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
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!
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.
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!
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
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
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!
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
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!.
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.
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!.
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.
That’s right, A few of you found me from Mr Perri Fractic’s channel on Youtube
The Video, 27 minutes in!, ME!!
There’ll be a little more coming up i’ve been told!
Highly recommend if you like anything slightly retro, give his channel a watch, superb production quality to it, great sense of humour and , generally seems to be a lovely chap that really brings out your inner childhood enthusiams for these weird old gadgets that a lot of us love.
Also, he’s getting close to 100,000 subscribers, so definitely is doing something right
A very talented Hans Liss from the Facebook group – TheC64 Mini has make a perfect assembled kit.
Drool over the photos below
Note the extras like the hacked up USB hub to make it slimline
The Extra UART connector that he’s added, and the nigh on perfect Keybaord keycap butchery!
Hans also helped by pointing out a few errors i’ve made with the original firmware sent out with the kits. I spent a couple of weeks figuring out how to fix it and have a new HEX file for those that want it.
There’s still some ‘not quite exactly commodore’ quirkery happening – which i’m working on, but i’ll bet that 99% of you won’t be able to figure it out. I’ve only found out due to Hans’s extensive knowledge of the C64 inner workings and also me, downloading the original user manual for the Commodore 64.
Have been promising a long time to do this, so finally took a few hours to butcher another mini!
Some views are excellentAnother great view And the worst view
As you can see, for the most part, it’s pretty good, but NOT perfect
what I’ve discovered…..
2 part epoxy works best
Each keycap row is a different depth – the top one needs the least glue, row 3 the most
My errors here. I used a hard plastic glue from Bostick. it doesn’t grip well enough on the top of the keyswitches. I glued everything, waited a few hours, half the keycaps didn’t stick
glued the rest, waited, half again didnt’ stick…rinse and repeat about 6 times, adding more glue till finally they all stuck.
The 2 part epoxy stuck fast and hard! – but I used too much.
The repeated adding of more glue caused the multiple key levels you can see in the picture
Correct orientation of the switchesCorrect orientation from the top. (Except the shift lock…oops! That’s why I put extra switches in :-p)
A funny story about multi sourcing components and the importance of testing before shipping!
I used a supplier on Aliexpress to purchase a few thousand switches in a few orders over a few months but their prices went up quite drastically after the last order (doubled!!) they weren’t the cheapest to start with but were reliable and friendly, worth the extra ££
I found another supplier who did a good deal for a full bag of 4000! Ordered them and waited, very quick delivery and friendly also (will buy again!)
I built my first test new keyboard with the new PCB and switches
It didn’t work. Well, actually, it did! Work perfectly…but in reverse :-p …..
If you mashed every key simultaneously then only released the key you want to press….it worked!! Yeah, the supplier sent me 4000 ‘inverted’ switches! My fault for not checking prior to ordering, they ‘look the same’ so ‘must be the same’ was a wrong assumption on my part! (At least they all weren’t the shift lock type!!)
It’s a VERY easy fix though (found after several panicked hours of testing and building Keyboards)…rotate the switch 180 degrees and it’s perfect!
In each kit I’ve included a small errata note and list of basic instructions to help. It’s an annoyance but for you guys it really just means the silk screen doesn’t quite match the switch orientation so just ask first. Look at the pictures and of any doubt, email/messenger/twitter/Reddit me 🙂
Cut one leg shorter on the diodes – Use scissors . About 1-1.5cm is good
bend the short leg side to a right angle
Note the orientation of the diode – The F Key diodes have a diode picture on them. The white bar matches the location of the black bar on the diode.
put diode in holes and bend slightly to lock in
repeat for all diodes
Solder all diodes
clip the excess legs back
you have a few spare diodes so don’t be afraid to experiment on one or two to get the right bend / fit
ARDUINO HEADERS
Probably best to solder these in now before you forget
I’ve found it useful to PLACE the arduino on the headers (DO NOT SOLDER YET) so it keeps the headers parallel
Make sure the black part of the headers is on the underside of the PCB
Solder one pin of each header
remove arduino
finish soldering
SWITCHES – STEP 1, JUST TACKING IN PLACE
Pay attention to orientation
don’t worry about straightening the switches at this stage, the goal is to just ‘tack’ them in with a single solder blob to hold them in place. They can be wonky, it doesn’t matter.
