Makibox issues

After I assembled my Makibox last night, I ran into a number of software issues.

Firmware: current 2.11
OS: MacOS
Host:

1 Lockups

Makible 5D Print in Google Chrome

In layer 5 of a test shotglass it just stopped and locked up. Wouldn't resume after power-cycling the printer and using the pause+resume function.
No error messages.

No manual jog controls for the extruder or Z axis => can't quickly move the head to a safe height and retract the filament after a failure.

Pronterface

Stock Pronterface/Printrun with Makibox settings.
I can jog each axis but loading any gcode and executing it, nothing happens.
It stays in line 0 (line 0 is a comment), doesn't heat up, doesn't home, nothing.

Update: gave Pronterface another try. This time it started printing but locked up just like 5D print did. So clearly this is a firmware issue or an issue in the common codebase (5D print started with a fork of Pronterface or so I've reat.)

Pronterface is incabable of stopping a print.
Pause, Reset, Stop, even Disconnect doesnt work. On Disconnect it executes the last 2 lines of g-code over and over again.This means the firmware has a bug and doesn't forget about already executed commands. At most it should finish the current command and then stop!


RepetierHost

I tried RepetierHost with these settings.
I cannot navigate to any but the first page in the preferences window. ("Host", "Slicer", "3D visualisation", "Colors")
It seems to not update the graph or textual output of the current temperatures.
Do NOT check the "( ) printer sends OK even after error" box for the Makibox to work.

....it just locks up like all the others.

Temporary solution: I switch from a Macbook Pro to a desktop iMac and a different USB cable.

Findings:

• On the MacBook Pro with MacOS 10.9 "Maverick" the printer just randomly locks up independent of the host-software used.
• On the iMac with MacOS 10.8.5 this doesn't happen.
• It seems to happen less on the iMac when I move the mouse every few minuted to prevent any kind of light sleep mode.

Currently investigating the USB port power requirements as a possible reason.
(Original Printsboard allows for being powered by USB or internal regulators from it's stepper/heater power supply.)
If so, a powered USB hub should solve the lockups.


Solution: Raspberry Pi with Octoprint

2 Stalls and filament grinding

At random points in the print, the filament stops.
The drive gear has ground a hole into the filament.
The filament above that hole is nearly half ground away by the drive wheel.

1. Repeated the bed leveling and all the tuning steps on the Makibox support page
2. The hole for the axis of the plastic wheel in the extruder was too small. sanded it and the wheel now spins freely. (all injection molded parts where oversized on this Makibox.)
3. Raised the temperature of the supplied "makibox HT test cube v0.2 PLA" from 192 to 218°C.
4. Retract the filament after printing. Don't leave the filament to cool inside the hotend. Don't re-insert it before the hotend is <120 br="">

 Currently testing....

Possible next steps:

1. Sanding down the surface of that springly plastic wheel to reduce friction.
2. lubricating the rods and the axis in the extruder.
3. Designing a different extruder with multiple drive-gears to increase grip without increasing pressure on the filament.

3. Slanted prints

...still working on this issue.

1. Check your stepper voltages. Maybe go slightly above the recommed 1.45V reference volrage
2. Check that your axis and hotend aren't fastened too tight.
3. Check the motor coupling for breakage or being loose
4. Check the bed-leveling bolts.
5. ...TODO

• Makibox forum thread about lockups
• Makibox forum thread II about lockups
• Makibox forum thread about jamming 
• Pronterface settings
• Some Makibox firmware modifications that could be interesting in the future 
• unofficial FAQ 
• Makibox Google Group