Saturday, February 18, 2017

Surprisingly Involved

I've spent pretty much all of yesterday and today modeling the enclosure for my CNC mill in my 3D CAD program, Rhino3D.  There was other work interspersed with it, but not as much as I'd like.

The problem is that the design isn't really documented on the DVD I bought.  There are glimpses here and there and some descriptions, but most of the information is spread between online forums and YouTube videos.  I got the material list from one of the forums and bought the hardware, but other than some rough guidelines, didn't have dimensions to cut anything to.  So it came down to drawing it up and counting hardware.  (There are things in this image besides the mill and enclosure.  It's just like leaving stuff lying on the floor in real life.)
I had the drawing for the wooden chip tray that has been shown here before, and was able to get a CAD model for the extrusion from the place I bought it, Misumi.  After that, it was a lot of calculator work, and design on the fly.

Then it was time to try to find sources for things like the plastic panels.  When I found I couldn't get the corrugated plastic I wanted for the original design with three panels, I changed it over to four panels today. The back panels and two of the side panels, seen in yellow here, will be white plastic.  The smokey/translucent panels will be clear plexiglass.  The four panels on the front are hinged on the ends and in the first seams, which are doubles of the extrusion.  The double extrusion in the middle is where the doors open and close. 

There's still lots to figure out, probably as I'm building it.  The upper rim of the back and sides will have some LED strip lights like these to get some light into the work area.  It's not very well lit in that corner of the shop, so the more light the better.  I'm not quite sure how to hook that up, either, if I want to be able to disconnect them to take off a side panel or something. 

Oh, yeah.  I hear the president was in town today.  Missed seeing or hearing Air Force One, and if I had been sitting in line all day, this would be very different. We were outside waiting for the SpaceX launch when they scrubbed.


6 comments:

  1. What CAD package are you using for the drawings you post on your site?

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    1. Everything has been done in Rhino3D. I've been using it about 10 years, since version 3 and it's at 5 now, with 6 in development.

      If I was starting from no experience, I'd be looking at Fusion 360. Fusion (it's from Autodesk, the folks who put out AutoCAD) is a very professional package, but what really stands out is that they include CAM, so the same software can be used to design parts and do the machine tool paths.

      Here's the kicker: it's free for hobbyists and small business. If I recall, that means with sales less than $100,000.

      I actually have installed it and played at it, but really need to do the tutorials. It's just different enough from Rhino to really screw me up.

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  2. Thanks. I'll take a look at both. When we first moved into our house I used TurboCAD to build a 2D plan of the yard and interior. It works well enough but it might be fun to try out some alternatives. Thanks.

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    1. To add a bit of coincidence, TurboCAD was the one I tried to start with, but just couldn't wrap my head around it. I took the mandatory drafting class in college, and Rhino's default interface just worked for me. It's a four panel display, with the normal Top, Front, Right and Perspective panels, just like our drawings.

      Getting the thing I'm drawing to look exactly like I want it to is still a struggle. Rhino makes a big distinction between solids and surfaces, but that's due to the math it uses (NURBS, Non-Uniform Rational B-Spline). When I'm drawing something, I don't care about that; a surface never exists except as the outer part of a solid.

      Well, not really enough room to get into that here, but I'm hoping Fusion is a bit easier to use in spots.

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  3. Wouldn't a polycarbonate panel wear better than a plexiglass panel. Quite a few homebuilts (aircraft) are even going to polycarbonate. indyjonesouthere

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    1. Good question. I don't know. The panels aren't likely to bear an impact bigger than a chip, but I'd rather not bet my life or various body parts on that. I've been shopping by price, but maybe it's a good idea to make the front panels, where I'll be sitting, "bulletproof".

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