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coseyfannitutti / mysterium

TKL keyboard that can be entirely assembled using only through hole components, including usb type-c
GNU General Public License v3.0
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Question about standoff heights in Mysterium case. #15

Closed nchieng closed 3 years ago

nchieng commented 3 years ago

https://github.com/coseyfannitutti/mysterium/blob/master/case/README.md#L25-L26

Calls for standoffs: 14mm for the case 8mm for the feet

Stacking the case layers, it totals 20mm Stacking the feet layers, it totals 12mm

Was there a reason why shorter standoffs were prescribed?

dhanakane commented 3 years ago

Are you taking into account that the top and bottom layers are only for the screws to pass through? The standoffs do not pass through all the layers of the case.

nchieng commented 3 years ago

No, I'm not accounting for the screws to pass through. If the screws pass through Top-1 and Bottom, How are these pieces held in place?

dhanakane commented 3 years ago

The screws are only 4mm. So you have 4mm screw --> 14mm standoff <-- 4mm screw. About 2mm of the thread engages the standoff on each side. The top and bottom sides of acrylic have smaller holes that only allow the screw body to pass through but a standoff cannot.

nchieng commented 3 years ago

I think I get it. Thanks for the explanation!

So the top and bottom layers are essentially getting clamped by the screw caps and the standoffs.

image

dhanakane commented 3 years ago

Yes! And the acrylic layers the screw threads pass through. The standoffs align the case and provide a body for the screws to thread into as well.

On Tue, 29 Sep 2020 at 14:02, Nick Chieng notifications@github.com wrote:

I think I get it. Thanks for the explanation!

So the top and bottom layers are essentially getting clamped by the screw caps and the standoffs.

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/coseyfannitutti/mysterium/issues/15#issuecomment-700686800, or unsubscribe https://github.com/notifications/unsubscribe-auth/AEBHXEZ2C3LOMG7PUJXJAK3SIHLETANCNFSM4R5M6ZAA .

coseyfannitutti commented 3 years ago

That table is great. So, yes the standoff area length is ~15mm, and 14mm standoffs are used because of the slight variance in layer thickness of cast acrylic sheets.

It is the same for the feet, with ~9mm standoff area length, so 8mm standoffs are used.

nchieng commented 3 years ago

Thanks! That now makes sense to me.

Here's the same table for the feet. image

nchieng commented 3 years ago

@coseyfannitutti Sorry to keep this alive. Can you point me in the right direction for the clear bumpons users at the bottom of the case please?

dhanakane commented 3 years ago

They’re very similar to these “3M Bumpon Protective Products SJ5312 Blister of 56”

They’re widely used in domestic applications.

Sent from my iPhone

On 30 Sep 2020, at 04:56, Nick Chieng notifications@github.com wrote:

 @coseyfannitutti Sorry to keep this alive. Can you point me in the right direction for the clear bumpons users at the bottom of the case please?

— You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.