Author Topic: Electronic Cycloid Drawing Machine  (Read 820 times)

Offline cfellows

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Electronic Cycloid Drawing Machine
« on: November 29, 2018, 07:33:36 PM »
In my early teens I ran across plans to build something similar to this in a Popular Mechanics magazine. 



I've long been interested in building one of my own but just never got around to it. In recent months I've begun thinking about an electronic version where the gears would be replaced with stepper motors.  Three steppers would be required,  a primary gear stepper, a secondary (driven) gear stepper, and a stepper to drive the center rotating table.  More steppers and even linear motions could be added to increase the movement variations.

Each Stepper motor "gear" would be contained in a separate little box with a magnetic base.  Since the steppers don't need to touch each other, they could be positioned at various locations around the center table using a steel plate for the base to hold the motors firmly.  An Arduino will drive the steppers using mathematics to maintain the gear ratios much like gears with teeth.  The number of teeth on each "gear" can be changed dynamically and each of the motors can be reversed independently of the others.

I'm working through the user interface at the moment.  Programming will be next and actual construction of the moving parts should be dirt simple.  Stay tuned.

Offline efrench

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Re: Electronic Cycloid Drawing Machine
« Reply #1 on: November 30, 2018, 12:35:20 AM »
That's not complicated enough  :D Search for 'geometric chuck' on the web.  You'll find one with seven layers  :ddb:

You may want to look at using a Teensy 3.2 (or higher) for driving the steppers. It's a 32 bit version compatible with Arduino.  One library, TeensyStep, can do synchronous  motors.

Offline BillTodd

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Re: Electronic Cycloid Drawing Machine
« Reply #2 on: November 30, 2018, 04:40:47 AM »
Geometric Chuck   :thumbup:


Electronic version: now you've got me thinking about a python version ...
Bill

Offline BillTodd

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Re: Electronic Cycloid Drawing Machine
« Reply #3 on: November 30, 2018, 04:53:44 AM »
Chuck,

I can recommend this Pulse Train Hat (http://pthat.com)  for a Raspberry Pi  . It has the great advantage of four DSS (Direct digital synthesis) oscillators that have super accurate and wide frequency range (9 significant decimal digits -  0.000 to 500,000.000Hz) .  It is serially controlled with ascii text strings so can be controlled via arduino if you prefer.

Bill
Bill