C64Mini working keyboard – The Butchery Part 2

Mmmm, Mini Cake’s been baked

A quick dry overnight and….It’s a success!.

BEFORE this point (or, worst case, at this point) I’d highly recommend you clean the keyboard thoroughly and go, purchase some clearcote / clear lacquer. I haven’t done it yet but will be spraying my next keyboard to get some longevity on the text and paint……...

The mould’s quite bubbly and not really useful for much other than being a support…But, if done with more care – who knows!, Maybe C64Mini Chocolate keyboards?

Next step, Power Tools!

ROUND 1

Mwahahahaha!

Still not entirely sure if it’s even possible to quickly and repeatedly butcher the C64Mini’s keyboard reliably with good quality.

For doing your own / one off’s, this step, you can take as long as you want. if you plan on doing a few though, taking a day or two individually dremmeling out the keys isn’t my idea of fun.

I do have a CNC – so, worst case I’ll have to learn how to actually use it, then I’d just need to make a protective jig, sit the keyboard on and just CNC the keys out. I’m not really in the mood to spend a few weekends firing that workflow up yet

Failure

The Angle grinder wasn’t really a success…..The blade’s too small and the sanding is going to be too uneven. There’s no way this will work .

Round 2………..

Larger surface area = larger chance of evenness?
Too much vibration

Ok, first thoughts, it seems to work, abeit slowly and with making my hand a bit sore….

new sandpaper should do it

At this point, I figured if I use something soft and large, I could hold the keyboard in place and sand it without hurting my hands so much…..

Puzzled over this one for quite a while till I looked down……..

Found an incredibly inefficient lawn cutting method! – Orbital sanding

Seems to have done the trick!…Pressing down into the grass holds the keyboard in place and also helps resist the vibration of the sander, making it sand more efficiently…………Win Win….Also i’ll patent pend using oribital sanders for domestic grass management.

But……

Poor Lawn

I moved to another bit of the lawn to avoid totally destroying a good bit of the grass…….I found that sanding till you can see the blacks of its eyes…….the lines between the keys seems to work well. At this step, you’ll want to remove as much material as possible to avoid so much processing / sanding later on

Do resist the urge to twist / remove the keys, try to let them come out almost by themselves

oops

At this point I’d realised that an average household lawn is actually quite abrasive..Have a look at the whiteness of the edges of the keys!

Oops! – ah well, this is why i’m experimenting, so you don’t have to. I’m going to run with the theme though -these keys look a bit battle worn now, no going back so i’ll probably add a similar theme to my C64mini case 🙂 will be good to relive the old days of creating scenery and my Warhammer 40,000 airbrushing . never really did play it, just enjoyed hacking up the plastics……..Anyways…

Keep sanding, get as much material off as you can (it will save a LOT of time later)

Once you’ve got them all separated, make sure to lay them all out in order so you can admire all the keyboardy keycappy goodness that’s resulted from the dismemberment of an innocent miniature recreation of an 80’s 8 bit home computer.

Eeeeeeeeeeeeeeeeeeeee

Now, go spending several hours in the garden trying to find the most commonly used letter in the English alphabet!

I’d neglected to factor in the ability of these tiny keycaps to fling themselves a considerable distance in various directions whilst being vibrated several hundred times per second.

Suffice to say, if you’re doing the same thing, try to do it in a location where the floors relatively clean and uncluttered

A colourblind person trying to find a brown keycap in a green lawn that’s not too long, but just long enough to expose the also brown ground beneath……..Yeah, not fun.

After an HOUR of searching though………………..Eeeeeeee….A full keyboard

full c64 mini keyboard keycaps!

Next step – post processing. Removing supports.

This step i’d say is the most important. Sand down a bit the bottom and curves of each key. Get rid of all the burrs, bits, etc. you won’t get much of a chance to do this once they’re stuck. Spend a lot of time on this, cleaning each key, just getting it ‘right’

Mini Mould All filled

Once your keys are all looking great and sanded, smooth – arrange them again into a the keyboard layout. Then, one by one, transfer them into the mould.

you’ll wanna make sure you get this part right 😛

I did them line by line, starting left to right. I also had taken a picture of the keyboard prior to refer to. Check twice, place once……………

Now i’ve realised that I haven’t actually considered how to stick these things in! – i’ll need to go research glue, D’oh! gotta pause this for another week of research and buying bits

C64Mini working keyboard – The Butchery Part 1

Time’s progressing and it’s still taking a long time to obtain a satisfactory print of my CAD keycaps. Some quotes have come in and…they’re quite a bit.

so, time to change focus for the short term to let me actually play games on the mini with all the keyboardy goodness that a working keyboard will allow

So, on to some butchering

The Plan….create a plaster of paris negative of the original keyboard – to hold the keys straight when attaching them.

