Printer loses precision after doing 10-30% of the print

Hello,
I have built a Prusa I3 Rework from scratch. I been doing some calibration after finish building it but i have got one problem that i doesn't seem to solve. When printing the first 10-30% of the layers gets perfect but after that the precision seems to fail. Do anyone have any idé why it happens?

It also occurred when printing small details, but it did not happen when i printed out a very thin hollow box from “The Essential Calibration Set”.

I have attach some photos of the prints that failed and the hollow box.

Very thankful for help!

Failed prints





Hollow box

Check again your axis belts and probably recalibrate your steps per mm in all axis, your extruder need some calibration too, it looks like you have some over extrusion. But as always needed what material are you printing with, what temperatures, layer heights and speed, also what kind of extruder and hotend you are using.

... could be, your bed is to hot and the extruder not hot enough ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks for the quick response!

I print in PLA. The print in the first picture the hotend is set around 180-190 degrees and the other print 200-210 degrees, in both prints the heatbed is set at 55 degrees. Layer height is from 0.10 - 0.15mm(don't remember exactly what i had on print in the first picture).






Spec
Hotend: E3D V6 Direct 1,75mm
Nozzle: 0.4 mm
Heatbed: MK3 (but it's probably some mk2 clone)

I will test to recalibrate the printer later today and see if anything change.

Ok, one thing I noticed is that you have your first layer extrusion set at 200% and most likely the reason for the elephants foot shown in your prints, either lowered to 110 or 120 max or set it to 0. You are actually printing slow so you can keep low extrusion temperatures between 185 and 195.

Since is PLA, and they are small parts are you using a cooling fan for the printed parts?

Try printing 2 at the same time

---

_______________________________________
Waitaki 3D Printer

Sorry for late answer
I recalibarte the printer axis per step but it didn't do any big different. Now i have got a bigger problem, I get MIN TEMP REACH on the heatbed even if its way over 5 Celsius (which is the mini temp). This happen at nearly exact same layer on every print. Anyone has any idea of what it can be? I have changed the thermostat to a new one and installed the programs on a another computer but i still got the error.


Tomorrow i will test to lower first layer extrusion and to print two objects at the same time with the heatbed turned of and see which result i get.
I don't have a cooling fan more than that one sitting one the hotend, should i have one over the heatbed?

Edited 1 time(s). Last edit at 08/26/2016 06:45PM by AMpro.

Not facing directly at heated bed but to the filament coming out of the nozzle without blowing to the nozzle.

Check the traces in your board and see if it have any cuts or bad soldering, you can change the pins in the firmware and use other connectors for the heated bed thermistor.