3D printing keyboard case/plate

[DonnyD]

I checked shapeways.com website with my 3d models, and prices are reasonable, but not in metals. Printing my model in aluminium will cost nearly 300, which is a bit too much. But in metallic plastic, which looks quite good and interesting, cost about 70 USD, with PLA or other plastics can be cheaper. ( I need to make thicker plate, though. Also cutouts for switches to clip in). Keyboard will be hand wired.

So what do you think about this idea ? Do you tried printing something and can comment on physical properties ?

Photo of case with integrated plate as viewed from bottom.

[xondat]

3D printed plates in plastic are pretty common as it's the easiest way to have a custom plate. I say go for it.

It'll be a softer bottom out feel than metals, but I think that's obvious.

[TalkingTree]

Do you tried printing something and can comment on physical properties ?

I made a PLA case for my keyboard and it's reasonably solid and sturdy. Although the looks are not the greatest, it could still be used for daily usage.

[DonnyD]

I contacted shapeway for 3d printers accuracy, so maybe detail would be good enough to not bother me Also, IMO metallic plastic looks better, especially with sparkle-like dusts. Don't forget this will be my first ever mech keyboard, so it will be great starting point. And if I like mech keyboards in general, this definitely wont be my "End game".

[DonnyD]

Do you tried printing something and can comment on physical properties ?

I made a PLA case for my keyboard and it's reasonably solid and sturdy. Although the looks are not the greatest, it could still be used for daily usage.

What you think about keeping 1.5 thick plate ? I will be using 2 standoff near F and J keys(Tada68 layout), but will it still be sturdy enough ?

[TalkingTree]

What you think about keeping 1.5 thick plate ? I will be using 2 standoff near F and J keys(Tada68 layout), but will it still be sturdy enough ?

Yes, I believe 1.5mm plates are more than enough on their own for a 65% keyboard.

[Leslieann]

It's not going to be $70.
When you get a print estimate, it's usually with little infill or even hollow, you need a lot of infill. You can do it for $70, but it's going to be fragile.
When I did my 60% case, I did 2 perimeters and 70% infill, same as I use for my printer parts. Overkill? probably, but wasting a little plastic now is better than redoing it again.

You will also should thicken the plate... A LOT. It will probably be okay on a 60%, but it's easy to do so why not do it right?
You need it to be the recommended thickness where the switch clips in, but there is nothing saying you can't have webbing that sticks down further around the switch body, like this:



Also if you haven't done this before (or used their service), take a small corner, with a single switch spot and have them print that for you to test tolerances. On my machines, for a loose fit I usually need 0.4mm, a tight fit 0.3mm, but it depends on a LOT of factors, not just the printer itself, but the material and even the temps and software used to prepare the print can impact tolerances. For example if I use an older version of Cura slicing software, I need an extra 0.1-0.15mm clearances. And if you switch to a a larger nozzle you tend to need even larger tolerances.

[DonnyD]

It's not going to be $70.
When you get a print estimate, it's usually with little infill or even hollow, you need a lot of infill. You can do it for $70, but it's going to be fragile.
When I did my 60% case, I did 2 perimeters and 70% infill, same as I use for my printer parts. Overkill? probably, but wasting a little plastic now is better than redoing it again.

You will also should thicken the plate... A LOT. It will probably be okay on a 60%, but it's easy to do so why not do it right?
You need it to be the recommended thickness where the switch clips in, but there is nothing saying you can't have webbing that sticks down further around the switch body, like this:
(Attachment Link)


Also if you haven't done this before (or used their service), take a small corner, with a single switch spot and have them print that for you to test tolerances. On my machines, for a loose fit I usually need 0.4mm, a tight fit 0.3mm, but it depends on a LOT of factors, not just the printer itself, but the material and even the temps and software used to prepare the print can impact tolerances. For example if I use an older version of Cura slicing software, I need an extra 0.1-0.15mm clearances. And if you switch to a a larger nozzle you tend to need even larger tolerances.

Thanks for your reply !!
I don't see option to choose infill % ? Do they do 100 % ??

[vvp]

If the printing method is SLA or SLS then it will be 100 % infill by default.

[DonnyD]

If the printing method is SLA or SLS then it will be 100 % infill by default.

So metallic plastic would be 100% infill ?

[vvp]

Ooops, SLA method may have less than 100% infill. Depends whether the part is printed top down or bottom up.
I have never seen SLS method without 100% infill. The material would be lost anyway so one can just fuse it too.

