I am looking to build a cheap (under $300) CNC machine that won't involve too much precise cutting...

I have been interested in CNC for a while now, and now that I have a fairly good supply of money I think it's time to try my hand at building one. My criteria for the CNC are: *It has to be smallish (about 20" deep and up to 36" wide...) *I don't want to do too much precise cutting as I don't own a bandsaw. My cutting methods are hacksaw, Miter Saw, Jigsaw, and Circular saw... A kit would be nice (as in one with all parts included like the one oomlout will eventually come out with...) *I would only use it for foam most of the time, but it would be nice to be able to cut and carve wood and other materials as well. *A Hotwire machine might be nice... *I would like to build my own controller for it, because the prebuilt ones are expensive, right? *I would like it to have 30 inches x travel, 20 inches y travel, and up to 6 inches z travel. Like I said, it will probably do sheet foam most of the time, so even 6 inches or less z travel would probably be fine. Any of these sizes could be adjusted, I'm not set on the exact size... This machine would have to be able to work off of free or relatively inexpensive software. It would also have to be able to be stored 4 inches off the ground. I might bring it up to my benchtop when I use it, but it would be nice if it could stay down there on the shelf.

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frollard8 years ago
Look to the right> :) the related has lots of cnc projects - accuracy IS key however - so you might want to upgrade your ability to cut accurately. Searching instructables 'CNC" gives a tonne of projects. Recently one was 'winner'd and its pretty easy to make out of mdf, designed for foam cutting....searching.
snowpenguin (author)  frollard8 years ago
I have pretty good cutting skills but the wrong tools for the job...
snowpenguin (author)  frollard8 years ago
The first one is the right size but the wrong price, and the second one is the wrong size but the right price! I can't win! :)
thomoky95 years ago
I was doing a similar project and I found that when I used an AE-MDL-STPR811 board I got the best results. It provided more torque and still gave me the option of using external Schottky diodes. I also could have added a surface mount heat sink and a fan, but it wasn’t needed for my project. The board can be connected to all controls signals by two .100” header connectors and jumpers, if you want to hard code it, which is what I did. Here’s more info about the board http://www.avayanelectronics.com/Products/AE-STPR8811/AE-MDL-STPR8811_Manual.pdf. I found some really cheap ones at DriverDudes.com, you can get just the board or have it fully assembled. Here’s the link http://driverdudes.com/product_info.php?cPath=22&products_id=1
Whackmaster7 years ago
I have found what appears to be a good 4-axis stepper controller with parallel port interface for $70.  It would appear to be at least as good as many of the plans I have seen on Instructables, so unless you can source all of the parts for free and are willing to etch your own PCB I don't see how you could possibly beat the value and price of this one:


I would be very interested in someone with more CNC controller experience than me taking a look at it and telling me if I am profoundly wrong.  For example, would 1.5A constant current drive be sufficient for a small CNC that would cut through wood, or is that just too low?

Snowpenguin, I would suggest that your expectations for working area may be unrealistic.  So far all of the inexpensive machines and plans I have seen are for dramatically smaller areas.  Don't forget, since this is computer control we are talking about you may be able to "n-up" your work; let's say you want to carve a foam sign that is 30" x 20", but your CNC's bed is only 15" x 10".  You could do it by sectioning the cuts into multiple panels, or with GREAT effort you might be able to rotate your material around on the bed and carve out one quadrant at a time.  The predictability and repeatability of CNC makes that theoretically possible!  :)