Enclosures
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From: Gunther Mannigel on 22 Mar 2010 08:49 Am 19.03.2010 18:32, schrieb D Yuniskis: > I'm wondering, instead, if I can't hack together something > with a sheet metal skeleton (or, maybe even a cardboard or > wooden form!) and fiberglass? This doesn't need to be > terribly strong, structurally. And, I could no doubt > come up with a way of mounting everything to a *base* > (i.e., to eliminate the need for fasteners *in* the skin). Have a look at http://www.toolless.com/ Google with "plastic enclosures no tooling" gives a lot more of them. cheers Gunther
From: MooseFET on 22 Mar 2010 09:24 On Mar 19, 10:32 am, D Yuniskis <not.going.to...(a)seen.com> wrote: > Hi, > > I need a small quantity (~20) of small {plastic,aluminum} > enclosures. But, I'm looking for something other than a > simple rectangular prism shape. > > So far, I haven't found anything "stock" that looks > appropriate (I did find a COTS "console-like" case but > the angle is too shallow). > > If push comes to shove, I can have a friend mill them > out of blocks of aluminum but that seems terribly wasteful! The aluminum can be recycled. > I'm wondering, instead, if I can't hack together something > with a sheet metal skeleton (or, maybe even a cardboard or > wooden form!) and fiberglass? This doesn't need to be > terribly strong, structurally. And, I could no doubt > come up with a way of mounting everything to a *base* > (i.e., to eliminate the need for fasteners *in* the skin). > > Has anyone done this sort of thing before? Pointers to > helpful tips as well as things to avoid... :> Sheet metal with a box and pan brake is not to hard to do if you don't need exact dimensions. If you use tin-plate you can solder the joints. This makes a very nice looking box if you do the soldering work on the side that can't be seen.
From: 1 Lucky Texan on 22 Mar 2010 09:51 On Mar 20, 11:24 am, Mark Borgerson <mborger...(a)comcast.net> wrote: > In article <lf-dneqPZ_GqIDnWnZ2dnUVZ_j2dn...(a)earthlink.com>, > fr...(a)far.from.the.madding.crowd.com says... > > > > > On Fri, 19 Mar 2010 10:32:42 -0700, D Yuniskis <not.going.to...(a)seen.com> wrote: > > > Hi, > > > > I need a small quantity (~20) of small {plastic,aluminum} > > > enclosures. But, I'm looking for something other than a > > > simple rectangular prism shape. > > > > So far, I haven't found anything "stock" that looks > > > appropriate (I did find a COTS "console-like" case but > > > the angle is too shallow). > > > Need an odd-shaped "container"? > > > Carve the front and back of the shape you want into two blocks of > > wood, then hammer sheet brass (aluminum, if you must) into them. > > > Remove, and bolt, screw, weld, or solder the two halves together > > around their contents. Apply Brasso lightly with fine steel wool > > to shine it up. > > > Repeat 19 more times. > > Wouldn't it be a lot more fun to mill a female mold from > steel stock, then lay an aluminum or steel sheet on top > of the mold and top that with a few ounces of suitable > explosive? That way you compress all the hammering > into a few milliseconds! > > Mark Borgerson You could go with hydraulic die forming; http://www.ganoksin.com/borisat/nenam/practical-die-forming.htm
From: BobS on 22 Mar 2010 20:03 On Mar 22, 8:51 am, 1 Lucky Texan <alcky...(a)swbell.net> wrote: > On Mar 20, 11:24 am, Mark Borgerson <mborger...(a)comcast.net> wrote: > > > > > > > In article <lf-dneqPZ_GqIDnWnZ2dnUVZ_j2dn...(a)earthlink.com>, > > fr...(a)far.from.the.madding.crowd.com says... > > > > On Fri, 19 Mar 2010 10:32:42 -0700, D Yuniskis <not.going.to...(a)seen.com> wrote: > > > > Hi, > > > > > I need a small quantity (~20) of small {plastic,aluminum} > > > > enclosures. But, I'm looking for something other than a > > > > simple rectangular prism shape. > > > > > So far, I haven't found anything "stock" that looks > > > > appropriate (I did find a COTS "console-like" case but > > > > the angle is too shallow). > > > > Need an odd-shaped "container"? > > > > Carve the front and back of the shape you want into two blocks of > > > wood, then hammer sheet brass (aluminum, if you must) into them. > > > > Remove, and bolt, screw, weld, or solder the two halves together > > > around their contents. Apply Brasso lightly with fine steel wool > > > to shine it up. > > > > Repeat 19 more times. > > > Wouldn't it be a lot more fun to mill a female mold from > > steel stock, then lay an aluminum or steel sheet on top > > of the mold and top that with a few ounces of suitable > > explosive? That way you compress all the hammering > > into a few milliseconds! > > > Mark Borgerson > > You could go with hydraulic die forming; > > http://www.ganoksin.com/borisat/nenam/practical-die-forming.htm- Hide quoted text - > > - Show quoted text - The lowest cost small enclosure is a piece of plastic electrical conduit capped with a rigid or soft plastic cap(s), or a strain relief inserted in the end. The plastic conduit can be purchased in a big box store for <$1 to several dollars per 10 Ft length depending on diameter. May not be the prettiest thing but the conduit has some reasonable electrical - mechanical properties.
