Show your MODS

[midnitmike]

Since this thread is about mods to the MakerFarm i3 I thought I'd share the ones I incorporated into my build. Besides using standoffs to mount the Rumba board instead the supplied bolts, I think the first one was to do away with the zip ties that hold the end stop switches. You gotta love zip ties, but when it comes to mounting these switches there had to be a better way. When rummaging through my parts bin I came up with a set of 2mm or 3mm bolts that fit perfectly, all I had to do was countersink the head into the plywood bracket.

Endstop.jpg
These new switches presented other problems as well, since the actuating arm is shorter than the old model I had to reverse the direction of the Y bed endstop so the "flag" is up, and add a piece of scrap plywood to the inside of the X carriage to actuate the switch .

After I began printing I noticed my build plate needed constant adjusting to stay calibrated, and the culprit was among other things loose bolts holding the concentric adjuster. According the build document you set the tension on these bolts like all the others, tighten the nyloc until you feel the bearing begin to bind and then back off a little. For me this didn't work all that well as the nyloc was barely engaged at this point and would eventually loosen up. This was remedied by swapping out the stock bolts for a longer versions and adding a nut between the bearing and concentric. This made several improvements possible at once because now the bearing rode on the shank of the bolt rather than the much smaller threaded portion, and I was able to adjust the two parts individually.
IMAG2529.jpg

Another modification to the Y-Bed was to do away with the spring loaded adjustments for the build plate and go with a solid mount. As before longer bolts were substituted and locked in place with nuts. A simple lock nut system was employed to both adjust and hold the heat bed in position, once set they do not move. I reused the springs since they provide just enough resistance to hold that lower nut in place.
Heatbed.jpg

I also added an inch of fiberglass insulation to this after my first Y-Bed warped beyond repair. This may be particular to the 12" model because of the larger heat bed and Y-Bed, in any case MakerFarm has already come out with a mod to help address the issue.

After untold hundreds of filament jam and weeks of frustration I was finally able to resolve the issue..it seems that not all Hexagons are created equal and I happen to get one of those. While I was clearing yet another jam I noticed that after I had reassembled the hot end the barrel and nozzle hole were slightly out of alignment. Chamfering the lead of the nozzle resolved the problem but not before I redesigned the extruder and hob bolt. I had tried using a small tube to take up the slack in the oversized hole of the extruder, and that helped to some degree. I wanted a more permanent solution so I modified the extruder stl file so that it fit the 1.75mm filament...I know this design is supposed to be a one size fits all, but I'm not convinced that's the right way to go. Here is a MakerFarm branded extruder designed for 1.75mm filament.

1.75mm Extruder mod(2).stl

I also made a hob bolt to fit this filament and I was surprised at how easy this was. I used a previously printed extruder block to hold the 5/16 bolt in place with bearings on both ends so that it turned freely. I then used a Dremel tool and large cut-off wheel to notch the bolt in exactly the right spot. To make the teeth I took a new hack saw blade and set it in the groove, and with lots of down pressure began to roll the bolt back and forth with the hacksaw blade. In just a few minutes the teeth began to take shape and once I was satisfied with the results installed my new hob bolt...it's been working flawlessly ever since.

And lastly I modified the fan shroud to keep the hot end hot...the stock one was too short in my opinion and made keeping the temperature of the hot end up during large prints almost impossible.
ExtendedShroud.stl

Those are my simple mods.. I hope some of you find them useful.

Mike