Building a Penny Pusher Arcade Game

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raynerd:
I'm no woodworker but £15 lighter after spending it on 18mm MDF have this together. It is took me a good few hours. I've no tool to rebate the inside of the window for Perspex - hummmm, not sure how I'm going to get plastic into this windows and make it look acceptable :-S

Mine and my daughter best efforts.

John Rudd:
looking at the photo of the unit I'd say the pwm is based on 555 timer chip....yes the pwm frequency is set by the module.....

if this is the case,check to see if pins 6&2 are connected together :
There should be a cap between pins 6/2 and pin 1

Reducing the cap value by a factor of ten will increase the frequency ten fold......See how you go with that...

S. Heslop:

--- Quote from: raynerd on August 01, 2013, 03:27:44 PM ---I'm no woodworker but £15 lighter after spending it on 18mm MDF have this together. It is took me a good few hours. I've no tool to rebate the inside of the window for Perspex - hummmm, not sure how I'm going to get plastic into this windows and make it look acceptable :-S

Mine and my daughter best efforts.

--- End quote ---

Something like this might work. The rails could be glued and/or screwed on. Hope it's clear.

They might also serve to strengthen those struts. MDF is a bit of an odd material and tends to sag over time when used in things like shelving.

Bluechip:

--- Quote from: raynerd on August 01, 2013, 03:25:07 PM ---Bluechip - so basically, am I correct in thinking based on your information that it is the Pwm controller and its specific base frequency that is causing a frequency in the audible range?

--- End quote ---

Chris

Yes errr -ish :scratch:

Whether you like it or not, every mechanical device has a resonant frequency, including any bits that are in it. So, imagine we have a PWM controller running at 1kHz. Every 1mS the armature gets a kick of current producing a kick of magnetic field which interacts with the permanent magnet field and jerks it round a bit. Now we have converted electrical pulses to a mechanical vibration. If there is some bit wanting to vibrate at 250Hz it will get what it wants every 4th poke from the armature and vibrate it will. ****tering wine glasses trick etc.

I'm not quite sure why you are going the PWM route on a bit of kit that will run at just one speed. I would determine the DC volts required and make a linear, possibly with something like a L200 ic.

PWM is nice for lots of motor antics but it's not the only way.

Dave BC

EDIT Why do I get ***** s h a t t e r i n g is not a profanity AFAIK

wheeltapper:
Probably because sh something t sounds like sh something else t. :Doh:

Roy

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