Hi folks,
my Dual Extrusion Head arrived last week Thursday. Germany, ordered on first day of Preorder campaign. Got a tracking notification the day before delivery by the delivery service.
I will not be able to test the printhead for another one or two weeks, since I am in the middle of another project, but I want to share a few first thoughts:
Good:
- The toolhead is robust and looks well-designed - the articulating hotends seem a clever idea to me.
- The bowden tube solution for the enclosure is well thought through, with nice little details like stow-away clips for the time you do not need the tubes (i.e. when milling or lasering)
- They thought about the spool holder, and every scenario is covered. Nice! Only thing: The second spool holder is shorter than the first - no idea why.
- The thermistor is now in a capsule and fixated by a screw. Reduces the risk of thermal runaway/fire:
- Exchangeable hotend modules - that may quicken the workflow.
- The hotend modules seem not to be encoded with a chip, but “only” with a resistor. I like that - if you decide to keep the hotend and just exchange the nozzle, you may change the resistor (needs soldering skills) and have auto-detection in place. I can even imagine using a variable resistor to encode the hotend “on the fly” - available space might be an issue there. A propriatory chip might have made life more difficult.
- Feeder: The feeding wheels, which may suffer from abrasive filaments, look exchangeable and perhaps are even standard parts, easy to source. Not too sure about it, but certainly the feeders are better maintainable as compared to the single extrusion head.
Not so good:
- It weighs 1.05 kg - that’s hefty! I hope moving around this mass is not inflicting print quality at higher speeds…
- Mounting points/loss in build volume - It was to be expected that the double nozzle will result in less build volume since each nozzle will not be able to access the same places as the other at the edges in X. However, there’s loss in build volume in Y and Z also, which IMHO at least partly might have been avoided. To illustrate this, here the old and new print head aligned (you are supposed to use the red circled mount holes with Snapmaker 2.0):
You can see how much you loose in Z! I do not understand why they did not put the mount holes lower, at the same height as those that I assume are for the Artisan. A reason might be that with the plug on top you’ll get in a tight situation with the enclosure roof, but I think with a bit of additional engineering of the jack that might have been avoidable. I might at some point decide to use the alternative mount holes if I need more Z. This will even more decrease accessible X-width, but in Z it would add 2 cm. That would still be 2 cm less than the old head, but the mechanics need to go somewhere, I can understand that.
The loss in Y-direction seems unavoidable with the extra mechanics in the head, so nothing to be done about that:
Here’s the difference in X with the suggested mount holes (the old nozzle is basically in the center between the dual nozzle config, which makes sense) and the “wrong” mount holes (additional loss in X):
Intended mounting:
“Wrong” mounting:
Things I’m not so sure about:
- Pogo pins - I have had problems with pogo pins, especially with high currents like for the heater - bad connections, sparks, unreliable connections… Let’s see how the Snapmaker pogo’s perform in the long run.
- The levers of the feeder and the hotend modules are made from plastic. Since they are exposed to some heat, there’s a chance that they over time get brittle and may snap. However, they seem exchangeable, so repair hopefully will be possible.
First posts of made things in Facebook look not too shabby, but not too great either, but I guess people need to tune in a bit. All in all I expect good results!