DO NOT SOLDER MORE THAN 1 PIN OF EACH SWITCH IN ONE GO
The switches are easily heat damaged – they become ‘sticky’ and no longer move smoothly if the plastic is melted due to excessive heat. During the entire soldering procedure for the switches, do ONE leg, move to the next switch. when all are done, move back to the first switch and repeat.
I’ve damaged only 2 switches this way soldering the prototypes but it can happen if you’re not careful
Note that the white part of each switch is asymetrical. One side has a ‘dip’ / inset which guides the switch up and down. the other side is smooth
there’s a marking on the PCB to represent this dip / inset.
ALL switches go the same way
Get a sheet of paper
Insert the top row of switches into the PCB
Place PCB on sheet of paper and fold paper over the top, tightly
flip the PCB over
hopefully all the switches stay in place
Solder just ONE leg of each switch – any one – say the top right
Repeat for Row 2
DO NOT FORGET TO SOLDER THE ARDUINO HEADERS IN PLACE
Repeat for Row 3
DO NOT FORGET TO SOLDER THE ARDUINO HEADERS IN PLACE
Repeat for for row 4
(Hopefully you didn’t forget to solder the Arduino headers in place?)
and finally the space bar
SWITCHES – STEP 2, Straightening
This is probably the most important step to getting a good looking keyboard with all the switches aligned. Spend some time getting this right, you have a handful of ‘spare’ switches so now’s the time to make mistakes and fix them whilst there’s only a single solder blob on them
I’ll post a few videos shortly but there’s a technique.
Hold the board in the air
Use your index finger to push in, and slightly down on each switch whilst soldering the previous blob. The goal is to move the whole switch slightly so that it’s slightly at the top, or the bottom of its footprint.
when you melt the solder whilst pushing in and down, the switch will move slightly, sometimes you’ll hear a little click or snap as the solder melts
repeat this for each switch, pushing in and down slightly – when you look at the final position, there’ll be some of the pad visible at the top of each switch
NOW IS THE TIME TO TEST EACH SWITCH FOR SMOOTH MOVEMENT
of the 5 keyboards i’ve soldered, I’ve had two defective switches, this is partly the reason why there’s a few extras in the kit
of the 5 keyboards i’ve soldered, I’ve broken 3 switches by either over-heating, or trying to remove after putting them in backwards. unless you’ve got a hot air gun, they’re tricky to remove intact, hence check NOW whilst there’s only one solder blob!
When you get close to one side of the keyboard, you’ll have to fiddle a bit to keep pushing the switches in the same direction. I’ve found that changing technique a little and ‘flip’ the board lengthwise works. hold the board against yourself and use your thumb to pull the switch down instead of push
repeat the alignment technique for ALL switches!
SWITCHES – STEP 3, Final soldering
This is the easy / relaxing bit!
DO NOT SOLDER MORE THAN ONE LEG OF EACH SWITCH AT A TIME
do it by rows, clusters, however works for you, but here’s what worked for me
Solder ONE pad of each switch, then move to the next
once all switches are done, start from the beginning
Solder another pad, etc etc
A SMALL CHEAT – You only actually need to solder 3 points. Two on the ‘bottom’ of the switch – these are the electrical contacts. ONE on the ‘top’ – this is for mechanical stability. As you look at the keyboard, the bottom two pins are the important electrical ones. Pick any on the top
on my prototype, I found soldering all 6 pins tiring, so on my second version I just soldered 3 and it worked perfect. Up to you, but DONT SOLDER MORE THAN 1 PIN AT A TIME
Arduino
Note the orientation of the Arduino by the Small USB socket and a mark on the PCB. Also the silk screen on the PCB will match the letters on the Arduino.
these need a little more heat to solder to the pins
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
