Nigel's MRRC project sorted

Nige’s controller successfully tested after a transistor and wiper board change back to the old standard 108 ohm total for the Tip36c. How I ever worked without this simple tester......? I will try amend the blog postings to drop all references to the ill conceived shorter travel and less ohm spreads, when I have a mo.

Nige’s board soldering attempt suggested for me (personally) that below is a far more logical approach in buying a Difalco pre-made board, complete with resister arrays that can be unplugged to change to a whole range of values – helluva cheap at the price for a Rolls Royce bolt on to the MRRC, with the bonus of 30 bands..... Just fit pots, tranny and hook up wire only – I have ordered my own through North Coast Hobbies.

1/32 HD30 UPGRADE PCB (Suits the Le mans MJ type)
DD553: HD30 Upgrade PCB: Convert. You get the HD30 circuit board with a standard 290 ohm resistor network board installed. Simply unsolder a few wires and remove the old PCB. Transfer the original brake and sensitivity rheostats over to the new HD30 board. Now bolt the PCB to the frame and solder a few wires to their correct positions. Simple instructions included.

Or

1/24 HD30 UPGRADE PCB (Ok for the Tip36C type or use the DD256 113 ohm array for exact)
DD261: HD30 Upgrade PCB: You get the HD30 circuit board with a standard 148 ohm network board installed. Simply unsolder a few wires and remove the old PCB. Transfer the original brake and sensitivity rheostats over to the new HD30 board. Now bolt the PCB to the frame and solder a few wires to their correct positions. Simple instructions included.

DD255: Standard Resistor Network. 180 ohm
DD256: Standard Resistor Network. 113 ohm
DD257: Standard Resistor Network. 78 ohm
DD262: Standard Resistor Network. 290 ohm
DD258: Custom Resistor Network. 136 162 and 192 ohms.
DD260: Custom Resistor Network. 64, 87 and 113 ohms of total resistance.

That completes all my committed or otherwise foisted on projects and no more third party projects will be entertained – it was spoiling my attendance at racing, even if that is spotty;-)

Simple controller checker for three pin plug type

Given my infrequent trips to Ecurie and distance involved, any transistor controller repair or development had ground to an effective halt as a consequence of the tedious delays in testing the units. A simple diagram off the British Darkside slot car site (see link at bottom) suggested that the new three pin plug and socket system now provides an excellent opportunity for a simple test unit.

A chat to Erlo and a tip from flying buddy Mark lead to the purchase of the white 5amp three pin plug socket shown at the left. I flirted with retaining the US controller three colour red/white/back approach but then decided I would stay with black/red colour shown for intuitive ease of hook up to the DC power supply source and test motor/car. When I can actually locate the Brit diagram drawn to controller colours on the net again, I will add that but for now it is actually easier to tell than draw:

1. Two negative black wires twist together and connect to the earth E (bigger) terminal [controller red]. One negative black lead connects to the DC power source and the second negative black lead connects to the test motor or car left negative braid.

2. One positive red wire connects to the live terminal [marked "L" - controller white] and across to the positive lead of the DC power source.

3. A second positive red wire connects to the neutral terminal [marked "N" - controller black] and across to the test motor or car right positive braid.

That's it! The DC source can be max 13.8 volts DC right down to my 8 volts DC unit Lance made us for Dremel cutters etc and worked fine in my case. Obviously mounting the 5 amp socket in to a box would be the next step.

The controller in the second pic down is Jono's, which was a basket case example of why unravelling insulation tape is a poor second to heat shrink tubing. Both adjustment pots and the NPN transistor had been changed without success but it was suspected that the thin red wire to the insulated wiper may have fractured internally under movement load or the intense heat when the the controller cooked. It was simple exercise to check, replace and immediately test the controller on the new tester - with great success. Those up the north coast may have heard the cheer at midnight last night ;-)

The controller savvy folk will by now have twigged why the German slot car racers insist their controller cable colouring is correct and the more common US colours incorrect. Our red "brake" cable is in reality the negative (black) common feed from power source to car!

Now that I at last have this bogey controller repair sorted, I can aim to finish off Nigel's new MRRC project...... ;-)

The useful "build a simple controller checker" article located here:

http://www.darksideracing.co.uk/page19.html
http://www.darksideracing.co.uk/controller%20checker.pdf