A500 Mini PCB’s have arrived!!

….and, already there’s a small electrical issue!

But….they fit perfectly, everything looks fab!

Now comes the long process of test and tweak 🙂

Pimped up A500mini!

The picture shows the three PCB’s and the 1 3D printed part inside the A500 mini.

Also shown is the A1011 mini which contains a single PCB and 3 3D printed parts.

And finally shown is the floppy disc, which is going to be two 2D printed parts, one 3D printed part and a single electronic component!

Phew…..it was only supposed to be a small single PCB keyboard kit, that’s feature creep for you

*disclaimer, it may also be able to be a single PCB kit to save people ££, other PCB’s will be options to ease installation and add features

A500 Mini – HD+

This one’s been nagging away in the back of my head for some time now…I Always wanted one of these containing a hard drive when I briefly owned an Amiga. This is a GVP HD+ / HD8. and maybe a few other products also. This design really struck a chord with me when it continued the Amiga 500’s contours rather than just shove a box on the end.

No idea what I’m gonna use this for – likley a USB hub or ‘something’

This’ll need to be printed to ensure everything aligns, some of the proportions don’t look right – but seem to measure OK.

Have already updated the rear ‘fins’ they were just too long in this shot

First time the shell command has worked well for me!

A500 Mini – Floppy or hard?

Prototype PCB’s will be here late next week 🙂

So, whilst waiting, I’ve been playing around a little with the CAD and the ‘extras’ for the keyboard kits – the Real Mini 42″ scale floppy disc.

The cocnept is – to have a ‘working’ floppy disc that you can play games off.

The concept, once again!
The Sliced and supported Floppies!!
Real mini floppy
Real mni floppy rear

Still some work to do optimising, but i’m rather happy with this second attempt at printing. The metal part has been cut out on my KNK ZING vinyl cutter and has been extracted from a projected sketch.

That works for the Amiga side – But, people will need a way of getting the games onto the floppies , so – Early days yet, An External mini floppy disc drive for a PC!

Cutaway view

A 1011 Clone!

This was surprisingly quick to knock up . I found an image of an eBay sale, imported as a canvas, ‘traced the canvas’ and set the scale around the floppy disc slot. I’ve never owned one of these so had to work from many pictures. Still a lot more to do, but fundementally, i’m keeping the exact same PCB’s and mechanism / holder that i’m creating for the A500 Mini. Just putting it in a shell and using a different USB cable….

I will be releasing the design files publicly for this thing so anyone can print up / adjust and make their own ones as international postage gets expensive for things larger than 25mm high here in the UK…I’ll also offer up these for sale with keyboard kits

And, if you’re wondering, just how many picures…and files needed to create a floppy drive and disc…….Here’s a quick snapshot of my A500Mini folder – just for the floppy! and these are the ones i’ve kept for now….

Still Here Update – PETSCII

I Did a thing.

I had somewhat of a PETSCII induced fever over the past few weeks, one that needed Sating before I could practically start anything anew, or even continue anything existing……..

So, when I (eventually) re-make the C64Mini keyboard kit to be less soldery, more easierer and betterer, It may well have PETSCII on those keycaps, for all your milliputty smudgery into-ey goodness!

A500 Mini Prototype 2 is in the post, Every C64Mini keyboard kit and parts have been posted – I’m finally fully up to date!

A500 Mini Keyboard – Prototype 2 almost ready!

Three PCB’s are pretty mich ready to go . Just last minute checking, double checking, triple checking needed!.

I’m lacking lemmings on most of the boards, but be assured, there’ll be a few on the production units.

I’ve also now pretty much finished the keyboard CAD…Had to do yet another iteration to allow for the new switching mechanism i’m using..It’s really been a case of design, print, test, iterate, repeat!…Still ‘a few months away’ as always, Real life is taking over a little, meaning less time to perfect this lot.

On the plus side, I really do think this Prototype 2 will be ‘good enough’ for general testing and useage. Everything after prototype 2 will be geared to making it easier to install and add (or remove) extra features. Lots of pics after the break……………..

The USB Fake mini floppy adaptor

Continue reading “A500 Mini Keyboard – Prototype 2 almost ready!”

Oh No! – a quick segue

Made loads of ‘progress’ on the A500 Mini keyboard!

Yesterday evening was mainly procrastinating and playing around with Printed Circuit Board silkscreen / soldermask / copper to optimise the speed at which in could display many sprites simultaneously.

The result of too many hours.

Have a Lemming!!

