Hackers always have their eye out for a good deal, so when [Gadget Reboot] saw a good price on square stickers he had to pull the trigger. There was just one problem: his logo is a circle. He could have rectified the problem with a pair of scissors on a lazy afternoon, but we think building an elaborate circle cutting machine was a much better use of his time.
But this project isn’t just for the Giotto wannabes. Even if you don’t find yourself in need of an infinite supply of perfect paper circles, the video after the break provides an excellent case study in getting stepper motors to do your bidding; whatever that might be. [Gadget Reboot] walks the viewer through the design and construction of a dual stepper motor controller that could be used for a multitude of tasks.
With an onboard Arduino Pro Micro, OLED display, and rotary encoder, this controller just needs some custom software to make your CNC dreams come true. [Gadget Reboot] is even using low-cost optical endstops in this build, which are a great non-contact way of making sure your machine doesn’t go out of bounds. That’s particularly important when the machine happens to be wielding a razor blade.
If you’re a thoroughly modern hardware hacker who prefers using a web browser to twiddling knobs, then perhaps you’d be interested in the WiFi enabled stepper motor controller we covered recently.
[Thanks to Dan for the tip.]
Communication Designer tips: If it’s going to be cut the image should go over the cutting area (it’s called bleed), that way you ensure you never get unprinted areas near the border. Common bleed in industrial printing is 3mm of bleed
If you have to do any marks for diy cutting, in this case the black border. do it instead in yellow. It’s so light that if the cut is slightly misaligned no one will ever know.
The dual stepper motor PCB looks great. I found the sketches on GitHub, but is the PCB or even a complete board available for purchase somewhere?
The bare PCB can be ordered from PCBWay (I would receive a small commission on any orders), but I don’t sell it myself or an assembled version.
I just uploaded the project there so it’s awaiting approval but the link should be:
https://www.pcbway.com/project/shareproject/Dual_Stepper_A4988_Driver_with_OLED_Display_and_Rotary_Encoder_Menu.html
I still need to create a bill of materials but the parts are relatively generic since it relies on the plug in modules for most of it.
Similar boards with room for upto 4 of these stepper motor plugins are available from Ali / Ebay / China for a few bucks probably under the name “CNC shield” or similar.
The original designer of this board was pissed that his open source design is being mass produced for cheap in China, and has written some lengthy web pages about this, and stopped making updated designs public.
The pinout for the stepper motor driver PCB’s has also become a defacto standard.
there are a lot of different boards from the simple DRV88xx to the more advanced allegro stepper motor IC’s and they are (mostly) pin compatible and exchangable.
There have probably been a lot of similar boards designed.
Here is a link from a PCB design beginner who is (rigtly) proud of his first design.
https://forum.kicad.info/t/first-pcb-looking-good-i-think/22762/7
If you don’t want other people to use your design, why would you open source it?
When you open source it and people start using it, that seems like a win.
https://images-na.ssl-images-amazon.com/images/I/61qZpY01gTL._AC_SL1469_.jpg
I was a little concerned when I saw he as using a pcb instead of a tangle of jumpers, breadboard and electrical tape, but he redeemed himself when he broke out the hot melt glue gun and Legos. +1 for the huge gobs of hot melt holding things together.
What did I just look at… 🤨
Hmmm… I look over at my 3D printer replacement boards and consider the four stepper motor drivers, multiple inputs and outputs, and the encoder operated UI LCD that I got several years ago “just in case” and I wonder why this was necessary… perhaps as a vehicle for a PCBway promotional?
Nice enough, but easily doable with off the shelf parts.