I do not know what infill your selection has. It is not clear from your picture what 3d printing method is used. Search the user interface whether it is SLS. Or send a question to the support.

If the printing method is FDM or FFF then the default infill will not be 100%.

Also if you do not intend to use a PCB then make sure the plate is thicker as Leslieann recommended.

[DonnyD]

In my picture it says: Technology: Selective Laser Sintering, so it should be 100% infill. I am making similar supports as in Leslieann picture at 1.5mm thickness (so plate at thickest point is 3mm). Here is some pictures of my case:

[DonnyD]

3D printer accuracy is 0.15mm, is it good enough ?

[vvp]

3D printer accuracy is 0.15mm, is it good enough ?

The cherry mx spec requires precision 14 ±0.05 mm horizontally and 1.5 ±0.1 mm vertically. So it is not enough. But if you are willing to file the openings if they would be too small and glue the switches in if they would be too loose then you can use it. I just make the openings a bit bigger and glue the switches in. You can see the gluing(*) job here: https://deskthority.net/post347675.html#p347675
(*) some glue which solidifies into somewhat rubbery stuff

In my picture it says: Technology: Selective Laser Sintering…

Good eye!

[Leslieann]

SLA (Resin) is rarely solid, not just for monetary reasons but also technical reasons and need to be designed for it. SLS will be solid unless you leave holes to bleed powder from the cavities and even then you will likely still be charged for it so you may as well make it solid.


3mm is a pretty solid piece for something that has sides for support such as a 60% case, but for a flat part, 3mm is not that tough. Remember, even sintered, these are not going to be as dense as injection molded parts and it's still plastic. I did my plate at 5mm total thickness, maybe see what the price difference is and go from there, if it's not much more, go thicker. You only need to leave the bottom of the switch available in order to solder, so why not use as much as you can?

0.15mm accuracy is quite good, but I would expect nothing less from a $150k+ SLS machine (which is what Shapeways uses).
FDM industry average is 1mm or 1% whichever is larger, though 3dhubs is trying to cut that in half, many machines, especially deltas can struggle to even make the old standard.

Keep in mind, accuracy is not the same as tolerances.
Accuracy tends to be about overall dimensions, while tolerances tend to be about clearance. You can have a 200mm plate that accurate to 0.15mm which is awesome, but if you make your bolt holes with that as a tolerance the bolts may not slip through your holes. If you make your plate a press fit with that as a tolerance, will it slip together or need some sanding? See the difference?

This is why I said, have a small sample done to check your clearances, you want a slip fit or even a slightly loose fit for switches. Get it too tight and you are either ordering another revision (at full price) or spending a lot of hours with a jewelers file. If you are not sure and just want to go for it, give each hole 0.2mm clearance per switch side, so .4mm across and .4mm vertically. That should be enough regardless and still be tight enough for the switch to grab. If you do a test, it doesn't even need the full skirt, just the switch hole and some material around it (say 5mm).

[Leslieann]

The cherry mx spec requires precision 14 ±0.05 mm horizontally and 1.5 ±0.1 mm vertically. So it is not enough. But if you are willing to file the openings if they would be too small and glue the switches in if they would be too loose then you can use it. I just make the openings a bit bigger and glue the switches in. You can see the gluing(*) job here: https://deskthority.net/post347675.html#p347675
(*) some glue which solidifies into somewhat rubbery stuff

The spec has A LOT more leeway than Cherry claims (at least horizontally), if it didn't universal plates wouldn't even function and many keyboards do not even have a plate at all.

The spec was designed for the switch to clip into place so that if you were to tug on it without a pcb it would not come out. You don't need that really, it's probably more of a manufacturing aid than anything. The pcb holds the switch down, you just need the plate to keep the switch from putting too much pressure on the pcb and give a stiffer feel.

[Findecanor]

I would suspect that a "metallic plastic" would sacrifice strength for a specific look. Do read up on the specs for this material!

I have cast up to 50% metal powder in a type of plastic a few times to make them look like metal. Those looked convincing after I buffed them but there were much more fragile than the same shape out of 100% plastic.

BTW, I would thicken the walls of the standoffs and add more standoffs. I would also change the model so that there would be countersunk holes in the top for bolts threaded into a solid metal bottom. I would not count on being able to tap the holes in plastic. You would also need a special tap for tapping a hole to the bottom — the ones you'd find easily in a hardware store are for tapping all the way through.