Thursday, January 22, 2015

3d Printer Part 2

I had not grounded pin 1 on the 555 is why it wasn't working. The following gif is a simulation of what it looks like working:

I took a picture of it on and one of it off and since I had to touch the camera the image moved. I edited the rest of the image out with an opaque mask but didn't align the two images positionally. That's why the gif looks like universe warps around the lit led. The real circuit is flashing about twice as fast as it is simulated here. The rate can be changed by fiddling with the resisters and/or capacitor. The is a formula one can use to maintain tight control but I don't need it for what I'm doing. I wish I owned an oscilloscope- then I could be one of the cool kids.

I'm powering this stuff with an atx power supply. Red wires have 5v+. Ground out the green one and the power supply gets turned on- oo la la!

This is the circuit I'm using minus the led connected to vcc.

Notes to self:

A+ = Black
Acom = Red
A- = Brown
B+ = Yellow
Bcom = Blue
B- = Orange

https://learn.adafruit.com/downloads...per-motors.pdf

Wednesday, January 21, 2015

3d Printer Part 1

I am going to build 3d printer for a cheap as I can.

The posting is meant to document my progress and keep me focused and motivated.

In holiday season, I'm always slow because people don't get their crap repaired when they're busy buying new crap. Consequently, I'm broke right now so some forward movement will require waiting on me to get out of this financial hole. I was wanting to buy a 3d printer outright all built, but for a few reasons(besides brokenness) I'm going to build one. I read a few books and watched a documentary on the subject and his dude's instructable convinced me I could adapt current open source firmware and supporting software to any Cartesian printer as the g code language never changes. The printers are surprisingly simple in what they do..

To begin I dug around in the garage and found a scanner I have knowing the travel will be pretty long. Too bad I've thrown away a zillion printers and scanners in the last year- doof. Here it is sans lid with some of the guts removed:


And here is how I am going to use it with the scanner's glass as a traversing build bed-. I believe that to be the x axis.



I can't order the computer yet but I can mess with the motor and of course that is more complicated than just plugging two wires in. The motor in the scanner and all of the other motors I'll be using are stepper motors so they require some orchestration. Right now I'm making a pulsing circuit from a 555 timer as I have done many times but this one isn't working:


Once I get the pulsing circuit working, I'll figure out the pin outs and sequence to drive the motor and run it on a ttl counter. The final project won't need all those shennigans as stepper motor drivers will be mounted right on the RAMPS Arduino shield.

Monday, February 17, 2014