A500 Mini II Part 6 – past the half way mark! – keycaps

Quite a lot of progress, but it doesn’t look like a lot of progress.

Firstly, I’ve had to re-do most of the keyboard CAD – I simply didn’t like the ‘blocky’ effect of the wider topped keycaps I’d created – as you can see below they look a lot more square in real life than they did in CAD…

I’ve now clocked well over 200 hours developing this set of keycaps, likley there’s going to be tens more tweaking / optimising!

So, along with the less blocky (more slopey) keys, I’d discovered my workflow in CAD had created tapered keys – the tops when viewed from above look like parallelograms, wheras the original Amiga had more square keys – it was quite a lot of work to alter this – see the parts below by the red arrows – the bottom bit is in towards the middle more than the top bit.

Tops not parallel with bottoms
Tops are parallel with bottoms
Continue reading “A500 Mini II Part 6 – past the half way mark! – keycaps”

A500 Mini Keyboardification Chapter two, part 4 – Moar CAD

Have been tweaking things over and over, I’m now finally ready to…….

3D Print a sample!
And, the complete thing

I think there’s going to be a few people out there actually using this keyboard in anger, so i’ve widened the keyswitch tops a little and added larger fonts to make it easier for someone to fill in some colour if they chose to do so.

Some other progress –

The Floppy Disc insert! – a FULL scale floppy disc fits well

I’ve refined the floppy disc insert thingy – I really think I can make this work – lots of parts on order so i’ll iterate this design over the coming weeks. I’ll do the first prints of the plug in module soon

Alternate View – with the Clamp PCB in black, the A500Mini PCB in green

Speaking of prints….

I knocked up a few of the mini-Floppies. Printed in various orientations to see if it’s even possible to do these. The best print is the angled one..Turns out, it’s going to be tricky as can be seen from the various failures above. Have re-designed a little and will run off some more sample prints soon. The supports on this one will be critical and hopefully not so wasteful as the C64mini keycaps were.

And, almost finally –

Here’s a collection of ‘stuff’ rendered so far. The Keyboard PCB is unfortunatley upside down – due to the way I started modelling stuff, no big deal but makes the renders look odd. The case slopes don’t need to be modelled (at this time) so i’ve just left them flat for now.

There’s loads of parts waiting to arrive in the post, but there’s also loads I can be getting on with, not just on this project, but on numerous others also!

A500 Mini Keyboardification Chapter two, part 3 – PCB’s

I’ve spent a couple of days designing, and and a today, spent nearly a hundred quid at JLCPCB ordering a bunch of prototypes

The first revision of the Keyboard PCB
First ‘space sample’ of the top mounting board.
Floppy Disc Micro SD card holder!
Rear of the floppy discc.

I had to bite the bullet and spend some money as I now need to move on with the Keycap CAD. I have a big concern about the fitting of the printed keycaps onto the smaller switches. I’ve gone with ALPS switches as they used to be a huge brand name back in the day and i’m hoping should provide some consitency.

The prototypes will help also to test and develop the PRK Firmware i’m planning to use.

The ‘Clamp’ adaptor is fairly non-functional. It has a Rasperry Pi Pico footprint onboard and a 40 pin FPC style connector to act as a ‘stand-in’ for the Raspberry pi Pico which is currently on the back of the main PCB.

The whole idea of the ‘clamp board’ is to allow an ‘ease’ of installation – I’ll use some Pogo Pins to sit on the test pads by the 3 USB sockets on the back of the A500 Main board.

The plan is to have a basic matrix keyboard PCB, which connects to the clamp board via the 40 pin FPC.

The clamp then accesses the USB and hopefully it can all be fairly easy to assemble.

I’m also testing the Fake floppy connection with the clamp board – no idea if that’ll work or not, we’ll see.

Now the long-ish wait for Aliexpress to deliver my connectors, pogo pins, and a couple of weeks for the Cheapest post option of JLCPCB to ship the assembled keyboard! – nearly 100 switches and diodes on this one, those can be automated in assembly. I’ll need to hand solder on the rear the FPC connector but those are easy enough!

A500 Mini Keyboardification Chapter two, part 2 – Progress

This one’s a good ‘un

Progress to date has been surprisingly quick – most of the ‘easy’ stuff is now done and I’ve added some extra functionality. Most of the research is now done – have spent waaaaay too long googling connectors, Pogo pins and component types / dimensions.

