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P3Steel - Prusa i3 3mm Steel Laser cut (aka Leonardo)

by irobri, published

P3Steel - Prusa i3 3mm Steel Laser cut (aka Leonardo) by irobri Sep 28, 2013


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This is a remix of twelvepros redesign of Josef Prusa i3, the printer was built in April 2013, decided after attending a local Maker show in Zaragoza, Spain.
I liked the Prusa i3 single plate design but then I saw twelvepros and thought it was a better option, I just wanted to get rid of the threaded rods y axis mount and adjustments.

Although this is not based on it, I want to mention S. Graber and his Graber i3, he came out also with a very nice redesign of twelvepros of a complete laser cut i3.

The printer is made of 3mm laser cut steel since I wanted it to be sturdy and I had a laser cutting machine available at work:


  • Steel is 10 times cheaper than aluminium
  • Laser cutting steel is easier and cheaper than cutting aluminium
  • Steel is stronger than aluminium


  • Steel is 3 times heavier than aluminium

The design is for 3mm thickness steel and with lots of carvings to reduce weight. All square holes and tabs have special rounded corners for accommodating corresponding parts and give a very good fit between plates. No threading required.

I hope someone finds this design usefull.

(Leonardo is just the name of my printer, here in our local reprap group we give names to our printers...http://www.reprap.org/wiki/Proyecto_Clone_Wars)

Over 50 people have recently made this printer in Spain, they have been working a lot and they have created a wiki (thank you guys!) for this printer model which they have named P3Steel, the wiki has a lot of helpfull info for building the printer and it even has an animation of the assembly of the printer, I post the link because I am sure it will help anyone that decides to build it, the wiki is both in English and Spanish: http://reprap.org/wiki/P3Steel

Since the number of made printers is increasing exponentially and now everyone knows the printer as the P3Steel I just updated the name to the new one!


I have included some photos to help the assembly and also some 3D assemblies (just discovered Google Sketchup...)

Version 1.2: Leonardo original printer, the one I made.
Version 2.0: After some requests of a spanish group buiding around 30 printers I have modified the bed, now it holds with 4 LM8UU instead of 3 and it has also a system to level with 3 points intead of the original 4, it should be easier with this new design. I kept the original 4 points also just in case someone still wants to use them. I included in the gallery some 3Ds of the new bed. The rest of the printer is exactly the same as version 1.2

Check the wiki! http://reprap.org/wiki/P3Steel

Everything snaps together and hold with a lot of M3x12 screws (mainly), I also used nylon self locking nuts to prevent future problems due to vibration.

The printer uses 8mm chromed smooth rods (Z axis: 2 x 320mm, Y axis: 2 x 341mm and X axis: 2 x 375mm) and only two M5 threaded rods (295mm aprox each since depends on motor coupling and if you want some stick out through the top) for the Z-.axis, printed parts required came from a standard Prusa i3, you only need the parts for the x-axis assembly and the extruder.

The printer structure is assembled quite fast and needs no adjustments. The electronics are installed in either side of the frame, horizontally, holes provided are for an arduino mega and ramps 1.4.
Motors are NEMA 17, GT2 pulleys, LM8UU and 608zz bearings
Hotend is budas type. MK2b hotbed.

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Would these designs work for a Folger Tech prusa i3? I previously ordered an aluminum i3 frame from a website but the frame ended up being too small for my printer. I just want to make sure before I go out and buy some steel haha

I don't understand how to install the y belt holder , the one you have in the thing files here. Any help?

200mm x 200mm same as prusa i3

could you send me the steel cut pieces?

Nope sorry, you'll have to order them somewhere, google it, there are stores selling the structure


Hi, I want to order the frame laser cutting . When I open the .dxf and .dwg files , the dimensions are very large.

I have found that by measuring the width is 390 inches and should be 390 mm. How I can change this to carry it cut?

sorry if consultation is an absurd but I need to ensure that give the correct measurements .

Thank you

AutoCad -> Config -> User Pref ->> mm


Hi, I'm about to start the construction of my first RepRap, and it's gonna be just the P3STELL v2.0. I want to know if the Arduino Mega 2560 is the appropriate electronic card for this model of RepRap. Wich electronic card would You recomend me? The rest of the electonic components (engines, hotend, etc) change depending on the card I used? A lot of thanks!


