- When affixing the MK4 idler pulley to its bearing, try to center it. The washer-spacing method in the default instructions did not centre my pulley. It seems to grip filament more reliably if properly centered, and then mounted with a single washer spacer on each side.
- Always add a copper sleeve or hose clamp around your heater insulator barrel. This will save you if you accidentally run to hot and start to deform the insulator.
- If your filament has a "skirt" around it (or multiple threads) when you back it out of the heater, it means that the seal between the insulator and barrel is failing and you need to shore up the strength of your insulator barrel and probably reduce your temperature, and check for nozzle obstructions.
- The MK5 extruder idler pulley wheel does not work with the MK4 extruder gear
- Put a 'flag' of masking tape on your extruder feed 2mm calibration rod. If you are debugging feed problems and need to repeatedly remove your motor for cleaning, you will probably and up trying to calibrate the feed mechanism with the heater element attached. And, if you are clumsy like me, you will probably end up dropping the calibration rod into the heating element.
- Let the machine warm up for 10 minutes before turning on the feed. The thermistor only reports the temperature at the tip of the extruder. Give the machine a while for this heat to diffuse along the barrel
- If you haven't specially calibrated your thermistor settings, you might have to tweak the temperature settings in skeinforge to get the plastic soft enough. In my machine, the extruder jams for all temperatures lower than 230C. So, I had to go deep into the skeinforge-raft settings and make sure _all_ extrusion temperatures are above 230C. warning: 230C may be more than enough to melt your insulator barrel if you are using the white PTFE part that ships with the kit. I bought a PEEK barrel from MakerGear and am currently praying to various gods that it does not suffer the same sort of failure at my PTFE barrel.
- Counter-sink the build platform and use tapered bolts in order to prevent accidental collisions between the print head and the platform mounting bolts.
- I noticed that setting infill to 0.0 causes skeinforge to do a divide by zero... but 0.001 seems to work for "make it hollow"
- Level your build platform with masking tape or painter's tape. I am putting the tape on the Y stage platform; Move the stage using the control panel from corner to corner until all corners are the same distance from the nozzle.
- Do this calibration tutorial: http://rapmanv3.blogspot.com/2009_09_01_archive.html
- The Z rods that MakerBot ships with are inferior and possibly should be replaced to get a fully functioning makerbot. On my kit, version 11, I have rebuilt the Z stage assembly several times and keep it excessively well oiled to prevent slipping. Essentially, the problem is that the rods are slightly bent and also corrode which adds friction. Replacing them with stainless steel equivalents seems to solve these problems. For now I am running a software patch that slows down the Z axis to reduce the odds of lost steps during a build.http://groups.google.com/group/makerbot/browse_thread/thread/dd42b58921ff32a7
- The heated build platform kit as it ships is incomplete. The way they suggest hooking it up to the extruder board will not work. To complete the kit, you either need to procure a heat-sink setup for the power mosfets on the extruder board, or a relay to take the load off the extruder mosfet. I used a relay. They recommend insulating a part of the wire with heat shrink tubing, but I didn't see any heat shrink tubing in my kit. I could just have missed it though.. unclear. Other surprises may include : you need to do some surface mount soldering. The instructions recommend solder paste, but it is possible to do this with a normal soldering iron if you are careful.
- The M6 pre-assembled heater-core from MakerGear simplifies building the hot part of the plastic extruder.
