prusa i3 aluminum frame w/ aluminum upgrades

by thainfamousnate, published

prusa i3 aluminum frame w/ aluminum upgrades by thainfamousnate Mar 31, 2013


ive modified twelvopros design with the back braces to fit m10 threaded rod on the y axis, and upgraded alot of printed parts to be CNC cut out of 1/8" aluminum to match the 1/4" CNC'd aluminum frame. i3XL (300x300mm) is in development, look at the derivative for a sneek peek!!!
note: the stl files are from twelvopro
to mount a buda schnozzle or prusa nozzle to the x carriage use-- http://www.thingiverse.com/download:147063, (the buddasch_i3 file)
to mount a j head use --
http://www.thingiverse.com/thing:8252, ( the wades wildeyed mount file)

Recent Comments

view all

What scale should the frame be cut at?

i have a spare one i could sell

just cut out one on cnc plasma, the only file that worked on my machine for some reason

More from 3D Printers

view more


this is my derivative of twelvopros i3 design. i upgraded most of the printed parts to 1/8" aluminum parts, the only printed parts are the x carriage, x motor bracket, x idler bearing bracket, the heated bed lm8uu holders, the endstop brackets from obijuan, and belt x tensioner from thinkyhead. i am working on making all parts out of aluminum.

designed for: m10 threaded rod, m8 threaded rod, m8 smooth rod, T2.5 belts and grub screws, lm8uus, a budaschnozzle, gregs extruder, and a RAMBo Board running repetier host, repetier firmware, and slic3r.

done calibrating
firmware tweaked
build is complete!!!
new .4mm prusa nozzle!!!
video soon!!!

Sourced Parts:
All smooth & threaded rods - Fastenal.com
Budascnozzle, RAMBo Board w/ cord & power supply: - Lulzbot.com
Printed Parts, NEMA 17s, lm8uus, & everything else: - ebay.com
Prusa Nozzle:

Cut List:
M10 threaded rod - 2@18"
M5 threaded rod - 2@12"
M8 threaded rod - 3@ 9"

                          - 1@11"  

M8 smooth rod - 2@ 12-5/8" for z

                          - [email protected]" for y  
                          [email protected]" for x  

second build i used 5/16" threaded rod instead of m8 and 3/8" threaded rod instead of m10. i also shortened the y axis by 1.5-2" to reduce the amount of tension needed on the belt a little.

Build Notes:
i put the m8 smooth rod in an air drill and rubbed it with 0000 steel wool to make the bearings slide a little better( probably took off .002"). second build i used O1 steel rod from mcmastercarr and didnt have to steel wool it at all!

i bought two sets of 12 lm8uus and used the best of both (the inner plastic sleeve is of low quality). second build i used lm8uus from easyreprap on ebay, and every last one of them slides smoothly.

the marlin firmware wasnt working right so i switched to repetier firmware, much better

i am done calibrating all axises and extruder and am working on the endstops and home position.

software and firmware tweaks finished

up and Printing! 4/20/2013

added tiny heatsinks to the drivers and a fan on the RAMBo Board.
also a 75 mm LED ring around the nozzle to see the print area better, wired straight to the power supply( if i knew more about the firmware i would wire the LED Ring to the Board to turn on when a print starts).

prusa nozzle! 5/18/2013

What scale should the frame be cut at?

just cut out one on cnc plasma, the only file that worked on my machine for some reason

How thick is the metal? If you look at the photo - does not seem to 3 (1/8 ") mm.

I would like to buy the aluminum

Well done. Working on cutting the frame for my build. For those making your own, insure your materials are actually .25" thick. Mine are .258", which made assemply a challenge. Should have adjusted the holes for actual material thickness. Love the design, I will post pics when done.

Is it possible to get a full set of the drawings...the pictures are cropped and I can not see everything. I have the main frame CNCed from 1/4" alum but need the drawings of the corner blocks. Thanks

i couldnt get marlin to work for the life of me so i swear by repetier host and firmware. if you want my repetier configuration file i can email it to you, the rigidity of the frame of this printer allows me to crank up the speeds, this thing zips around!


I love your printer and actually made one from your plans! would you be able to send me the marlin firmware definitions so i can get started? thanks man

When are you going to start selling frames? Where can I find one?

I'll second that

i have a spare one i could sell

Hello, Great job !!

But I dont understand in you production_i3.dxf file, the pieces on the right are CN in 3mm aluminium ?

Have you a clear BOM list ? and may be some making doc or have you use this ->

Thanks for your answers

All the best for your projects.

yes, on the right 3mm(1/8"), i do have a BOM, a outsourced parts list, and a hardware list( one overall nuts and bolts shopping list, and one hardware list showing what hardware each Plastic parts uses. i will post it soon after i verify it, ive been busy trying to CNC frames and print plastic parts to sell. also i changed some parts back from 1/8" aluminum to printed parts as they add more cnc time and are overkill. stay tuned!!

Ok thanks for you answer, feel free to share with me ! I already order from a friend the CNC part of your Production file and upgrades, and the electronic will arrive soon. I have an Ultimaker for plastic print, and will try with hope for my contribution to the rep rap project :)

ive added callout pdf's showing where hardware goes, a outsourced parts list, and a hardware shopping list in the download section. let me know if i missed anything!!

Wow very impressive job you have done here, with all this pdf files. I will group all this in one pdf and check it !

I will let you know if I notice something wrong.

the main frame, back braces, and heated bed carriage are meant to be CNC'd from 1/4" aluminum(roughly 6mm) and the parts "upgraded" from plastic are meant to be CNC'd from 1/8" aluminum(roughly 3mm). i reposted the updated files shortly after lamerhouse pointed it out, they now match the y corners.


I'm sorry for the ignorance but how many mm are 1/8''? And is it correct? I have found a lot of other frames that are 1/4''.


hello ...

sorry but the printer feet which you used .. that are not the original ones and some m8 and m10 .. do not go well with your measurements


i checked and yes its slightly off. im modifying the dxf of the frame to show these modifications . funny thing is the machine pictured was built with those exact pieces and it doesnt seem off at all. i found the spacing from floor to M10 Threaded rod was off by .06". is this the amount of the off measurement you got?

if you've already CNC'd the frame the Y Corners could be modified so you dont have to file into the frame. i can't believe the one pictured went together so well with it being off by a .06", weird...

Hi, Whats the fitting at the top of the z axis threaded bar to the alloy plate? Can't quite tell from the photo's.

608zz bearing, the m5 rod isnt constrained by it, it just floats around slightly and prevents the rod from rubbing against the frame