First print of the keyboard PCB and CAD fitout – pretty close

My workflow generally is to eyeball, sketch, measure, adjust….Then when it’s close enough, i’ll print on paper, adjust in CAD, print again then………3D print

a 3D printed space sample

I’m quite chuffed – the first 3D print seems to fit reasonably well! – there’s some adjustments needed, mainly the top of the keycaps are a little too wide, but overall for a first run, not bad.

The PCB outline

To work out a PCB outline, I’ve scanned the A500 Mini on a flatbed scanner and trace around the important parts, measuring many with calipers

the Keycap CAD
Another view – the big circles are the curves / slight indents in the top of the kecays
The CAD compared to a scan of the actual A500 Mini

Before I 3D printed the sample, I put the A500Mini on a flatbed scanner to match up the holes – as you can see, it’s pretty darn close! – you’re seeing a canvas underneath the actual CAD model of the keycaps in Fusion. The Enter key is black as i’d discovered a slight profile error, so spent half hour correcting a 0.2mm height error 😛

But, wait, there’s TWO

During the design phase, there’s a process of discovery. My main discovery for the A500Mini keyboard was that….I’d possibly need TWO PCB’s!!

If you look above at the underside of the keyboard you’ll see that there’s no space on the top for electronic components! The PCB needs to mount entirely flush to the case of the Mini. This means I’d need a PCB assembly service that can handle double sided boards (a possibility) – And to also consider a two PCB solution. There’s cost and ease of install considerations for both ways.

The A500Mini has a number of test points on the back, I think using Pogo Pins I can maybe make a clip-on PCB that can securely tap off the USB test points, meaning, a solderless install! – hence the upper white PCB that sits in place of the A500 PCB above

And, now I believe I’m going to go with a THREE PCB solution…….because…

the one with the holes in sits above the stock PCB

That’s a scale floppy disc! with a Micro SD card in
quick render of the floppy slot in the case

I saw a few posts on facebook linking to a guy that’s made a ‘fake’ floppy insert for the A500Mini – https://www.printables.com/model/170947-amiga-500-mini-a500-mini-mini-floppy-disk?fbclid=IwAR3if5FRp3opclhKoTyrkUe63XQtRW-mckg2ymWSKKi1cZvSk1KuRRkzmR4

I figured I’d go one better and make a REAL fake floppy disc. and, the best thing, after several solid days of research and CAD testing, I believe it can work 🙂 – it’ll only need two small cuts inside the A500 case and be totally stock outside. there’s a little more tweaking needed for the floppy disc design to make the MicroSD slot more elegant . I’ve ordered a whole bunch of parts to physically trial this and see if it’s viable.

So, Summary. Still a long way to go, the Keyboard itself is the priority here, the ‘floppy disc’ is just a whimsy on my part for the time being, its development is secondary and may not even make it to a real release if it’s not robust enough.

Keycap CAD – Cosmetics finished, Just needs the ‘switch’ solution figured out

Main PCB – Outline finished, needs routing, quick job to finish

Secondary PCB – Outline finished, needs routing and Pogo Pin solution testing

Tertiary PCB for the floppy disc connector – Concept – parts ordered

Fourth + Fifth PCB’s – the floppy disc itself – parts ordered.

Firmware – Standard keyboard layout is done! – Just needs tweaking and testing on a real A500 Mini

A500 Mini Keyboardification Chapter two, part 1…The Evisceration and Dimensionality

I received yesterday my A500 Mini! – Haven’t even powered it up yet 😛

My assumption about the 43ish percent scale was about right – and the work i’ve done so far on the PCB pretty much stays the same – which is a relief.

However, till now i’ve been using a full sized Amiga 500 to infer dimensions. I can’t easily do that going forward as the scaling factor for the Amiga is ‘a bit weird’ – I think I can see why it’s been done, but, it’s far far easier to re-start the CAD from new…or at least shift the fusion timeline back to the beginning and see what i can recover 🙂

Much more to do, will update later as there’s also a few ‘gotcha’s i’ve found, and a few ‘woo’ moments also!

Dimensioned to within about 0.3mm

Spmeone should hide my screwdrivers

A500Mini keyboardification – alternate technology

Had a major ‘procrastination’ research binge over this past week, trying to figure out just how I could cheaply and reliably get 3D printed keycaps onto tiny switches.

I’ve found I think two ways that can be successful.

The first – a small tactile switch, with an ‘oval’ or keyed button. The A500mini’s keys are probably just over 7mm square, I can’t use the 6mm switches i’ve previously used as there’s not enough space.

