Saturday, May 12, 2018

Redesigning the CNC Mill Enclosure

When I finished converting my milling machine to CNC, I moved onto building an enclosure for it. More details here.  Briefly, the enclosure always struck me as an afterthought on an otherwise very worthwhile DVD of plans I bought.  The creator, Daniel Kemp, better known as Hoss, did good drafting quality drawings for all of the parts involved in the conversion, but the construction of the enclosure was in a handful of videos on his YouTube channel and the materials needed were found on his dedicated forum at CNCZone.   The only drawing was for the plywood chip tray that the mill sits in.  I've run this picture before, but this is the enclosure when I finished it. 
As the system has aged, a couple of issues have surfaced that have gotten to the point that I need to change the front over to something else.  The biggest annoyance is that the doors are just too short, and I scrape my head on the top rail far too often.  The doors slide on a screw captured in the track on top, folding in at their middle - they're bifold doors - and so I can't put some foam or something on the middle of it so I don't scrape myself.  (The track is also source of another annoyance - the doors come off the captive screws and fall into the enclosure, suspended by just the hinges at the end panels.)

After a lot of research, I'm going to completely redesign the front.  I'm going to three doors, with the middle door sliding to the side to access the center of the mill where most work needs to be done.  I'll put the middle door in one sliding track so that it can slide to either side, and there will be two doors on another track, so that they can slide to the left or right and allow access to the corresponding end of the table.  It's going to look more like this:
The doors will still be clear Lexan; the smokey, almost purple color here is an artifact of the rendering in Rhino3D V5.  The frame is sitting on the front board of the chip tray in this rendering; the new pieces will all be wood, 1x2s, and mounted to the aluminum extrusion top and bottom.   

Most importantly, the doors will be 33 inches tall instead of 25.  That should keep me from hitting my head.  Right now the top rail is the same distance above the floor as my upper lip.  The extra 8" ought to eliminate that problem.  If the Lexan I can find is 36", I'll make the doors .36"

I'll need to work this into the shop at some point, where I'm working on the fire eater engine.  This week's work has all been on the big lathe, but there's a little work to be done on the milling machine before I interrupt everything. 



9 comments:

  1. Same thing here, but in the garage. Got a cheep workbench because standing up, holding on to somethings as you work on it, is NOT how to do things!

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  2. If you are going with sliders, could you hang them like a shower door? You can get the glass door roller mounts/clamps at HD, and possibly the overhead tracks. Might have to look in the door dept to find the track. There are about 1/2 doz different guides for the bottom of the doors, depending on width, etc. Those glue or screw down, and are normally plastic. Note that the door rollers come in two diameters and round or flat rolling surface, to match the rail. Find the rail first.

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    1. I haven't had luck down this road yet, but I also haven't given up yet.

      West Marine has some plastic tracks like you speak of, intended for windows on boats - so subject to splashes. No rollers.

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  3. Go with three tracks for the doors, not two. Otherwise, in a few months you'll be pulling one of those doors out every time you need to mess with something that's wider than what you currently expect.

    And of course make sure the panels overlap sufficiently when they're closed to prevent debris from spewing out into the room.

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    1. I had planned to leave the ends open so that any door can be removed at any time - or slid farther out than normal. But I've also considered three tracks, like you say.

      The biggest question is how I put all this together. Do I use bigger aluminum extrusion, or 1x2s (as drawn). I don't know if the 1x2s will be strong enough. All the existing extrusion is 15mm square, just about 0.6". 80/20 extrusion starts at 1" which is stronger. Bending under any load would be less - since area moment of inertia is almost 8 times better for 1" over 15mm.

      And, yes, the doors won't have gaps where they overlap. It won't be fluid proof, but direct splashes and chips flying from the cutter won't get out.

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  4. Have you considered something like parallel pivoting arms to lift the entire front overhead?

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  5. You may be able to buy new overhead track directly from the manufacturer. Can't recall the name/s, but you can check online or at the hardware store. Some parts are not available separately, only in the door assembly kit, such as the glass doors. I can't recall if they restrict any of the aluminum parts, or if all are available. An alternative source would be home or bath re-modelers, as they commonly get replaced to make a bath look new and improved. Remember, if a door gets broken, they have to buy a complete assembly, so builders end up with extra parts.

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  6. Check with 8020 https://8020.net/shop/2210-black.html That is 3-way track (by the inch)

    As for the size of the doors, they make 4X8 sheets of lexan - up to close to 1/2 inch. It isn't cheap.

    Do you need 3 doors? Could 1 big removable piece of lexan work? Maybe held with magnets?

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    1. I was at 8020 last night, looking at the 1" square extrusion. I might go that way.

      I'd prefer the ability to just open the door because it seems I spend most of my time with them open, make a few minute's worth of cuts with them closed, then open them for more setup. Opening and closing them all the time makes the idea of just sliding it - or even keeping the doors as bifold doors, just taller - seem the most convenient way to address it. Right now the panels are .080 lexan (IIRC). I was thinking of 1/4", but that's not necessary.

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