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Picture of Drawbot!

This instructable will document the construction of a Raspberry Pi controlled drawing robot that allows you to turn any flat surface into a canvas. Once you've built the drawing robot you'll be able to calibrate and send drawings to it via WiFi.

*This was built in the Black & Veatch MakerSpace from plans created by MakerSpace patron and creative wonder Andy Wise. See the Drawbot project on Github by Andy for more information.

Step 1: What You'll Need

Picture of What You'll Need
PrintedParts.jpg

3D-Printable parts:

Polargraph gondola - https://www.thingiverse.com/thing:372244
Servo horn extension - https://www.thingiverse.com/thing:2427037
Drawbot motor mount and spool (x2) - https://www.thingiverse.com/thing:2427037
Drawbot electronics case (optional) - https://www.thingiverse.com/thing:2427037
Drawbot Pi + Stepper mount (optional) - https://www.thingiverse.com/thing:3122682
Suction Cup Dome with hole(alternative) - https://www.thingiverse.com/thing:3132569

Hardware:

NEMA 17 Stepper Motors (x2)
Suction Cups with Quick Release - Harbor Freight item #62715 (x2)
Spiderwire 80-pound fishing line
Micro USB cable 10-ft. (x2)
Micro USB breakout (x2)
USB type A female breakout (x2)
Raspberry Pi Zero W (or another WiFi enabled Pi)
Micro SD card
EasyDriver Stepper Motor Driver V4.5 (x2)
SG92R Micro Servo
6003zz bearings (x2)
3-pin servo extensions (several)
2.1mm x 5.5mm barrel jack
12v 1a power adapter 2.1mm/5.5mm lead
USB Micro Power Adapter for Pi
Pololu Universal Mounting Hub for 5mm shaft, #4-40 holes (x2)
#8-32 x 1-5/8 in. Eye Bolts (x2)
8 screws for spools (#4-40 x ~½")
8 screws for motors (M3-.50 x 6mm metric machine screws)
1-2 small screws for gondola to secure pen/marker
Standard wire or jumper wires
markers
Measuring tape/stick

Tools:

Computer
Soldering Iron
Wire Strippers/Cutters

Optional:

Paper
Mounting Putty
USB Fan
Hot Glue
Paperclip
Header Pins
Breadboard/Perfboard

The drawbot github will have some links to specific sellers/items.

How to get the svg picture Why some of the pictures I made can’t be used
I've built this and find that the steppers become really hot- as do the EasyDrivers. Does anyone else have this problem? I've picked up some heat sinks to attach, but wonder if there might be another problem.
MrBulp7 months ago
i wonder is it possible to use solenoid instead of servo?
jocomakerspace (author)  MrBulp7 months ago
In theory yes. As long as you can trigger/power the solenoid and the solenoid plunger is long enough and strong enough to push the pen off the surface don't see why not. The gondola would need to be redesigned to hold the solenoid as well.

would you be interested in working on something similar with the following changes?

1. motors are in the gondola, all you need to do is secure ballchain in corners

2. battery operated, no wires

3. it has an on board web server

I have been working with it for a while. I need to update github with the latest results.

https://github.com/SuddenDevelopment/WallPlottE

These changes would make the Drawbot more portable, but would make the gondola heavier and less responsive. So it's kind of a trade-off.
Printing out the spools locally has worked out well, now I'm stuck getting nodejs to actually move the darn steppers. They work from python scripts, so I know I've got them hooked up properly.

Any thoughts on howto debug this better? Do you have any simple nodejs scripts to run steppers?

jocomakerspace (author)  AnthongRedbeard11 months ago

Seems like an interesting way to make a polargraph more portable/flexible being battery operated and almost everything included in the gondola without need of external power/connections. I'll be following your progress!

On the web server part you should check out the drawbot github, it uses a WebSocket.

kodehine9 months ago
Hello there!
I am making a drawbot, following this nice Instructables. The stepper motor drivers I have got in possession are not the same than the ones used here. I don’t really know how to wire my drivers. I have got those models from Adafruit https://learn.adafruit.com/adafruit-tb6612-h-bridge-dc-stepper-motor-driver-breakout/pinouts
In these Instructables, there are only 3 wires connected to the Pi for each driver. With the drivers I have got, there is no DIR or STE mention!
Is there anyone there who could help me to wire my drivers?
Thanks
l8gravely-pro10 months ago
Hi,
I'm finally getting into steppers and such and wondering if you have any pointers for alternatives for the 3d printed parts, since I don't have a 3-d printer at all that I can use. Been looking for 5mm dia shaft pulleys, but most of them have gear teeth, which isn't really ideal.

Any suggestions of what I could buy pre-made? Or can I order stuff from thingverse? As you can tell, I'm clueless about 3-d printing issues.

Turns out my local library has a 3-d printer, so I've got one spool and waiting on a second. Now I've got the drawbot software running, but it's not actually talking to the GPIO pins at this time.

I've got a stepper.py script which I'm using to test, but I'd appreciate any debugging hints. I suspect it's because of my troubles getting the gpio nodejs module installed and working properly, even though I thought it was all set.

Is there a nodejs script I can run from the CLI to do a quick test to confirm it's all installed properly?

jocomakerspace (author)  l8gravely-pro10 months ago
I imagine you could re-purpose some sewing machine thread spools, or just directly wind the fishing line on the stepper shaft. There are lots of hardware options for mounting steppers out there. Seems most gondolas are 3D printed or made from laser-cut wood or plastic. I've even seen some gondolas made from a Frisbee and PVC.