Tamiya King Hauler Project

Page 5:  Installing the Multi-Function Controller



My intention had been to build the whole truck stock and only install upgrades after I was done.  However it occurred to me that I had no speed controller because I had intended to install the Multi-Function Controller in this model.  So what is the MFC?  It is a combination speed controller, lighting controller, and sound system.  This is an expensive option, costing as much as the whole truck and therefore doubling the price.  I didn't really know what to expect, but I had to give it a try.   This system is much easier to install now during the initial build than later.



Inside the box you'll find quite a pile of parts.  There is the controller, 21 LED lights, a speaker, a vibration unit motor, some switches, and a bunch of plastic parts which make it possible to install this kit in any of the Tamiya 1/14 scale trucks, even an old truck like this which existed before the MFC.


   

After labeling all the wires with the included tags, I just had to hook everything up on the table and try it out.  At the left nothing is connected.  The wires you see coming from the control unit for the motor, the power, and the receiver are hard wired to the unit.  On the right only the lights are connected.  You can see white, amber, and some red hidden in the back.  There are 15 connections for lights labeled J13-J27.  Many of the light harnesses contain 2 LED lights, but some such as the blinkers or shift markers contain only 1.  If every slot is filled there would be 23 lights.




Now everything is connected.  The MFC controller needs to be connected in series between the radio and the servos so that it can react to transmitter input.  You need to study the provided complex wiring diagram pretty closely to get everything right, but all the important bits have unique connectors so you can't really screw them up.  After you've connected the lighting, there are no too many connections left.  There are 3 harnesses (a 3-wire, a 5-wire, and a 7-wire) that go to the control box which has switches to turn everything on and off and adjust settings.  There is one connection for the speaker and another for the vibration motor.  Finally, there is one for the remote switch which will sense when a trailer is connected.  There is also an empty slot which can be used if you connect trailer lights later.




Here I've installed the vibration motor.  This is a little electric motor connected to an offset mass.  It is most noticeable right when you start the "engine" because the whole trucks shakes.  It also runs continuously as long as the model is on and it's speed is proportional to throttle position.  The vibration it produces is significant and hard to miss. You can adjust the relative speed of the motor with a little switch on the controller.  This is important if you have anything that might be resonating and causing a problem.  It goes without saying the vibration motor needs to be mounted solidly in a strong location.




Here is the speaker box.  This is a sizable speaker and it gets much louder when enclosed in the box.  The speaker goes inside the cabin so you can't use the seats, pedestals, dash, or steering wheel when using the MFC.  In order not to see the MFC and all the wires when the model is finished, the instructions recommend painting the windows with "smoke" which is a dark translucent color.  I followed this advice and it worked very well.  You can control the volume of the speaker from the control box.  The speaker is loud enough to be heard far down the road and to drown out the sound of the electric motor.




A micro-switch has been installed in the coupler.  This allows the MFC to know when a trailer is attached.  It makes a "clunk" sound as you hook up, and then the sound of the engine pitches down when towing to reflect the higher strain on the truck.




The is the control box which takes the place of one of the battery boxes under the driver's door.  I was a bit surprised to see that there are three separate wire harnesses connecting this controller to the MFC; it seems like they could have all been combined into one.  From the control box you can switch on the system, switch between modes, control the lights, and set the volume.  The 3 modes are:



Now I've installed the MFC in the truck.  There was a pretty big problem here.  The MFC has instructions for how to install the unit in various truck models, and it says to see the truck instructions for more specific details.  For the King Hauler, there is just an overhead view but it doesn't say how to install anything.  The vibration motor obviously needs to be screwed to the deck, and the speaker gets connected with Velcro, but from above all you see is that the controller goes on top of the battery and there are no further details in the truck manual.  I checked the Grand Hauler manual which is a very similar truck and it showed how to install a mounting platform above the battery.  However, the King Hauler does not come with the parts for this mounting platform.  I had to make my own platform by making some supports from chunks of sprue and using a surplus coupler plate as a platform.  After an hour of work and a lot of CA I got something that works OK.  I am surprised that Tamiya missed this though because they generally think everything out very thoroughly.

As you can see, there are a LOT of wires here.  Most of them are for lights.  Only 6 of the 21 lights attach to the chassis, the rest all connect to the body and therefore have to be connected only when the body is attached which is far from easy.




Step 40 installs the front and rear bumpers.  I went ahead and installed the LEDs at the same time.  Here you can see the tail lights and turn signals.  The tail lights get brighter when braking.




Although it is not time to install the body yet, I couldn't help but dry fit it onto the chassis to see how it looks.  It is still pretty dark and featureless without the stickers and trim.  Of course, the room is also pretty dark because I do most of my building between 9:00 p.m. and 1:00 a.m.

I went back later and swapped out the MFC-03 "Euro-Style" for the MFC-01 which has a better sound for this kind of truck.  I also replaced the front white LEDs with a variety that looks more like old halogen lights.

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©2017 Eric Albrecht