Step 1 – Print out the case design from my last post

Fits like a glove……..or does it?

Step 2 – realise that I’m making a NEGATIVE and the keyboard needs to sit INSIDE the box, ‘upside down’ Redesign and re-print…

Better

Step 3 – Coat liberally in spray oil… Wife wasn’t too happy that I’d used her pricey artisnal olive oil from our trip to Italy, nothing but the best for my Mini though………

Step 4 – Knock up a batch of pancake batter Plaster of paris…About 50 grams of powder and 60ml water worked for mine….not too viscous.

fill the keyboard case just over 1/2 way to measure what you need

Step 5 – Fill up the mould

Screw on the keyboard – making sure the keys are aligned and straight with the F Keys and wait overnight…

Use the holes either side to top up the plaster so it overflows a little

Give the whole combo a dozen or so short sharp drops / knocks on the table to free up any air bubbles

Mmmmmmm….Keyboard Cake?

C64 Mini – Cutting the existing Keyboard Part 1

Did an attempt at a jig to make hacking up your own keyboard just a little easier….

it’s fairly easy to hack up the existing keyboard into bits….(get hacky thingy, cutty thingy, hack, cut…maybe smooth off burrs if you’re feeling artsy)

Getting the brand new hacked up bits of plastic that once looked like a keyboard to sit straight on the switches and resemble the previous keyboard resemblance …..not so much.

Turns out that making things ‘straight’ is hard……..so, some ideas

3D design and print new keycaps with locking mechanisms that work with my chosen keyswitches (still onging, it’s been MONTHS of work)

My first other idea…….. create a form to fill with plaster of paris, press the plastic full keyboard into that form, leave to set…

Remove keyboard and admire a perfect negative image of the keyboard.

Two things that could be done with this

Use that plaster of paris as a form to create resin keycaps (without any lettering) – I’m working on that!

second – it can be used as a perfect ‘form’ to sit the newly butchered keycaps in, fill with epoxy glue, sit keyboard PCB on top and let the keycaps become glued on, all nice and straight like!

it’s fairly easy to export the keyboard PCB outline from EasyEDA as a DXF then import to Fusion, extrude and…voila!

But…There’s an ever so tiny mistake in the image above

That’s the printed version…The holes line up great!

But….

Yeah, the keyboard should be face down!, D’oh!

i’ll see if the snips’ll work

The other thing….

Fits like a glove….

Nice and snug – Note the top row of keys is level…..

Some small design work needed but the idea has promise!. I just need to re-jig the hole widths a little to accommodate the angle of the keyboard better!

I’ve purchased another couple of C64 Minis so that I can improve this jig more. I’m not quite certain where the keys will ‘fall’ once they’re seperated from the base of the plastic moulding.

The more I think about it, i’m thinking that there could be a shedload more work in this jig – one ‘saving grace’ though – due to the way injection moulding works – there’s a slight taper on the existing fake switches. And, I suspect that the rear of them has been modded so that they’re almost perpendicular to the base. this will help the whole mould ‘pop off’ the injection machine…

That also helps me with this jig as it really means that, at the base of the keys, all the keys seem to have the same uniform rear rising, almost perpendicular taper and front curving taper. kinda like the below diagram

That could turn the whole change into just re-extruding the jig key holes at the 8 degree angle of the keyboard as above……..

C64 Mini Keyboard – More CAD

The first mediocre print!

It’s taking way too long, but I think I now have the lettering ‘just right’ – at least on the screen.

This was printed a bit too hastily at 0.08mm layer height on an Ender 3 printer. I’d used a brand new roll of untested filament and didn’t bother changing any settings. – it’s dimensionally ‘spot on’..

