MakerFarm 8" i3v Prusa build by Printbus

[printbus]

WIRE ROUTING (PART ONE)
Although there are a few things I'd likely do different, I'm pretty happy with how the wiring and cable routing turned out.

FOLLOWUP COMMENT: In response to issues others have had in understanding how to wire the heat bed relay, I've tried to provide some detail in thread Clarifying i3/i3v heat bed and heat bed relay wiring

Materials Used
In addition to zip ties, I used (mostly 1/4-inch) expandable sleeving and a number of cable clamps to attach most of the wiring. Anyone who has used the expandable sleeving knows how frustrating it can be since it tends to unravel as soon as you cut it and try to feed anything through it. For this build I used "clean cut" sleeving I found on eBay that is a lot easier to work with. I also had obtained some aluminum rail slot covers from Openbuildpartstore. In addition to possibly being used for decoration, the slot covers can be used to create a wire raceway in the aluminum rails.

Every wire was custom fit to length, cutting off the connector and splicing it back on as required. I could have crimped new connectors on instead of splicing, but that would have required a lot of new contacts that I didn't have. Besides, almost all the heatshrink covered splices are now hidden inside the sleeving.



AC Power Switch
I added a push on/push off type power switch to the front of the printer.



Power Supply Terminal Block
The power supply had three 12V and three return screws, so I routed three pairs of wires from the power supply to the other side of the printer. Heavy #14 wires were used for sourcing power to the heat bed relay. A dedicated pair of #18 wires provides power to the RAMPS board. An additional #18 pair fans out to low current loads like cooling fans and the LED lighting.

My power supply didn't come with any type of protective cover for the terminal block, so the AC connections are exposed. With time, I'll look into printing something to use.



LCD Ribbon
I simply folded the excess ribbon from the LCD display and tied it to the upper member of the frame behind the LCD.

FOLLOWUP COMMENT: In the later GARBAGE DATA ON LCD DISPLAY post, I add a zip tie loop to pull the ribbon cables tight to the frame, away from the noise-laden bundle of wires from the X carriage that gets looped over the top of the printer. This helps reduce noise coupling into the LCD ribbon cables and messing up the screen.



Y endstop switch wiring
Here I took advantage of the side channel of the aluminum rail and routed the wires through it. Wires are held in place behind a section of the black slot cover that was cut to fit. These wires get bundled with the wires from the Y motor at the back of the printer.



More routing info to follow... I've used up the five-pictures-per-post limit.

[printbus]

HEAT BED CLIPS
Binder clips in the SMALL size are the common method of clamping the print surface to the heat bed. I found the MINI size works out better. Even installed all the way, they aren't as likely to protrude into the printable area. The smaller wire wings also keeps them from getting in the way, so they're easier to just leave on.



For a clip installed to the rear left side of the heat bed, bending the wings a bit allows the clip to clear the left sidewall of the frame. Leaving the wings in place makes it easier to remove the glass, so I'm likely to clean it more often.



MICRO sized binder clips are also available, but I don't think they open wide enough to grab both the glass and heat bed when using 3mm glass.

FOLLOWUP COMMENT: Note that I am using glass that goes from one edge of the heat bed to the other edge, or about 8-3/8 inches in width. This allows me to use clips that don't encroach into the print area, minimizing the chance that the hot end nozzle will hit a clip during homing, etc.

FOLLOWUP COMMENT #2: IIRC, I obtained the mini clips from the office supplies area at Walmart. I think they came in a package of 70 for $4 USD.

[AbuMaia]

I also had obtained some aluminum rail slot covers from Openbuildpartstore. In addition to possibly being used for decoration, the slot covers can be used to create a wire raceway in the aluminum rails.

I liked this idea, and incorporated it in my own printer. I've got the covers on the top slots of the Y rails, the front slots, bottom slot of the top rail and top slot of the bottom rail of the X rails, and the front slots of the Z rails.

I did have some trouble with the Z covers and the lower X cover moving. The Z covers slid down due to gravity, but the lower front X cover was moved by the bolt heads holding the X carriage extruder shelf rubbing against it. The Y covers are held in place by the wood pieces front and back, plus nothing rubs them.

For the bottom of the Z rails, and the ends of the X rails, I put a washer on an M5 bolt and screwed it into the threaded center hole of the rails. The washer is just large enough to hold the covers in place, since the M5 bolt head is not. I did try to superglue the covers in place, but that just left a white film on the covers, and didn't hold long anyway. The bolts are unobtrusive and do the job well.

[printbus]

NEW MOTORS AND MORE
Based on testing in Marlin Motion Related Configuration.h Settings for MakerFarm i3v that suggested the CW 42BHH48-050-24A motors from my older i3v kit were limiting my max Z feed rate, I opted to replace all the CW motors in my 8-inch i3v with more Kysan 1124090 motors. A Kysan has worked out well on the extruder for the last couple of months. Replacement of the motors was no easy feat since I had dressed and bundled all the printer wiring. The Kysan's have heavier gauge wires than the CW motors, so I didn't want to just cut off the wiring at the CW motors and splice on the Kysans.

The Kysans run cooler, so I took out all the motor fans and related wiring that had been added for the hot-running CW motors. Good riddance.

By leveraging additional torque provided by using 1/4 microstepping (1000 steps per unit for Z) instead of the MakerFarm default of 1/16 microstepping, the Kysans seem to be able to reliably drive the Z axis at over 3mm/sec feed rate. As an incremental increase, I'm now testing 2.5mm/sec for a while. This provides a worst-case Z home duration of about 90 seconds on my 8-inch printer.

