes a diode is used on one end of the connection, but it is important to note that Hitec and Futaba are fully compatible but will not work in QPCM or PCM mode, both have to be set to PPM, also linking JR(Spektrum) to either Hitec or Futaba poses a different problem as the signals levels and the first 3 channels are in a different order. This can be overcome by using one of Ken Hewitt’s intelligent buddy box leads found on http://www.hewittonline.net/lead/lead.htm

If you decide to build a buddy lead, try to opt for a screened cable as to reduce interference and solder each end to the relevant pins on a corresponding plug for the type of transmitter you are using.    

Simply remove the crystal from the transmitter which is to be used as the trainer, connect up the lead and set each transmitter up as Master and Slave respectively and you’re set to go. You can also buddy mode 1 to mode 2 depending on the transmitters used.
Early Futaba 8UAP used a 10µH coil on the trainer board which went open circuit when connected to a Hitec trainer unit with the TX battery in!

Futaba 9ZHP has 5V + through centre pin which is earthed to plug shield on
Hitec buddy boxes!

So do check voltages/signals and pinouts first!! Just remember that not all transmitters are compatible and if you’re no feeling confident and competent with wiring then just buy a lead or check with local model shops.

Wireless systems are available and can be found at http://www.2icrc.com/features.html

I also believe that Futaba have developed a ‘wireless trainer system’ WTR-7 for FASST 7-channel mode which could be worth considering.


Flight Simulators

PC simulators are a fantastic tool that really can improve flying.

Many simulators are available ranging from £20 to £150, but I chose FMS as it is free.

Its options and graphics are improving and at present ‘Version 2.0 Alpha 8.5’ (Windows 95/98/ME/2000/XP) is the latest download.


Below is the FMS home page link where you can download the basic program and various aircraft along with basic landscapes.


Simulators are a great way to learn but are always going to be slightly different from flying at the field.

The truth is that if you are a beginner or have a small amount of experience in flying, this simulator is perfect. Its muscle memory that you are trying to achieve, that split second decision which way to move the sticks and not trying to replicate characteristics of particular models and situations i.e. dead stick or engine and prop size! 

I’ve incorporated a few screen shots just to give you an example using landscapes downloaded from http://cmreel.com/?page_id=58


Indoor F3P Manta                  Extra on the field                                                        


Pitts over Beach and sea


My first attempt (around 6 years ago) to interface a transmitter to the PC involved using a resistor and zener diode inside a 25 pin D type through the serial port. The transmitter I was using at the time was an old Futaba M series using a DIN connection but worked very well considering it cost about £1.50 to make.

Other options like I use today are the USB interface to a square 6 pin Futaba block, which requires a lot less setting up and for around £10.00 ESKY and GWS offer a range of leads at a very sensible price with the option of changing the plugs to suit whatever transmitter you choose to use.



The above link shows you how to make your own cable if you’re interested.

By removing the transmission components i.e. crystal / antenna (so as not to overload the final o/p transistor stage) the transmitter can then be then connected to the PC.

A stall at one of the recent model shows were selling FMS with a basic transmitter all packaged up for around £20.00, which is fantastic value but they usually come in mode 2 and require converting if you’re a mode 1 flyer, so why not use your own transmitter, set up as you like it with neck strap etc, download the same program for free and just make or buy a lead!

Try allocating a spare model space in the transmitter’s memory just for FMS but be sure to change back and replace the crystal before trotting off to the field!

Hope this helps

James Gamble