21 st Century 1/6 scale M5 Stuart R/C tank   |   home
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first R/C conversion
the infos on this side are outdated , but I figured I leave this here ,
as reference for the guys followed these steps

( back to the up to date version )


converting this M5 Stuart tank to a fully proportional Radio system is almost a must
I plant to do this with Tamiya's multifunction-system out of one of the 1/16 scale tank's
but as an cheaper solution I was thinking about this conversation here
the main thing is to have proportional control over the 2 drive-motor's
what can be done with 2x 12 volt ESC's ( electronic speed-control )
( my choice here cost's around $ 55.- each )
I am assuming that you already have a 4 channel radio-system with 4 servos
( if not , a 4 channel 27mhz system starts already at around $ 100.- ,
or a 75mhz FM system for arround $140.- )
The idea is to use the existing 27mhz transmitter but ( the transmitter-board only ) installed inside the tank ,
and the function's get triggered over 8 micro-switches ( a couple bucks out of an electronic-store ) mounted to 4 servos ..
( of course I could re-engineer the existing 27mhz receiver-board , but this here is done a little quicker )..
I believe by shortening the antenna from the 27mhz receiver-board and using the transmitter-board inside the tank
it should work okay without catching any outside interferences from other 27mhz radio's
the 2x 12volt ESC's would be connected parallel to the 2 micro-switch-equipped servos
( triggering the driving-functions on the transmitter-board inside the tank )
the other 2 micro-switch-equipped servos would be used to control the turret-rotation and machine-gun and main-gun firing
adding an additional micro-switch-equipped servo or even an small ESC
could be used to control the in future installed gun-elevation,
or even what I have in mind to install a paint-ball-gun...
in that case a 6 channel radio would be a better choice ...
but this idea here is mend to be as a quick-fix and as cheap as possible ,
but still to archive the proportional driving-functions and keeping the original sound-board...

this was the first version , installing the modified transmitter-board inside the Stuart tank
the final version by just using the original Stuart R/C board with proportional interface see below


here now the first photos from that "budget-conversation"
here at my first test I had only the drive-motor's connected proportional....
but since that work out okay , it should be not a problem
to connected the turret-rotation and machine-gun / main-gun-firing the same way
below you see the first photos from this "test-setup" before I installed it in the tank..
for this test I had used the 9 volt battery for the transmitter-board,
and not rewired as shown in the diagram above...
I also replaced some connectors with better ones
and changed the way I will route the wires inside the tank
detailes and photos how it looks installed will follow ......


I am asuming you have a 4 channel-radio with 4 Servos,
the 2x 12 volt ESC's , the 2x servo-Y-connector's and the 8x Micro-switches is arround $ 160.-
and then you need 3 - 4 feet servo-cable,
 what I used as connection between the transmitter-board
and the micro-switch equipted servos


tracing from the individuel functions on the transmitter-board


right now only the controls for the drive-motor's are connected , rest will follow !!!
in the moment I powerd that transmitterboard with an ordinary 9 volt battery connectd via a battery-clip..
what could be also placed in the battery-compartment
or a little more high-tech , connected via a voltage-regulator..
the transmitter-switch stays always on , since the power will be switched , or just the battery connected ...
the soldering on the transmitter-board is a little tricky ,
you have to be very carfull and good in soldering ....
if anybody has problems with that or doesn't feel like he can do it ..I am more when happy to do it for you....


shown here each side from a micro-switch-equiped servo ...
the functions ( switches ) on the transmitter-board are negative-switched ...
the black-wire is used as ground/negative and each colored wire activates 1 function....
micros-witches used are NO ( normaly opend )


these are the 2 x 12 volt ESC's ..very nice units , very smooth ...2.4khz switching-frequency ,
10 amps continues current ..what is good enought for the type motor's installed in the Stuart
( see here  Motor analyses   )
these ESC's are original designed for large model-rail-roads , like the LGB or similar ..
therefore no brake , but a nice smooth reverse like forward ....and completely water-tide !!
1 button-setup , super easy ...with 5volt 1 amp BEC-circuit ...
these ESC's are made by Mtroniks in the UK
on the left ESC you can see that I removed the power-wire ( the red one ) ,
 since it can lead to disturbances if you use 2 BEC-circuits running into 1 receiver ...
I soldered a plug on this wire and also connected a negative ,
that way I have an additiona 5 volt 1 amp source for additional functions in the future ..
the thicker red / black wires are the looped 12 volt , the yellow and blue wires are the motor-cables,
yellow = positive / blue = negative
the switches on each ESC will stay always on , since the main-power ( 12 volt ) is switched )
each one of thee ESC's is connected parallel ( over a servo-Y-cable ) with 1 micro-switch-equiped servo
to the receiver ...

this is not a must , I just wanted to get rid of the cheap connector's .....


2 more Servo's with micro-switches are needed  for turret-rotation and machine-gun / main-gun-firing

photo's how it look's installed will follow ,
also detailed instructions how to do it and where to get the part's from ....
so far I just can recommend you guy's not to run out right away and go shopping for parts ,
first I have to finde a better quality-micro-switches, the ones I used from Radio-Shack are cool because of that little roller ,
but I am not thrilled with them with the switching reliability.......
I also need to do a few more test's when everything is installed in the tank
( I had it in there , for a " dry-dock-test " ),
to find out the best routing from the wiring not to create any disturbances,
also the right lenght from the receiver and transmitter-antenna ...
I am also considering the option , insteed of using mirco-switch equipted servo's,
the use of electronic-switches..( means transitor-triggered ) with small relais
soldered directly to the transmitter-board
( the additional relais are needed because we need a tru open-contact for these functions ,
a transitor-switch still has always an resitance smaller when infinity ..
it work's for lights or motor's , but not for sensityve switching like we need to do in this case )
( that is a little more expensive , but will have a higher reliability )


these electronic switches ( shown here a 2 channel-switch )
are also adjustable , means the triggering-point for each channel can be preset
that way a function like at Tamiya's MF-tanks ...
gun-elevation and shooting on the same channel
could be done with 2 of these switches connetced to the same channel
but preset with different triggering-points
I get these 2 channel-electronic-switches as kit's ...
somewhere arround $ 20.- .. ( 4 needed )
small relais are arround $ 5.- ( 8 needed )
so by using these electronic-switches you are looking into aprox
$ 110 .- ( 2x 12 volt ESC's ) + $ 20.- ( Y-connector's )
+ $ 120.-( electronic-switches and relais ) = $ 250.-

if any of you electronic-wiz's out there has the time.... ..
the next upgrade would be to eleminate the transmitter-board
and use these switching-funktions just with the receiver-board
since I didn't had the time to examine the receiver-board ...
( this deal with the transmitter-board was  easyer and quicker to figure out )
maybe one of you guy's could get his head smoking on that one ...
the same parts I use here to trigger the transmitter-board could be used for the receiver-board ,
is just a matter of finding the right connection-points .....

okay here we go , Ted has it figured out :
( thank you Ted , saved me some time ... )


and here I found a real cool mixer-board , not just an ordinary Elevon-mixer ,
this one is optimized for dual ESC track-vehicles,
very smooth , gives you that Tamiya DMD style driving ....I tested it and I love it ....

connected between the receiver and the 2x ESC's ,
has even a function for inverted driving ....
Status-LED makes setup real easy ...

so know it's time for you guy's to warm up your soldering-iron's and get to work ....
here now the updated wiring-diagram

this was the second version


It's done now !
proportional controlls via interface with the Stuart receiver-board !