Something like the below could do the job – it has a slightly tapered switching bit in the middle, so I can do push fit keycaps that should grip on. it’s also 5mm on a side, and 3mm on the other, this frees a huge amount of PCB space up, BUT, it’s still quite ‘large’ and the top isn’t tapered as much as i’d like. visually it looks fine, but datasheet suggests it’s straight

There’s also an older, more ‘retro’ type of approach. So, i’ve gone and knocked up a very rough CAD drawing – it’s innacurate, until I get an actual A500Mini in my hands…

and i’ve gone and emailed half a dozen companies to request some MOQ’s. and some pricing!. I’ll fill this in later with more specifics

In other progress – the A500Mini Manual is now available – and, the Keymap is shockingly simple 🙂

So, that means getting firmware working should be a breeze.

There’s becoming quite a few ‘RP2040’ public circuits available now, so that part’s done and dusted on my PCB, all i’m really waiting for is to get some accurate measurements so I can knock up a prototype!

A500Mini Keyboardification – Part 6 or 7 I think

Minor update on progress…made the schematic a bit clearer for me to understand, also am doing a dual footprint style setup – where I overlay multiple component footprints incase one becomes hard to get.

I’m also creating two ways of driving the matrix, an on-board RP2040 chip and, if they become hard to get, a seperate daughterboard which can house a Pi Pico

Kinda pausing PCB development until my Amiga 500 Mini device arrives in the post, but i’ll be playing with the PRK firmware next!

A500 Mini Keyboardification – Part III

Early days – Square keycaps to create a layout grid in EasyEDA

A little more advanced

Little bit of progress now – Thanks to this superb thread – and some other random pictures, I’ve gotten fairly close dimensions to a proper Amiga500. Same old story, Mine’s down my parent’s in Wales and I procrastinate over picking it up , so waste too much time analysing, measuring stuff online! It’s not accurate, but is close enough to get a 50% scale PCB layout done now, and tweak accordingly once the real A500 Mini is released

Incidentally, someone confirmed that square keys are 18mm on a base (thanks Dan) from that single dimension, i’ve been able to recreate most of the keyboard, with only now some uncertainties as to the remaining key sizes.

Why I’ve created this CAD – to use as a template to create a PCB!

Project the ‘keyboard’ bodies into a fresh sketch

It makes creating a ‘clean’ Sketch really easy. Just project the switch bases onto a fresh sketch, Export that sketch as a DXF….then import DXF into EasyEDA..

Voila, a 100% sized Amiga keyboard outline imported into EasyEDA

Of course, I’ll need to scale this lot down 50% to ensure things’ll fit in the Mini!

In some good news, I may not need to fully design the CAD for the Amiga Keycaps as someone in the scene has reached out and offered their CAD designs. Best case, I can simply modify their designs. Worst case, I can use their designs to measure the curves and ‘simply’ recreate in Fusion360. Either way, it means it’ll be a LOT quicker than the C64 Mini’s keycap development

Finally, onto the PCB design – I’ve already replaced the horrendous keyboard matrix schematic with one more resembling the genuine Amiga’s. Unlike the C64 Mini one, this one won’t be fully compatible with an actual Amiga due to there being some periphery circuitry to convert the matrix into a serial format for the motherboard to receive. BUT, keeping the same matrix – for everything other than the ‘standalone’ modifier keys should help some people to do ‘other stuff’ with this.

As for Software – PRK has had some great updates of late. I’ll be figuring that out soon enough

Oh, and I noticed that some of my previous assumptions about the 32u4 being used in the Mini were incorrect – It’s a bit bigger than I’d realised. it has 26 GPIO (kind of) when used in the raw chip form!…I thought it was 20 (D’oh!) that means you can (in theory) have a matrix with 144 switches AND a couple of pins left over for LED’s!!

Amiga 500 Mini – Keyboardifying

Very early days yet – But, this is the first start for making the Commodore Amiga Mini working keyboard kit! About 1/2 way done on the matrix, then the peripheral components to go.

Then i’ll ditch it all and start over as the above is a bit of a mess ;-P

The New mini is coming from https://retrogames.biz/thea500-mini at some point in the next few months

I plan to use PRK Firmware now i’ve got it working with the C64Mini

and, Now RP2040 AKA Raspberry Pi Pico Chips are widely available, and ‘cheap’, I’ll be using one as the basis for the Mini

The BIG unknown right now is ‘switches’ – in the C64 Mini I was able to use 5.8mm ‘square’ switches – something like these – https://www.sunrom.com/p/push-onoff-switch-58mm

I’m currently working on a design assuming I can use the same again. There’s very few switches on the market with a ‘square’ style centre part that can capture keycaps. I have leads on a few others, but plan this time is to find surface mount versions and try to get a batch ‘mass produced’ – i.e. little to no soldering needed for you lot!

