Saturday, 29 April 2017

Bolt the Thirde

In the mail today, a package from the UK - not subjected to import tax just yet - containing my third hobbed bolt, this one from E3D, so goes well together with my hotend. I expect them to make good stuff, and having it made out of steel rather than brass ought to keep it going a bit longer.

The design is a lot simpler than the Hyena from

Just plain grooves, nothing particularly fancy. If they prove dissatisfactory, I might go for that place that sells a hardened steel Hyena.

First simple extrude test took 80mm filament when asked to extrude 50mm. But oh! Did it do it beautifully:

Nice and precise extrusion
This matches nicely with the fudge factor of 50/78 I had put in Marlin. Removing that, and the extrusion of 50mm extracts... 94mm? Let's try that again. Yes, quite accurately that much. Ah, but I was looking at the wrong copy of the Marlin sources. Why do we even have that lever? The right one had 41/50 correction factor. Changing that to 50/96 clearly slows down extrusion, and brings us to - extruding 2x50mm for extra accuracy - as close to perfect as I'm able to measure.

Time for, of course, a calibration cube! Today's Z offset is 0.5mm at an indoor temperature of 20C, outdoor humitidy of 96%,  and pressure of 1008hPa. Clearly I need to hook up my little Grove humidity sensor so I can get a usable humidity reading. According to that, I have 25% humidity and 22C. Now I should set that up so that I can just have it running at all times and store the results - for science! Or something.

The cube came out really nice, fewer gaps at the top than usual and nice even walls. I'm liking the bolt so far.

Had to do another Benchy, of course, building up the fleet. This one was even nicer, the writing on the bottom partly legible, fewer gaps in the foredeck, though still some unevenness around the middle of the side.

The first thing to get printed has to be the further Settlers of Catan pieces, this time the Egyptians. It's a new day, calibration is still at 0.5mm Z offset at 25% humidity and 20C. Curiously, when I connected Octoprint (since I think I have the gcode ready there), it centered the X and Y axes reeeally slowly. Looks like the G0 comment uses the wrong speed. But eventually it came up and I was right indeed.
Pyramids and sphinxes and sand-covered roads, oh my

The problem I have with Octoprint is that it has no way to adjust Z offset, so I have to have the GCode contain the Z offset, which is not handy. Getting my prober up and running would be better, unfortunately the prober mount design I found doesn't work with Sturdy Mendel90.

Before delving into modifying a prober STL, I took a look at doing a simple adapter for the dog basket mount I have on my bike. Required a bent tube module, which was easy to find. Also requires a proper way to slice, so I installed the Slic3r plugin. Wasn't too difficult, but for some reason the STL file uploaded doesn't allow slicing - the icon is disabled. No obvious error messages, but Octoprint has started to behave oddly, loading very slowly and sometimes not connecting. Re-uploading the STL after having installed the Slic3r module and enabled it didn't help. The other computers can't run Pronterface without a printer attached enough to actually slice.

1 comment:

  1. Congrats! That starts to look like usage, instead of setup :-)