Making a resin HHKB case?

[RESPRiT]

So, I've been sitting on this idea for a while, and might try it out when I get back to the US in a few months.

Basically, because I'm not a huge fan of the stock casing for the HHKB, I was thinking of just making my own mold and making a resin copy. I'm pretty sure this isn't a terrible idea, although it could be a bit costly, and I'd have to remove all the sliders for the top half, but besides that, is there any reason why I shouldn't give it a try?

[Pacifist]

resin casting something that size is a bit complex and expensive. it would be better to 3d print it

[RESPRiT]

resin casting something that size is a bit complex and expensive. it would be better to 3d print it

In the very least the bottom half of the case alone isn't very complex.

[Pacifist]

to avoid bubbles you'll need some expensive vacs or pressure pots

[Binge]

resin casting something that size is a bit complex and expensive. it would be better to 3d print it

no.. no....

[SpAmRaY]

resin casting something that size is a bit complex and expensive. it would be better to 3d print it

no.. no....

binge your setup is big enough isn't it?

 make us some HHKB cases

[Dgsbllx]

Ye binge get making! 

[RESPRiT]

I don't think you really need that big of a setup, just a box large enough to house the mold, and luckily the HHKB is decently small.

[lowpoly]

The mold will be made out of what?

[Binge]

I don't think you really need that big of a setup, just a box large enough to house the mold, and luckily the HHKB is decently small.

for a hhkb case?  It actually takes quite a bit of space.  For a case you would want to pressurize the resin to make it structurally sound.  My setup is not big enough for 60% cases and I have a 5 gallon pot.

[jwaz]

I think acrylic would be more cost effective, I'm not sure a resin case would work that well, especially because the case and plate are combined.

If one was to make a case you would need to make an assembly for the slider to fit into on the plastic/ metal plate. Maybe a CNCed outer case with a plastic plate, that would be sweet but ideally I'd want to replace as much of the plastic casing with aluminum as possible.

[Michael]

You actually don't need to pressurize the resin. Special FX shops do large scale casting without it. You just need to make sure you can pour it evenly and distribute enough venting holes so you don't catch air bubbles.

[Binge]

Some long set time resin may do the trick with enough vents, but I would still pressure cast to make it sturdy/toolable.

[Michael]

Some long set time resin may do the trick with enough vents, but I would still pressure cast to make it sturdy/toolable.

The purpose of pressure casting is to remove air entrapment. If your mold is ventilated properly, you won't need it to be pressurized. Also, you aren't going to find a consumer-level pressure device for an affordable price for something that size. Pressurizing it will not add any more strength to the material than not doing it. If you have degassed the material, then it will be structurally sound in either case.


A glove molding system would be recommended for something this size, that needs to maintain strict dimensions and removing the possibility of mold flex

[Findecanor]

The switch housings on the HHKB are part of the top casing ... and the fit against the sliders is very tight. Much of the appeal of Topre is the high tolerances in manufacturing and the lube used.
Both the silicone mould and the urethane resin shrinks and warps a little bit, not enough for you to spot with your eye, but it could be enough to cause problems. 3D printing may not be precise enough either.

If I were you, I would either:
- Make only a new bottom, or ...
- Rebuild an existing top, with "plastic surgery": (pieces of sheet ABS, putty, paint), or ...
- Make the new top use plate-mounted switch housings from a Topre Realforce keyboard.

[Binge]

Some long set time resin may do the trick with enough vents, but I would still pressure cast to make it sturdy/toolable.

The purpose of pressure casting is to remove air entrapment. If your mold is ventilated properly, you won't need it to be pressurized. Also, you aren't going to find a consumer-level pressure device for an affordable price for something that size. Pressurizing it will not add any more strength to the material than not doing it. If you have degassed the material, then it will be structurally sound in either case.


A glove molding system would be recommended for something this size, that needs to maintain strict dimensions and removing the possibility of mold flex

Great recommendation especially degassing before a large pour.  What about the screw holes? wouldn't you want to fill them in/smooth them and then re-tap?

[Michael]

The switch housings on the HHKB are part of the top casing ... and the fit against the sliders is very tight. Much of the appeal of Topre is the high tolerances in manufacturing and the lube used.
Both the silicone mould and the urethane resin shrinks and warps a little bit, not enough for you to spot with your eye, but it could be enough to cause problems. 3D printing may not be precise enough either.

If I were you, I would either:
- Make only a new bottom, or ...
- Rebuild an existing top, with "plastic surgery": (pieces of sheet ABS, putty, paint), or ...
- Make the new top use plate-mounted switch housings from a Topre Realforce keyboard.

You can grab extremely low-shrink resins that would work for this application. But the issue is, the mold would need to be very heavily ventilated to account for all of the possible air traps. So either way you go, it's going to be an expensive endeavor. It gets really tough for the top part of the HHKB case, where you have many areas that would need to be ventilated. Even using a pressure cast setup, you would still need to have some ventilation there as well. As either way, air bubbles can get trapped.

[mashby]

Sounds like we should buy some BroCases, amirite? 

[Michael]

Sounds like we should buy some BroCases, amirite? 

If I did it, it would be injection molded aluminum molds

[SpAmRaY]

Sounds like we should buy some BroCases, amirite? 

If I did it, it would be injection molded aluminum molds

THEN

 I would have to buy another HHKB

[Michael]

Ice clear HHKB cases would be pretty awesome

[mashby]

Ice clear HHKB cases would be pretty awesome

[Dodgy]

Ice clear HHKB cases would be pretty awesome

Or trans red with black caps... Ah jeez...