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!

C64 Mini – Cheap and easy keycap ‘solution’

It’s taking ages to get progress on the 3D printed keycaps, I’m so close, but still have a few months of tweaking until I get it perfect enough to consider it a saleable item. watch this space 🙂

In the interim, I went and purchased a bunch of these

https://www.aliexpress.com/item/1005001616660795.html?spm=a2g0s.9042311.0.0.27424c4dI4vhMo

They’re a “100Pcs A28 Tactile Push Button Switch Cap 6*5.1mm Applies to 5.8*5.8 7*7 8*8 8.5*8.5 Self-Locking Switch Button Cap”

And, judge for yourself……

Old school!

Err.

Well, it’s more comfortable than nothing, and certainly opens up some options for unusual keyboards in the future 😛

yes, it’s not perfect, BUT for £1.68 you can have non painful pokey bits and actually do a reasonable job of typing on basic

or, splash out £3.36 and go for a dual colour like I did 😛

BONUS PRIZE TIME………………..[edit, grabbed by someone! ]

THE first person to order a kit and mention that they want these keycaps, I’ll chuck in a set of grey/black ones as pictured for nothing – I purchased enough to do properly do 2.5 keyboards, or 3 if you don’t mind a mix / match of black and grey!

Note, if you’re ordering your own keycaps off aliexpress, the internal dimension is key here, they fit, you can go a little smaller

the absolute maximum external dimension is 9mm, this leaves about 0.48mm clearance between keycaps.

C64 Mini keycaps, Bleugh’s Log, date 12012021….second print!

This one went well 🙂

Note, the intentional ‘stone effect’ finish 😉

Most people would say this was caused by an over excited person, whom, upon waking early and discovering the complete print decided to not follow the correct drying / washing procedures in order to get it finished quickly!

I, err, disagree…

Either way, I now have a firm grasp of changes needed to the CAD model and also the supports needed in the slicer.

Those changes are fairly substantial, so I expect it’ll be a little while for my next update, happy to document them also if anyone’s interested.

Freshly dried and washed
Perfect size
A quick comparison

C64 Mini Keyboard – Small bit of Keycap Progress

It’s going to be a while yet, but I’ve finally fixed some long standing issues with the keyboard model i’ve been building in Fusion360

Doesn’t look like much!?

The main issue was a badly created model!. I’ve junked quite a lot and started back prior to when some odd dependencies crept in and really put some roadblocks on scaling things correctly and adding finishing touches.

But, it’s been worth it

That previous picture is the underside of the Keyboard – Those holes in the keys are 2.2 x 2.8 holes. it’s a first run at fitting the key switches into the keycaps. a lot more iteration needed to hollow it out a little and create some form of inbuilt snap-fit with stress relief, but…it’s a start!

The silver / grey keys over on the left are the ‘parent’ keys

If I make an update to the curves or size of a parent key – it rolls out to all the same sized keys in its row

if I need to iterate the hole size for the key switches, I simply change a few parameters for the hole size and it rolls out to all the keys in one go.

I’ve taken so long to develop it parametrically as it’ll now be so much quicker to iterate

Lots of parameters to change!

and, here’s a new render!……..going to spend the next few weeks iterating, and hopefully over Christmas , fire up the resin 3D printer for the first time!

C64 Mini Keyboard Kit – Contents

Just realised that it’s not easy to find an image to show what’s in a kit.

Here goes


what you need to add;

  • YOUR OWN KEYCAPS – Freshly butchered
  • plaster of paris / silicon for the mould
  • Solder
  • Glue

What’s In the Kit

  • 1 pre programmed arduino pro micro with headers
  • 70 normal switches
  • 1 locking switch
  • 70 diodes
  • 1 PCB
  • 1 USB hub
  • 1 4 core wire
  • 2 short USB cables one of which you cut the end off if you want, or cut / reuse the USB hub one)
  • 4 Screws (to help align the mould)
  • 1 3D printed plastic mould / jig to create a mould to put your keycaps on straight
  • 2 small pieces of heat shrink tubing

C64 Mini not included, but this is what yours will look like once you’ve assembled the kit

Coming at some point in the future (late 2021 at this rate) – 3D, resin printed Keycaps!

C64 Mini Keyboard Kit – New Firmware available

New Firmware upgrade available

It’s been an intense and frustrating few months trying to figure out QMK in spare time here and there – today, something ‘clicked’ and…..I’ve made a new keymap.

Please email me – KEYBOARD AT BLEUGH DOT BIZ for a new HEX file. also happy to help you flashing the thing with the Arduino IDE (it’s quite easy!)

Why I developed a new keymap

A couple of users have reported that the key mapping is a little wrong when plugged into the mini.

By ‘key mapping’ it means, when you press a key, or combination of keys, you don’t get the character that’s shown on the keycap.

Most people will know this if they’ve ever used a US keyboard on a UK computer or vice versa, that Shift and 2 gets annoying after a while when you’re trying for the @ sign!

So, I’ve dun fixed those minor niggles that people observed….AND, i’ve gone and added quite a bit more!

Continue reading “C64 Mini Keyboard Kit – New Firmware available”

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 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”

C64Mini – Keyboard Mod

img_0717
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”