NEMA 17 Stepper motors

The printer requires 5 stepper motors. X and Y axis use one each, Z is using two and one for extruder. I spent way too much time figuring out what kind of stepper motors I would get. Based on the information and advices I found, I tried to choose reasonably priced, under 2A stepper with close to 0.44 Nm holding torque. I was trying to make my mind up between 42BYGHW609 and 17HS4417. Both have very similar specs but I was able to find 5 pcs located with 53e shipping included from Germany instead of China. So they should arrive a bit sooner and no need to pay tax or custom fees.

Bearings, belts and pulleys

I have ordered bunch of bearings, GT2 belt and pulleys from China. The quality of those bearings will be a mystery but I have an idea to replace some of the LM8UU bearings with printed or IGUS bushings later on.

The most difficult part to find is a good set of round smooth linear rods. I would like them to be chromed stainless steel and preferably correct length. I think Y axis of P3Steel can accommodate longer than specified rods but all the others should be spot on. I don't really like the idea of cutting 8mm chromed bar with Dremel.

M3 nuts and screws

P3Steel is using M3 screws and nuts almost everywhere and there are three different lengths for screws. The amount of screws required is around 80 pcs so price matters here as well. I have been trying to source parts as locally as possible but I did not manage to find reasonably priced ones. Local stores stock only M5 or larger and specialist shops have a bit silly prices.

I ended up ordering the set of 100 pcs M3 Nyloc nuts, 80 M3 screws with different lengths and 20 M3 washers from UK. Bolt Base Ltd has a nice selection online with reasonable prices. In case of using their ebay store, remember to ask combined shipping price.

Power supply options

Basically, there are three or four options for a RepRap power supply. A laptop power brick is an easy and safe way but the max power is usually too low for printer with a heatbed. One could get a separate brick for heatbed, though.

A bit more common approach is to use ATX power supply. Unfortunately I don't have any spare ones around and a new quality ATX providing 30A 12V is not free. Second hand ATX I found were generally too old and weak.

LED strip power supply is pretty cheap compared to its power but the quality varies and I really don't like the idea of wiring the mains socket to terminals and somehow securing them from accidental poking. As I have little kids running around this alternative is ruled out.

Now, after reading about this topic for a while I came across an idea of using server power supply. These are high quality units meant for 24/7 use. They come with safe mains connection and they output more than enough power on 12V lines. I decided to buy a second hand HP DPS-600PB B 575W which provides 47A on 12V.  The best part is the price - 30 euros delivery included.

I will post more details about this PSU as soon as I receive it.

Frame sourcing

The frame of the P3Steel is 3mm structural steel. RepRap site hosts DWG file for couple different versions and the parts are neatly laid ready for laser cut. I chose version 2.5 by AndrewBCN as it supports dual extruders better than earlier designs.

There are several shops in EU selling ready cut P3Steel frame. But the problem with those is that the version of the P3Steel is not mentioned in most cases. Also, the postage of the reasonably heavy steel frame to Finland is rather expensive.

So I decided to send request for offer to several laser cutting companies nearby. I got good amount of replies and now going through details with the cheapest one. Most likely I will order a set of 10 frames or so. I hope I will eventually find other P3Steel builders so I won't end up storing plates of steel in my living room for very long.

Introduction

This is a build blog of a RepRap P3Steel 3D printer. It will cover the steps from sourcing the parts to assembly and printing.

http://reprap.org/wiki/P3Steel