plastic cases (Interesting subject line, amirite?)

[pixelpusher]

I keep asking why we don't have more nice plastic case options.  The usual answer is that the molds are way too expensive to create.  Apparently it costs a small fortune to get someone to make a mold.  I honestly don't know of anyone who has approached a manufacturer to get back actual numbers,  but whateves.

Can't you cast it instead of injection molding?  Isn't there some sort of plastic that is nice and strong that can just be mixed and poured into rubber molds that someone could make at a smaller shop?  Model makers do pretty complex kits that look nice, right?  You could sandblast it for texture, or paint it, or dye it.  I've seen printed plastic cases and poured resin cases, but I'm thinking something more like ABS.  Anyone?  Does this exist?

[rich1051414]

I keep asking why we don't have more nice plastic case options.  The usual answer is that the molds are way too expensive to create.  Apparently it costs a small fortune to get someone to make a mold.  I honestly don't know of anyone who has approached a manufacturer to get back actual numbers,  but whateves.

Can't you cast it instead of injection molding?  Isn't there some sort of plastic that is nice and strong that can just be mixed and poured into rubber molds that someone could make at a smaller shop?  Model makers do pretty complex kits that look nice, right?  You could sandblast it for texture, or paint it, or dye it.  I've seen printed plastic cases and poured resin cases, but I'm thinking something more like ABS.  Anyone?  Does this exist?

Not really, but a cheap option would be PVC, which can be vaccuum formed. It would still be expensive, and most people would tend to spend a little more for metal instead at that point. It is about the expectations of those who would be buying the product.
I will say this, a good plastic case actually can have amazing acoustics. All metal cases tend towards pinging and ringing unless there's a ridiculous amount of plate mounting points.

FYI, thermoplastic typically needs to be injection molded, which is similar to the idea you are saying, but with machined metal molds, with ports the plastic is injected into. This is needed to make large production inexpensive,but it's extremely expensive for small production. The inverse is true for machined metal bodies, where the 'per piece' cost doesn't change as significantly with order size.

[pixelpusher]

I keep asking why we don't have more nice plastic case options.  The usual answer is that the molds are way too expensive to create.  Apparently it costs a small fortune to get someone to make a mold.  I honestly don't know of anyone who has approached a manufacturer to get back actual numbers,  but whateves.

Can't you cast it instead of injection molding?  Isn't there some sort of plastic that is nice and strong that can just be mixed and poured into rubber molds that someone could make at a smaller shop?  Model makers do pretty complex kits that look nice, right?  You could sandblast it for texture, or paint it, or dye it.  I've seen printed plastic cases and poured resin cases, but I'm thinking something more like ABS.  Anyone?  Does this exist?

Not really, but a cheap option would be PVC, which can be vaccuum formed. It would still be expensive, and most people would tend to spend a little more for metal instead at that point. It is about the expectations of those who would be buying the product.
I will say this, a good plastic case actually can have amazing acoustics. All metal cases tend towards pinging and ringing unless there's a ridiculous amount of plate mounting points.

FYI, thermoplastic typically needs to be injection molded, which is similar to the idea you are saying, but with machined metal molds, with ports the plastic is injected into. This is needed to make large production inexpensive,but it's extremely expensive for small production. The inverse is true for machined metal bodies, where the 'per piece' cost doesn't change as significantly with order size.

Yes, maybe PVC could work.  I am 100% on board with the acoustics opinion.  That's why I want a nice. custom plastic case so badly.  I also enjoy the sound of wooden cases, but plastic is still better to my ears.  Aluminum is nice and heavy and durable but like you said, tends to sound more harsh.  Well, i guess I just determined that sound is one of the most important things for me in a keyboard.  I'm probably not in the majority there.

This was why I didn't get in on the Norbaforce GB.  I don't see any advantage to putting a topre board in an aluminum case.  I think it could only make it feel and sound worse. 

Can you not take a big chunk of plastic and mill it out just like aluminum?  That would remove the need for molds, right? 

[ag36]

Regarding resin cast used for artisan keycaps, it is possible however resin casted case would cost nearly as much as an cheap aluminium case. Usually it's for extreme low quantity use and larger casts tends to wrap. There are other casting methods but all of them involves very large MOQ and setup cost.

Plastic usually can't milled because heat, exceptions may apply.

[AuthenticDanger]

Regarding resin cast used for artisan keycaps, it is possible however resin casted case would cost nearly as much as an cheap aluminium case. Usually it's for extreme low quantity use and larger casts tends to wrap. There are other casting methods but all of them involves very large MOQ and setup cost.

Plastic usually can't milled because heat, exceptions may apply.

What's the volume of a 60% case? Resin is pretty cheap and I could do the math, but I don't know the volume of a case to start with.

For reference, I can make a keycap for $0.033 in resin, so if a case is 1000x the volume, that's only $33.