I’ve purchased a 0.2mm nozzle for my next trial , it’ll take ages but i’m hoping that those fine details on the characters come out a little better.

Why it’s taking so long……..

I’m learning as I go. I’m ‘tracing’ letters i’m finding on the net, creating them as a new sketch along the whole rows. There’s 4 differently angled rows so each needs to be extruded in a different direction to ‘cut’ the key.

This first run matches the C64 keyboard font as close as I can get. I’ll then ‘archive’ this layout for future use and create a second ‘3D print’ version.

This version will forgo the accuracy of the font and make features much wider, more rounded to allow the characters to come out better once 3D printed. The complex ones like ‘run stop’ won’t ever come out great on a standard filament printer, but the letters already come out pretty good…that’s a win for me!

a full keyboard!

The full keyboard is above – and you can see part of one of the adaptors i’m designing to click them onto the keyswitches. each keycap is hollow. that small grey part will sit inside the keycap

Where the time’s being spent…..

And finally – part of what’s taking so long.

Each key/character is taking on average about 1/2 an hour to an hour to design. Lets say 45 minutes.

65 keys to label

That’s a LOT of minutes…and i’m only getting an hour or two every few nights – a good solid weekend ‘free’ would be great and have this sorted.

On top of that labelling (which is now finished) I have to try to make each letter more legible and easier to 3D print. Generally that means ‘bevels’ everywhere – you can see above that i’ve done ‘Run Stop’ and ‘Shift Lock’ but SHIFT is still to do….it’s not as easy either as ‘copy, paste’ the Shift from Shift lock – that’s a different sized font on a different sketch plane.

Just one example of the issues I’m seeing…The Letter B

The Letter B – trying to create a fillet – rounding off the edges

The Letter B above has an issue with the geometry – just by the 0.1 – there’s a part internally up towards the arrow that shouldn’t be there – that’ll could play havoc with a slicer when set to really small layer heights

B – Alternate view

But, the Fillet also creates a zero thickness surface which looks unsightly and will probably cause issues if I don’t correct it now

So, Back to the sketch

Letter B – The Sketch

As you can see, i’ve kept the characters with few (if any) constraints. this way has been easier to freehand and eyeball as I can drag stuff around till it looks right by ‘locking and unlocking’ lines. most constraints used to create right angles, etc have been removed after to help with the process of making it 3D

Anyways, the ‘issue’ with the fillet seems to be around the place where the two control point splines meet – i’ve highlighted one in blue above.

I re-coincide each spline (have found deleting and un-deleting works, as well as hitting coincident )

That change should hopefully roll back up the timeline to allow me to make the fillet work.

To Create the key lettering I the character by 1mm elsewhere in my workspace, then move it to over the key.

Then extrude the face of the character into the key and ‘cut’ ….

this may seem odd, but it’s a really quick and easy way of consistently creating cutouts on a row of keys and making quick changes later.

That didn’t work, so, jump into surface mode – delete the entire inner arc of the B. Re-create the arc as a ‘patch’. Stitch together the lower part of the B. Then stich the whole keycap, then re-apply fillet and…..Voila…..3/4 an hour later, one filleted B…And a learned workflow if the same thing happens on another key!

Note, as-is, the keyboard fonts are a bit innacurate. I’ve sized everything based upon the smallest characters that need to fit – i.e. run stop, etc. The individual letters could be bigger – but any bigger and they’d look too big compared to those……….

Next steps,

DFM – Design for manufacture.

Just because you design a 3x2mm hole, doesn’t mean it’ll print at 3×2. Generally Filament printers do outer perimeters a little larger, inner perimeters a little smaller. The first few tests i’ve done now prove this. so, After a few months of ‘out of the box working’ on my Ender, I’ve finally gotta bite the bullet and calibrate it. The plan is to create an offset in the CAD file so that I still design the holes accurately based on measurement, BUT, can add a accurate ‘calibration figure’ Fudge figure to make them a little larger or smaller as necessary.

Right now my Printer is doing slightly oval prints – which should be easy enough to sort out if my D9 Adventures were anything to go by

C64 Mini Keyboard – Rev2 assembly

Lovely and sunny outside. I’m in the conservatory kinda enjoying the outside………
Through Hole Diodes should make for an easier assembling kit

My Kids hate me, my wife’s lonely but the march towards C64-Mini Keyboard workery continues – That and they let me have a few hours to tinker on the weekend!

