Alternative Parts

Discussion in 'Tool heads & ToolChanger' started by Spoon Unit, Aug 24, 2019.

  1. Spoon Unit

    Spoon Unit Well-Known Member

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    First alternative parts from me are as follows:

    Wiper

    I didn't have the right size brushes to fit the wiper part, so revert to a silicone wiper.

    [​IMG]
    This is designed to accept push-fit threaded inserts for M3 threads:

    https://uk.rs-online.com/web/p/threaded-inserts/0278534/

    [​IMG]

    The holes go 25mm inside, so you could use a pretty long screw, but the ones supplied fit fine. I ended up using a nylon standoff.

    I sized the hole for an M6 grub I had lying around. I don't think the grub is totally necessary. Also, I had intended for the silicone to be more embedded than it is, but it works as is. This was just a miscalculation.

    [​IMG]

    I don't want to get involved in you mashing your machine, so I'll just give the movement coordinates part and leave you to damage your machine alone.

    Code:
    ;wipe
    G0 X-38 Y149 F6000
    G0 X-20 Y149
    G0 X-38 Y139
    G0 X-20 Y139
    G0 X-38 Y149
    G0 X-20 Y149 F50000
    Dock Cables

    I mangled the thread when I tapped it and the grub wouldn't hold the metal strengthener in place. So, as I have a bag of threaded inserts:

    [​IMG]
    Push an insert flush, then wind the grub in. This gives a super solid hold. In theory, if you've mangled the hole like I have you could just ream it to 4mm and then push an insert.
     

    Attached Files:

    Ntesla66, mhe, Rob Heinzonly and 2 others like this.
  2. Spoon Unit

    Spoon Unit Well-Known Member

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    Not an alternative this time, but a simple addition.

    [​IMG]
     

    Attached Files:

    Greg Holloway and mhe like this.
  3. mhe

    mhe Well-Known Member

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    Nice design!
    I'll probably machine something adjustable on the lathe but this already looks so amazing that I might just use this instead, thanks for this!
     
  4. Spoon Unit

    Spoon Unit Well-Known Member

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    Well it's Greg's design. I just added bearings because ...

    Well there is a because. I had a horrific off-kilter reel that the bed jammed into with that horrible motor straining sound, so simply had to find some way to improve rotation before going to some external mount option. Still, you're right, an the absolute sense. A circle was a great design. I'm not sure who we can thank for it, but they got it right. I just extruded between two of them :)
     
  5. Spoon Unit

    Spoon Unit Well-Known Member

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    Alternative PCF Bracket

    [​IMG]
    This would permit 3 points of connection for a larger blower, i.e. same flow, less noise, or more flow.

    [​IMG]
    It's the same width as the original at present.
     
  6. mhe

    mhe Well-Known Member

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    That screams for a fan duct that blows towards the nozzles from all directions instead of just the one we currently have.
     
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  7. Spoon Unit

    Spoon Unit Well-Known Member

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    Yes. Working on it, but it's a design challenge. The first version won't fit, and I think I'll need to rework the whole thing...

    [​IMG]

    [​IMG]

    I know there's lots wrong with it.
     
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  8. Spoon Unit

    Spoon Unit Well-Known Member

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    Just realised I didn't actually upload the alternative fan mount.
     

    Attached Files:

    mhe likes this.
  9. Spoon Unit

    Spoon Unit Well-Known Member

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    So, for the spool internal mounts, I encountered a couple of problems. I'm not sure if I made the problem worse by adding bearings, but I was finding that from time to time, the spool would 'walk' off the end of the rod and land on the bottom of the printer. So far, I've always been around to hear that. I really didn't want to find out what would happen if that occurred when I was asleep, so I've made a further change. Now the spool is trapped by a 'bolt' and 'nut':

    [​IMG] [​IMG]

    The center of the bolt is sized to take a skateboard bearing. It's a tight fit and may need some (careful) bashing.

    The nut and bolt then hold the spool with the bolt aligned to the center, and the bearings on the metal rod than almost complete constrain the movement of the spool to rotation around the center, which completely (in my experience so far - YMMV) removes any potential for walk.

    [​IMG]

    As an added bonus, this also works around any deficiencies in your rod length. I didn't quite have enough rod on hand and my shortest is about 65mm. For reference, the bolt is 87.5mm long.

    https://www.thingiverse.com/thing:3846735
     
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  10. Spoon Unit

    Spoon Unit Well-Known Member

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    OK. I really couldn't continue with the internal spools. I considered swapping to the spool holders from @Rene, but there's still the issue of purge/prime material dropping on the spool at the back left (or right if that's where you purge/prime). So I ended up mounting the spools on the front. It's not quite the same pretty package, but access is easy.

