What friends, coworkers and charity did not want.
I am a bit sorry, but there weren’t many options left.
I have decided to get rid of a good portion of my printed books. An estimated 3000 books are up for graps, mostly german Science Fiction and Fantasy. I am still sorting out many english books where i haven’t decided yet what to keep and what not.
I just want to give them to a good home so they are not up for sale but i will simply give them away to anyone who is interested in reading them 🙂
If you are interested mail me at firstname.lastname@example.org
All books have to be collected here in Friedrichsdorf.
On the left printed @0.15mm Layer height with an 0.5mm nozzle on my DuoCore @210°C. On the right printed @0.2mm Layer height with an unknown nozzle @200°C on a friends i3. What is interesting are the differences in slicing, the left was sliced using S3D, the right one with Slic3r.
I was very positively surprised by the new GreenTec filament from Extrudr, that i ordered on a whim alongside a couple of kilos of my usual ABS.
Not only does it produce a nice matte finish, it prints without any hint of warp, the stability is excellent and it is a dream to postprocess with any kind of tool.
The only two drawbacks i found so far are that it sticks so strongly to the printplate (aluminum with 3Dlac @60°C) that damage to the part or printplate are a very real threat and the current price of €56 / Kg
I hope the price goes down over time, but even at the premium it might be worth it, especially considered that i don’t have to feel so bad about producing garbage prints since GreenTec decomposes neatly, different to PLA.
As it turned out, it was a lot earlier than expected that the silicone sleaves from this posting
Silicone Sleave for Merlin made the trouble worthwhile. Some peculiar behavior of Marlin lead to a thermal runaway for a couple of seconds at full power. The silicone, that is rated for 450°C deteriorated, but the extruder remains unharmed and even the hotend survived thanks to the new cooling.
For those interested, what happened was that while homing Z Marlin stopped working completely. Everything was frozen including menu and the PID for the hotend, which got stuck with the heater switched on. I haven’t found the reason for the behavior yet, but i’ll do the homing before the heating in the foreseeable future.
These two extruder bodies were printed in clone mode. The white one shows serious stribes that resemble Z wobble, but the blue one doesn’t. Since only X movement was different between the two it is either that, which i don’t believe due to the error existing on all sides, or it derives from the difference in the material. Interestingly the original setting was for the white material. If anything the blue one should show small signs of underextrusion since the filament diameter for that was smaller than for the white.
Interestingly the problem is uneven movement along z, not perpendicular to it.
On the RepRap forum the question came up how the Merlinb hotend is cooled when printing Polycarbonate @ 260°C
The design i currently use is rather simple, it focuses on cooling the lower part of the PEEK and guides the airflow as far around to the backside of the hotend as possible. Ultimately i would like to be able to press all air through a small gap at the lower end of the PEEK, but that is a tight fit given that the heater block needs to be insulated.
For testing purposes i bought a spool of the new Esun ePC polycarbonate from RepRapWorld. While not cheap it isn’t actually very expensive with €20 for 1/2 Kg. Given that the Merlin Hotend uses a PTFE inliner i was a bit sceptic if it would withstand the 255°C, but no problems turned up at all.
As can be seen in the images bridging does not seem to be optimal, there are even some holes in the top surfaces, something that did not happen with a simpler testprint before. Maybe a bit slower print speed (this one was done with 130 mm/s default in S3D) or maybe lower temperature will help. The stability is good, i destroyed an earlier print using a pair of pliers and i had to use quite a bit of force. Also noteable, the layer adherence was excellent, the part did not brake along layers at all.
Given the very good heat resitance (even better than ABS) i think i will find a lot of uses for machine parts, especially extruder parts since according to Esun the ePC material is not inflamable.
One thing to note, the ePC did not stick to glass when i used 3DLac, i had to print it with an ABS raft, easy enough with the DuoCube 🙂
Trying to print a 50% scale Benchy with a layer height of 0.02mm. A first test to print a M4 screw did work, the screw was functional and stable, showed that there might be a problem with bridges and steep overhangs at this scale. Als Top Layer don’t close easily.
This time i try it with a maxium speed of 40mm/s instead of 20.
Edit: As it turned out, overhangs and bridging don’t work at all. I have to invest a lot more time in determining a working setup for this,