Academy 1990 1/35 M60 with low cost RRC setup

[modler]

This is my first 1/35 scale Academy model tank. It compares well with the Tamiya model. I can not decide which one I like better,

This Tank comes with a 2 channel "Wired Remote Control | WRC" system and will be converted to Radio Remote Control |RRC using a inexpensive ebay 1/72, 2 channel, RRC M1128 Stryker.

Anyway, in this thread I will show how an inexpensive ebay 1/72 scale radio control M1128 Stryker donated its 2.5 channel, 27mhz radio control receiver,Transmitter so the M60 could be put into operation with an inexpensive yet good working radio setup.

I ordered a pair Stryker's about 5 months ago and after running them around several times, realised they would be good donors for my model fleet. I have somewhere around 50 model tanks or so and like to have a dedicated radio for each one so I often use "toy grade" models as the source of the radio gear. The ones they are making these days work better than ever and are very small and robust and contain all that is needed (dual ESC's, RX) and can run on a lipo cell or 2,3,4,5 cell nimh batteries. Most of mine run on lipo cells.

The Stryker runs off a LION cell which is pretty sweet as these cells hold their charge indefinitely it seems. LION cells work best in low current applications and the Stryker is definitely low power but the radio will be reconfigured to use 4 cell 400mah nimh battery.

It takes a bit of soldering skill to convert one of these receivers and a bit of electronics knowledge but nothing too extreme.

note, the M60 model as not been finished as far as outer body parts.

The hardest part is converting the receiver to use 1.5 micro connectors. These must be soldered on the circuit board then, the receiver can be installed of removed quite easily. There are some other little things that I do to them during the conversion that will be discussed here.

Meanwhile, I will share this video I made yesterday showing how well this RX works.

https://youtu.be/-G1ivbDPMKI

The cost of this radio conversion, $20! + a couple of hours time but then its a hobby

[modler]

Here are some pictures of the radio gear used in the M60

[c.rainford73]

Very nice it runs quite well nice and smooth

[modler]

Very nice it runs quite well nice and smooth

Yes it is smooth and the reason is that the low impedance (3V) motors are wired in series and a custom DTL array controls the steering. I have developed this configuration after much trial and error over the years (in my spare time).

You are seeing the result of this work in the video. This is how $15 worth of electronics controls this M60 tank in a very smooth and precise way.

Here is the short video again. Both Tanks in this video use the DTL circuit and work the same even though they have different receivers in them thanks to the DTL circuit.

https://youtu.be/-G1ivbDPMKI

In the picture below, two analog DTL circuits are shown. The one on the right was freshly built and used in the M60 of this thread. The input side (2 pins) is the right channel (L|R) input. The single pin is the serial motor steering output which is connected to the serial motor steering input wiring.

This DTL circuit can be custom tuned to compensate for track tension variation etc but generally is tuned for the different radio output motor drive circuit strength.

Basically inexpensive RRC receivers are non linear voltage\current strengths between the positive and negative outputs of each channel. This DTL circuit corrects this issue which is only a issue when trying to get precise control output voltage\current from a inexpensive RRC controller.

The DTL circuit consists of, 1 NPN 4401 Transistor, 2 small signal switching diodes with a FWD V drop of .7V, 1 1k 1/4 watt Resistor. My goal in the design was a very simple circuit that could be whipped up pretty quick from common generic electronic parts.

I only recently perfected this simple design

[modler]

In this video I show a King Tiger with a metal hull (very heavy) 1/35 scale model with the DTL circuit and a low cost toy RRC controller. If you watch the Tracks full screen, you will see the scale like performance in the left turn shown in the video. Now this is a heavy metal hull tank that is hard to control as the transmission is under a heavy load and it has rubber tracks. The King Tiger (I think that is what it is) was originally a single motor free running switch controlled model with a metal hull. I modified the transmission to dual motor (15 years ago) with twin gearbox (won't do that again) and it would usually run a few times before the transmission would start to slip or grind. I realised that it needed better track control for the fragile transmission to survive so this was the impetus for the DTL mod. It all started here with this model. Originally, after the twin engine mod with gearbox upgrade, the motors were wired in parallel with a common (dual stick) control method like used on most toy RC tank models. I never liked this type control method because both hands are required to operate the Tank. So I went series wired twin motors which gives you some more options and is a more sophisticated type control IMO. Why? because the L|R turn can be done with better control with help from a DTL turning circuit that does a (hard wired programed) twin track turn control that is more reliable and less repetitions than "twin up|down" track control.

https://youtu.be/m7nmXfySaP0

here is another..less than 3 minutes, This is a heavy Tank with a modified gearbox, 1 motor upgraded to 2 motor, not easy lol
https://youtu.be/pK2dX8otI98

[modler]

The M60 runs very good with the toy grade receiver and DTL steering tuned serial motos. The Radio control receiver used has 2 speeds out, low\high and has a dedicated small Transmitter and is very simple and easy to operate. My wife who is not a model enthusiast can operated it after a short training session and is not intimidated by the Transmitter. If I handed her a HG TX she would probably say "Oh, this is too much" and hand it back and have no interest if proceeding further with a Tank run. Also it requires little to no prep to use a simple TX at a moments notice and other benefits to Toy grade radio gear. I have found this gear lasts for decades and is very robust.

Here is a short White Table run of the M60..
https://youtu.be/0-V7tXjSTOo