    [​IMG]

    The first change here is to the spool mount, which just has new holes for screws:

    [​IMG]

    These take M3 screws which attached to T nuts with hardware M3 nuts:

    https://www.thingiverse.com/thing:3199057

    Trying this on it's own led to spools wanting to unwind a bit:

    [​IMG]

    So I added a guide to the mix:

    [​IMG]

    This then feeds to a second guide:

    [​IMG]

    These guides take a small piece of tube to allow motion and prevent binding. In the end it looks like this:

    [​IMG]

    The spools now rotate smoothly, are easy to swap, and have no rubbish dropping on them.
     
    Miasmictruth and Greg Holloway like this.
  11. Ben Kay

    Ben Kay Well-Known Member

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    Hey Spoon Unit, did you get anywhere further with you fan duct design? Or is anybody else working on improvement to the cooling on the standard tool?
    I'm finding that the worst part of the machine at the moment...cooling not sufficient (especially anything pointing away from the cooling outlet).
     
  12. Spoon Unit

    Spoon Unit Well-Known Member

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    Sorry no. Nothing to add at this stage. The main issue is the constrained 'depth' of any solution. Ultimately a new dock piece might be the solution to provide a little more depth at the back of the tool. This would then allow you to have the heatsink fan right at the back, facing the dock, with a blower each side of the tool pointing down. With that construction, you would no longer have the challenge of getting air from one side of the tool to the other.

    The one sided cooling really shows it's weaknesses in certain print styles and limits the speed you can run:

    [​IMG]

    In this print I was tanking the speed up continually until I started getting this deformation front and back. It's a vase mode print spiralling up, so the two single thickness sides getting full blower action were fine, but front and back were clearly much less well cooled.
     
  13. Ben Kay

    Ben Kay Well-Known Member

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    Yep, I'm finding even Benchy for instance, at standard speeds, once it gets to chimney etc...the filament is just a molten mess.

    p.s what's that print surface?
     
  14. Spoon Unit

    Spoon Unit Well-Known Member

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    I did print a benchy and it came out fine. Perhaps I printed it slower. As with anything to do with 3D printing there are just SO many variables to consider.

    The print bed is a PEI coated Aluminium plate from Clever 3D in Germany. They've been doing this for a while and during the time that the forum was alive with discussions of the Bigbox, @Alex9779 came across them and designed a plate. A number of us ordered one. I have one in black and one in silver. Sadly I don't think they do colours anymore.

    This is where they sell it:

    https://clever3d.de/epages/7a4290fc...-9b99-eadef22228e2/Products/c3d-DDP-PEI-natur

    Once there, select '315x215x5mm E3D-bigBox-Clipfix' from the drop down. The 'clipfix' part of the name references that fact there's a cutout all the way round so that the clips hang on below the main surface height. However, with the HT bed, the heating element below bulges a bit too much for the swiss clips to sit nicely. Probably needs a custom clip to make a great fit.
     
  15. Ben Kay

    Ben Kay Well-Known Member

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    Great, I miss PEI sheet from my Prusa (actually it would be great to have a flex-plate solution for the TC).....
    What's actually to stop one using the "eckig" version, counter-sinking the plate, and essentially "sandwiching" the HT bed between this plate and the standoffs?

    i.e. eliminating the clips.
     
  16. Spoon Unit

    Spoon Unit Well-Known Member

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    Hmmm. Not much really. Not sure if the design has counter sunk screw holes, but if not they could be added in a new design.
     
  17. Spoon Unit

    Spoon Unit Well-Known Member

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    In the end, I moved away from the bearings in the center of the spool holder. Too little friction can lead to unwinding with poorly wound spools. So, I made another alteration to the screw and nut.

    The 'bearing' is now part of the Spool Bolt:

    [​IMG]

    And there are actually 4 of them built in. They're beveled to facilitate mounting and also to enable printing.

    [​IMG]
    Interesting ... that's almost a silencer design.....

    Also, the 'nut' has a bevelled entry to make it less hassle to attach:

    [​IMG]
     
  18. Digi2life

    Digi2life Active Member

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    I was disappointed with the wire bundle situation on the tools, so I modified it to make a bit more room and hide the mess at least somewhat. The excess wires are now zip tied to the taller walls I created. I'll post this on thingiverse if anyone likes it.
     
  19. Spoon Unit

    Spoon Unit Well-Known Member

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    Looks intriguing, but not entirely clear how it works. Beautiful looking print though.
     

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