Quotedro WhhiskeyMike, I was looking for the same parts list and I was able to find some stuff through reddit (http://www.reddit.com/r/3Dprinting/comments/1x6qd3/update_150_worth_of_free_stuff_from_my_company/) and I completed the rest. The following list is for the Prusa i3 rework (http://reprap.org/wiki/Prusa_i3_Rework_Bill_of_materials). Hope this helps. Dro This BOM needs work. The GT2 pby zipmsp - General
I forgot about how resistance adds in parallel versus series. I can convert the parallel board into series by making three cuts and moving one of the power connections. The total resistance of the parallel circuit is 1.2 ohms and there are four resistors in parallel. Solving for the resistance of one resistor: 1.2 ohms = 1 / (1/x + 1/x + 1/x + 1/x) x = 3.33 ohms Resistance adds together in serby zipmsp - Controllers
I'm looking at the MK1 heated bed and I'm trying to figure out what Prusa meant when he said it is easily converted to 24v. Current = Voltage / Resistance Power = Voltage * Current With a 12v power supply and 1.2 ohm heated bed, current = 10A and power = 120W. With a 24v power supply and 1.2 ohm heated bed, current = 20A and power = 480W. So I need a much larger power supply for 24v, and it seby zipmsp - Controllers
Several places list this motor in the ~ $50 USD range. Applied Motion HT17 The first google result for NEMA17 stepper is a ROB-10846 for $17 and seems to outperform the HT17 in several regards. Why is there such a drastic price difference between these motors? HT17: Part Number HT17-277 Frame Size NEMA 17 Motor Type High torque Part Number w/Double Shaft HT17-277D Part Number w/Encoder Hby zipmsp - Stepper Motors, Servo Motors, DC Motors
Thanks everybody for taking the time to reply. This has been a good learning experience, even if just a thought exercise. I plan on using a pre-made switching power supply to build a 3D printer and building a linear power supply for bench type work in the <1A range.by zipmsp - Controllers
MacSkyver, what did you use to draw that schematic? It looks professional. Thanks for the regulation circuit idea. I plan to look into that next. I've been reading about voltage and amperage needs. Arduino MEGA operates on 5V and the recommended input voltage is 7-12V. Arduino's voltage regulator starts to overheat above 12V. Is the higher voltage output by an unloaded transformer going to fry tby zipmsp - Controllers
Thank you both. Limiting the use of LM338 is clever. I plan on starting with a simple approach and adding complexity over time through multiple revisions. It might be fun to eventually print the transformer frame and wind the magnet wire by hand.by zipmsp - Controllers
I am building a 3D printer as a way to learn more about electronics. Most plans use the 12VDC rails of an ATX power supply. Since I am not in a hurry and would like to learn and apply electronic concepts, I plan to build my own power supply. I can build a 120VAC->{1.2 to 32}VDC power supply with a step-down transformer, full-wave bridge rectifier (diodes), a filter (big capacitor), and a rectiby zipmsp - Controllers