Yes, Arduino mega is perfect, you'll need a RAMPS board on top of it. Normally rest of components are independent of the card chosen. Check the wiki and Internet, lot of info available.

nice work
What are the difference of version P3Steel V2.5?

Dec 9, 2015 - Modified Dec 9, 2015
pedro01 - in reply to mogey336

Hi, here You have the profile of the P3Steel in the site of RepRap, there you have all the differences between the diferents frame versions of this model. http://reprap.org/wiki/P3Steel

I see on reprap.org/wiki/P3Steel a version 4.0 would you be able to tell me what parts I would need to build it? I'd like to make this my first machine build.

Comments deleted.

dear Irobri are all the 3dprinted files need included in the files tab because it seems to just be the y axis idler


In the info you have the link to the P3Steel wiki that includes all required part files and several versions of some of them, check it out.

were can you get 3 mm steel in the US or do you have to order it in euprope in and ship over

this version is designed for US 10 Gauge Steel plus it is a 12" version that can also take a 8" bed if you have existing parts
can either use Round rod Guides or V Slot guides whatever you prefer or have

NORTH COUNTRY SPECIALTIES Free DXF download 12 inch 3d printer the NCS P3Steel I3V
by trentjw

Is it possible to laser cut acrylic instead of steel ?

3mm acrylic probably to weak but feel free to try and give us feedback!

Does anyone have this .dxf file changed for 11 gage stainless steel.
If not I was going to go through the pains to modify it for the 11 gage steel.

1/8" steel? try this one ;)


Prusa P3 I3+ 1/8" Steel Laser cut


I am finding it very hard to source this here in the United States. The only sites that ship overseas are kitprinter3d, and shipping is 70 euros. Also, 3mm steel is a very uncommon size here. The closest we have for carbon steel is 11 gauge (3.04mm). I've gotten quotes as high as $200 to cut this frame. Is there any options out there for us Americans?

Hi teshdor,
You can order P3Steel version 2.01 frames from MakershopBCN, they'll have them in stock on January 15 for €64.90 + shipping and as far as I know they have very reasonable shipping rates to the US. I suggest you also buy the set of 8mm stainless steel smooth rods from them, if you cannot source 8mm rods in your part of the US.
The problem with using non metric parts or materials with the P3Steel is that the frame is designed with very close tolerances so that everything fits together perfectly when assembled, there could be problems with 3.04mm thick steel. Also having a single frame laser-cut is just not worth it, the cost to setup the laser cutter is too high.

Shipping from them is not to the US now.

Anyone know how i can import this design into Autodesk Inventor? Been having a bit of trouble with all the files

If if mod the y build plate to accept SC8uu bearings, will it lead to any complications in the setup?


I don't think so, you will just lift the base a few milimeters but that's not a problem.

What 3dprinted parts are required in this setup? Is it just the ones available in the thing files?

Oct 10, 2014 - Modified Oct 13, 2014
irobri - in reply to rupin

Please check the wiki, printed parts required are just both x ends, x carriage and extruder, this is the bare minimum.

I'm looking forward to making this also a 300x300x300 version. Could you share the project files (if such exist)? Maybe there is someone who's did it already?

How did yall handle the electronics? External? or could someone point me to a good attachment point? cheers! almost done, photos coming

Hi, I am planning on using a Bowden setup for this frame, and was hoping someone has done this before. I want to use the Greg's Wade Reloaded extruder, but I am not sure how to attach this to the frame. For the hot-end I am planning on using the E3D V6 1.75mm universal, just in case this changes anything in the design of the extruder. Can someone please help me, or point me to a "thingy" here that solves my problem? Any help would be greatly appreciated.

thanks.. I did download this repository already, I will mix and match a little. I was looking for the thingy to attach the extruder to the frame, but that's okay, I will figure it out, thanks again..

thanks.. I did download this repository already, I will mix and match a little. I was looking for the thingy to attach the extruder to the frame, but that's okay, I will figure it out, thanks again..

its possible makes one version 300x300x300 of this laser cut ? i dont have cad skills to make this :(

Have you had any troubles with metal on metal? Vibrations and so forth? Have you ever used rubber washers or plastic washers?

No troubles, many people use metal washers but I didn't, they are really not necessary, what you should use is nylock m3 nuts so that they don't came loose with vibrations over time.

