4 ms·

Most of that "$10,000" is because of paying someone else for custom parts. If you use existing parts or make the custom parts yourself (if you have the ability/

by joemi 5y ago

Most of that "$10,000" is because of paying someone else for custom parts. If you use existing parts or make the custom parts yourself (if you have the ability/tools), it's less than $100. So the software equivalent would be if you oursourced a large chunk of your project to someone else, and in that case, I think $10,000 might not be too far off.

6510 5y ago
Interesting take, I guess trees can be pretty cheap if you grow them yourself.
- bee_rider 5y ago
  I'm fairly decent with clay, always wondered if I could make something like a raspberry pi case with sculpey. But not curious enough to ruin my toaster...
  - webmaven 5y ago
    > I'm fairly decent with clay, always wondered if I could make something like a raspberry pi case with sculpey. The short answer is yes you can, but it's a PITA. Among other problems you have to deal with shrinkage and drooping. I'd only use that approach for a quick and dirty prototype that just needed to hold parts together and survive rough handling. A better option is to build a case from parts you cut out of a sheet of plastic (anywhere from 1mm on up) that you then glue together. Once built, rounding the edges will make it a lot nicer to hold, but it will still basically be a box, and the glues you use are generally pretty toxic so don't breath in the fumes OR get it on your hands. More involved would be making the case by vacuum forming a heated sheet. The forms (one each for the top and bottom instead of the two you need for injection molding) are typically hand sculpted or machined from wood, filler and primer rather than metal, and vacuum forming is something a hobbyist can accomplish at home with a DIY setup. You can get a case nearly indistinguishable from an injection molded part, at least from the outside. The more complex the shape the more labor intensive the fit and finish will be (for example, getting the edges of the case halves to match up). However you make the case, there would be a lot of keyboard holes you'll need to carve out with something like a dremel rotary tool. It might be easier to make the case with a single large hole that you glue a thinner insert into that will be easier to cut holes in with a hobby or utility knife, but I've sliced my hands up a lot when doing this sort of work. A rotary tool seems scarier if you're not already familiar, but with as little as 30m of practice you'll probably have much better control than you would over a knife and lower risk of injury (as long as you use eye protection, etc. You really don't want the plastic shavings flying around getting into your eyes).
    - watersb 5y ago
      > A better option is to build a case from parts you cut out of a sheet of plastic (anywhere from 1mm on up) that you then glue together. Not a bad way to go, but I found that for hand assembly, I had a really hard time with the glue out of control; I probably needed a better applicator than the default tube of epoxy. Instead, I would go with VHB (Very High Bond) tape. Also weird to use, if you are using the thin 1mm width, but I can position the tape more carefully before I press it into place.
      - kragen 5y ago
        I don't know anything about this stuff, but from YouTube I'd think other options would include: - machine a form out of wax or delrin (or clay), pour a silicone mold, and then pour liquid plastic into the mold, either a not-yet-polymerized resin such as a thin epoxy, or a molten thermoplastic; - similarly, but use plaster instead of silicone and burn out the form in a kiln before pouring (not applicable for clay); - 3-D print the case, and if you don't like the layer lines, smooth them out with either a coat of paint or by smoothing an ABS print with acetone vapor; - 3-D print a form for molding. Even for injection molding, you might start with an aluminum mold, which won't last as long as hardened steel but will cost a lot less. But I don't know anything about this stuff so maybe it's not applicable to this case?
        webmaven 5y ago
        > molten thermoplastic Unless there are products I'm not aware of, mostly thermo plastics require high pressure injection that isn't feasible for a hobbyist setup. > a not-yet-polymerized resin There are lots of products like this (a bewildering variety, really), but in general they aren't particularly convenient to use, and you'll have a lot of failures. Factors that can mess you up include temperature, humidity, air bubbles (so many air bubbles!), mixing ratios, over mixing, under mixing, contaminates on the mold surfaces or your mixing containers, pour holes too small, not enough exit holes, entry/exit holes in the wrong places, molds held together too loosely leading to leaks, too tightly leading to distortions, etc. Except for the possible exception of relatively simple shapes and small items (like dice), just about everything you can imagine going wrong will, and you'll end up with a lot of waste before you get something you can use, and disposing of the failed attempts responsibly is another challenge. There is a caveat though: if you're trying to make a soft part (whether in a hard or soft mold), the materials are generally a lot more forgiving of errors, but that's tangential to the challenge of making a case.
Taniwha 5y ago
Injection moulding is not cheap, getting the high quality steel mould produced costs $1000s, a largish portion of this is just the cost of a giant block of steel (there are two moulds here)

by joemi 5y ago

6510 5y ago

Interesting take, I guess trees can be pretty cheap if you grow them yourself.

