Overall

Revision 2 is coming!

After few months usage of the current MK2Clone with good results, I’ve decided to go further and create a… MK2Clone Revision 2 (r2).

All the parts was reviewed – modifications, some smallers and few biggers was made. There is a new frame, designed to be lasercut from 10mm plywood. Spool holder taken from MK3, adjusted to fit 10mm frame. Parts refined to be more easily printable. Fixed a lot of misalignments in the stls due to differences in mechanical parts.

There will also be a lot quieter printing, thanks to Trinamic stepper drivers and quiet-enough SUNON fans. Additionally, filament runout sensor integrated with extruder body – no more ruined prints due to end of filament.

Unfortunately, the printer will be not as cheap as the first one. Trinamic stepper drivers are more expensive than the standard a4988. Original E3D Hotend, bigger heatbed, even the SUNON fans – all that parts will make the printer far more expensive. For the people looking for cheaper version, there will be still a option to use cheaper parts, I’m planning to publish a list of cheaper replacements.

Additionally, there will be a full guide describing how to build the r2 step-by-step, with photos.

All the parts for r2 (it’s still beta!) can be found on MK2Clone on GitHub in master branch (the master branch should be called dev for this repo ;)) – https://github.com/q3ok/Prusa-i3-MK2-Clone/tree/master

Stay tuned.

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New firmware, summary and more

IMAG3101

Current state of MK2 Clone build

The “Original” thing

Josef Prusa already announced and started sale of the Original Prusa i3 MK3 printer, with a whole bunch of new sensors. Unfortunately, as he was publishing almost everything to the community, currently his company is making everything by themselves, and its hard to buy the things from other suppliers. It was already same with MK2, but there wasn’t so much parts like that as now.

What about firmware?

There are already new versions of Marlin firmware available (1.1.x) which has a lot of new functions, with Unified Bed Leveling on top of them, and also skew correction algorithm. As the firmware which I made for MK2 Clone wasn’t stable enough, and also the X/Y skew was only the calculator, not the true algorithm to compensate it – I decided to abandon it. Additionally, the chinese MK3 aluminium heatbeds are not perfectly cutted, so the results wasn’t good enough.

-> Configuration files for Marlin 1.1.8 are available in the MK2 Clone GitHub repository

IMAG3105

Freshly compiled software

Skewed Z axis

As dulouie noted that the x-end-motor and x-end-idler made by achim_boers has lightly skewed position for brass, he made also a new parts, which are linked in Bill of materials, and available on GitHub as well.

IMAG3109

Skewed Z axis

Make it quieter

Most noises are made by stepper motors driving X and Y axes. The cheapest way is to replace the A4988 stepsticks with Trinamic TMC2100, even the chinese cheapest ones. When inserting the TMC2100 then the active cooling for electronics is almost a must, otherwise the stepsticks can skip steps due to protection agains overheating.

IMAG3108

Electronics active cooling

What’s next?

Even more quieter: the second loudest noises (in my opinion) are made by the 30×30 fan which is responsible for cooling the hotend. I’ve already found the 30×30 fans made by TITAN, and the manufacturer declares noise level on 21dB. Sound promising.

Sensors! As the MK3 few new interesting sensors, I’m planning to put some on the MK2 Clone. Prusa Research are making a lot custom electronics right now, and I want to focus on electronics generally available on the market, to allow everyone to make the MK2 Clone in their homes.

Test print – Clone vs Original

My clone is already fully working, I’ve made some tests.

I didn’t wrote that before, but I’ve replaced Z axis stepper motors with chinese ones with integrated trapezoidal Tr8x8 screws, as because of the coupler the Z axis was unable to go low enough to print. I strongly recommend to also do that, otherwise You can have similar problem. It will also help to avoid wobbles, which are mostly caused by the couplers.

The chinese motors which I’ve used are with screws 300mm length, and its enough to drive the Z axis to the top, even if they are not long enough to be over the Z-tops.

I’ve put the printer on karimata (joga mat), to (mostly) reduce noise.

IMAG1729.jpg

On the chinese MK3 heatbed there is directly sticked the cheapest adhesive surface, I found that at my local reseller.

I didnt wrote anything yet about mounting the heatbed, but its really a easy task, just put the MK3 on plywood, use 4 M3 screws and heatbed springs, and using self-locking M3 nuts – screw it.

Eventually, the test print: (3DBenchy by CreativeTools)

One of the prints is from the Clone, and the other one is from Original Prusa i3 MK2S.

Filament used: ESUN PLA+ Green
Layer height: 0.2mm

Are you able to guess which print are from which printer? There are small details which should tell you that.

I’ve made also a short video from print on the MK2 Clone.

I am really surprised with the print quality from this clone, I wasn’t expecting that it will print so good.

Soon I will finish the Bill of materials, with a links to stores where you can buy all of the parts to build a MK2 Clone.

At the begining…

If You don’t have experience with 3D printers, I strongly recommend to buy a Original Prusa i3 MK3 directly from Czech Republic (from Prusa Research).

To build that clone You will also need a 3D printer already, or a friend who print.
I am not sure what will be the results of that project, maybe the printer finally will be worse even from Prusa i3 Rework, but maybe it will be a great printer? 🙂

There is also a similar project about building a Prusa i3 MK2 Clone by Thomas Sanlanderer (its available on YouTube and also on his webpage – https://toms3d.org/2017/02/23/building-cheapest-possible-prusa-i3-mk2/)

All the printed parts can be found on GitHub – https://github.com/prusa3d/Original-Prusa-i3

I am buying a lot of parts from local stores. I will be converting all the costs to USD, as its my preferred currency on Aliexpress.
The costs can be different for You, depending on how expensive the metal/wooden parts are at your location.

For the metal I am always trying to obtain parts with property class at least 8.8 (ISO). The availability of that parts are smaller, but I believe it will help with the printer overall stability.

On the post image there is Original Prusa i3 MK2, which You should buy, and I am strongly recommending that.

Stay tuned!