Comments deleted.

Hey all,
I am looking to build a P3Steel as well, I have gather most of the parts required for the build. I will be heading out to the hardware store to purchase my smooth rods, screws, nuts and washers.
Would someone be able to provide a list of the required screws, nuts and washers (size, dimensions and length) for the assembly?

Sorry it's in spanish but I think you will manage ;)
8 tornillos M3x10 inox A2 + 8 arandelas M3 inox A2: para los motores NEMA17 del eje Z
40 tornillos M3x12 inox A2 + 40 tuercas M3 inox A2 autoblocantes: para las uniones del chásis y base de la cama caliente
1 tornillo M3x20 inox A2 + 1 tuerca M3 inox A2 autoblocante + 1 arandela M3 inox A2: para el eje del rodamiento del eje X
3 tornillos M3x20 inox A2 + 3 arandelas M3 inox A2: para el motor NEMA17 del carro del eje X
4 tornillos M3x20 inox A2 + 4 tuercas M3 inox A2 autoblocantes: para los tensores de la correa del eje Y
4 tornillos M3x20 inox A2 + 8 tuercas M3 inox A2 + 12 arandelas M3 inox A2: para el Motor NEMA17 del eje Y
1 tornillo M3x25 inox A2 + 1 tuerca M3 inox A2 autoblocante + 2 arandelas M3 inox A2: para el eje del rodamiento del eje Y
2 tornillos M3x25 inox A2 + 2 tuercas M3 inox A2 autoblocantes + 8 arandelas M3 inox A2: para fijar la cama caliente a la base móvil en la parte delantera (1er y 2do puntos)
1 tornillo M3x25 inox A2 + 1 tuerca M3 inox A2 autoblocante + 6 arandelas M3 inox A2: para fijar la cama caliente a la base móvil en la parte trasera (3er punto)
2 tornillos M3x8 inox A2 + 2 tuercas M3 inox A2 autoblocantes + 4 arandelas M3 inox A2: para fijar la pieza de nivelación de la cama en 3 puntos a la base caliente
Extrusor + Hotend:
1 tornillo M3x8 inox A2 + 1 tuerca M3 inox A2: para la polea del extrusor
3 tornillos M3x10 inox A2 + 3 arandelas M3 inox A2:para acoplar el motor NEMA17 al extrusor
1 tornillo M3x25 inox A2 + 1 tuerca M3 inox A2 + 1 arandela M3 inox A2: para la pieza móvil del extrusor que empuja el plástico
2 tornillos M3x40 inox A2 + 2 tuercas M3 inox A2: para montar el extrusor en el carro del eje X
2 tornillos M4x60 inox A2 + 2 tuercas M4 inox A2 + 4 arandelas M4 inox A2: para regular el paso del filamento en el extrusor
1 tornillo M8 "Hobbed-Bolt" + 1 tuerca M8 inox A2 autoblocante + 4 arandelas M8 inox A2: para el eje del extrusor
2 tornillos M3x20 inox A2: para asegurar un fusor de tipo J-Head

I am going to build one of these. I already have all parts apart from the frame. The only thing that bothers me is there any form of prevention of movement of Y-carriage smoth rods? Are they just fitted tightly into the frame?

Those rods will never ever move.... After hours of struggle, and lots of blood, sweat and tears, I finally got them in. It will take the hand of God to remove them though. :)

Comments deleted.

Hi there! Look on my designs, i've created the piece to block rods! Bye

It's not a problem, they should fit tight and if they move is because you have a friction problem in the Y axis, anyway some people have created a retainer part for this but really think it is not necessary.

Yeah i know that, but then screws will be a little bit losing fix, and they can release bolt...i hope you understood my point of view about bearing LM8UU. Any way, using my rod blocks you will be sure that rods wil never lost their position, i saw other mades from other makers and some of that used blocks like mine, but flat and made of steel. My design will be easy replicated by any 3D printer. It's just another piece ;) THANKS for all IROBRI!!!

What program do I use to see/edit the DXF and DWG file ?
I have access to Solid Edge V15, but when i open the file in solid edge/ sheet metal, I get some strange measurement, way to big numbers.
Hope someone can point me i the right direction.

