interesting little tolerances’bug’

I’ve now printed a good handful of test keyboards, got them pretty dialled in with the old Standard resin.

I’m now switching to a more robust ABS like resin, and, have discovered some interesting quirks

Who’d have thought that being ‘too airtight’and having too good / close tolerances would have been a problem!

Firstly, here’s a super close-up showing the now *perfect* letter formation with the new resin , I have the exposure almost perfectly dialled in

BUT, there’s a small issue. When fitted to the keyboard, The Keycaps all sit at differing heights.

I did some experimentation and discovered that the new resin and exposure settings are so precise that air and liquid from poor drying are being trapped when pushing the keycap onto the stem of the switch!…

Yep, It’s AIRTIGHT.

When there’s a little more tightness for the stem jamming in the hole, the cavity above the switch stem holds more air / whatever, so it becomes larger, and the keycap sits higher as it can’t be pushed down onto the stem.

I’ve possibly inadvertently created the world’s first air-damped/suspended keycap mechanism?

Who’d have thought it.

The solution of course is to prevent these pockets of air being captured in the first place…….

So, TWO HOURS and 96 manual sketch creations (and a post on Fusion forums to request a feature add to save about 600 mouse movements and clicks in future) I’ve added a small channel next to each keystem hole to ‘let the air out’ whilst i gently mash down the keycaps……

Of course, now this process is all fine tuned, a manufacturer would go and release, what seems on paper to be the PERFECT miniature keyboard keyswitch.

and, another manufacturer releases one that’s better, but not perfect.

So, More keyswitch samples on order, I may eventually have to re-do the whole switch assembly in the future IF these switches are as good as i hope!

(and i’ll re-purpose the 6000 purchased for my Spectrum Next mini project which doesn’t need the new ‘perfect’switch features)

Testing begins.

I may need to sell some Three-Dee printed fingermajiggy-minimiser attachments for ones phalanges!

My fingers, which are relatively svelte for a bloke in his mid 40’s have trouble not mashing several keys simultaneously;-)

My repeated mashing of the tiny keys gloriously results in mis-spelled or even incomprehensible gibberish, thanks to those n-key rollover diodes !

You’re gonna struggle to QA O&P on your keyboard input platformers, it’ll be more like 1QWTABCAPS and I think the buffer runs out there!

Wooooooo

I know There’s supposed to be two colours for the keycaps, I however got too excited and stuck the enter key on…..

Which is a one way journey, once on, They’re not coming off again without removing the switch underneath.

So, behold! The Beige monstrosity

(Complete with working caps lock key!!)

Lots of small steps TheA500 Mini.

Tower of power, only when TheA500 is reached will the keyboard be complete…

Ive got the print settings dialled in!

The keys Dont take much effort to remove from the supports! Perfect..

Amusingly I’ll have some further fine tuning to do once the colour is settled.

The Anycubic Resinc I’ve been using since owning a Resin printer has pretty much doubled or tripled in price of late.

So, I’m going to try Elegoo resin for a change!

Anyways, onwards and upwards, darker keys are next 🙂

Dialling in the print – TheA500 Mini

Purdy!!

Almost there, but not quite.

To get those small letters crisp, it’s a juggle of exposure times, wait times and light intensity.

As I’m using heavily pigmented resin, the normal numbers needed to print Dont apply, Ive gotta figure it out, one print at a time!

Here, I’m at 1.8 seconds, 75% power.

I recon 1.7 and 70% will possibly work!

And…then I gotta repeat the exercise when I develop colour for the darker keycaps as, different coloured pigments react in different ways, some are more transparent to UV, some less, so, I may need to increase exposure, and lose detail, then decrease light power to gain detail back and stop the blowouts like you see on the ! On the 1 key!

Colour matching the keycaps

Iterating slowly! This last revision needs a little more yellow I think!

This one looked ok when mixing, but printed rather grey!