Metal plate for G81-3000 handwire project (work in progress)

[ojrask]

Started working on a CAD model for a metal plate which I will use for my G81-3000 handwire project.

I'm using OpenSCAD which is a programming first CAD modeling program, really simple and awesome so far. My first endeavor in CAD modeling.

The plate is otherwise a regular-ish 104-ANSI plate, but with a WKL-style bottom row, split Right Shift and split Backspace.

Still need to do measurements and so on, also mounting holes are missing and such.

[ojrask]

Some progress. Bought better measuring equipment and tried to read some values from TalkingTree's GH80-3000 PCB project.

There are some areas which I'm still a bit worried about, for instance, the LED corner. The case is soft-ish plastic so I can always carve holes here and there but getting things to line up is not that simple.

I'm looking for a local 3D printer where I could print a prototype for this, would rather not order a $100 metal prototype (local prices it seems are quite high) to just find silly mistakes or measuring errors all over the place. The difficult part is to find a printer that supports dimensions up to 45ish centimeters.

Though first up I need to use my company printer to print on some A3 paper with lines to cut out, as the first step in prototyping. I think out office printer supports A3 size.

[TalkingTree]

Some progress.

Looks good. Big thumbs up for the 7u spacebar.

tried to read some values from TalkingTree's GH80-3000 PCB project.

Feel free to ask anytime.

There are some areas which I'm still a bit worried about, for instance, the LED corner. The case is soft-ish plastic so I can always carve holes here and there but getting things to line up is not that simple.

Are you still going fully handwired? Because, in that case, you need something that holds your LEDs. That obviously can't be the plate itself because the LEDs would short. I guess you should be cutting three circles and later on glue some rubber or plastic support for the LEDs.
Otherwise, you just need an opening for the LEDs to go through. Again, circles would do just fine.
Keep in mind that cases have two big prongs in the top right corner to coil the cable around. Make sure your frame keeps clear of them.

I'm looking for a local 3D printer where I could print a prototype for this [...] The difficult part is to find a printer that supports dimensions up to 45ish centimeters.

You can split the plate into pieces with jigsaw joints and then glue them together, but I don't think a 3D printed plate could be any cheaper, unless you opt for a low resolution print which, at this point, won't be much of use. However you might want to ask someone with a better knowledge of 3D printing, Leslieann to name one.

Though first up I need to use my company printer to print on some A3 paper with lines to cut out, as the first step in prototyping. I think out office printer supports A3 size.

Or split the file into two and print it on A4 papers. Leave a couple of columns on both papers so you can easily overlap them.

[ojrask]

Some progress.

Looks good. Big thumbs up for the 7u spacebar.

tried to read some values from TalkingTree's GH80-3000 PCB project.

Feel free to ask anytime.

There are some areas which I'm still a bit worried about, for instance, the LED corner. The case is soft-ish plastic so I can always carve holes here and there but getting things to line up is not that simple.

Are you still going fully handwired? Because, in that case, you need something that holds your LEDs. That obviously can't be the plate itself because the LEDs would short. I guess you should be cutting three circles and later on glue some rubber or plastic support for the LEDs.
Otherwise, you just need an opening for the LEDs to go through. Again, circles would do just fine.
Keep in mind that cases have two big prongs in the top right corner to coil the cable around. Make sure your frame keeps clear of them.

I'm looking for a local 3D printer where I could print a prototype for this [...] The difficult part is to find a printer that supports dimensions up to 45ish centimeters.

You can split the plate into pieces with jigsaw joints and then glue them together, but I don't think a 3D printed plate could be any cheaper, unless you opt for a low resolution print which, at this point, won't be much of use. However you might want to ask someone with a better knowledge of 3D printing, Leslieann to name one.

Though first up I need to use my company printer to print on some A3 paper with lines to cut out, as the first step in prototyping. I think out office printer supports A3 size.

Or split the file into two and print it on A4 papers. Leave a couple of columns on both papers so you can easily overlap them.

I opened the EasyEDA editor for the GH80-3000 PCB but the measurements seemed a bit funky in places, might need to download and use something like KiCAD for better measurements on it.

