1

Hi all,

I’ve recently acquired another Mendelmax 1.5 but the print results keep on puzzling me. It seems to be able of producing some very accurate prints but I can’t get rid of the lines on the side of the print. I’ve printed both Benchy and the 50mm calibration tower in PLA with a .25mm layer height.

Looking at the Benchy you can clearly see that the line pattern is very consistent. The calibration tower however seems to improve going up. If anything on the printer was not not alligned properly I would expect the opposite. I’ve tried the flowrate, printspeed, checked the belts, played with the temps, etc.

Any idea what could cause this?

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20170228_144405.jpg4032×3024 2.85 MB

2

To me that looks like one of two things: Either it’s some kind of Z-wobble (are you using regular threaded rods or proper lead screws?) or it could be a heated bed running in Bang-Bang mode. If the Z-axis is using threaded rods it is quite likely that those are the problem as regular threaded rods almost always are bent due to the way of manufacturing. The best way to solve this problem is to replace the threaded rods with proper lead screws as all other solutions really are just bandaids to cover the faults in the motion system.

However, if you already are using proper lead screws the wobble you see is likely to come from changes in temperature of the bed, causing this to expand an contract and ultimately, if it can’t move, bend up and down. A normal solution for this is to use a PID-loop to control the temperature which will keep it more stable than a bang-bang controller.

3

Hi, thanks for the advise. The bed temperature is stable so I’ll start with changing the threaded rod for some proper lead screws. Will order a set now and update once in place.

4

check this out mite help Print Quality Guide | Simplify3D Software

I’m thinking it looks like a inconsistent hot end??