MakiBox Pellet Drive - Nice Output Quality

2021-07-04 17:40 by Jonathan Buford (comments: 0)

MakiBox Pellet Drive - Nice Output Quality


Today, we finally started getting the output that we need from the pellet drive in terms of quality to print. We need to increase the quantity, but that is an easier problem to solve, as it involves gearing and tweaking how the material is heated. The measured tolerance was less than 0.10mm for the output we did, which is similar already to the existing filament supplies.

It looks like this will likely be the last prototype model and the next will be a pre-production model, capable of spewing hot filament at printing speeds. 



In this situation we will look at using stainless for everything or brass for just the portion where the melt is supposed to happen. The compression seems to have gotten rid of the air bubbles, and the output only got lumpy or otherwise when the temperature was too high. My guess is that we are spreading out the heat too much with this current setup, so we may look at how to focus the melt zone and heating zone more than it is now. 

So, I'll be going back to adjust the CAD model tomorrow and we will target having the revised parts by Friday. As soon as we can get improved output rate from this, we will start doing the integrated build and test the output of the system. This has been a good day.



Bernd responded:
Hi Jonathan,

great work you Guys do there. I cant tell you how mutch i like your progress. I keep my finger crossed for you Guys. On the end this will be a nice machine to have.


cdurst responded:
So I assume the extruder is expected to feed directly into the Teflon tube that goes to the printing hot end.

I assume you want the filament to be solid (but flexible) for its journey through the tube so that it doesn't stick, expand, clog or break while in the tube, and that it would still be able to convey enough pressure to melt it consistently at the final hot end.

Are you optimistic that the travel through the tube won't be a problem if you can get the created filament to the right size?

Have you thought about how the heat of the newly created filament will dissipate once it is feeding directly into the closed tube? Or will this not be an issue?

Disclaimer: I'm a software guy with no plastic melting or 3D printing experience, so what do I know?

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