drawing machine, cnc x/y plotter

Hi All,

I've had an arduino a short while and enjoyed experimenting with it making traffic lights and controlling a DC motor, but want to get on to making an actual project. I would like to build a drawing machine. something that holds a pen (or any mark making device pencil, paintbrush etc...) and moves this around the x & y axis and allows it to make a mark on a page on a tabletop. I have seen there are some tutorials and videos online for tabletop machines as well as ones that use gravity and a pen hanging from string. I am only interested in the tabletop version at the moment.

something a bit like this: Arduino Controlled XY T-Slot Table - YouTube

As far as I understand I would need three motors: 2 stepper motors to control x & y axis movements and another motor (servo?) to control pushing the pen down onto the paper. Is this correct or is there another solution for applying the pen to the paper? And would this be a suitable motorshield for this project:

http://www.oomlout.co.uk/motor-shield-for-arduino-kit-p-207.html?zenid=55a242d859e77a4647a6dc0d6512a383

It can control 4 DC motors or 2 stepper motors. It also says it can control 2 'hobby' servos, I'm not sure if that means you can also run 4 DC or 2 stepper as well as the 'hobby' servo motors. If not can I connect another motor to one of the unused ports on the arduino to control the pen applying to the paper? Or do I need another motorshield/approach entirely?

Any advice on the suitability of this motorshield, or another motorshield, or approach/technique, is greatly appreciated.

Thanks,

David

you can drive a (several) servos directly from your 'duino

Thanks mmcp42,

So I can use the motorshield to control the x & y axis movements and then a servo direct from the arduino to control the pen marking the page?

Any advice one what motors to get for this project? I'm based in the UK.

Cheers

yup

I got my steppers from zapp automation
if all you are doing is drawing you'll not need much power
you could even raid an old scanner (that's where I started!)

you could use drawer slides as x and y axes
take a look at this thread http://arduino.cc/forum/index.php/topic,90236.0.html

PS update your profile, then we'll know where to find you!

Thanks, I'll check that thread...

(location now added)

That thing's noisy!

It looks like an automated version of the old pre-ACAD drafting boards, only loud.

Most big plotters I've seen move the paper on 1 axis and the pen on the other. Some could do size E.

Yes I have seen a few of those too, hacking up old printers to move the paper. But I think they are less flexible in terms of how you draw (order of strokes in terms of position on page) and what mediums you can use as a really wet medium like paint would get smudged if the paper went backwards through a roller.

I'm at very early stages with this, only just started planning, but this is pretty close to what I'm envisioning (without the carbon paper)

I did something similiar a few years ago, and I found that 2 old flatbed scanners made a nice table - and I got them for free for the asking.
once you remove the stuff you dont need, you get steppers and the gearing.
I got X/Y by putting one on top of the other, and used the glass from one to make the platform.

I never completed it though, as a house move meant I had to trim down my junk collection :frowning:
As a result I didnt get to finish the pen holder but the few tests I did went ok.

Video is shaky and may cause boredom/seizures, but included to show what I used. I also didnt use arduino back then as I had not discovered its many joys.

might inspire you, might scare you :slight_smile:

Thanks ghoti,

I have been recommended to look at the grblShield | Synthetos.com as it handles all the complex grbl drawing code and can control 3 stepper motors.

But first I need to walk before I run, so will build something with just one stepper motor— I'm thinking about a motion control unit dolly for moving the camera during timelapses. [ I'll open up queries about that on a new thread... ]

Thanks to all for the advice.