Monday, December 26, 2016

Making Slot Car Tires


As Christmas approached when I was a kid and Rudolph the Red Nosed Reindeer aired on the TV, Dad would return from the garage with an enormous box emblazoned with "Thunderbolt III" and a picture of two race cars battling to victory.


We set up the Strombecker slot car tracks and, grasping the blue speed controllers, we brought to life the epic struggle of white Chaparral 2D and yellow Ford GT 40 Mk II, father versus son.

I still have that old slot car set. And now a child of my own. And though Dad left this life in 2010 and mom passed away in September, they'd be happy to see my 7 year old daughter and I reliving those moments from my own childhood.

Except... when I finally unwrapped the cars, stored carefully 35 years ago, the tires fell apart in my hands. Rats.

After some online research, I discovered one can create custom slot car tires using a 2-part RTV silicone rubber. So that's what I did.

Saturday, December 24, 2016

Hello LED

My wife and daughter adore Hello Kitty. No, I mean really, really adore her. No, see, I don't think you quite understand. Here, let me just show you what Christmas looks like at the Bot Thoughts laboratory:


This Christmas we faced a major problem that would totally ruin our holiday season.

At night, the smallest of the inflatable Hello Kitties were really dim! And the lights inside them were --gasp-- not user replaceable!

Before: Small kitties are dim!
Well, we are not users, are we, gentle reader? With a little knowledge of electronics, we can fix the "unfixable". Here's how things looked with only 3 kitties left to fix.

All but three kitties have been upgraded
So, here's how we brightened up our Christmas Kitties...

Monday, December 12, 2016

DIY Vehicle Speed Sensor Buffer

Here's the riveting tale of how I created a Vehicle Speed Sensor (VSS) interface circuit for my Jeep Grand Wagoneer (yeah, that Jeep).

Jeep VSS
Speed sensors are used by cruise control systems and by fuel injection computers. Jeep used one for the former.

I wanted the sensor for the GM throttle body injection (TBI) system I retrofitted onto the Jeep's old AMC 360 c.i. V8.

Back when my Jeep was built, vehicle speedometers were driven by a flexible steel cable, the speedometer cable, connected by a tiny gear to the output shaft of the transmission.

Jeep, as with other vehicles of the era, split the speedo cable in half and stuck the VSS in between.

So, with insufficient hobby funds to buy an expensive, off-the-shelf Vehicle Speed Sensor/Buffer, but wanting to reap the benefits of a VSS, I created my own interface. Here's how it went down...