Tuning

• Bed Leveling

Level the Bed or plate by first getting Pronterface, or by using an LCD like the 2004 LCD panel.

Make sure the endstops work. A key is that the hotend must be able to rotate and trigger the endstop, but should not be so loose as to easily move up and down relative to the pivot screw. The Z offset, or the difference between the enstop trigger and the actual nozzle should default to about 1.4mm.

KEY POINT:

LARGER Z offset values move the nozzle farther from the plate.

SMALLER Z offset values move the nozzle CLOSER to the plate.

Adjust the Home position.

Home the system and heat the nozzle to 200C or your PLA temperature if you know it.

The nozzle should rise 10mm. Now using the LCD or Pronterface lower the hotend 10mm.

Now use the old sheet of paper test to see how close or far away you are from the plate.

Adjust the Z offset value and repeat until you get the desired distance.

Adjust the far X position.

Now unlock the steppers or use Pronterface to move the X axis near its maximum reach.

Shim the plate captives and adjust the plate holder to raise or lower the plate to the same paper thickness.

• Stepper Voltage Calibration
• Z end stop adjustment

• Skewed Printing

Skewed prints normally arise from something causing a skipped step in the open loop drive design.

In the SmartRap with fishing line drive, the user should pay attention to any fraying of the line. A dangling fray will catch on the motor shaft and cause a skipped step. Replace the line and try again.

Be sure that the fishing line has sufficient tension. It does not have to be as tight as a guitar string but 6mm play is probably too loose.

Sticking or jittery bearings may also cause this problem. Oil or relubricate the bearing. For metal roller bearing a lightweight machine oil is used, this should flush out any grit over time. For PLA or plastic bushings, furniture polish will reduce the sticktion affect of the plastic.