From: D Yuniskis on 23 Mar 2010 04:46
Hi Joe, Joe Chisolm wrote: > D Yuniskis wrote: >> I need a small quantity (~20) of small {plastic,aluminum} >> enclosures. But, I'm looking for something other than a >> simple rectangular prism shape. >> >> I'm wondering, instead, if I can't hack together something >> with a sheet metal skeleton (or, maybe even a cardboard or >> wooden form!) and fiberglass? This doesn't need to be >> terribly strong, structurally. And, I could no doubt >> come up with a way of mounting everything to a *base* >> (i.e., to eliminate the need for fasteners *in* the skin). >> >> Has anyone done this sort of thing before? Pointers to >> helpful tips as well as things to avoid... :> > > I've done fiberglass molds before. If you want 20 or so > units I would do a female mold. Modeling clay, foam and Bondo > work great for shaping the male plug and fixing any problems. So you are making the mold out of 'glass, too? > I use tooling polyester resin. Any cheap resin will work. Most > local fiberglass suppliers will have some brand. Do not use > styrofoam with polyester resin as it will turn into a lump of goo. Yes :> > Use a pvc foam - there are several makes. Use Bondo or some > resin with a filler to coat all the foam and make sure and sand smooth. > Coat with car wax or some other release agent. Then start to make your > female mold from the male plug. Use lots of resin and a fine weave > cloth for the first layer. For the other layers I usually use some > fiberglass mat and any scrap cloth I have in the bin. Glass in > some small wood blocks for stability in making the real parts. > > Let this all cure and then carefully pop the mold off the male plug. > You might have to persuade it a little with a rubber mallet. Clean I had thought of trying something like plaster for the mold. I.e., something that could either be *dissolved* or *fractured*. > up any imperfections in the mold with Bondo and some sanding. Dremel > with a cutoff wheel works great for cutting the edges of the mold. > You can scribe drill marks and cut marks in the mold that will show up > on the finished part. I have used a BB bonded to the female mold as > a drill "center punch". Ah! > You can get gelcoat from local suppliers or on the net or you can make > a poor man's version using some clear casting resin and some pigment. > I have gotten pigment and supplies from TAP Plastic in the past. > > http://www.tapplastics.com > > For the final part make sure and wax the mold several times. I > usually add some form of spray on mold release as the final step. > Lay down a nice layer of gelcoat or resin and then use fine weave > cloth for the first layer. If needed stiffen the part by using > foam and glass on the inside in various locations. For standoffs > and screw inserts you can use a small block of foam. I use screw > inserts and just fill the threads with a blob of hot glue. Any > resin just pops off and the hot glue plug will pull out of the Clever! What about just leaving a screw *in* the insert? (and backing it out later) > threads. If there is going to be any real stress on the screws you > can carve out a pocket in the foam and fill with a milled glass - > resin mix. Let it cure for a minute or 2 to thicken and then push > the screw insert into the pocket. Biggest problem I had was making > sure they stay aligned. What I did for one part was made a wooden > jig where I could screw 4 insert onto locater screws and then > pressed them into the milled fiber mix. The jig held everything > square. How did you later get the inserts "unscrewed" from the "locater screws" (since the locaters were part of the wooden block)? > Take a look at http://www.fibreglast.com > > If you want to go the acrylic sheet method browse US Plastics > http://www.usplastic.com Thanks! Lots to think about, here... |