This is the continuation of my attempt to build a 3D printer with a minimum budget of around $400 using new and recycled parts.
Waiting for funds and shipment….
Build cost for this section from Ebay Seller zyltech and leap3d
- $10.93 – 1 – NEMA 17 Stepper Motor 57 oz-in
- $2.49 – 1 – Nema17 Stepper Motor Mount Mounting Bracket L-mount
- $8.79 – 1 – 8ft 2.5m 2GT GT2 Timing Belt & 2X Pulley 2X Idler 4X Tensioner
- $2.00 – 1 – Pulley Bracket
- $1.00 – 1 – Belt bracket under build plate
- $1.00 – 1 – Stop Switch and Bracket
- $11.99 – 1 – MK2B PCB Heated Hot Bed for RepRap 3D Printer pre-wired for 12V SMT LED soldered
- $4.99 – 4 – 3D Printer Heated Bed Adjustment M3 Brass Thumb Nut
- $9.99 – Borosilicate Boro Glass 3D Printers Rectangular 200 mm 214 mm 3mm Heat resistant
- $53.18 – BUILD BED SUB-TOTAL
- $50.00 – FRAME SUB-TOTAL
- $42.81 – Y-AXIS RODS and BEARINGS SUB-TOTAL
- $145.99 – TOTAL SO FAR
The completion of this section will actual let me test the Y-axis, what a great start! We could call it the first 1D Printer but I think we need to go a bit further don’t you?
Here is a sub-assembly of the idle pulley. It is attached with bolts to the center of the front frame edge. The parts are in order…
M5 – 40 Bolt, Washer, Bracket, Bushing, Lockwasher, Idler, Lockwasher, Bushing, Bracket, Washer and Self-locking Nut.
The 1 1/2″ bracket is a perfect height to match the Pulley on the stepper motor on its mount.
The Y-stepper is mounted on the 90-degree bracket that was bolted to the frame. Note that the motor screw taps are metric and need a special length for your bracket. The belt is looped and attached to the bed on both ends. Four Plastic Zip ties are tight around the belt loop the teeth of the belt mesh together and will not let it move. How does it feel? The belt will be fairly tight when it is correctly adjusted. Mine come with springs that you slip on the belt to tension it with. The deflection should be about a 6 to 8mm on the long side.
The bed heater is made of a PCB board and has a hole on each of the corners. This gives you a way to level the bed to the extruder. A bolt going through the hole and washer and nut to makes a stud on which you slide a spring. The spring keeps the bed adjustable with the second nut under the base plate. I bought a thumb screw for that but still looking for an M3 x 40 bolt to be long enough to make all of that work.
Before attaching the bed make sure you don’t forget the thermistor which lays underneath. I used high-temperature aluminum AC tape to keep it against the heater.
For the heater to maintain temperature it helps to insulate it from the aluminum plate with a pad of cork. I got it from the craft store for $5.00 it is about 3mm thick.
The last layer in this sub-assembly is Borosilicate Glass it is 213mm x 200mm x 3mm and is attached typically with office filing clips. After the part is printed you can un-clip the glass and remove it from the printer. Making it easier to free the part from the glass. This glass is special for this purpose so I would not just use cheap plate glass here.
The stop switch bracket is just temporarily mounted because I do not know the exact zero point for the axis yet.
Building this printer is very rewarding but requires information from others to be successful. If you have ever taken a machine apart and wondered what does this odd part do? Well, there is most likely a good reason for it because it solves a problem, improves reliability or performance. Sometimes it was used to make it easy to assemble or just make it lighter and use fewer construction materials. I can already see that the fewer parts that it is made from less to break down and be cheaper to build. This printer is full of parts and a lot of them move. I still see it as a simple doable project if I take my time and see the details.
Two more axis to go but we are on our way.