Early days yet, it’s been quite hard to ‘get back into the grove’ . here’s hoping I get this finished in 2022!

C64 Mini Keyboards – COLOURED LETTERS! (by end users)

Lots of pictures here, But looks like the latest batch of C64 Mini hackers are quite the clever lot. Batch 21 has been arriving around the globe, and look wot some guys gone done!

First email arrived early this morning – Vinz!, You’re a genius…..My jaw dropped!

Some explaination of the pictures…….

In photo 1, I used a ruler with double sided tape to solder switches as straight as possible

in photo 2 I used white putty to color the caps

in photo 3 I cleaned the excess putty

in photos 4 and 5 I painted the caps with matt transparent water-based paint, in this way the filler is protected

in photos 6 and 7 the work is finally done

Continue reading “C64 Mini Keyboards – COLOURED LETTERS! (by end users)”

Bit of Monday Commodore Bling!

Switches will be here in a day or two!, i’ll email everyone about kits shortly.

Purchased some ‘old gold’ pigment from https://www.resin8.co.uk/ and tried it with the keycaps for something different. Came out ‘ok’ – nice and gold on the top, but lacking in gold on the sides. I suspect the particles weren’t being agitated sufficiently and sank to the bottom.

I’ll try again soon with a higher concentration of pigment and see how that goes before considering offering these as a product!

C64 Mini Keyboard kits stock – First emails being sent out

Hi All,

I’ve now packed up 10 kits ready to be shipped and have emailed the first 10 people on the waiting list.

It’s been an expensive couple of months with the bad PCB’s and wrong arduinos, but, payday at the day job was two days ago, so i’ve already ordered enough additional parts to make everyone happy within a few weeks

I’ll work may way up through the waiting list and let you all know when I can finally make general stock available.

C64 upMini Keyboard kit – stock coming shortly

My New PCB’s will be here today! DHL shipping is expensive, but great when you need stuff quickly!

What this means – I should have general stock next week.

Timeline – I’ll get a test board built up this week. if that works, I’ll email out everyone who expressed an interest.

I’ll get everything kitted up through the week (time permitting) so I can get some posted this weekend.

The rest of the weekend will be spent kitting up everything I have so I can start selling again.

Sorry for the delay guys (and gals). Been a perfect storm of wrong components sent, big customs delays, non-functional PCB’s. I thought the ‘march’ timeline was generous and had plenty of padding in for worst case.

For general availability, i’ll be reviewing the price. Most things have gone up by over 20% in general (Brexit, Yaay), some have come down, and i’ve made some optimisations. These projects aren’t a get rich quick scheme for me, they’re just a way for me to get funds together to buy more tools and things to make more projects! It’s pretty much a cost neutral hobby 😛

One final update – Keycaps. I’ve started manufacturing and at the time of typing, I have sent out a few test items to kit owners. I’ll await some feedback before I can hit ‘go’ and make more.

Those are just some of the prints i’ve had to do to get to where I am now. This isn’t representative of the typical resin printing workflow. its generally a bit easier than this, BUT, I had to start from scratch, learning how to do everything, including stuff that hasn’t been done by others. AND I needed the base level print to be ‘perfect’ to avoid the need to paint them. There’s over 80 hours of actual printing time in this picture, on top of that, there’s the cleanup time, CAD time, setup time….these are the ‘successful’ failures, there’s almost as much again that i’ve binned due to total failures, where keycaps were unusuable for anything, not even experiments (as these ones have been used for). fortunatley most of those failures were caught early to avoid too much wasted resin….but when I get only 1 chance in the evenings on some days to quickly iterate, get the printer going, 1 failure can set me back a few days.

Anyways, now i’ve finalised everything……..

I’ve used an entire bottle of resin over the last couple of weeks making test manufacturing prints back to back to tune the process, changing nothing, just print, print, print… By that, I mean, it’s…

  • Print
  • Remove Print, clean up
  • top up resin
  • print
  • Cure cleaned up print
  • repeat until bottle is empty

I’m now at about 70% success rate for good saleable keycaps. the other 20% have minor blotches or surface uniformity issues, so i’ll sell those discounted for those that are interested. I’m still getting about 1 in 1o that can’t be used in any way.

Good enough, and i’m sure i’ll get better as time goes on. Each print takes 6.5 hours – slow, but reliable and a 25uM layer height so about as good as it gets on resin printing for surface finish.

