MakiBox A6 Pellet Drive First Model

2021-06-27 18:20 by Jonathan Buford (comments: 0)

MakiBox A6 Pellet Drive First Model

We've been working on making the next revision of the pellet drive this week and plan to cut the parts for this one tomorrow.


What is shown in these renderings is the updated design for the pellet drive with modifications for gearing the stepper and using a wholely stainless barrel assembly.


We will also try to do the nozzle itself in stainless and see if the output is improved with the higher concentration of heat around the output area.

The barrel can probably be shortened to make it fit even better, this is based around a common length of pipe that is available in the market currently, and we could order custom lengths to tweak for size after testing this design. 

The hopper is one just for testing, so will be modified to handle larger loads and to use the large space available as you can see in the back view. Potentially someone could fit a double assembly and do dual output by stacking these mechanisms in the back, with the tradeoff of only having a smaller hopper available. 

Not shown in the rendering is the teflon tube leading to the extruder on the output, that will be similar to the original layout, but the tube size will depend on the output size from the pellet drive.



David Contreni responded:
Ok. . .So, the black assembly with the rounded bottom is the hopper? ALL the pellets fit in there? One more thing that has me curious is the path from the extruder to the hot end. Wouldn't the extruded filament be moving in an upward path as soon as it's filament?

You just KNOW that the doubters among us are not going to be happy until they see a test print from scoop to removal. Mulitple camera angles. In real time. Hi rez.

That being said--It looks like it's coming together nicely.

David Contreni responded:
Maybe I got it now. So the teflon tubing will be connected from the output of the extruder, to the hot end; and the filament will make its way there on its own? IOW, no manual intervention from the time the pellets are poured and everything is started?

Just trying to stay on your page Jon.

exilaus (Twitter) responded:
need see it in real action think some complex to manage and assemble.

Jon, one information in this days of test never try to use pet or other different type of plastic?

Use pet it a really great gr"ee"n & fr"ee" solution but test various type it need for see your solution are good for use any type of pellet find in maket.

thanks and nice job...i votee for you and your team !!!!

Evan responded:
Jon, what about rotating the motor 90 degrees so it's vertical? That might shorten the whole unit (so you can have a larger bend radius on the output). Obviously this would be a pain with a direct-drive system, but since you've added a gearbox already it's probably not quite so much work to use a pair of bevel gears to change the shaft direction.
Jonathan Buford responded:
Sorry, just seeing these comments, the Posterous notices have been going to junk mail, I'll need to see how to not lose them.

@David the hopper here is just big enough for testing, and we will create a larger one after testing this one. Yep, the way you outlined is how it works.

@exilaus I think this will be about the same as a filament drive to assemble and use from a complexity standpoint. Granted, it can be simplified if the whole machine was larger or just re-organized, but that is what the next generation is for. PET I have not played with yet, but will be spending a lot of time with different materials once we have this first machine ready to ship.

@Evan we already have the space for this existing mechanism, the main limitation is on the pellet hopper needing to be gravity fed. I'm going to try out a shorter barrel to give more space for curving the output around. Also, bevel gears are by necessity chunkier than direct drive gears, so they actually take up potentially a lot of space and they would be difficult for us to CNC.

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