I can control steppers on the PI!

Dear blog followers,

Sorry I haven't been keeping up with the blog. I will use this post to catch you up on the last few weeks.

 Much progress has been made on the laser cutter. I have acquired the Raspberry PI that I will be using to govern the hardware, and the stepper motors and stepper drivers. I will discuss the BOM of parts here and later present the CAD model.

Here are the parts that I have sourced: 

Coupler:

https://www.amazon.com/LGDehome-Coupling-Coupler-Alumlnum-Casing/dp/B072LRBBM7/ref=sr_1_1_sspa?s=industrial&ie=UTF8&qid=1519147729&sr=1-1-spons&keywords=5mm+to+8mm+coupler&psc=1

Shaft:

https://www.amazon.com/gp/product/B002BBF9SY/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=AFLT987H7WA7G

Pulley:

https://www.amazon.com/dp/B071W6CHN9/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B071W6CHN9&pd_rd_wg=p6Yzx&pd_rd_r=H3ZJFG8EV1T66DHHSHKE&pd_rd_w=cy9KL

Timing Belt:

https://www.amazon.com/SCStyle-Meters-Pitch-Timing-Printer/dp/B076LQMD9L/ref=sr_1_1?s=industrial&ie=UTF8&qid=1519148520&sr=1-1&keywords=6mm+timing+belt

Stepper Mount:

https://www.amazon.com/Stepper-Motor-Mounting-Bracket-Screws/dp/B073R2NR3W/ref=sr_1_1?s=industrial&ie=UTF8&qid=1519148875&sr=1-1&keywords=nema+17+motor+mount

Steppers:

https://www.pololu.com/product/2267/specs

Drivers:

https://www.pololu.com/product/2133

I am still waiting on my tax return to purchase the rest of the parts. There are some McMaster parts that I need to order as well, specifically 80-20 beams and connectors to join them together. 

Here is a basic timeline delineating when I plan on accomplishing certain goals. The Laser Cutter will have an aluminum frame that can be disassembled. The Cross Bar will be driven with Timing belts and pulleys attached to stepper motors.

Week		Milestone
1/29/2018		Purchase Steppers, Raspberry PI, Belts, Pulleys
2/4/2018		Create Model of the Base, Purchase other materials
2/10/2018		Fabricate Base
2/16/2018		Preform Calculations of Steps, Motors, Power, Etc
2/22/2018		PCB Layout and design. Print PCB
2/28/2018		Begin GUI design
3/6/2018		GUI design- vector
3/12/2018		GUI design- image
3/18/2018		Test Functionality of base/ code
3/24/2018		Refine System- Base (ADD LASER MAYBE)
3/30/2018		Refine System- Code/ Speed
4/5/2018		Refine System- Aesthetics
4/11/2018		Prepare Presentation

Project Proposal:

I have always wanted to own a laser cutter. A good laser cutter can cost a lot of money. Earlier this year I took ME EN 570, and for my final project I designed a 3D scanner. During the project I learned a little bit about GUI design and serial communication. For my project I intend to design a working base for a laser cutter, that can correctly read DXF files and trace out the patterns. Lasers are a little pricey and I will attach one to the base if I am able to. I will also design an accompanying GUI to read and design the print. I intend to use a raspberry pi to govern the base, and the GUI would be created on a Windows computer.

Challenges with this project:

- I don't know how to cross compile from a windows computer to raspberry pi
- I don't know much about raspberry pi's in general.
- I don't really know how to read a DXF
- Splines will be tricky
-The base needs to be ridged
-How do I keep it from blowing up?

Andrew Moulton