Taking advantage of the disassembly required to swap out the motors, additional preventive maintenance was completed. The X and Y belts are now tighter than before, and I replaced both Z threaded rods and the Z nuts in the X-carriage. I worked to straighten the replacement threaded rods as best I could. To prevent accidents like the granddaughter grabbing one of the Z rods and bending it over, I've added support brackets at the top of the Z rods to protect them - http://www.thingiverse.com/thing:636381.



I've also been pretty aggressive in cleaning out the hexagon hot end nozzle a few times. Thinking I might have enlarged the nozzle tip in this cleaning, I wanted to replace the tip. Unfortunately, 0.40mm tips for the hexagon never seem to be available individually. I've installed a 0.40mm tip intended for use on the E3Dv6 hot end.

[gmay3]

NEW MOTORS AND MORE
Based on testing in Marlin Motion Related Configuration.h Settings for MakerFarm i3v that suggested the CW 42BHH48-050-24A motors from my older i3v kit were limiting my max Z feed rate, I opted to replace all the CW motors in my 8-inch i3v with more Kysan 1124090 motors. A Kysan has worked out well on the extruder for the last couple of months. Replacement of the motors was no easy feat since I had dressed and bundled all the printer wiring. The Kysan's have heavier gauge wires than the CW motors, so I didn't want to just cut off the wiring at the CW motors and splice on the Kysans.

The Kysans run cooler, so I took out all the motor fans and related wiring that had been added for the hot-running CW motors. Good riddance.

I hear you on this process! I totally redid my wiring and fixed some of the safety issues (soldering screw down power wires). It took forever but was definitely worth it to swap out our old hot motors for the Kysans .

I replaced both Z threaded rods and the Z nuts in the X-carriage. I worked to straighten the replacement threaded rods as best I could. To prevent accidents like the granddaughter grabbing one of the Z rods and bending it over, I've added support brackets at the top of the Z rods to protect them - http://www.thingiverse.com/thing:636381.

Looks fantastic! Any chance you may be able to provide links to the replacement rods and nuts you ordered? I bent the tops of mine trying to get them into the clear plastic tubing the first time around and would like to swap em.

Unfortunately, 0.40mm tips for the hexagon never seem to be available individually. I've installed a 0.40mm tip intended for use on the E3Dv6 hot end.

I ordered the 0.3mm hexagon tip from makerfarm and really like it. Could be worth a future try

[gmay3]

Thanks very much for the pictures guys! They look great, I think I'm going to do that with mine now and will post pictures! No more flashlights for me haha

[printbus]

GARBAGE DATA ON LCD DISPLAY
The LCD screen has frequently been displaying garbled data. Initially this was when I was trying to do something with the rotary encoder. I thought static was perhaps being passed through the metal knob I had on the encoder, but I still saw the display get messed up at random during prints after replacing the knob with a plastic one.



I've written microcontroller software for similar displays before. For those that don't know, with these displays characters can be displayed from an ASCII character set, an alternate character set, or a number of user defined character bitmaps. While the specifics of the alternate character set vary by manufacturer, some of the characters I see on my screen are typically found in the alternate character set. I'm not sure how data from the alternate character set is being written to the LCD, but others with the Marlin-type display have reported the problem often is noise coupling into the LCD ribbon cables. My ribbon cables were touching the X carriage cable harness passing over the top of the printer. I drilled a few holes in the right side of the frame and added a zip tie to pull the ribbon cables away from the X carriage harness. Looking good so far, although I've only ran one two hour print job since the mod. Next time I'm ordering from the likes of Mouser or Digikey, I'll likely order new connectors for the ribbon cables and shorten them up, which others have also reported as an occasional fix.



FOLLOWUP COMMENT #1: Moving the ribbon cables has definitely helped. There still is a sensitivity, however, to fingers reaching over the top of the frame and touching the LCD circuit board when reaching for the knob.

FOLLOWUP COMMENT #2: After a few months, I got around to building new, shorter ribbon cables. I'm not sure that made any difference. An explanation on what is happening that results in the garbled display is discussed in the Garbled LCD Screens thread in the Firmware Enhancements to Marlin area.

FOLLOWUP COMMENT #3: Looking into the firmware associated with the LCD panel, I grew to realize that the existing firmware base has a built-in provision for restoring the display once it gets into this garbled mode. Assuming the printer isn't busy printing from the SD card, insertion or removal of the SD card will restore the display to proper operation.

FOLLOWUP COMMENT #4: Newer versions of Marlin have yet another built-in recovery scheme. When the printer is at the top status screen, pressing in on the panel button will also restore the display.

FOLLOWUP COMMENT #5: I'm still getting the garbled display a lot. While it does usually happen when I touch the display, I have seen the display garbled during a print when I haven't been close to touching the printer.

[beerdart]

Nice and neat great job. One thing I changed was the screw terminal connector on the Ramps(POS would cause power drop outs). I removed the connector and installed two weatherpak connectors with the wires directly soldered to the board.

[printbus]

...One thing I changed was the screw terminal connector on the Ramps(POS would cause power drop outs). I removed the connector and installed two weatherpak connectors with the wires directly soldered to the board.

Thanks for the insight. I've stayed away from the pluggable screw terminals in my designs because of that possibility, but I figured I'd leave these on since the board came that way. Now I'm not so sure...

[1stage]

This is the most ridiculously anal-retentive build of a Makerfarm Prusa 8" i3v I've ever seen...

...AND I ABSOLUTELY LOVE IT!