Check DraftSight, it is free and quite good for 2d drawing, it is the one I used to design the printer structure.

Thanks, now the measurements make sense.

Getting a quote for steel and not sure what to answer on type? Mild or stainless?

haz01 - in reply to wisar

I quoted around 70% more for stainless over using mild. I would just stick to the mild and paint it.

Has anyone had steel for this printer cut in the UK? If so, for how much and from whom? Speaking of cost, how much is the steel and cutting costing elsewhere? Looks pretty cool...'specially with stability of my plexiglass printer being an issue!

irobri - in reply to wisar

Hi wisar, here in Spain people are paying around 45€ for the complete structure in mild steel laser cut, I guess prices are quite cheaper here!

haz01 - in reply to wisar

I was quoted around £86 from http://lasermaster.co.uklasermaster.co.uk that includes vat and delivery. The firm is located in Cornwall I ask them for a quote due to dealing with them previously Ebay. I have not contacted any other companies ask of yet. So I don't know if £86 is a good price or not.

wisar - in reply to haz01

Thanks, it looks like aluminum frames are around 60 quid on eBay. I would say that 86 does not seem terribly far off the mark if you assume that steel is better and that the cost of aluminum frames is leveraged by people producing more than one at a time. I am not sure I am going to replace my current printer but if I do I will post any quotes.

This printer looks amazing!!
You think it's suitable for beginners who have never assembled a 3D printer before? It look easier to assemble then the original I3.
I have quite a lot of experience in electronics and I understand the Arduino environment I have made a few projects with it.
I'm attracted to this this printer due to the simplicity of the design and the considerable cost saving.
I ready have bought the Arduino mega, the ramps board and the stepper driver boards no going back now!!

TH3D - in reply to haz01

It is MUCH easier to assemble this than the original prusa I3 (I have both). I just assembled and painted my "p3steel" today, hopefully the paint is dry enough tomorrow so it can print this weekend :-)
Edit: I assembled the main body in about 15minutes, my first i3 took hours to assemble and adjust.

irobri - in reply to haz01

Thanks haz01,
Regarding your question I think this is a perfect printer for beginners, that was the reason behind the redesign of the printer frame, to get rid of all adjustments and make a chassis that could be assembled like a puzzle, many people, mostly beginners have assembled this printer (now renamed to P3Steel by them) and I have received many comments regarding the easiness to assemble it.
With the experience you comment you have in electronics you won't have any problem at all.
Go on and say something when you finish it, check the wiki made by the spanish group about this printer, you have the link below somewhere, it will help you a lot.
Good Luck!

This is the one for me!
One question, is this design interchangeable with aluminium or is it too thin for Alu plate to be sturdy?
Secondly, if its steel, do you seal it or paint it and how?
Do you seal and paint it after or before putting the frame together?
Cant wait to get started, I had to leave my previous babies behind when i moved :P

Sorry for the late reply, I think in 3mm Alu it may be to weak, I would go for steel, it is cheaper and also easier and cheaper to laser cut also, I painted mine with primer and final coat, spray can paint previous to assembling it, tolerances normally are enough to take care of the paint thickness, there are a lot of people in Spain and in other countries who have built the printer (here in Spain it has been renamed as the P3Steel), there is a wiki in spanish and english, check it, you have the link below in another comment.
Happy printing!

Hi Irobi. Here the company that will laser cut the sheets works with AISI 1010 but in 3.17 mm, will be ok? I was told that perhaps some joints would have trouble to fit in due the extra thickness? Thanks!

That would be very tight!, probably the sheet will be little above 3.17mm with usual tolerances, I think it is too risky, try to stick to 3mm to be on the safe side, you can check in the dxf that tolerances are quite tight in the design already, sometimes people have to grind a little to fit the parts even with 3mm depending on the sheet they have used.

I'm building P3steel, bit I have some issues.
I can't fix my RAMPS electronics to its holes because I have a shield for the LCD. Holes should be moved 10-15 mm, but maybe I miss something...
Next: I can't fix the Y motor support to the frame (without using some washers) because the nuts hurts the motor.
And the last one: using the three point leveling system, the central bolt can hurt the pulley/belt. Do I am using a too long bolt (30mm)?
Correct me if I'm wrong.
Bye and thanks for this wonderful design.

What x-ends are you using in these pictures?