Each print also takes another 30 minutes or so to ‘turn around’ –

  • Remove from bed
  • clean bed
  • set printer up again to print the next item
  • clean print (1 minute soak in IPA, then 5 minutes in ultrasonic bath then another couple of minutes under a warm running tap)
  • Dry Print – This is critical to good finishes. Some are taking up to 3 days, overnight in cardboard boxes near the radiator. I need to do a few checks in that time to ‘dab off’ excess moisture that leeches out of the print. Any moisture left on the tops of the keycaps alters the surface finish.
  • Cure print – this takes time also. I’ve found using UV lights (wash and cure station) warps the keys more often than not. Once the caps are dry, I leave them a couple of days in the conservatory. After that, i’ll blast them for a few minutes under UV light to finish the curing
  • Then it’s pack them up ready for posting!

And, Pack some up, ready for posting I have! I’ve done a mix of ‘on the supports’ and ‘loose in bags’ to see how these things go. I’ve posted a couple to myself via friends overseas to see if they survive!. once I know what i’m doing is working, I’ll make them available for sale!

8 sets of keycaps ready to go, waiting feedback from testers before I can ship!

C64 Mini Keyboard Kit – Progress on stock

Hi All,

Quick update –

Arduino’s are still stuck in Limbo. I received 50 incorrect ones a long while back, ordered another 50 and they’ve been stuck somewhere in the UK for a couple of weeks now. I did order 10 locally at about 2x the price I normally pay to work through some of the waiting list, but that exhaused my supply of PCB’s

So, I ordered back at the beginning of February some more PCB’s

They arrived yesterday, and, I quickly soldered one up to test, so I can start ‘kitting up’ the keyboard kits.

I may have discovered an issue with the way that i’m Using EASYEDA, which has recently shown up in an EASYEDA update….it could be a bug, or a behaviour change, but, it’s B0rked my PCB!

This will set back the kit availability a couple of weeks whilst I address it and get new boards made. I know what the issue is, I can re-create it and have a work around to order more PCB’s so it’s no major worry

Here’s the C64 Keybaord matrix that i’m using. I’ve always used number prefixes for the number keys. i.e. if it’s A, I’ve used the PREFIX A, 1, Prefix 1, etc , etc.

Something changed in EASYEDA a couple of months ago which now means that Prefixes with a single digit number now all seem to tie their nets together.

Here’s the resulting PCB – Note, the nets for the centre pins are all the same!

I didn’t spot this in the one that I just had made! and despite the thoroughly heroic efforts of the JLCPCB staff to fix a couple of cockups i’d made , I have to now trash this batch .

Here’s what happens when I select the Net – ALL the numbers light up as they’re all connected!. oops

Ah well, off to learn a little more about EASYEDA, quite an expensive mistake though, but this shows why, when you make changes, testing is important.

You can imagine how amused I was when I discovered that EVERY key worked on my board, except the number keys, which only typed 0 or 9 !

In other news – I purchased one of these

An Ultrasonic Cleaner – Dual Frequency 28KHz and 40KHz. I’ll do another post about it later.

All i can say now is WOW – No need for the wash and cure station now! – this thing superbly and consistently cleans the prints, giving a good surface finish. Prior to this, it was impossible to get a good finish on every key, every time. Now, i’m 4 prints in , and 3 are perfect, 1 is crap due to over-cleaning! I’m dialled in and ready for production

Tolerance!

The mechanical, fitty holey type tolerance, not the other type of ‘oh, that’s annoying, but i’ll put up with it’ type….

Here’s the keyswitch fitting into the space bar. zoom in. we’re talking fractions of a millimeter fit, which I can achieve consistently and reliably! there’s about 0.1 mm available on the sides with the latches and about 0.2mm availavle on the longer sides. the extra really being there to allow some grace when placing the keycap on to fit it. less clearance means it’s a royal pain to get the switch located into the hole.

BUT, the keys don’t ‘latch’ into place on the switches. So, to try to address that (if it’s even possible) i’m now adding a small feature

See that bit in Blue!

This is the underside of one of the ‘F’ Keys. That small part in blue is a 0.1mm ridge sat about 0.8mm up from the bottom and 1mm from the top. I’m hoping that will be enough to latch the keys on, AND allow ease of fitting without breaking the keycaps. Everything else is done now, this is the only barrier to releasing. I’ll run off a print tomorrow to see how it works out. I’ll run off further prints with this sticking out even more if i need to

Just one more Tweaketto! Give it to me…C64 keycap sales are soon to be..