Figured whilst assembling the new boards, I’d see just how long it takes to solder them….

Quite a while as it turns out

1/2 hour to solder in 65 through hole diodes

1 hour to solder 67 switches

another 1/2 hour testing and programming

So, about all up, we’re probably talking 2.5 hours for me to fully assemble one of these…….

Except, that 1/2 hour of testing and programming actually turned into a 5 hour ‘session’ of bug fixing / fault finding – one of which…..

One of these is not like the other………..

A back to front key causing lots of characters to repeat accross the screen…..M, Space – which are both on the same column of the matrix too!

Fixed that and have discovered that it’s not really possible to re-use the switches once you’ve soldered them in – UNLESS you use a hot air gun to remove them. I’ll definitley include a few ‘spares’ in each kit

The next problem – A sticky, grindy P key – I lifted a pad removing it , fortunately, the pad wasn’t electrically connected – only 2 actually are – which will save you some time! – just solder 3 holes for each switch – that’s 201 solder connections for switches instead of 402!

The next problem…the Fantastic QMK Just refused to work and compile 😦

Kept getting “qmk avrdude.exe: butterfly_recv(): programmer is not responding” the thing just wouldn’t work over USB like the others had

which turned out to be a couple of things.

You can’t use AVRDude when the Arduino IDE is open…

Arduino Leonardo type devices (well, the clones anyway) can be a bit finiky with the USB…

Generally sending them a ‘blink’ sketch does the job…BUT, they very often need a quick ‘double tap’ reset pin to ground whilst uploading……..that’s why I have a RESET header on this board – if you want to solder one in, feel free, it’s mainly to help me when developing it.

Another issue was the frequency setting in the rules.mk file – I’d previously used a 5V Arduino pro Micro (Atmega 32u4) , somehow a 3.3v one had snuck into my spares box – these run at 8MHz, not 16MHz

Changed the firmware, recompiled and……..It’s alive!

First row lined up – second just tacked on with a single joint, ready for lining up
Finally added a bit of heat shrink

Straight!, got the technique sorted – Note the two that are slightly ‘off’ to demonstrate what happens when you change the way you ‘hold’ the switches when flipping the PCB to solder

The case fits the keyboard like a glove!

Also got a bit of a chance to progress with the CAD……

This one day may turn out to look like pretty rough keycaps! mini ones! for a mini computer!

C64 Mini Keyboard – ‘Invisible’ fitting mod – Part Deux- More images

Not much of an update, I put a shorter USB cable inside so thought I’d take some pictures of the top of the USB cable wiring…..

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I’ve not installed heatshrink yet on the sticky-outy USB Pins – this WILL be needed to provide strain relief – being truthful, I hadn’t expected it to work first time so didn’t bother 🙂

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Showing the complete wiring –

Joystick USB port -> USB Hub ‘output’

Keyboard -> USB Hub ‘output’

C64Mini Circuit board -> USB Hub ‘input’

There’s two free internal USB sockets now!

C64 Mini Keyboard – ‘Invisible’ fitting mod

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Spent a few hours this week adding an internal USB Hub, getting ready to start on a basic instruction sheet for the kits

As can be seen – you can’t see it’s modded externally (well, other than the keyboard). Both external USB ports still work and internally there’s a free USB port for a USB Stick 🙂

Continue reading “C64 Mini Keyboard – ‘Invisible’ fitting mod”

C64 Mini Keyboard Part 7 – More CAD -Anatomy of a keycap

C64 Keyboard Caps 5

After couple of weeks of work, I’ve finally cracked surface modelling with Fusion360 (a bit)

Here’s a bit of a step by step in creating your very own f1 Key! This is a very brief summary of what I should have done if starting from scratch, I’ve left out the trials, errors and headbanging……….

Continue reading “C64 Mini Keyboard Part 7 – More CAD -Anatomy of a keycap”

C64 Mini Keyboard, 1/2 alive and Some CAD

Bit of a change of pace from the electronics, onto the CAD…Here’s a first draft of the first key on the C64 Keyboard – the Left Arrow!

