deskthority

[*] The plastic barrel plate had big holes where the screws had to come in. They would not create any pressure, leaving the plastic barrel plate lose at this very point. I used some filament and heat, applied with a cheap solder, to first fill the hole to then drill (with a dremel) a new hole ...

These flippers are less conductive than the original ones. I had to reduce the threshold in the Leyden Jar firmware. I am typing with activation offset of 7 (instead of the 20 which I have been using with my "regular" FSSK.

Congratulations! I specially approve of the extra step you took to ...

..I tried photogrammetry to make a 3d scan of the flipper, but developers nowadays are too lazy to write anything without CUDA, so I failed. If anybody wants to help - I can send you the photos and you can use colmap (I hope) to create the model.
I only got to "point cloud" step, which is basically ...

Batch 3 was ruined by washing in the hot water on internet advice. So here's batch 4:
batch3.png

numbers are elevation at rest, in degrees.
5 is whisper-quiet, but also almost linear feel. The spring is buckling, don't get me wrong, but almost imperceptible, even with original barrel+stem. Rarely ...

I have two real IBM Model F boards, but I never did use them as my primary keyboard, one being for my IBM 5150 and the other being that annoying AT layout, so it's perhaps not fair to compare them. They are both awesome though, and the reason I was interested in the F104 in the first place.


If ...

Built to last months, not decades

LOL. But let's just wait until those beam springs accumulate 50k keypresses, that storm will be way larger.

@mbarszcz, can you post a photo of the keycap insides? There are 4 "corners" of each keycap which actually stabilize the keycap within the barrel, I ...

pull all the key caps off.
Make sure flippers move freely inside their barrels and don't protrude outside of the barrel into the area that will be occupied by PCB - it's quite easy to dislodge them and either break them or simply wedge them into the barrel so they can't move.
Then use however many ...

I accidentally silent buckling spring. Sadly, it's LINEAR.
Turns out, tactility turns out to be generated by flipper dropping on PCB and vibrating the hell out of the whole mechanism.
PXL_20250204_013712766.jpg

You may notice there's a window where the spring SUPPOSEDLY hits the barrel. SURPRISE ...

TIL "Alps buckling spring" is a thing: https://www.paulbramhall.uk/bits-n-bobs/keyboards/1990-alps-sm-101/spring-forward-with-the-alps-sm-101-exploring-a-rare-and-uncommon-buckling-spring-keyboard/
Shorter spring is a benefit - I was able to shorten the barrel to 15mm in height, but cherry MX switch ...

I looked at Elegoo Saturn 4 Ultra. I would not go for it.
Me neither, knowing what I know today! But alas, missed my return window with surgery and all that. I'll make it work, just disappointed.

I personally do not like also the two level build plate. Cleaning resin from it must be a pain ...

I sometimes compensate for elephant foots by chamfering the bottom. Sometimes elephant foots do not matter for functionality. In such a case, I do not care.

Currently, there's also semi-random squishing of bottom 0.35-0.45mm because of the damn "automatic build plate leveling". Chinese New Year ...

It looks to me that you can modify the flipper model so that it is printable in vertical position without support.
That's easy - just rotating the model 90 degrees will do. Some supports will still be needed (because 0.35mm will be squashed and elephant-footed, and I want to actually use the ...

dcopellino wrote: 31 Jan 2025, 12:13In the meantime have a look to these very big and hi res pics.

https://www.flickr.com/photos/triplehaa ... 617851639/

Thanks for pointing me to this link. I might be able to access that particular keyboard.

"The product is spreadable, but still has odor issues"
(if you want the full source - google "One can already spread it, but not yet eat it.").

Current issue list:

Stem barely fits into the barrel. It does fit into OG barrel pretty OK - not too wobbly, not too tight - but it's too tight with ...

> https://ex4.sakura.ne.jp/kb/tech_bucklingspring_e.htm

Wow. That guy.. That guy has a PHENOMENALLY SHARP SAW!

And similarly sharp observation skills - for example he is pointing out that it's a slanted base that nudges the spring to buckle that particular way, not "having springs positioned to 12 ...

@vvp I have Elegoo Saturn 4 Ultra.
I guess my measurement system is too precise - I have 0.01mm resolution digital calipers. 0.02mm over 5mm is less than 0.5%, after all - but those damn marketoids shouldn't promise "16x24 um" resolution then.

I bought a heater - it heats AIR, not vat - but I guess ...

@ChairmanMeow yeah, I just given up on properly setting up my resin printer, and will work around what I've got instead. So I should be able to produce some physical items to test them real soon.

However.

Model F flipper is 16.7x16.8mm. It's a moving part, so it needs at least 18x18mm free space ...

I thought that I'll be resin printing power user, but instead it turns out I'm an EARLY ADOPTER. Yes, resin printers are like 10 years old tech, and yet.
I mean, it's OK for printing miniatures - i.e. where absolute size doesn't matter. But the moment you want something that needs to actually be 5 ...

Another alternative is to enter in the three points at the same time.

"at the same time" implies luck. Consider yourself very unlucky when designing such things: multiple exits are OK, multiple entry points - not so much..
So, considering you want to keep flipper position in the mold intact ...

There is only one low point and a high point.

If there was high/ultra-high vacuum inside the mold - that would indeed be the case. But there's 1atm air there, and as epoxy flows into the mold, it will eventually create air bubbles in the flipper feet (pointed by bent arrows on the drawing).
In ...

I went into general anaesthesia for 2 hours and literally this happens.

Hello DMA,

Good to see that you are back on track :) !


Not yet on track - can post but can't really do anything yet, even getting up is a bit of a trouble. But I'm getting there.



I must admit that the intended proportion was 5+5ml (epoxy) + 5 g graphite.

That would be 33% - probably ...

3 g graphite
14 ml epoxy
[*] My flipper does not work! The level change happens, but it is too low.

3/17 = 17%. 4g graphite+13ml epoxy will be 23% - which might just be the ticket (could be mechanically unsuitable, in which case better carbon black might work - may be even at original 17 ...

OK, my small additive manufacturing facility is ready for the pilot. See ya after surgery! (which is tomorrow)

macmakkara wrote: 07 Jan 2025, 13:31As i have been laid-off from my work for unknown time frame

This sucks, man. Hope you'll find something before money runs out.

You may want to jump to the minute 6:40 to see how graphite is mixed with the resine.

One note upfront - graphite is way worse than "conductive carbon black". From datasheets it looks like things become "conductive" at about 15% of the stuff by weight, depending on actual stuff. And even then ...

Probably terrible idea:
Not quite! It's not even that hard to make flippers a bit smaller - but doing that will change the sound (not feel) of the keys.

a curved PCB
Curved PCB isn't actually needed - original IBM ones are curved simply because they were sandwiched between plates for 30+ years ...

Great !

Elipse: (Give and take) why don't you please share the information you hold (CAD, springs specs/source and how to purchase from China) with the community to help in producing the flippers in the same way the community has done with the critical components you have (and still are) using in ...

Displays are problematic because they change every year - basically, unless you're talking about HD44780 varieties, you can only ever buy 1(ONE) batch of a particular display.
The reason is quite interesting - LCD panels are made by, like, TWO companies in the world - and so MOQ is in literally ...

I tried to print some calibration targets on a newly-bought resin printer and not printing anything anymore until I build a fume hood that vents to outside. Stuff like "mars mate" with charcoal filters not only won't really work, but also bankrupt it's owner for the filters :)
So, see you after fume ...