5 colour printing using a purge "bucket"



  • Ian, A slow turning screw would work well. It's more like a spiral wound piece of wire (square stock) We have them at work on most of our machines to carry metal chips out of the machines. If I knew how to post a picture on here I could show you what they look like.

    I think they would be easy to implement, now if we can get David to add another mcode to turn them on /offโ€ฆ. ๐Ÿ™‚



  • We already have M42 so it shouldn't be too difficult to cobble something together that could be switched via an IO pin.



  • Ian,
    I just email you some pictures of the screw auger I was talking about. I think I am going to try something along this line.

    Tim



  • @timcurtis67:

    Ian,
    I just email you some pictures of the screw auger I was talking about. I think I am going to try something along this line.

    Tim

    Hi Tim. Haven't received any email yet but yes, I understand what you mean by an auger and that's along the lines of what I was thinking.



  • I've actually been thinking of doing something just like this.

    Would bumping the part fan to 100% help manage the waste filament?

    Could also do a "wire brush" area for the nozzle to run through to get the big chunks then hit the silicone strip for the final wipe before returning to the print area.

    Personally, I think giving up a little bit of build volume is worth while for the amount of filament you save.



  • Bold text below is just to distinguish my comments from the original quoted text and not because I'm shouting ๐Ÿ™‚

    @Mk_Nick:

    I've actually been thinking of doing something just like this.

    Would bumping the part fan to 100% help manage the waste filament?

    That's a very good question. It'll cool the filament as it comes out and should make it solidify quicker. I don't know if that would be a help or a hindrance. If I get chance, I'll test it (it's easy enoughy to do).

    Could also do a "wire brush" area for the nozzle to run through to get the big chunks then hit the silicone strip for the final wipe before returning to the print area.

    I think the problem with this might be that the the brush gets clogged or at least retains some of the previously purged filament which could then stick to the nozzle on the next pass. That's what happened with my "MK1 bucket" so I made the "MK2" which essentially has no bottom and allows the filament to drop through.

    Personally, I think giving up a little bit of build volume is worth while for the amount of filament you save.

    Also, if you use any sort of "tower", it will also take up some of the available space so a bucket is no worse than a tower in that respect. (I guess that's not strictly true as a tower could be positioned at some other unused part of the bed to suit the model being printed).


  • administrators

    Tim if you post pictures on a file sharing site like imjur you can then embed them in your post.

    Ian, loving your work as usual!



  • I've just tweaked my blog post to elaborate a bit on the purge gcodes that I used. So for those who have already read it, the additions I have made are as follows:

    Firstly, I'm using firmware retraction so for anyone who wants to try it and doesn't use firmware retraction, you'll need to substitute G10 with whatever gcode you use to retract filament (e.g G1 E-nnn Fnnn) and likewise for G11 un-retract.

    Secondly, the first command of the purge sequence is G10 (retract). I'm using Slic3R which by default puts a G10 before the tool change so thee could be 2 consecutive retract commands in the gcode file. I've left it in though because other slicers may behave differently and Duet firmware won't act on a second retract if there has been no preceding unretract, so it does no harm.

    Lastly, there is an unretract immediately before the extrusion which may seem unnecessary but it is needed because I want to retract after extruding to prevent any oozing so there has to be a preceding unretract (hope that makes sense).



  • @T3P3Tony:

    โ€ฆ...........
    Ian, loving your work as usual!

    Thanks Tony but I'm not claiming to have done anything new or ground breaking. The principle of using a purge bucket has been around for a long time. I just thought it might be useful to do a write up on my particular approach to implementing it. (It's always nice to have one's efforts appreciated though).



  • Nicely implemented!



  • Nice machine! love the sound the machine made while traveling.


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