Building a Printrbot 3D Printer - Overview

This is the first part of a tutorial on building a DIY 3D printer. The model I have chosen is a member of the Printrbot family, since it is probably the most compact, simple and cheap desing out there Tongue out

Mine is called "Lucy", this guide will be based on it, here is a picture:

You can find the main details of this design in these websites:

I encourage you to check those links out. Also, you should get an overview of other open-hardware 3D printer designs, if you haven't already done so. For example, my other 3D printer is a "Prusa MendelSmile

The original Printrbot design is nice, but we will be using some modifications to make it even more convenient to build.

Differences with the original Printrbot design:

  • Everything is measured using metric units instead of imperial, so it is easier to get hardware parts in the EU.
  • It has a bigger build volume: XYZ 20x20x21cm (Z expandable) VS the original 16x16x20cm (aproximately)
  • It uses M8 rods and LM8UU linear bearings.
  • I have found the Printrstand to be essential for the stability of the printer.

OK, now we have cleared that, let's get started!


Bill of materials: (last updated: July 2nd, 2012)

First of all, here is a list of all the required parts (with the suppliers I got them from), to get a rough estimation of the costs:

  • Electronics & motors:
171.42€+VATSanguinololu v1.3a board DIY Kit + stepstick motor drivers Or you can find the v1.3b (easier to build) cheaper in eBay
555€+VATStepper motor (NEMA17)
134.99€+VATExtruder set 3mm v5 This one is working for me, but there is still a big discussion about which is the best extruder
124.99€+VATPCB for heated bed
24.98€+VATAxial Fan 30x30x10mm 12V
1~2€Heatsink adhesive pasteDealextreme:

Electronic parts (3 micro switches -endstops-, NTC 100k thermistor), wires, heatshrink tube and connectors

Electronics store. I will detail the required parts later on the tutorial

12V/20A ATX power supply (PSU)

You can easily get a suitable PSU from an old computer. Make sure it's at least 17A rated on the 12V output
Sum (aprox.):210.38€+30€240.38€ I have included 30€ which goes for the RepRapWorld VAT and shipping


  • Mechanics:
1Read supplier3D Printed partsIf you alredy have a 3D printer, it's free! In other case, you should ask in proyect Clon Wars
1Free?Glass sheet (21.5x21.5x0.5cm) for heated bedWent to a glass factory and they made them for me for free because they liked the project :D IKEA has a mirror set that fits our purpose
27€+VATTiming belt 1m x 2.5mm (T2.5)
216€Metalic T2.5 pulleyI think they have it in RS. -pending supplier-
2Free?Small spring (20x5mm)They *might* have valid ones in a hardware store. You probably have valid ones lying around, though
61.5€+VAT608 bearing
1119.25€+VATLM8UU linear bearing
126€20cm adhesive Kapton tape (33m)From eBay:
1Free?25x32cm 5mm plywood boardI had a suitable one laying around, you can find it in any hardware store or similar. I recommend using plywood instead of MDF since it will bend less with heat and humidity.
10.25€M8 7cm bolt with hexagonal headHardware store 
110€Screws, nuts and washers (various lenghts, see table below)Hardware store 
23€1m M8 threaded rodHardware store 
317€1m M8 smooth stainless steel rodI bought these online, shipping is included and they cutted them for me You can find them much cheaper though. Madrid:
15€50 Nylon cable tiesHardware store
18€Industrial grease and oilHardware store
16€Fire cement (1200ºC resistant paste)Hardware store
61€Small (2cm) metallic paper clipsHardware store/stationer's shop
Sum (aprox.):120€+30€150€ I have included 30€ which goes for the RepRapWorld VAT and shipping


Screws, nuts and washers (detail):

Exact quantitySuggested quantityItemNote
810M3 screw 8mmFor the motors on the X axis and the extruder
810M3 screw 10mmFor the two motors on the Z axis
23M3 screw 15mmFor the motor on the Y axis, it needs to be shifted down with 3 washers on each screw
1214M3 screw 20mm 
57M3 screw 25mm 
12M3 screw 30mmFor the X axis endstop
45M3 screw 35mm 
12M3 screw 40mm For the Y axis endstop
23M3 screw 45mmThese are used to fix in place Reprapworld's hot-end  v5
2030M3 washer 
2935M3 nut 
46M4 washerM4 parts are for the extruder's mechanism. I've tried with M3 but it doesn't feel as solid as with M4
23M4 screw 50mm 
23M4 wing nutYou can also use normal nuts, but it is more easy to switch filament with wing nuts
2835M8 nut
1220M8 washer 

Note: Cheaper screws are usually flathead, those are OK. If you can't find the exact length, simply choose the next longer one available.

  • Tools (Free?):
    • Two wrenches (hexagonal for M8 nuts)
    • Screwdrivers
    • Pliers
    • Scissors
    • Cutter/modeling knife
    • Soldering iron (small tip) and tin.
    • Digital caliper (you can find it in eBay for like 10€, I consider it free as it is a tool).

So, you could theoretically build this 3D printer for around 395€ Smile

Note: If you finally order from remember to buy some 3mm plastic filament. Your 3D printer wouldn't be very useful without ink Wink I would say 1kg of PLA and 1kg of ABS plastic of different colors is a good start. has a large variety of PLA colors.

Now go ahead and buy everything you need. Some parts will take one or two weeks to arrive ordering them online, but the highlighted ones can be found on any hardware store.


Rod sizes:

You must cut the steel rods into these pieces. Maybe your supplier can do that for you:

  • Threaded rods:
    • 4x 32cm for the base
    • 2x 25cm for the Z axis (if they are longer you can print taller, with this you get around 21cm)
    • 1x 40mm for mounting the idler bearing on the X carriage
  • Smooth rods:
    • 2x 31cm for the Y axis
    • 2x 35cm for the Z axis (same note: longer rod -> taller prints)
    • 2x 33cm for the X axis (try to be very precise with both having same lenght)
    • 1x 2cm for mounting one bearing on the extruder

This will give you a printer with the same size as mine, though you could make a bigger printer scaling parts as required.


I have found that a threaded bar connecting the top of Z rods will make the frame more stable. I am using the parts for this job from the Wallace's design.

You stated 1m of M8 threaded rod, but 4x32 plus 2x25 is 178cm. Better 2m dividided in 3x32 in first and 32+2x25 in second. Or, all two dividided in 32cm parts.

You stated 1m of smooth rod, but 2x31 + 2x35 + 2x33 is 198cm.

Sorry, I misread your table. You put two one meter rods, which is correct. My mistake.

As you didnt published it, yet, one could refer to this 15 chapter guide on youtube:

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