Allright, folks, let me show you a piece of brilliant trash that became valuable.

*Have to tell you first, that this instructable would be a difficult one to follow, because some parts I used are kinda unique, but it will be still useful as an example of recycling ideas in different areas.* - I used to think so before I've read other Trash to Treasure entries, now I know my is relatively simple, tools are basic, parts are available, total price is under $100, usability is fantastic.

Step 1: Inventory

So, this is a 3d-printer made of aluminum tubes (length depends on shafts you attach), plywood (I had a small piece of 12mm plywood), some ripped office appliances with broken car parts including shafts and bushings and cheap stuff available on internet and hardware shop.

Step 2: Begin From the Top

As you can see, those 8mm black shafts on the top used to be gas springs of a car, broken, so I received 'em for free. REMEMBER, when you saw/drill gas spring always put on eyes protection, it has inner pressure and liquid lubricant inside. Better do it outdoors.

Plywood board has a piece of 15mm aluminium tube on both sides, where we mount the shafts. Tightening nuts one by one you can finally mount it absolutely parallel to each other and perpendicular to another axis below.

Step 3: Second Axis

Those shiny 8mm shafts are taken from old scanners, one has a couple of holes, but it doesn't matter since I use plastic bushings instead of bearings with tiny balls inside. This couple of shafts is mounted the same way as previous - tightening the nuts one by one you can move the shaft ~1mm left&right to find perfect position.

Bushings are taken from old laminator machine, there were eight pieces, just enough for both axis. And finding it isn't an incredible luck or something, 8mm diameter is a very popular one in hardware and office appliances and I have many more of this kind, but if you don't want to waste your time looking for it - just take a brass nut and drill a hole of needed diameter (if you're able to do it with precise accuracy). All of the bushings are glued to plywood parts

AFTER

the shafts were mounted in parallel to each other. Plastic and wood are simply glued together by most of the hobbyists glues, use the one you have.

Step 4: Z-axis

So X-Y axis are mounted on the square frame made of aluminum tubes, another square is in the bottom and both are mounted on more tubes. It's light, strong, easy to drill, I recommend.

Here comes the vertical Z-axis and that's the part, which is difficult to follow, because two 14mm shafts are taken from old plotters, which must be way more rare than regular gas springs and office equipment. As an alternative I recommend 10mm gas springs, it's realy hard. Realy.

I left those original bushings with bronze rings inside, just cut everything to make flat surface and sawed to make it longer to decrease the backlash. As far as we use square tubes, perpendicular installation was simple using basic tools only.

Step 5: The Bed

Next step is to attach this primitive plywood construction and aluminum profile which used to be a part of interior somewhere. The glass is also taken from scanner, I cut it by myself so two edges are imperfect. As you can see, the base of the bed is consructed crookedly, my bad, but it does not really matter, since the glass is holded by bolts, springs, washers and nuts and you can simply adjust the height of every corner.

Step 6: Z-axis Motion

On the other side there is a leadscrew and nut, RepRap's classic ;) The nut used to slide out of this mount, but a piece of wire fixed the problem. Next!

Step 7: Coupling

First I used a piece of hose as a coupling, but it was not hard enough and the surface of printed models had waves, than I've printed plastic coupling and improved the quality.

Step 8: Motors

Since the printer has many flat surfaces, it's easy to install stepper motors simply tightening them with a cheap hardware. Average GT2 belt is mounted on 625 bearing on the opposite side. This bearing is cheap, perfectly fits M5 bolts, also couple of M6 washers would keep the belt on. Extruder is made of a weak motor, but is tightened to a huge heatsink - massive aluminum frame - so you can add some more Vref on its driver and enforce it without overheating.

Step 9: Head

The hotend is attached to the metal mount from a local hardware shop and this mount is an additional heat sink (really cools), but to print on a very high speed I attached this 60mm fan from old motherboard. It's blades were broken, I printed new, looks even better. Also printed its mount.

Step 10: Electronics and Power

Electonics is classic - Arduino wit Ramps 1.4, mounted in a half of a plastic box, cooled by old computer fan. Controlled by laptop made in 2008 (I keep it to play Fallout 2 once a couple of years, WinXP is needed). Power supply is another recycled part - old ATX tightened to the frames, so every metal part of the printer is connected to the GND pin. Old sneakers protect the floor from vibrations and simplify moving the printer.

Step 11: Prints

So under $100 you can recieve a 3d-printer with pretty wide printing area and good qualityof printing (after changing Z-axis coupling) for such equipment.