bee_rider 5y ago
I'm fairly decent with clay, always wondered if I could make something like a raspberry pi case with sculpey. But not curious enough to ruin my toaster...
- webmaven 5y ago
  > I'm fairly decent with clay, always wondered if I could make something like a raspberry pi case with sculpey. The short answer is yes you can, but it's a PITA. Among other problems you have to deal with shrinkage and drooping. I'd only use that approach for a quick and dirty prototype that just needed to hold parts together and survive rough handling. A better option is to build a case from parts you cut out of a sheet of plastic (anywhere from 1mm on up) that you then glue together. Once built, rounding the edges will make it a lot nicer to hold, but it will still basically be a box, and the glues you use are generally pretty toxic so don't breath in the fumes OR get it on your hands. More involved would be making the case by vacuum forming a heated sheet. The forms (one each for the top and bottom instead of the two you need for injection molding) are typically hand sculpted or machined from wood, filler and primer rather than metal, and vacuum forming is something a hobbyist can accomplish at home with a DIY setup. You can get a case nearly indistinguishable from an injection molded part, at least from the outside. The more complex the shape the more labor intensive the fit and finish will be (for example, getting the edges of the case halves to match up). However you make the case, there would be a lot of keyboard holes you'll need to carve out with something like a dremel rotary tool. It might be easier to make the case with a single large hole that you glue a thinner insert into that will be easier to cut holes in with a hobby or utility knife, but I've sliced my hands up a lot when doing this sort of work. A rotary tool seems scarier if you're not already familiar, but with as little as 30m of practice you'll probably have much better control than you would over a knife and lower risk of injury (as long as you use eye protection, etc. You really don't want the plastic shavings flying around getting into your eyes).
  - watersb 5y ago
    > A better option is to build a case from parts you cut out of a sheet of plastic (anywhere from 1mm on up) that you then glue together. Not a bad way to go, but I found that for hand assembly, I had a really hard time with the glue out of control; I probably needed a better applicator than the default tube of epoxy. Instead, I would go with VHB (Very High Bond) tape. Also weird to use, if you are using the thin 1mm width, but I can position the tape more carefully before I press it into place.
    - kragen 5y ago
      I don't know anything about this stuff, but from YouTube I'd think other options would include: - machine a form out of wax or delrin (or clay), pour a silicone mold, and then pour liquid plastic into the mold, either a not-yet-polymerized resin such as a thin epoxy, or a molten thermoplastic; - similarly, but use plaster instead of silicone and burn out the form in a kiln before pouring (not applicable for clay); - 3-D print the case, and if you don't like the layer lines, smooth them out with either a coat of paint or by smoothing an ABS print with acetone vapor; - 3-D print a form for molding. Even for injection molding, you might start with an aluminum mold, which won't last as long as hardened steel but will cost a lot less. But I don't know anything about this stuff so maybe it's not applicable to this case?
      - webmaven 5y ago
        > molten thermoplastic Unless there are products I'm not aware of, mostly thermo plastics require high pressure injection that isn't feasible for a hobbyist setup. > a not-yet-polymerized resin There are lots of products like this (a bewildering variety, really), but in general they aren't particularly convenient to use, and you'll have a lot of failures. Factors that can mess you up include temperature, humidity, air bubbles (so many air bubbles!), mixing ratios, over mixing, under mixing, contaminates on the mold surfaces or your mixing containers, pour holes too small, not enough exit holes, entry/exit holes in the wrong places, molds held together too loosely leading to leaks, too tightly leading to distortions, etc. Except for the possible exception of relatively simple shapes and small items (like dice), just about everything you can imagine going wrong will, and you'll end up with a lot of waste before you get something you can use, and disposing of the failed attempts responsibly is another challenge. There is a caveat though: if you're trying to make a soft part (whether in a hard or soft mold), the materials are generally a lot more forgiving of errors, but that's tangential to the challenge of making a case.

Taniwha 5y ago

Injection moulding is not cheap, getting the high quality steel mould produced costs $1000s, a largish portion of this is just the cost of a giant block of steel (there are two moulds here)