The three holes in the upper right are mounting holes for LEDs which I plan to glue into place, yes. The upper right has more work to do anyhow as the case has loads of protruding elements in that area which are not required after the plate swap.

One big mystery I need to solve is where to cram a Teensy++ 2.0 which I plan to use for this build.

I was planning on doing a low resolution proto 3D print first, just to make sure the plate fits into the case and the switch holes are aligned properly in terms of fitting the top part of the case on them properly.

I will check those 3D printing and A4 printing techniques. Many thanks!

[schmoktopus]

Would it be possible to somehow just jam this into an g81-3000 together with the pcb? If yes, then this is exactly what i have been searching for.

[ojrask]

Would it be possible to somehow just jam this into an g81-3000 together with the pcb? If yes, then this is exactly what i have been searching for.

I have been wondering about the same thing but so far all solutions require custom plate shape and case modding from what I've seen.

[ojrask]

Did a 2 x A4 paper print prototype today. From the looks of it, it could be pretty much done apart from a few holes here and there!

The switches line up pretty much perfectly, but the plate itself needs to be a bit higher (currently there are 2mm gaps at the top and bottom after "installation"). Not a big issue if the screwholes line up and hold the plate in place properly.

Also the numpad top edge padding needs to be a bit thicker, there is now a 1-2mm opening between the top case and the plate edge there which might be too much. I will add 1mm to that area to cover the hole better.

[ojrask]

Made some adjustments that I learned from the paper prototype. I now think it is quite good to go. I ordered a wooden prototype to see a proper plate with proper dimensions before commiting to a larger metal plate order.

Biggest changes happened in the status LED corner, as some parts of the bottom case interfered with the previous design.

[ojrask]

Wooden proto arrived! It revealed some things which the paper proto did not (e.g. some small parts of the case need to be incorporated into the design better and so on). Screw holes and such match well and no need to alter those. I also now know that the bottom row will not support PCB mounted switches, but luckily the PCB feet can be cut off from any switch to make it plate mount compatible.

I installed some switches and caps to see that I got the main cluster spacing and stabilizer holes right. They are 99% correct, need to finetune the stabilizer positioning just a bit.

Also, I guess MY switches are a tad taller than MX, as the keycaps seem to be seated quite deep under the edge of the top case.

[ojrask]

I have made the adjustments that I felt were necessary after evaluating the wooden prototype. Main changes are a minor adjusment to stabilizer positioning and fixing the pin holes in the led area strip. Now I feel confident in ordering a larger batch of plates via GB or something. Will be ordering a few for myself in any case.

As mentioned I wanted to minimize the alterations the case requires, but for a handwire there are quite a few that need to be made to allow wiring to pass through properly (columns mainly), also the numpad vertical 2u keys need bigger holes to allow switches to fit properly.

Here is a photo of the naked wooden proto when installed inside the case:

[ojrask]

Update:

I intended to run a GB this month for the last design but as I got busy with other stuff I decided to postpone the GB phase. In the meantime this meant more time for me to refine the design a little:

1. Minimize case modding required
2. Maybe allow support for a PCB+Plate combo
3. Minor adjustments here and there.

This time I've added some more cuts to the plate into spots where the top case would interfere if the plate was to be installed at the "optimal" height (~5mm higher than the wooden proto is sitting at). This would mean less cutting on the top case extrusions meaning easier installation.

This also means that you can use a PCB with this (once I manage to design screw holes that allow both plate installation or PCB installation to work. Or then I just create a plate mount plate and a PCB mount plate with different screw holes.

One thing I'm concerned about is rigidity: will the long cutouts make the plate less sturdy and floppy? I think stainless steel will be OK?

The edges of the plate have been shaved off by around 4mm, meaning no case modding should be required at the edges of the plate apart from a few finicky spots near the top right corner. Additionally, the LED area works better now.

Let me know if you notice any mistakes, I did try and measure the holes so they align with the top case extrusions best. The extrusion holes are 2mm in width as the extrusions themselves are around 1.25mm, this means they should have plenty of wiggle room.