Today was a tremendously eventful day! I first worked greatly on my 3d printer, but that’s not the subject of today’s post. Today, I nearly finished my 3D scanner platform… and cost me about $4 in total cash spent!

I’m a parts hound. I find a broken printer; I take broken printer. See a scanner pick it up, all the day you’ll have hacker luck. So, I’ve lots of my own collection of gears, motors, switches, LEDs, and all sorts of smaller mounting objects. But, what have I ever made from this junk I collect? Let’s find out what I did.

This is my first part, and the only part that cost money. Remember, I am a cheap ass so I can buy shiny stuffs elsewhere (like wine for the girlfriend). This cost me a whole $3 and some change, and can handle 300 lbs. Gods help me if I put that much weight on this scanner.. although it will be able to hold it. They sold 3 sizes of these bearing brackets, and I chose the smallest. 4 in or something like that.

And here is a fine example of a stepper motor with a nice gear train that I harvested from some long ago printer. It’s a M35SP-7N stepper from Mitsumi. There’s specs on the web that are easy to find and (ab)use. So this is my donor motor. And it was free from a dead printer pull. I also got a nice gear belt for a cost of 0$. No clue if it was what went with that stepper and gears, but the teeth on top of that pulley align well.

Here at Bloominglabs, we have a 40W CO2 laser cutter at our disposal. I could have done exemplary perfect circles cut into plywood or acrylic. However, in the sense of being cheap (and wanting others to be able to duplicate my stuff so far), I used a pencil and thin wire to make a circle on scrap wood. Of course, if you have a better circle maker, USE IT! I wanted to demonstrate that I could make it with almost no extra cost or special tools.

So, I found a diameter that I liked for the center platform, and then proceeded to mark it on the plywood. So yeah, I used a band saw, but you could easily use any saw to cut it.

Remember that CNC machine made out of wood that I took apart for those juicy motors??? Well, this base is one of the wood panels from that very machine. Waste not, want not I say. And I took it apart. I was just too lazy to take it to the dumpster 😛 And I also dropped holes in line with the brackets. So far, so good.

Well…… Those M3 screws I had with my printer look like they were going to work well. That is, until I realized geometries and ended up with an EPIC FAIL. Back to the donor and scrap screw bin to see what I can appropriate for my project. Of course, I do find these nice wood screws (they’re in wood, so they’re WOOD screws).

Now, the fun part is those wood screws I used… Well, they are a wee too long for the 5/8″ plywood I used for the rotating section. But they fit so well otherwise…… So I used metal snips from the space to “make them right”. Which is so wrong, but it worked. Goal: no money outlay for screws. NEXT.

So, from here, I got the turntable fixed on the board. And then, I wanted to put on the motor in an appropriate place: in the corner. I dug out some more “wood screws”, and carefully tension the belt (read: pull hard and screw down). I also used 2 nylock nuts for the back PURELY for spacing from the top as a support. The screws do not actually do anything in the nylock, as it’s like an M8 or something way too big.

Here’s a nice overview of what I have done so far. Do note that there’s the 4 tiny holes in my scanning platter. I’ll need to scrounge some wood putty and fix those. But that’s a small problem; nearly cosmetic.

And I have more parts. I was given the breadboard and I bought the breakaway connectors. As you can see, they were a whopping $0.47 , and I already got my use out of them. So I didn’t count them as a cost in this project. I used so far a total of 5 prongs. And the motor connector was NOT the same spacing as my breadboard. GRR. So, I broke off the nice little plastic, and pulled it off and proceeded to jam the pins in and force-aligning them with the board. VOILÀ! They fit.

Now… The breadboard has stickytape on its back. But there’s NO WAY IN HELL that it’d stick to mostly clean and un-smooth wood. So I used 3 more “wood screws” and locked it in place where you see. Lookin’ good so far.

And I proceeded to do some circuit wiring so far. I’m using IRLZ44N’s for the power MOSFETs. My dead dad had a bunch he gave me. So COOL. They’re something like $1.95 in Mouser, and I didn’t bother to check with Digikey. Cause I have a tube of 50 of ’em! So yeah, it’d be $8 here if you don’t already have something to drive the stepper. I used the appropriate resistors as well. The green lines will go to my arduino. So, this is what my project looks like as of yet.

Stay tuned.

UPDATE: crappy circuit diagram. Thanks Fritzing.