[Kevadu]

Yes more plastic cases please!  Totally agree on the acoustics.  Despite all the hype about aluminum cases they generally sound like ****

Acrylic sandwich style cases aren't bad but they do kind of dictate the look of the whole build in a way that not everyone is going to like.

I wonder why nobody makes a CNC milled plastic case?  Sure it's not the most efficient use of material, but plastics are generally cheap and that's how all these aluminum cases are made anyway.  While machining plastic does have its challenges it should be possible.

[BlindAssassin111]

Machining plastic cases could be an option, just depends on the quantity, for example a board I designed would cost almost $500 for a single half of the case but drop down to $75 for each half for 25. Now I may try and look into possible machining cases out of plastic, but then you are limited to what plastics as not all like to be machined nicely, and each have very different properties for these type of applications. But I am intrigued to say the least.

[pixelpusher]

I'm guessing one might want to start with a 60% or 65% board, since their overall design is simpler.  Hell, I would even break down and buy a 40% board if the case was compelling enough. Perhaps add in the possibility of Bluetooth (even though I don't use it myself), since a plastic case would make it possible.  Something familiar yet unique. Maybe borrowing design queues from the AEK or the Model M or even the Cherry G80. 

[davkol]

czarek/FalbaTech has been making machine-milled PVC ErgoDox cases for a few years now.

[ag36]

Regarding resin cast used for artisan keycaps, it is possible however resin casted case would cost nearly as much as an cheap aluminium case. Usually it's for extreme low quantity use and larger casts tends to wrap. There are other casting methods but all of them involves very large MOQ and setup cost.

Plastic usually can't milled because heat, exceptions may apply.

What's the volume of a 60% case? Resin is pretty cheap and I could do the math, but I don't know the volume of a case to start with.

For reference, I can make a keycap for $0.033 in resin, so if a case is 1000x the volume, that's only $33.

http://www.resins-online.com/ecommerce/casting/model-making/

2 part modeling resin are pretty expensive because they cures at room temperature, low toxicity and ease to handle made them ideal for small production. Also molds for there does not last more then few(usually less then 5~10)uses. Issue would be the thickness and structural reinforcements you need to make for something this big not to wrap so the volume you need can be much larger then keycaps.

[pr0ximity]

Milled polycarbonate cases are rolling out here and there, but they're fairly expensive.

TGR 910 Poly, MxSS, and a poly or acrylic 5 Degree are all out in the wild.

[ag36]

https://geekhack.org/index.php?topic=81338.0

Found milled plastic plate, I think it's beautiful .

[Findecanor]

Not really, but a cheap option would be PVC, which can be vaccuum formed.

I'm afraid of harmful fumes from heating PVC.
Many other thermoplastics such as ABS and HDPE can also be vacuum formed. The ABS typically used for vacuuforming contain more B (butadiene: a rubbery plastic) than other, so as to be more pliable.

The Maltron's top shell is vacuuformed. I don't know how the switch holes are cut out but the switches are glued in and then hand-wired and soldered. They seem to have made them that way in low volume since 1977.
The texture is from the plastic sheets being textured from the start.

[ag36]

Not really, but a cheap option would be PVC, which can be vaccuum formed.

I'm afraid of harmful fumes from heating PVC.
Many other thermoplastics such as ABS and HDPE can also be vacuum formed. The ABS typically used for vacuuforming contain more B (butadiene: a rubbery plastic) than other, so as to be more pliable.

The Maltron's top shell is vacuuformed. I don't know how the switch holes are cut out but the switches are glued in and then hand-wired and soldered. They seem to have made them that way in low volume since 1977.
The texture is from the plastic sheets being textured from the start.

Switch holes are likely cut as sheet plastic before it was formed.

[rich1051414]

Not really, but a cheap option would be PVC, which can be vaccuum formed.

I'm afraid of harmful fumes from heating PVC.
Many other thermoplastics such as ABS and HDPE can also be vacuum formed. The ABS typically used for vacuuforming contain more B (butadiene: a rubbery plastic) than other, so as to be more pliable.

The Maltron's top shell is vacuuformed. I don't know how the switch holes are cut out but the switches are glued in and then hand-wired and soldered. They seem to have made them that way in low volume since 1977.
The texture is from the plastic sheets being textured from the start.

Oh I see. I was unaware ABS was even being used at all in vaccuum forming. Yeah, the plastic has to become pliable but still solid across a significant enough of a temp range. I am sure a lot of plastics qualify, PVC just being the typical plastic for it.
AFAIK, unicomp uses vaccuum formed PVC for their top shells.

[HPE1000]

we had this a while ago https://geekhack.org/index.php?topic=88062.0

[Leslieann]

You don't see them because plastic is not easy to do at low volume.

Resin casting doesn't scale well, injection molding is cheap but expensive to get started, 3d printing is either lackluster, slow or expensive, and while you can laser and mill some plastics, the material cost is the only think keeping it from costing just as much as aluminum as the materials cost difference is surprisingly small. Vacuum forming would be viable, were it not for how limited you are in regards to shape so it would be limited to an extremely low end case.

