Tony Betts

Tony Betts

Tuesday, 17 February 2015 15:30

Bare Bow

Hunting by Moonlight

Tuesday, 31 March 2015 13:12

The Centrifugal Gun

Here is an article and drawing from the early part of the 20th century. Imagine this all in polished brass on a mahogany base. I can see a new project coming!

Though this silent shooter throbs with electric power, it’s based on just about the oldest ballistic principle on record—the one that helped David clobber Goliath with a sling: pick up a missile, spin it to gather force, then let go. Wham!

Not that this cannon is any giant-killer. We kept it small to be on the safer side. But it’s a great demonstration of centrifugal power, and it’ll shoot a BB 25 or 30 feet at a muzzle velocity of around 25 feet per second. This may set you thinking of the potential of a centrifugal gun whirled by a gas turbine at, say, 20,000 r.p.m. With an effective wing radius of about 6 in., you’d get a muzzle velocity of over 5000 f.p.s.— better than a high-powered rifle!

The spin mechanism is simple and cheap to build. The toy motor is mounted by sol­dering its lugs or bushing (or both) into a hole in the bottom of a cellophane-tape can. The rotor that’s spun by the motor shaft consists of a base plate to which is soldered a short tube, bent and slotted to allow free passage of the BB shot. This unit must turn without binding; the pick­up spike must pass freely through the end slot. Bevel the opposite end of the tube flush with the top of the can cover.

The end of the magazine tube is under­cut and bent so the dropping BB enters cleanly into the whirling pick-up tube. A large paper clip provides wire for the trigger. Pulling back on it releases one shot while blocking the others. This lets the rotor recover its speed between shots.

Friday, 31 October 2014 17:56

Arduino Powered Pinball Machine

Ah Halloween has passed but does that mean i have to stop playing my Elvira themed digital pinball machine.
A real Makers dream this was cobbled together using one 15″ screen and one 23″ HD screen. Powered using a low form factor motherboard, super fast graphics card and lots of memory.
software is XP running visual pinball withloads of tables installed
Sound from the internals of some speakers that were lting around the workshop
Custom built cabinet with 5 buttons and a wooden plunger.

But then came the difficulty how to control all the buttons, normally for this an IPAC or equivalent is used but not wanting to spend any more it was down to whats lying around the workshop!.
Luckily there was an Arduino Leonardo sitting around connected to a few leds not doing much. A quick search on the net and a few rewrites to get rid of button bounce and we now had our first Leonardo controlled pinball machine.
Great Fun and now up for sale as i need the room to build the next project!

Heres the code:
int timer = 500;
int timer2= 100;
int previousButtonState = LOW;
int previousButtonState3 = LOW;
int previousButtonState4 = LOW;
int previousButtonState5 = LOW;
int previousButtonState6 = LOW;
int previousButtonState7 = LOW;
void setup() {
// make pin 2 an input and turn on the
// pullup resistor so it goes high unless
// connected to ground:
pinMode(2, INPUT_PULLUP);
pinMode(3, INPUT_PULLUP);
pinMode(4, INPUT_PULLUP);
pinMode(5, INPUT_PULLUP);
pinMode(6, INPUT_PULLUP);
pinMode(7, INPUT_PULLUP);

void loop() {
//if the button is pressed
int buttonState = digitalRead(2);
if((buttonState != previousButtonState) && (buttonState ==LOW)){
//Send an ASCII ’1′,;
previousButtonState = buttonState;
int buttonState3 = digitalRead(3);
if((buttonState3 != previousButtonState3) && (buttonState3 ==LOW)){
//Send an ASCII ’5′,
previousButtonState3 = buttonState3;
int buttonState4 = digitalRead(4);
if((buttonState4 != previousButtonState4) && (buttonState4 ==LOW)){
//Send an ASCII ’9 replace esc’,
previousButtonState4 = buttonState4;
int buttonState5 = digitalRead(5);
if((buttonState5 != previousButtonState4) && (buttonState5 ==LOW)){
//Send an ASCII ’0′ replace enter,;
while (digitalRead(5) == LOW) {
// do nothing until pin 2 goes low
previousButtonState5 = buttonState5;
int buttonState6 = digitalRead(6);
if((buttonState6 != previousButtonState6) && (buttonState6 ==LOW)){
//Send an ASCII ‘z’,;
previousButtonState6 = buttonState6;
int buttonState7 = digitalRead(7);
if((buttonState7 != previousButtonState7) && (buttonState7 ==LOW)){
//Send an ASCII ‘?’,;
previousButtonState7 = buttonState7;

Friday, 29 August 2014 17:51

Valentines Arduino and Woodwork Project

Heres a fun design for valentines combining woodwork, electronics and programming skills.

What can you do with a box full of spare leds some scrap wood and a soldering iron!

This is a 40+ led message with a charliplexed heart in the centre all behind a birdeye maple veneer and cherry case.  Until its plugged in it just a nice polished wood case, plug in and the leds glow through the veneer.

Hardware is the brilliant shrimp arduino clone from, these have to be the cheapest easiest way to play with arduinos, add in a simple 9v circuit to give more power to the non arduio controlled leds and you have a really simple effect circuit.

Whats not simple is soldering the charliplexed heart, this has to be the most complicated cluster of wire I have ever soldered and definitely not for the faint hearted

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