I've been busy for the past few days preparing a beginner's tutorial for connecting and setting up the TK-22. Since I am using this board for this build, I figure this thread would be a good place to put it. The TK-22 is the first custom RC tank control board I have ever used, before that I had the old RX-14 board. I chose the TK-22 because of the following reasons:

-Easy to install - all the cables necessary are already included with any stock RX-18 Heng Long tank. This is pretty much plug and play as you will see very soon.
-Support for HL and Tamiya battle systems - even though I don't do IR battling very much, having compatibility with Tamiya is always a great thing.
-Servo recoil and elevation - This makes a world of difference when installing the turret functions.
-Great sounds - there are a lot of versions of the TK-22 available, each with its own engine sounds, depending on the tank you have.
-Easy and straightforward programming - No need to connect to a computer or playing around with computer programs, all the programming is done via a Sony TV remote.

So let me show you how easy it is to install this board. First, let's take a look at the electronics and cables that are required. Note that all of these cables and connectors are included with any HL RX-18 tank, the only modification I did was to extend the wire length.

First, we have the engines:

Next is the battery switch cable, the smoke generator switch, and the volume knob:

Here is the turret traverse unit and the MG ball mount with the gun barrel LED, they are connected to an 8-pin connector. The two cut wires shown were connected to the head lamp LED, I had to cut it to make disassembly easier:

Next is the IR receiver (apple) mount from the turret. Once again, to make removal easier, I've cut the two wires for the IR emitter LED in the mantlet, as well as the little thin wires from the recoil unit. The rest of the unit is untouched.

We also have the speaker, seen previously:

and lastly, we have the HL recoil and elevation units. I will not be using these as I prefer using the servo recoil and elevation features on the TK-22.

I've also disconnected the barrel flash LED (always found it a bit gimmicky).

Lower Hull Functions:

With all the electronics and cables gathered, let's take a look at where they go on the board. For your reference, I've made the pin-out picture below. You may want to save it for future reference:

First, let's connect the receiver cables. You must have a receiver of at least 4-channels, I'm using an E-sky 6-ch 2.4 GHz receiver. For standard Mode 2 transmitters, go ahead and connect the four receiver cables to their corresponding channel numbers on your receiver (CH1 -> CH1, CH2 -> CH2, etc). Note that for Mode 1 transmitters, you must switch the CH2 and CH3 cables (i.e. CH2 -> CH3, CH3 -> CH2).

Next, connect the drive motors, the speaker, the volume control, and the battery/main switch cable to their corresponding sockets on the TK-22 (refer to the first picture above). The connectors only fit in one way, so you don't have to worry about accidentally reversing the polarities:

Connect the 8-pin upper hull cable with the turret traverse and MG LED units attached:

At this point, we are ready to test the lower hull functions! Center all your transmitter control sticks and trims, set all servo reverse switches to normal, turn on your transmitter and the battery switch, you should not hear any sound coming from the speaker. For a Mode 2 transmitter, your right stick controls the directional functions, move this stick around and you should see both drive motors and their gearboxes move. Once again, there should not be any engine sounds coming from the speaker!

Now we are going to turn on the engine sound, note that the TK-22 allows you to run the main drive motors even with the engine sound off (as demonstrated previously). To turn the engine sound on, move your your left stick to the lower right position and hold it there for about 2 seconds.

You should hear the engine starting up and idling. If you don't hear any sound, play with your volume knob and check all your servos reversing switches.

Now move the left stick to the lower left, you should hear the machine gun sound, and the MG barrel LED should be lighting up:

Lastly, center your left stick and move it left or right along the center line. You should hear the turret rotation sounds and the turret traverse unit should be rotating. The great thing about the TK-22 is that the turret traverse function is fully proportional! The further you move the left stick, the faster the turret will rotate:

That's it for now! By the end of this post you should have a fully functional lower chassis and turret traverse. Next post I will show you how to install the servo recoil and elevation, which will require a tiny bit of programming with the Sony remote:

TK-22 Programming Tutorial - Servo Recoil and Elevation:

The TK-22 by default, is programmed to work with the Tamiya recoil unit. The the HL gun elevation unit can be installed as well, but requires re-soldering some wires to achieve bi-directional control (for more information, consult Clark's website: http://www.clark-model.com/eng/prod_rx20/index.html). For beginners, I recommend using servo recoil and servo elevation, since these do not require soldering, and are easy to install. This will also be a good opportunity to showcase the TK-22's programming functions. In this tutorial I will be showing how to program the following functions:

- Enabling servo elevation
- Enabling tank momentum
- Disabling track recoil
- Setting the gun reload time to 5 seconds

The servo recoil is enabled by default, so if you plug in a servo into the servo recoil pins, it will still rotate no matter type of recoil unit you connect (i.e. Tamiya or HL). This also means that no programming is necessary to enable the servo recoil!

Before we begin programming, you must connect the apple into the commander's hatch socket and the 5-pin IR cable to the IR Receiver and LED port. There are two 5-pin sockets on the TK-22 so be careful not to mix them up!



For a stock HL IR tank, the LED in the gun mantlet is actually an IR LED used to send the firing signal to the opponent tank. For programming purposes, you must replace this LED with a standard light LED because its flashes will be used as a visual feedback to indicate which setting you're on. I actually ran out of LEDs so I will use the cable that I made for my T-34 to demonstrate (this is identical to the set-up in the previous picture, minus all the grey plastic and with the addition of a red LED):



Next, you must short the first two pins on the recoil servo terminal using a jumper as follows (pic from Clark's website):



With the main battery connected, turn on the TK-22 but not the RC transmitter! Remember to install two AA batteries into the Sony remote.

Enabling servo elevation:

To enable servo elevation, press (do not hold) the green POWER button until the LED flashes 4 times:



Enabling Tank Momentum:

With the momentum feature on, you will no longer have the jerky start-up and stop like on a stock RX-18 tank. Instead, the motor will spool up and down slowly when you are accelerating and decelerating, simulating the weight of a real tank. To turn this on, press the SLEEP button until the LED flashes 2 times:



Disabling track recoil:

Never liked the track recoil when the main gun fires, it seemed too gimmicky and toy-like. To turn this off, press the SURROUND button until the LED flashes 2 times:



Setting the gun reload time to 5 seconds:

The default reloading time is 9 seconds, which was too long for my liking, so I decided to change it to 5 seconds. To do this, I pressed the "4" button until the LED flashed 5 times:



And that's it for programming! Now unplug the jumper from the servo recoil pins and turn the TK-22 off. Next, plug in the recoil and elevation servos, pay attention to the wire orientations here! The black wire should be facing outward:



Set-up is now done! Turn on your RC transmitter and the main battery on the TK-22, move the right stick to make sure that the drive motors are functioning fine. You should notice that with the momentum turned on, the gears spool up and down much more smoothly.

To fire the main gun, push the left stick to the topmost position, you should hear the gun sound coming from the speaker and the recoil servo should rotate as well:



To elevate or depress the gun barrel, move the left stick roughly to the "75% throttle position" and slide it left or right. You should hear the gun elevation sounds, as well as seeing the elevation servo move:



I recommend doing all of this with all the components disassembled from the tank and laid out in front of you. Doing so can prevent the tank from accidentally rolling off the table and also helps you identify any loose connections or incorrect wirings:



The TK-22 has much more programming options available, all done by pressing various buttons on the remote. For the full list, please see Clark's website:

http://www.clark-model.com/eng/prod_rx20/index.html

Anyways, this pretty much sums it up, I hope you enjoyed my tutorial!

Now back to the build...

Nate