Custom keyboards in general are low volume, add that they tend to be higher end and exclusivity based, a $20 cheap GH60 case probably isn't going to set the keyboard world on fire, and if it did, the Chinese injection molders would just drop their prices and either undercut you or make theirs a much better deal.

Low volume production is expensive so you need to make it a luxury item to make up for the cost difference and plastic has a hard time fulfilling that role.

[Jacob4341]

MAKE PLASTIC CASES GREAT AGAIN

[ag36]

MAKE PLASTIC CASES GREAT AGAIN

And make [insert people here] to pay for it?

[pixelpusher]

We just need to convince someone like Leopold or Filco to run a Special Edition product that they could sell a set of kits for in a GB as well

Then we could do cool stuff like TKC did with the 1800

[xtrafrood]

A resin project would be fun.

[Findecanor]

Switch holes are likely cut as sheet plastic before it was formed.

I doubt it. ABS is vacuuformed within a narrow temperature range when it is soft and stretchy. The holes would be pulled out of shape. When it is colder than that it is too solid to be formed by vacuum.
So, the holes would have to be cut after shaping.

I have done a bit of building Star Wars armour and helmets out of vacuuformed ABS and I have done many smaller parts from raw ABS and HiPS sheet that I have heat-formed (HiPS = ABS without the A, but not named BS for some reason...). I have been present during vacuuforming but not done it myself.
I know you can only bend ABS or HiPS by hand a certain amount before a critical temperature, but once you reach that (= vacuu-forming temperature), it sags and your armour part is ruined.

Vacuuforming machines can be built at home from parts at the hardware store but require a bit of room... and then a bit of manual labour and a bit of skill. If you do it wrong, the part can get either too soft and/or you can get "orange peel" effect on the plastic surface that you really don't want. (I once bought an armour kit where many parts were both too soft and had orange peel, which was a great disappointment.)
The shape is a bit limited also in that there are certain artefacts that would occur if the angle toward the base is too sharp. Some of those problems could be avoided by using a negative mould or tilting it a bit, but that is a bit of an art.

BTW. PETG can also be vacuuformed but is also a bit difficult.

[ag36]

I see, yes you can't cut plastic sheets before forming. I guess punch cutting will be pretty difficult for Maltron's shape right(while not an issue for simple flat plate/cases)? Perhaps laser cutting will be easy to setup for plates(since cutting resin don't need require fibre laser)?

[rich1051414]

Switch holes are likely cut as sheet plastic before it was formed.

I doubt it. ABS is vacuuformed within a narrow temperature range when it is soft and stretchy. The holes would be pulled out of shape. When it is colder than that it is too solid to be formed by vacuum.
So, the holes would have to be cut after shaping.

I have done a bit of building Star Wars armour and helmets out of vacuuformed ABS and I have done many smaller parts from raw ABS and HiPS sheet that I have heat-formed (HiPS = ABS without the A, but not named BS for some reason...). I have been present during vacuuforming but not done it myself.
I know you can only bend ABS or HiPS by hand a certain amount before a critical temperature, but once you reach that (= vacuu-forming temperature), it sags and your armour part is ruined.

Vacuuforming machines can be built at home from parts at the hardware store but require a bit of room... and then a bit of manual labour and a bit of skill. If you do it wrong, the part can get either too soft and/or you can get "orange peel" effect on the plastic surface that you really don't want. (I once bought an armour kit where many parts were both too soft and had orange peel, which was a great disappointment.)
The shape is a bit limited also in that there are certain artefacts that would occur if the angle toward the base is too sharp. Some of those problems could be avoided by using a negative mould or tilting it a bit, but that is a bit of an art.

BTW. PETG can also be vacuuformed but is also a bit difficult.

TBH, Mythbusters got me into vacuum forming many years ago. They can be built from scratch, it's a very simple rig, but yeah, the larger the parts you want to make, the larger the build.

For holes, typically the areas that need to be cut out are recessed on the mold, to make cutting afterwards easier. The challenge is that your final product will be slightly larger than your mold, so you have to compensate for that. Big negative if you are contracting a 3rd party company to do the vacuum forming, it's doubtful they will get it right the first time.

[Findecanor]

Haha. That was a messy pull Adam Savage did. Undercuts in the mould so the plastic stuck around the mould, and webbing formed at the bottom. Items you would produce in volume should have better moulds making the process much smoother.
Then, trimming the pieces could be quite labour-intensive. I would believe industrial vacuuformed parts get stamped somehow.

One thing I forgot to mention is material thickness of vacuuforming. The material is usually between 1.5 to 2.5 mm thick before forming but when it is formed it stretches out so the thickness gets different in different parts. There can also be quite some variance between different "pulls" from the same mould as well.