For those interested, and able to get a hold of a $199 prusa i3 upgrade kit, we built a printer around the kit that uses high quality genuine Hiwin rails, and precision waterjet parts, along with a bondtech extruder to achieve a very solid platform. It uses all stock prusa firmware, slicer, etc.
Follow along on hackaday: https://hackaday.io/project/19305-3d-printer-on-rails
Those are killer parts. Love it
that’s pretty similar to what i have on my test machine (please ignore the wire management which is going through changes now).
i am actually now comparing a stiff coupler to a flexible coupler to a top mounted belted system, and it seems that with this rigid a build it does not even matter, no z wobble what-so-ever in any of the setups!
Love it @Tom_Keidar how has it been printing for you?
Did you make the same pcb heatbed as them, for alignment? Or could it be that with a single machined baseplate, all the alignment issues are taken care of?
@raykholo the i3MK2 pcb heatbed comes in the upgrade kit, so we are using it. I dont expect alignment to be an issue, but since we are using the prusa bed, sensor, and software, it will not be an issue. Sidenote, I am planning on given cohesion a run on this machine, it should be pretty sweet with smoothie too!
in a word - perfect 
(and in a few more words)
i mainly print mechanical parts as well as toys and toy prototypes (part of my wife’s business is coming up with ideas for toys, she is in charge of concept and design and i’m in charge of making it happen in the real world and meeting her standards). i can basically print them at any speed marlin and the e3d titan can spin motors and extrude plastic and have never encountered any accuracy problems or the need to re-calibrate anything.
i mostly print at 60-80mm/s with accelerations set to 5000-9000.
i have recently backed the re-arm project by @Roy_Cortes and am waiting for my january pledge to be shipped. hopefully smoothie can help me get some better speeds for bigger parts with more accuracy (lots of things i hate about marlin).
i have been contemplating a move to corexy for the better part of 2016, and have made a few sketches (it’s just printing some small parts and adding a few 2020 extrusions) - but could not objectively convince myself it would be a worthwhile investment (well except for the researcher/tinkerer in me which always wants to try something else - it’s a disease really…).
right now the bed is 250mmx250mm (i also have a 300mmx300mm one which i use for really big prints).
and i would consider 300mmx300mm the limit for a moving bed (it’s why it has 4 leveling screws and not 3, and i have also moved to a tpu based cushion instead of springs for better stability), but i would definitely consider the move to a corexy for a bigger bed - since i would not want it moving on the x/y axes.
@Anthony_Webb since all the calibration stuff was written into Marlin and is not in smoothie, I am of the opinion that the sheet metal work will be precise enough. I have folded sheet metal machines I designed that don’t even require any bed leveling, so I am confident that it should be naturally square enough. As long as the mounting holes for the motors and such don’t have any clearances
I like it, I imagine about $450 in hiwin parts? Are you going to offer any kits?
Love it
I see all kinds of claims, but what I don’t see is comparisom prints showing what the output of this printer is like compared to a stock MK2.
@Brad_Hill The hiwin bits run about $300 shipped to USA
@Eric_Davies calm down, I dont see how print quality could be much better than the MK2, I have that printer already, and I absolutely love it. It is “near” perfect. I will say, after printing with the MK2 for several months now though that the machine is starting to rattle (prints are still fine though) I am thinking this is due to the bearings being attached with zip ties. The goal of my new build is to use all the things that IMHO make the MK2 hands down the best FDM you can buy now (bed, level sensors, calibration, and software) but improve on the linear motion bits replacing zipties and printed parts with precision rails and robust aluminum brackets. What will the end result be? That is still to come. I’d highly recommend the MK2 to anyone. But I’d prefer to spend the money on proper linear motion bits. We’ll see how it shakes out.
Very interested in this project. keep on!
@Anthony_Webb I got the rattle on my Mk2 and it’s not the zip ties but rather the bearings themselves which apparently are about the cheapest it’s possible to buy from China. I replaced mine with these:
http://www.igus.co.uk/wpck/2292/drylin_r_rjum_01?C=GB&L=en
Note it’s the RJZM-01-08, not RJUM, that I used; their website is a bit quirky.
Now no rattle on the Y, nice and smooth. I haven’t done the X yet (though I’ve got the bearings) but will do so when orders calm down.
