Enclosure design

Discussion in 'Motion System' started by Cam_Motion, Sep 8, 2019.

  1. Cam_Motion

    Cam_Motion Active Member

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    Has anybody designed or built an enclosure for their motion system? Does anyone have any thoughts on how the design could be adapted so that the build area is enclosed for temperature/humidity control. I was thinking of having extended side/back panels which could be joined at the top with another panel and a door placed on the front. If anyone has any ideas or examples to look at I would be interested to see them.
     
  2. Jai Stanley

    Jai Stanley Well-Known Member

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    I'm designing an enclosure at the minute; but have some questions for E3D regarding the max operating temperature of many of the components.

    Initially I was going to design a lid (like a record player) that flips up, laser cut acrylic panels and doors...

    Since then I have fabricobbled together a full enclosure with foam insulation and aluminium tape that leaves the electronics enclosure at the back open for cooling. It is working VERY well... I've been printing ASA, ABS, Polymax PC and even raw polycarbonate with very few issues. The chamber can heat passively to 55 degrees with a bed temp of 105; and 63 degrees with polycarbonate bed temps of 130.

    I'm still looking at the BOM and trying to work out if everything is going to be OK at these temperatures; and can't see any problems yet (question to E3D post coming soon) as I would also like to heat the chamber. The biggest issue I can see is that of thermal expansion: for instance if the X axis aluminium spar expands it may put stress on the Y axis bearings... this was one of my reasons for enclosing the whole printer: to let everything slowly come up to temperature; rather than have a gradient of temperature over the aluminium from inside to the outside. If everything is at the same temperature; and brought there slowly - it should all expand at the same rate: or at least get bigger instead of bowing.

    If I design a nice enclosure; rather than a big over the top one like I am currently, I'll post the files.

    Jai

    EDIT: later I'll try and work out how to post photos from google drive/photos and post what I've done. It's big, ugly and at the moment an absolute fire HAZARD (I've used polystyrene that I had already rather than fire proof celotex/kingspan type insulation that would have rewuired a trip to a builders merchant) so am a bit reluctant to post; but we're all growed ups eh?
     
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  3. Cam_Motion

    Cam_Motion Active Member

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    Ikea tables have been used before to make chambers though the one used the "Lack" table isn't big enough. I found the Bror shelving units, the ones 85cm * 55cm (come in various heights) would fit the printer and the design of the unit means you could attach panels/insulation with nuts and bolts around the printer.
    https://www.ikea.com/gb/en/p/bror-shelving-unit-black-s09272671/

    edit: Looks like someone beat me to it! https://www.thingiverse.com/thing:3194677

    I am hoping to put the electronics in a separate box to keep them away from the heat as this will shorten their life. I have not looked into how this could be done, some of the cheap chinese printers have a separate box which look like it would work.

    How are you going to heat the chamber?
     
    #3 Cam_Motion, Sep 9, 2019
    Last edited: Sep 9, 2019
  4. Jai Stanley

    Jai Stanley Well-Known Member

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    Consider that the extruder and X/Y motors also need to be cooled. The electronics are already in an enclosure with them; so it makes sense to me to pump air through it. Yes, some heat will be lost to the aluminium and acrylic, but not much. I might insulate the acrylic that separates this chamber from the enclosed print volume. In an ideal world you're right though. Get them out. Worth mentioning: I've never seen my MCU get above 39/40 degrees when the machine is running, because I have the rear of the machine pressed against an opening in the enclosure so is open to cool air.

    The machine can 'passively' heat (from the heated bed) my make-shift enclosure to 63 degrees when printing PolyMax PC (bed temp 120 degrees, PEI surface).

    For active heating, I'm just experimenting with 'low duty cycle' options: PEEK and the like need 150 degree chanmber temps and I wouldn't put the components of this system through that (thermal expansion/contraction more than absolute temperature). A different design that keeps motion parts out of the 'oven' would be required I think. To this end I intended to use a PTC enclosure heater for simplicity and safety. Then I found an air-conditioning inverter in a skip and removed a very sizeable heatsink off it! I intend using a 320x320 5mm aluminum sheet I have laying around, with this heatsink mounted on one side. On the other will be a thermo-fuse and a keenovo 750w 300x300 heat-mat I had destined for a heat bed on another machine. Placing this in the same enclosure, with a fan on the heatsink means I will be able to control the temperature of the heater (not the chanber per-se) with the Duet and an SSR - similar to a normal heated bed. Placed beneath the machine it should allow heat to rise through the cut-outs in the frame; air could even be pumped from the top of the machine to the bottom to aid this process.

    Ultimately, I am working up to being able to reliably print raw polycarbonate. As the machine sits at the moment it makes fantastic Polymax PC parts; but I am not convinced they are actual Polycarbonate, or at least a modified blend. It's a very different feeling/smelling plastic (you MUST try it if you haven't before: It's my favourite material ATM). Shooting for sky-high temperatures for Ultem etc is going to require a bit more thought/engineering and safety!

    Let me know how you're getting on! I'll post any sketches/photos I make and some progress reports when I can figure out a quick/easy way to post photos.

    Kind regards,

    Jai
     

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