Please check the wiki, you have the info there.

Hello, is very nice project.
What is the total size of the steel plate 3mm to lasercut?

Thanks a lot,

augus - in reply to mobiuz

16 x 32"

I'm needed work zone 300mm x 300mm x 250mm.

Smooth rod 12mm x 500mm ,

LM12UU linear bearing like this: http://images.ua.prom.st/34212808_w640_h2048_podshipnikscs20.jpg?PIMAGE_ID=34212808http://images.ua.prom.st/34212...

Help me please...

some one help u i need same print zone and i dont have idea how edit this files to make this print area

Have you found the design for 300x300 mm bed? Thanks

Hi, very nice.
do you have Bill of Materials and build instruction? Thanks,

It is very similar, with the drawings and instructions attached should be enough, there are about 50 people building it right now in Spain, they have made a wiki with a nice assembly video, it is in spanish but you should check it anyway


Hi, how are the rods secured?

They just fit quite tight, there is no need to secure them.

Hi, could you tell us the lenghts of the different smooth rods?

Added in the instructions.


Just uploaded version 2.0, basically the same but with new bed with 4 linear bearings instead of 3 and a new simple leveling system with three points instead of the original 4, should be easier to level now. I keep also original 4 leveling points for anyone that wants them. The rest of the printer is the same. You still have the prior version 1.2 in the files.
Included also in the gallery some new 3Ds of the new table.

Hope you like it!

Just corrected the misalignment found by integra386, new files version 1.2 uploaded.

Hi, I've started a Group purchase In the CloneWars Group to lower costs of lasercuting the parts needed to build your Leonardo printer. Everybody likes your design and we have grown from 1 (me) to 15 since yesterday. (you can see the group thread here:https://groups.google.com/forum/#!topic/asrob-uc3m-impresoras-3d/74rEdxCIG50https://groups.google.com/foru... and pass to say hello and get your credit ;) )

I've read the previous comment about the misalignment of the Z axis and want to ask If it's really noticeable, and if you plan to correct the design in the near future. Our plan is to get the list closed before the end of this month and start cutting.


Great jbabio!, I happy to see the someone finds my design useful!.
Regarding the misalignment, I have the printer since april this year and I didn't notice until integra386 told me, but I will correct it today and upload the new file anyway, I just have to move the holes of the top Z-axis holder 1.8mm towards the frame.

Hi ... i'm making your 3d printer Leonardo.

I've noticed a little incongruence with the position of the hole for the z axis's smooth and threaded rod.

The bottom holes (motor support) are not inline with those on the top ... there are few mm of difference.

I noticed this error while I was simulating the assembly on Google Sketchup, then I checked the misalignment in autocad

However, such a great design ... congratulations and thanks for sharing it!

Hello integra386,

I am also now assembling the model in sketchup, but I am bit behind you I guess, I will check what you comment but if you are talking about the holes on the top of the motors don't worry, you dont have to use them (that why I didn't notice I suppose), the threaded rods should be only attached to the motor, the other end is free, there has been a lot of discussions about this specific issue, my opinion is also that's better to leave them unattached so the threaded rod is able to wobble if necessary to absorb any minor misalignmrnts between motor shaft and the nut inserted in the x-end plastic parts.
The smooth rods are perfectly aligned, I can tell you cause I have the printer to my left working like a charm...

Oops, you are right integra386, I just checked and there is a 1.8mm misalignment, it is not much since the z axis rods are 320mm, that means 0.3 degrees but I will correct it, thanx for the info.

Hi, the yellow pulley holder for the Y axis seems a non standard i3 part (as seen on photo #9). Could you confirm this? Would you share the STL files for the 3D printed parts to complete the build.

I added the y axis idler part requested, it includes also an alternative part for y axis belt holder.

Buena vista jbabio!, You are right, this yellow part is self design, is not very elaborated but it works, anyway you don't needed since there are two small parts in the dxf that do the same function, the original idea for this design was to use as few printed parts as possible, in fact you only need, apart from the extruder, the xcarriage, the x motor end and the x idler end. I will publish it anyway as soon as I can, it is very simple design, the m3 screws are screwed directly into the plastic, I use the to adjust the tension of the belt.

Just updated the files, they are basically the same, just some parts rearrangement and removed a small artifact in the dxf.