Nailed it!

Happy chappy this morning. They finished printing last night, my draining widget worked a treat – I’ll put a quick GIF up soon.

But, forgot about them until a mad panic at close to 1AM remembering I’d left them on the printer. With these, you can’t as the resin in the concave surfaces will part set in the morning and cause an uneven surface.

So, quickly washed them in IPA, regretted it immediately as it was dirty. Did another wash in IPA to clean the resin and straight to the hot water tap and larger bowl with a brush to clean off the bits. I’ll strain out the bowl later.

Final tweak needed now is the amount of grip to the switches themselves, shrinkage is variable at the moment, can’t go too small or keycaps may break when putting on, can’t go too big or they’ll be too wobbly and fall off.

May need to go middle ground and require a tiny blob of something sticky in each keycap, I’ll know soon enough!

Space Bar, The final frontier

The final hurdle for ‘good enough’ for me now is the space bar.

Every key prints lovely, except the largest one……Take a look

Eeeeew, kinda looks like a ….

I’ve gotten all the ‘hard stuff’ over and done with first, or so I thought. Life’s taught me to generally avoid going for the low hanging fruit first, save the easy stuff for later when you need a boost.

Well, no matter what i’ve done (so far) in 12 iterations, have I been able to get a good looking space bar.

Now this has become my sole focus and roadblock for a successful print

Turns out that this is a combination of quite a few variables, I’ll list a few and probably follow up another time with clicky links and research

  • Exposure times are wrong –
    • They could be , I’ve really just gone and shoved stuff in to print and hoped for the best with standard settings. I Have now tweaked up the settings a little bit to 2.2s per layer due to mixing pigment in, and have had no real failures. I’ve also increased the first layers exposure times to 30s, still seeing minor issues there
  • FEP tension is wrong
    • Not really, This is a brand new printer, i’ve had zero catastrophic failures and have been overly cautious monitoring (and catching) early delamination from the print bed issues – Three times now
  • Bad Resin
    • Possibly. I’ve 3 types (all anycubic) and seeing the same on all 3
  • Temperature
    • Possibly, lots of people have been reporting issues in cold climates, I use the printer in the conservatory and it’s sub 10 degrees C in there regularly
    • Low temperatures cause increased viscosity and warpage issues with fine features from the FEP pulling them through the thicker resin
  • MY FAVOURITE
    • Exposure –
      • Too low exposure times on fine edges cause resin to cure, but not as hard as it should. So, when the layer sets on the bed, when it’s pulled off the FEP, it warps as it’s soft. This, I believe is causing the sagging issues i’m seeing on that space bar – it’s printed upside down, so the supports hold the points up, and between the walls sag, like an electric line held between two pylons

My solution……

Probaly waaay too many supports, but this way, each ‘sag’ will be between supports that are just 1mm apart.

I’ve also nearly doubled the wall thickness to about 1.8mm – from 1mm

Blue lines show original thickness, gold shows it doubled

Hopefully now, this is the last step, Colour’s good, CAD is good, Supports are good.

I’ve ordered 2 Litres of clear resin ready to go and have a colour that’s not exact, but close and, importantly , very easy to re-create

Resin8 Earthy Brown, 3 ‘blobs’ of the end of a lollypop stick to 100ml of resin. and Black, 1 blob.

– The Rich brown used previously was too red. I’ll experiment a little with more black when running off the final tests

https://www.resin8.co.uk/opaque-resin-pigment—earthy-brown-7468-p.asp

https://www.resin8.co.uk/opaque-resin-pigment—black-2383-p.asp

Coming soon!, more kits in stock, and Keycaps – March 2021!

Is that a space bar in your pocket (sized C64 Mini) ?

Trial run 13 underway with the resin prints. Colour should be pretty close, and Supports fairly optimal.

Trial 12 failed due to insufficient base size on the supports, caught it at 5% so no problem there other than a quick cleanup. I’ll know how it’s gone in about 5 hours!

Also, did a quick tweak on the space bar! I’m printing both new and old to see how they come out

Do animated GIF’s work here?

Did some work on the Blinkenator also, and got sidetracked quite significantly with Fusion360’s parametric sketches. watch those tangent curves and how you constrain them!.

Keycaps! C64 mini stuff

Doing some sideways progress now.

When planning something, always allow time for ‘unseen’ stuff, or even anticipated issues that probably show up but you hope they don’t.

Is that a banana in your c64 mini or are you just happy to see me?

