Arduino: Eh, just grab some pliers and bend the pins

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Arduino: Eh, just grab some pliers and bend the pins

Combo: Aug 19, 2003

Its been a very arduino Christmas for me apparently:

Two Unos, two different starter kits, a 4 relay module, and Programming Arduino and Projects for Evil Geniuses, both by Simon Monk.

They're my first crack at this sort of thing, I guess its time to start learning :v:

# ¿ Dec 25, 2012 16:28

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# ¿ May 16, 2024 01:21

Combo: Aug 19, 2003

Yeah, all of those listed sets are really similar to what I got. Just a small breadboard, bunch of wires, a couple of small servos, assorted LEDs, resistors, capacitors, a buzzer, 9V battery plug, etc.

I also happen to still have my starter kit from my EET 101 class which has similar things plus a larger breadboard.

# ¿ Dec 28, 2012 18:30

Combo: Aug 19, 2003

Ok, if this comes off as too "do my homework" ish, I don't mean it this way, I'm just trying to source some things for a project.

For a class, we had to come up with some projects to build and automate something. We came up with 3 different projects, and I'm on the group that will be building an automatic drink dispenser. Seems like the arduino is perfect for this.

I have a couple of different design ideas based on what I've seen online. One is a stepper motor on a slide like this video: https://www.youtube.com/watch?v=68-8QC2qU5w (though ours would be way slimmed down and nowhere near as cool as that, plus I'd want to do a few things differently on it to make it our own thing, I just like the slide assembly). It may be possible to scavenge this from an old printer?...though I'd probably have to come up with some way to control it.

The other, probably cheaper idea, was to put the cup on a lazy susan and use a servo to rotate it. My fear with that is that the servo will be too weak, but I don't know a ton about how powerful a servo can get.

Am I off base on that?

# ¿ Feb 11, 2014 06:00

Combo: Aug 19, 2003

Sagebrush posted:

Yep, you can almost certainly get a stepper, belt system and linear shaft like that from an old inkjet printer. Depending on how it's made, you might have some trouble getting everything mounted up correctly once you take it out, but fortunately the driving part is super easy. Thanks to 3D printers being a thing, plug-and-play stepper drivers are getting really cheap and common these days.

Guaranteed good quality for $16: https://www.sparkfun.com/products/10267
Anyone's guess, probably at least 3/5 of them will work, but it's 1/5 the cost: http://www.aliexpress.com/item/5pcs-lot-EasyDriver-Stepper-Motor-Driver-V44-A3967-Free-Shipping/1470167262.html

Those boards should work with steppers that have four, five or six wires. Four-wired steppers are the most common these days though.

As for putting a lazy susan on a servo: not the ideal solution. A large, powerful servo could drive the table around and index to different locations easily, but it can only rotate in a 180-degree arc. A continuous-rotation servo can spin 360 degrees but you need an encoder of some kind for your positioning to be reliable. A stepper motor, when properly sized and powered so it doesn't skip steps, is the best option for speed, accuracy and continuous rotation. Put a timing belt around the bottom of the turntable, run it onto a toothed wheel on something like a NEMA17 stepper, and use the same driver as above.

Awesome, thanks for the help on that. The first thing that popped into my head when I was looking at the design in that video was "that slide looks like the inside of a printer", and it made sense that it would use a stepper motor.

So that seems like the way to go, just have to find a nice (cheap?) linear assembly, or scavenge one.

As far as the lazy susan idea, what about a little motor with an encoder, rather than a servo?

# ¿ Feb 11, 2014 16:44

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