MakerFarm 8" i3v Prusa build by Printbus
Notes and observations from my i3v build are captured here. My assembly goals included seeing what I could do to improve the appearance of the completed printer. The i3v is expected to be my only 3D printer for a long time, and I want it to look good whether in use or on the shelf. Primary areas of emphasis were in gluing some of the wood components, filling the post and slot wood joints, painting, and a major effort on cable dressing and routing. Various mechanical tweaks were incorporated as I saw a need for them during the assembly. Whether these extra efforts were necessary or not is irrelevant. It's just part of how I approach things and part of the reason why I bought a kit instead of an assembled printer. I admit that I'm unusually nitpicky about things, but some of my observations and suggestions may still be of value to others.
Subassembly notes and pictures are provided in the same sequence of the MakerFarm i3v build guide. All notes here are with respect to the 8-inch i3v kit, build guide, and build videos as they were around May 2014. Note that in my case I had glued various wood components together in an initial assembly pass prior to painting. Info that follows is mostly derived from final assembly after painting.
FOLLOWUP COMMENT: Readers need to note that the bulk of the build thread is based on the 8-inch printer, and based on the 8-inch printer as it was in early 2014. While some concepts will apply to newer 8-inch kits and the newer, larger printers, MakerFarm has been making changes to the printer designs. All mods and improvements discussed in this thread should be assessed for suitability on the updated kits before they are attempted.
The thread includes a lot of detail on purpose. Feel free to skip it if you're expecting a quick read.
Also note that as of April 2015, 3DPrintBoard was having problems properly displaying images and dealing with other attachments. Printbus posts in the thread have been revised to now link to images and attachments stored offsite from 3DPrintBoard.
THREAD TABLE OF CONTENTS
GENERAL OBSERVATIONS
X MOTOR SUBASSEMBLY
X IDLER SUBASSEMBLY
Y IDLER SUBASSEMBLY
Y BED SUBASSEMBLY
X CARRIAGE SUBASSEMBLY
Y MOTOR SUBASSEMBLY
FRAME, X AXIS SUBASSEMBLY, and X AXIS INSTALLATION
X AXIS ALIGNMENT
Y AXIS
LCD INTERFACE AND LCD INSTALLATION
Z MOTOR
THERMISTOR BUILD
HEAT BED INSTALLATION
ENDSTOP INSTALLATION
EXTRUDER AND HEXAGON HOT END
POWER SUPPLY and RAMPS MOUNTING
WIRE ROUTING (Part One)
WIRE ROUTING (Part Two)
MOTOR TESTING and ENDSTOP ADJUSTMENT
BED LEVELING
GARBAGE DATA ON LCD DISPLAY
HEAT BED CLIPS
WRAPUP COMMENTS ON THE INITIAL BUILD
SIX WEEK STATUS UPDATE
Y MOTOR COOLING FAN
IMPROVED KILL SWITCH
NOISE AND VIBRATION REDUCTIONS
MINOR FIRMWARE PERSONALIZATION
EXTRUDER REBUILD AND NEW PRINT COOLER (Part 1 of 2)
EXTRUDER REBUILD AND NEW PRINT COOLER (Part 2 of 2)
DISABLING POWER FROM USB
TWEAKS TO THE COUPLERS ON THE Z-AXIS RODS
RAMPS STEPPER MOTOR DRIVER COOLING FAN
NOV 2014 BENCHMARKS USING MAKE: 2015 TEST MODELS
RUNNING SUMMARY OF CONFIGURATION SETTINGS
DISPLAY BEZEL
REPURPOSED SPOOL MOUNT
NEW MOTORS AND MORE
POWER MODIFICATIONS
NEW APPROACH FOR THE HEXAGON HOT END SHROUD
SMOOTHIEBOARD AND OTHER UPGRADES
DECEMBER 2016 STATUS UPDATE
PRINT BED REVAMP
FEBRUARY 2019 STATUS UPDATE
RASPBERRY PI AND OCTOPRINT
Z-AXIS LEAD SCREW UPGRADE
X-CARRIAGE AND EXTRUDER REPLACEMENT
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LCD assembly and installation
LCD INTERFACE and LCD INSTALLATION
I didn't like the way the build videos clamp down on the display board and bend it. To prevent this from happening, I used some 3/16-inch long spacers between the display board and the LCD bracket. The spacers really can't be any longer than this or the LCD bracket end will start to interfere with the SD card slot.
https://dl.dropboxusercontent.com/s/...bhwm/5704a.jpg
FOLLOWUP COMMENT #1: I've had several cases where the display either blanks out or displays random garbage after I first touch the encoder shaft or the metal knob I had installed on the shaft. There might be a static discharge issue here, so I replaced the metal knob with a printed knob to see whether the problem goes away with an insulated one. A better knob was later found on Thingiverse and used instead.
https://dl.dropboxusercontent.com/s/...0ii4f/5827.jpg
FOLLOWUP COMMENT #2: The buzzer on the LCD is quite loud. I tamed mine down by covering the hole in the front of the buzzer with a small piece of black electrical tape.
FOLLOWUP COMMENT #3: The display comes preassembled with one row of soldered pins fastening the two boards together. At some print speeds, I've had the LCD board vibrate against the larger board and/or vibrate against the wood frame. To fix this, I added a few dabs of hot glue between the two boards, opposite from the row of soldered pins. Double-sided foam tape or something similar could also be used to improve how the two boards are fastened together.
FOLLOWUP COMMENT #4: There were additional rattles coming from the LCD vibrating in the wood frame. Narrow strips of electrical tape were added as a cushion to either the wood, the circuit boards, or the metal frame on the LCD so that no two hard surfaces can vibrate.