I’ve had two partially failed prints now, one fully expected and designed deliberately to see just how far I can remove supports or just how many I need to add

And, the one you see above. A large part of the bed failed to adhere so I stopped at 65%, just enough to recover the space bar…should have waited to 70% so I could grab a few of the bottom row also.

I’ve noticed slight warping in all prints but haven’t been that concerned till this failure.

On the plus side though, my new pigment colours arrived !

Yes, it’s reddy. So, it’s not ready.

I now have a grip on how the colours mix and can iterate a little closer to the original brown now! It doesn’t help that I’m red/green colourblind so, matching brown, in the evenings , in the conservatory in non optimal lighting is probably a worst case scenario for me :-p

But, I can get close now and can get the wife to tweak the formula

One thing I’ve noted is that it can get expensive iterating colors in resin prints! I’m mixing 100ml at a time now, to start a new colour I’m dumping the old 100ml into my grey bottle! Can’t wait to see what colour that comes out as.

now, back to the print fails

First – Levelling. Seems my bed has become unlevel a little, so, I’ll need to re-level. This seems to be an excellent tutorial which i’ll follow.

Now, the warping. It’s something that I didn’t really experience much with my standard Filament printer, but now I clearly can see that it’s a common, but surmountable issue with Resin printers.

So, some research

I’ll need to re-design the space bar at least!.

https://www.3dhubs.com/knowledge-base/how-design-parts-sla-3d-printing/

And

https://www.3dhubs.com/knowledge-base/how-design-parts-sla-3d-printing/

I’d put a small re-enforcement bar all along the space bar which seems to have been an error and may well be causing more warping!

I’ll do another post with the re-design!

C64 Mini Keyboard – Rev 4 PCB experiments

This’ll be a while away yet, but the REV4 PCB, has some new, experimental features that will possibly allow some extra functionality when used with stuff other than a C64 mini!

For the purposes of this kit though, the board is a little easier to solder due to slightly larger pads, I’ve also added silk screen ‘dots’ to the rear to show the only two pads you actually need to solder (or possibly one of the two if i’ve gone and goofed up the positioning! ).

I’ve removed the USB HELPER pads, these weren’t actually that useful

The other thing being added are pads that say ‘Joy’ – I’ve no idea if this will work, but my plan is to see if there’s any way to map the C64 Joystick onto the keyboard and then into a PC / MiSTer or other device with a USB socket. I’m putting these unpopulated pads on production boards as, now due to Brexit, it costs a fortune in customs fees and shipping for small orders of prototypes. I mayaswell order 50 boards which are tried and tested, with small mods on. If the mods don’t work, no loss – the boards still function just as sold.

If they work, AND i can develop the firmware, AND the software then it may add useful features for some people! But, my focus right now is getting the mini version perfect and not any extra features that require a lot of time for me to learn how to enable! If they’re ever enabled, i’ll probably spin them into a SMT only board so I can sell a ready assembled version for a little cheaper than the £60 i’m currently selling for

Also on this one, i’ve fixed the C64 header pin ordering to save people having to make an adaptor cable due to me swapping two columns and putting the rows in reverse!, D’oh!.

Anyways, enough waffle – on with the pictures!

C64 Mini Keyboard Kits – Now awaiting stock

Hi All,

It’s been a rollercoaster few days with the Retro Receipies Youtube video.

I’ve now run out of some components for the C64 Mini keyboard kit. More have been ordered, I’m just waiting on a last few people to send over payment and i’ll pause things for a few weeks until parts arrive.

I’m hoping that the delay also will help some focus to drive the keycap development and a feature change to the PCB

I have to say Thankyou to Perrifractic for reaching out and increasing the profile of this little kit, and that the response has been unexpected. This is a little hobby that I have in my spare time between juggling the bill-paying day job and the wife and kids, it gives me the pocket money to buy more gizmos to help develop these gizmos.

I ordered most of the ‘long lead time’ parts last week, so i’d expect it to now be mid-late february before I can sell more full kits.

Hello!

Just a quick ‘Hi’ to anyone popping in from Retro Recipes!

And, if you’re just browsing here due to something else, go, have a look at Retro Recipes!

Whilst you’re there, go check out my “This Old Tony” style cameo in the video 🙂 ! yes, that’s official, it’s my HOLLYWOOD DEBUT!.

Oh, And it’s a little video about the C64 Mini keyboard kits, and a little reveal!

And, to get in touch, ping an email to KEYBOARDS AT Bleugh.biz

Cheers

Dean