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geekhack Projects => Making Stuff Together! => Topic started by: hexa on Tue, 06 October 2020, 19:12:13

Title: Help with Dimensions for a Custom Case
Post by: hexa on Tue, 06 October 2020, 19:12:13

Hi all,

I am designing an Alice case and have just about finished up, but I wanted to reach out for some help on a few dimensions to hopefully remove some extra space.

My questions are:

• Is there a standard for how high a plate sits off of a PCB (due to the stabilizers)?
• I don't think there is, but is there a general rule-of-thumb for how much space to leave between a PCB and the bottom of the case?

Thanks for your help guys  ;D

Title: Re: Help with Dimensions for a Custom Case
Post by: nevin on Wed, 07 October 2020, 08:30:08

1. yes, from where the switch sits on the pcb to the notch where it clips into the plate. (top of PCB to top of plate) thicker plates would be closer to pcb then a thin plate)
- i'm getting about 5mm on my viterbi
[attach=1]

2. no, it's all personal preference. just make sure it's at least enough to clear the switch legs or components that might be on the back side of the pcb. (connectors, separate/stacked microcontroller, usb daughterboard, etc...) and add some extra space if the case will be a conductive material. flexi pcb/plate, if too close, could short on a metal case when the plate/pcb flexes down.

Title: Re: Help with Dimensions for a Custom Case
Post by: hexa on Wed, 07 October 2020, 10:09:49

Awesome, thanks for sharing and taking the time to measure.

I'm assuming a plate thickness of 1.5-1.6mm for standard Alice plates and wasn't sure if perhaps different stab manufacturers had varying heights (Zeal vs Cherry for instance). I don't have the ability to measure precisely so that measurement helps me greatly.  :thumb:

Title: Re: Help with Dimensions for a Custom Case
Post by: Pyk_ on Wed, 07 October 2020, 11:07:03

5mm matches up with the data sheet. You might find this useful for other things: https://datasheet.octopart.com/MX1A-11NW-Cherry-datasheet-34676.pdf

Title: Re: Help with Dimensions for a Custom Case
Post by: nevin on Wed, 07 October 2020, 11:26:47

thanks @Pyk_ figured someone would link the datasheet.

the FR4 plate in the picture is 1.55mm

if there are any connectors, JST, 3.5mm trrs, socketed promicro, etc... you're going to need a minimum of 5mm under the bottom plane of the pcb to clear those components. not sure if your using an official alice pcb or not. if you are, look at the pcb and get spec sheets for the components (if you don't have the pcb)digikey & mouser usually have spec/data sheets on almost everything.

not sure where you're located, but the calipers i used are just a cheap set off of amazon (less than $20)

Title: Re: Help with Dimensions for a Custom Case
Post by: hexa on Wed, 07 October 2020, 15:57:29

Ooo thank you for the link and follow up information! Much appreciated!

I am testing with a Switch Couture (ver2?) and soon the new Adelais, so if I do a good job it should be compatible with both.  :D

5mm between the PCB and the bottom of the case is what I was originally thinking based on the acrylic Alice case dimensions but just wanted to be sure.