bare bones and dirt cheap cnc

project: cheap basic 3 axis desktop cnc machine
goal: extremely cheap first time cnc machine
items collected so far:
arduino uno r3 + extras i.e. wire, switches, sensores. ect, ect...
3x stepper motors 28byj-48 5 wire (cheapest steppers available with uln2003 driver board)

what would be the best way to proceed from here?
I thought about using $2.00 cutting boards from the dollar store to make the frame and maby aluminum also if needed.
I also thought about using (no flame please) all thread and rollerskate bearings for the movement on the x,y, and z.
any help is appreciated and welcome here.

so far, the price list is
uno r3 ~$20
stepper motors w/driver boards $4.00 each x3 =$12
off brand dremel ~$20

A google/youtube search should turn up many verities of DIY CNC tables. Searching for plotters may also find material. Is the CNC table in the end supposed to do anything useful, or is this just a construction project?

if it can cut plastic with a dremel. I would be happy even if it is slow.
I am aware that these motors can be very slow. something like 1/64 gear reduction

even if I have to make 10 passes to cut 1/4 in plastic sheet
because of the small motors, I thought about making a lazer cutter setup

I am aware that these motors can be very slow. something like 1/64 gear reduction

Yes, they are much too slow, and they have very poor repeatability. Don't even consider them.

what do you mean by "and they have very poor repeatability"?

being slow is just what I get for doing it on the cheap. and I think that more people can get into cnc if we could get the price down.
not everyone can shell out $20 each for motors and then another $20 for driver boards. so even if I have to make accommodations for $5.00 each slow small motors with driver boards, that is ok. even if it can only push a pencil or marker until one day when I can afford bigger more expensive parts.

I think that I should just call this a proof of concept machine
I will make it work with what I got and what I can afford
then I will work on getting the most I can out of the machine.

and I know it will be a work in progress. there will be many things that I will improve over time to make it better or stronger or faster.

You can absolutely build your own for pretty cheap.

Check out the Easy Mill (Easy to Build Desk Top 3 Axis CNC Milling Machine : 9 Steps (with Pictures) - Instructables), it's pretty much what you want and made out of easy to get parts.

For software I recommend grbl. It will be a million times easier than figuring out your own movement algorithms etc.

As you said this is a great way to get started, and once you have the basic machine up and running you can figure out what you want to improve etc. A Dremel isn't the most accurate tool but there's nothing stopping you from upgrading to a Proxon or dedicated spindle motor later on.

If you don't want to build everything yourself, another option is to get a Shapeoko kit (X-Carve | Affordable CNC Machine | 3D Carving Machine | Inventables). $225 isn't too bad for getting all the parts sourced for you.

Good luck!

well, I took magagna's advice and loaded grbl software on my arduino. but I need some help on the wiring.
the grbl pin out is here:

the motor and uln2003 infor here:

could anyone please help here? I am sure that I am just overlooking something simple. I just dont see what that is. thanks all

I guess my best bet is to buy the sparkfun easy driver boards. what do you guys think. I was trying to keep the price down but if I have to. then, well I have to

the uln2003 does not support the step and pulse and so I guess they are just not compatable.

Poor repeatability means you try to cut a circle and it comes close but doesn’t close.

I know someone else that’s got lots of that potential. I told him that for fixed-depth cuts he’d be better off with a line-follower cutter.