I've got a second-hand Renkforce RF1000 which I've gone into more detail about in this question.
The extruder works however, I get some inconsistent results. First I printed a calibration cube and noticed huge gaps in the bottom layer. Because of this, I increased the extrusion multiplier to 1.05. I noticed there still were some gaps but also other issues, I then printed one with the extrusion multiplier reset to 1.0 and a negative Z-offset. The results are shown below. In every image, the left cube has multiplier 1.0 and the right cube has multiplier 1.05.
Then, for a better idea about the consistency, I printed a hollow pyramid. This shows some heavy stringing. However, when printing a retraction test I barely get any stringing.
Does anyone know what could cause these inconsistent results? I assume some hardware tweaks might be needed, not just slicer settings. Any help is appreciated.
- I use Slic3r
- I use 3 mm PLA printed at 190 °C on a 60 °C bed with some glue (doesn't stick without). The first layer is 200 °C with a 65 °C bed.
- After three layers the fans are enabled.
- I have a negative Z-offset, it probably isn't calibrated 100 % correctly
- I don't know the nozzle size (a new one is being shipped) but use a size of 0.5 mm in the slicer
- retraction length 2 mm & 60 mm/s
- minimum travel after retraction 1 mm
EDIT: After the recommendations I've changed the following:
- All belts have been recalibrated
- The e-steps have been recalibrated through this method. Couldn't do a wall measurement due to a lack of precise tools.
- Changed first layer temperature to 210 °C and other layers to 205 °C
- Added two top layers
I printed two new cubes. One without glue and with a Z-offset of 0.05 mm and one with glue and with a Z-offset of 0.15 mm. The results are quite comparable to the original ones although slightly better. Any recommendations?
I'm aware of some cooling issues on my prints. Once a new nozzle arrives I plan on printing the current cooling system again. It's not really blowing air right effectively now.