Calibrating my 3d printer

So.. I found this guide to calibration so I thought, I work through it.–

http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide

X-Y steps.
I’m using belts/pulleys that I had picked up from inventables.

https://www.inventables.com/technologies/mxl-belting-open-ended

https://www.inventables.com/technologies/plastic-mxl-pulley-dual-flange

X-Y

steps = motor_steps_per_rev * driver_microstep / belt_pitch / pulley_number_of_teeth
So… I’m thinkingsteps= 200*16/(.08*25.4)/18 =87.489

Z-axis
steps = motor_steps_per_rev * driver_microstep / thread_pitch
200*16/(25.4/24)=3023.622

E-Axis////
Calculate E_steps = motor_steps_per_rev * driver_microstep * big_g+ear_teeth / small_gear_teeth / PI / hob_effective_diameter
So I have a direct drive so the gear teeth come out and I hoped my own gear… ~11.2
steps = 200*16/3.14/11.2=90.99

He’re what I had in there to begin wi`th:
float axis_steps_per_unit[] = {80, 80, 3200/1.25,94};

Revising to:

float axis_steps_per_unit[] = {87.489, 87.489, 3023.622,90.99};

The guide said the correct z-height should be a piece of paper barely catching. A piece of paper is about .003 inch thick.
At the moment I can easily stick a .026 feeler gauge under this..

On my setup, I have a space between the z-axis bearing support and the collar that holds the Optical encoder.  With .026 pace I have fit in a .281 gauge pin..
So need  to shrink the distance .023 soo… lets try adjusting the distance to .281+.023  = .258 Pin
That worked well.  One piece of paper goes… and 2 pieces of paper is a no go.

So… I had marked my filament at 150 mm and ran 100 mm of feed.  My resultant length was 58.78 mm.
IOW 100 mm theoretical correlates  to 91.22 actual

Soo.. the formula:
new_e_steps = e_steps * 100mm / measured_distance
= 90.99*100/91.22 =99.75

I’m feeling luck so this goes into the firmware..
Hmm. with that Adjustment I get 103.86 MM extruded.. Close enough now.

So.. Next steps in calibration is slicer settings.
I have a .35 mm nozzle so I’ll try a layer height of .28 and with of .4

—- Followup with intial calibration.

I’ve been gettin/*g some reasonable results with my qu-bd extruder, although from what I’ve been reading PLA can be tough material to extrude because of it’s high co-efficient of friction and it’s low melting point.   I wound up lapping the extruder tube with some lapping compound and I put some zinc oxide paste on between the cooling fins and the block that supports the cooling tube.   My theory is that the cooler I keep the tube away from the hotend  the better off I’ll be.

So far, I’ve been more or less successful with the 20 mm test cube: http://www.thingiverse.com/thing:38108
and the 5 mm calibration tube steps.
Other attempts without much success so far have been the :
pirate ship http://www.thingiverse.com/thing:12856
ender dragon: http://www.thingiverse.com/thing:33198
Darth Vader Head: http://www.thingiverse.com/thing:1783

I think there are some speed tricks I need to work out with the pirate ship to get the sails work out.

On the ender dragon I was having issues with the rafts sticking.  (My current theory is to keep the temperature down so I don’t heat the PLA so much that it jams.. Unfortunately, if I’m building rafts this causes problems

I started nothing skipping issues with the printer a little bit with the ender dragon and big time with Darth… Googling around a bit, it appears that the polulus with shut down if that get too hot.    I ran across this which looked worth trying to me.

http://reprap.org/wiki/Pololu_stepper_driver_board

Ok.. I wound u

*–**