Done at full scale, then at 50% scale

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Continue reading “C64 Mini Keyboard, 1/2 alive and Some CAD”

C64Mini Keyboard – PCB Layout Success

C64Mini - Final PCB Revision Maybe

After a loooong weekend and sneaking in a few hours – Success with the keyboard layout dimensions!

There’s few tweaks here and there remaining to align things perfectly and also to add some nice Silk Screen artwork

And, how I got there!

Continue reading “C64Mini Keyboard – PCB Layout Success”

C64 Mini Keyboard mod – More Electronics Part II – OOPS

After spending a while lining up the buttons and generally making the PCB layout a bit tidy, I figured I’d print a 1:1 and see just how well it aligns….

 

Oops…

img_0722

Continue reading “C64 Mini Keyboard mod – More Electronics Part II – OOPS”

C64 Mini Keyboard mod – More Electronics

Thru Hole Keyboard PCB - First spin
Looking a LOT better!

After a few days, I’ve now got something workable – The switches being Thru-hole allow ease of routing on both the top and the bottom layers. I’ve named each switch and diode with the keyboard’s actual Symbol to make placing them on the PCB much easier. you’re seeing the results of a few days work (maybe about 4 hours all up) of starting from scratch on the design.

Next step will be aligning the PCB layout and spacing with the plastic buttons

I’ve done what I can based upon rough assumptions above – the top row of switches for example – its row of buttons ‘just’ fits within my calipers – so it’s about 151mm wide

Whipping out the calipers again……. Continue reading “C64 Mini Keyboard mod – More Electronics”

C64 Mini Keyboard Mod – The Electronics

As mentioned before, there’s loads of ‘keyboard matrix’ tutorials out there, so, i’m going to not bother with any of those yet and work backwards a bit.

IF i’m making a micro C64 Keyboard for a mini C64, I mayaswell make the thing backwards compatible so that it could be used on a real C64…

The C64 Matrix…………(image pinched from THIS PAGE) 

C64_Keyboard_Schematics_PNG

 

This it’s quite quick to knock this up in EasyEDA

The Shift Lock key looks  a bit ‘odd’ as it just parallels up with the shift key.

I’ve thrown in some Debounce diodes also – because all the top mechanical keyboards have it, so why can’t I (no idea if this is a good idea yet, but easily removed before I get a PCB finalised) I’m not too worried about the Arduino bits yet – i’ll bolt on the decoding circuitry later – this is still just an excercise to see if it’s possible!

C64 PCB Matrix

This isn’t the first version – The pic shows the newest footprint before I figured out the issue below

After creating my own custom SMT switch footprint / component and arranging the parts on the board – I hit a few snags – Have a look at the layout below…. you’ll see that the SMT legs just stick too far out

Easy enough, rotate every other switch so some are ‘up / down’ , some are ‘left / right’ with the pads.

That does fit – just, BUT, i’m going to have to cut a leg off 5 or more switches to stop them mechanically fouling and electrically shorting!……D’oh!, Possibly back to the drawing board with the switch choice?

C64 PCB Matrix - SMT BAD VERSION

The diodes i’ve chosen (for now) are a larger SOD123 package, about 2.6 x 1.5mm or so…one of the larger packages and I just happen to have a few in the shed (somewhere!)

The row of connectors on the right is just a generic 2.54mm space 20 way header. This’ll probably not be populated in my ‘final’ version that sits inside the Mini, BUT, i’ll leave the pads on the PCB so it could be turned into a genuine working C64 Keyboard 🙂

C64Mini – Keyboard Mod

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The Bottom Side of the C64 Mini Keyboard

There’s Plenty of Volume – But what switches can be used to put inside the keyboard?

I’m not too worried about the electronics  side right now, there’s plenty of Arduino keyboard emulator tutorials out there.

 

Continue reading “C64Mini – Keyboard Mod”

C64Mini – Quiet but still Tinkering…Keyboard Mod

Some time back I purchased a Lovely little Commodore Retro item – A C64 Mini

 

thec64mini_web_0001-2
Borrowed off the Retro Games website – The C64 Mini

 

It’s a TINY C64…….With a non-functional, cosmetic appearances only keyboard 😦

Lets fix that…………….

Continue reading “C64Mini – Quiet but still Tinkering…Keyboard Mod”