Need help debugging possible extrusion problem

Hi,

I am trying to print the following item:
[www.thingiverse.com]

I think I am having multiple problems at once which is making it very difficult for me to articulate, for this reason I will show you a video instead.
[youtu.be]
* However the problems might be that, not enough extrusion
* and the plastic not sticking to head bed.

Plastic is 1.75 PLA
Extruder temperature is 205 C first layer
Bed is 70 C for all layers.

Currently the end product I have is a blob around my hot end, and nothing looking like the item I am trying to print.

I am not sure which settings may be of interest to you, so let me know and I will respond with the settings.

First it looks like your Z axis is not properly adjusted. You should just barely be able to slide a piece of paper between the nozzle and glass with a little friction. Next it does not look like you are extruding hardly any material. Have you calibrated the esteps?

Thank you, changing the extrusion multiplier, and rearranging Z has allowed me to progress.

It seems there is a lot more calibrations that I didnt know about at [reprap.org]
!!!

Did you calculate your e steps or just up your multiplier?

For now I increased the multiplier, and still need to figure out how to calculate esteps.
Increasing the multiplier resulted in having a good layer 0, 1, 2 (sometimes, sometimes it just becomes a big blob which is another problem). Remainder of the layers clump up into blobs. I dont know what the cause is but if you are interested I can reply back after calibrating Esteps.

Edited 2 time(s). Last edit at 01/29/2015 01:03AM by VolT1.

To calibrate e-steps, you want to measure and mark 120mm of filament prior to it going into your extruder.

You will then tell your printer to extrude 100mm of filament (this is filament entering the extruder, not the filament that leaves the hotend).

Next, re-measure the distance to the mark you made. Ideally, it will measure 20mm as you extruded the other 100mm, in which case no change is needed.

Otherwise, in the config.h file of your firmware, you want to locate your extruder steps per mm parameter. You want to multiply the existing value by 100 (the steps you intended to extrude) divided by the mm of filament you actually extruded. For instance, if your second measurement was 15mm, it would mean you had actually extruded 105mm of filament when you instructed you printer to extrude 100mm, so the formula would be as follows...

new steps/mm = (existing steps/mm) * (100 / (120 - 15))

Replace the existing steps per mm with the new steps per mm, recompile your firmware, and repeat the calibration process.

For reference, with my old extruder using a planetary motor, I believe my steps per mm were in the 600s. My new extruder using a simple Nema 17 motor is around 100 steps per mm.

Thank you Kurzaa,

Your explanation saved me a lot of time.

I would like to verify a couple of things:
In my config.h the only variable that may be what you mentioned is as follows:

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,4000,90} // default steps per unit for ultimaker {78.7402,78.7402,200*8/3,760*1.1}920
#define DEFAULT_MAX_FEEDRATE {250, 250, 2, 22} // (mm/sec)

I wouldnt think its the MAX_Feedrate, and DEFAULT_AXIS_STEPS_PER_UNIT doesnt specify the unit. So just being 100% that DEFAULT_AXIS_STEPS_PER_UNIT is the variable in question.

Also when you say count to the mark, do you mean from the green or the red line as shown below.

[imgur.com]

Thank you.

Edited 1 time(s). Last edit at 01/29/2015 10:04PM by VolT1.

I would use the green line. The point of measuring is to determine the amount of filament going through the extruder. It doesn't matter where your "fixed" point of reference is, just that it is easy to measure both before and after extruding the 100mm.

As for the value to change, I haven't used Marlin firmware, so I am not sure what the max feedrate is. However, I believe that the values for the steps per unit are X, Y, Z, and then the extruder, E. So your current extrusion steps would be 90.

For more details on the calibration process, my information came from Triffid Hunter's Calibration Guide, [reprap.org]

Thank you for your help Kurzaa,

I have calibrated my extrusion, and have exactly 20 cm left. I had an error of 7mm, and returned my extrusion multiplier back to 1.
And for Merlin the variable of interest for extrusion calibration is DEFAULT_AXIS_STEPS_PER_UNIT.

I will test to see what the effect of this has been on the print tomorrow and will report back.