Extruder and Hexagon Hot End
EXTRUDER AND HEXAGON HOT END
Before I added the extruder assembly to the printer, I opted to add some lighting to the X Carriage. There's a perfect area underneath it for mounting some adhesive strip LED lighting. I used two sections of 12V warm white LED strip lighting that I had leftover from a prior artwork project. A two-pin header was added to the sidewall of the X carriage extruder bracket for use as a connector on the LED wires. I thought about just tying the LEDs into the extruder fan power, but decided to run dedicated lighting wires in case I want to put the LEDs on a switch or dimmer circuit. I plan to sleeve the bundle of wires leading to the extruder assembly, and having a connector on the LED wires will allow me to disconnect the LEDs when I remove the extruder and cable harness from the X carriage for repair or cleaning.
FOLLOWUP COMMENT: A picture showing the heat bed illumination from these LEDs is here.
https://dl.dropboxusercontent.com/s/...hc3r/5725a.jpg
A locknut was used instead of the provided standard nut on the filament release pivot bolt. My printed parts seemed to have a looser fit than those in the build videos. After assembling everything I was disappointed to find a lot of sloppy mechanical play in the extruder tip. Multiple things were done to fix this. To improve how the bearings fit in the extruder, I added a layer or two of kapton tape around them. To minimize slop in how the hobbed bolt fits in the bearings, I added three or four turns of tape to the bolt where the bearings ride. The hex hot end was also a very loose fit in the aluminum mounting plate, so I added a layer of kapton tape to the post of the hex hot end. After final assembly, the extruder tip now has zero play.
https://dl.dropboxusercontent.com/s/...yjb9/5723a.jpg
https://dl.dropboxusercontent.com/s/...qs87/5721a.jpg
Envisioning how I plan to route wires, I oriented the extruder motor so the wires exit differently than shown in the build video. I found it necessary to lengthen the elongated motor mounting holes in order to obtain good gear mesh, at least with the gears in new and unused condition. M3 x 16mm bolts and M3 fender washers were used on the extruder motor instead of the provided shorter ones that are intended to recess into the wall of the extruder. The face-mounted fender washers should improve the hold as heat from the extruder motor starts to soak through the motor mount. Watch for conflict between the left motor mounting screw and the large gear; use of a button head screw will help reduce the size of the screw head.
The build video discusses the user printing a fan shroud for use with the hexagon hot end. A shroud was included with the hex hot end I ordered with my i3v. I found it challenging to add the shroud and fan on the bench with the hot end and aluminum plate still loose. I ended up mounting the extruder and hot end to the printer and then installing the fan and shroud. I had to enlarge the holes in the shroud for M3 bolts to pass through it.
https://dl.dropboxusercontent.com/s/...3tw2/5726a.jpg
FOLLOWUP COMMENT #1 - I later realized that since I had added more washers than usual under the large gear to clear my face-tightened motor mounted screws, the large extruder gear was now rubbing against the ends of the bolts for the top two wheels on the X carriage. I ended up fixing this by shortening the bolts with a file so they don't protrude from the lock nuts when they are installed.
https://dl.dropboxusercontent.com/s/...dz1m/5735a.jpg
FOLLOWUP COMMENT #2 - I applied it later in the assembly, but I followed the ZennmasterM recommendation of using Permatex Muffler & Tailpipe sealer to thermally bond the thermistor to the hexagon hot end. ZennmasterM's use of a syringe would be overkill for the hexagon front end; all I did is dab a bit of it into the dimple provided for the thermistor with a straightened paper clip. After all my wire and cable routing was complete, I redid the kapton tape over the heater and thermistor wires. With wire movement now fairly over, this is when I applied the Permatex sealer.
FOLLOWUP COMMENT #3 - In response to some suggestions I found elsewhere on the web, I've reversed the hot end fan so that it is pulling heat away from the hot end and exhausting it out the front of the printer. This reportedly works better than pushing cool air into the "boxed in" bottom part of the i3v X carriage.
FOLLOWUP COMMENT #4 - The stock shroud for the hex hot end is mounted with the two screws for the hot end cooling fan. The shroud also sort of snaps onto the aluminum barrel of the hot end. I'm not sure what the intent is since that causes the bottom of the shroud to melt where it touches the aluminum block of the hot end. I've subsequently printed the shroud in ABS and cut away the bottom of shroud so it just barely clears the aluminum block of the hot end. This has eliminated the problem with the shroud melting. Having the shroud only supported at the top led to an occasional vibration at some print speeds. This was fixed by adding a silicone isolator between the shroud and the fan.
FOLLOWUP COMMENT #5 - The stock extruder comes with #6 Phillips head screws for mounting to the X-carriage, with nuts that are recessed into the printed extruder base. I replaced the #6 hardware with M4 cap screws, long enough that fender washers and nyloc nuts can be used on the face of the extruder base. I used M4 x 25mm. Cap screws are easier to tighten than Phillips head. Using fender washers on the face provides a lot more surface area that should hold up better to any heat making it's way up from the hot end. Using nyloc nuts should help keep the hardware tight. The screw on the left side can accept a very large washer; I used a 3/16-inch ID washer there that is about 20mm in diameter, just about the same width as the base of the extruder. It's tricky to get the nylock nuts in place, but my hope is that this improved mounting method leads to messing with the mounting hardware less often.
FOLLOWUP COMMENT #6 - Some have had issues with the adhesive backing not holding on similar LED strips. Mine have held fine. I'm not sure if it is the fact that the LED strips I have used 3M branded adhesive or the nature of the painted surface. Adding the kapton tape to the aluminum u-channel has been tricky. In subsequent extruder rebuilds, I've been adding layers of kapton tape as required to the top, round end of the hot end, using the tape as a spacer to push the hot end down into the aluminum bracket.