Pngmaster External Coil Spring Mod

zrrion · 24 Apr 2018, 22:54

I felt that the switches in the pingmaster were to light so I made them heavier using some coli springs I had laying around from a mechanical typewriter. I did this to prevent an issue I've been having with the pingmaster wherein I will accidentally bump a key while typing and that would be enough to actuate the key I had bumped and I would end up with a bunch of random letters that I did not intend to type. By adding some external coil springs to the board I have found that bumping a key doesn't cause to be depressed enough to hit the actuation point. They're way too heavy now, but this is a nice proof of concept. (who knows it might grow on me even)

And for anyone who's curious, here's what the layout for the relegendable keys looks like:

orihalcon · 25 Apr 2018, 03:47

Digging the hand drawn relegendables

What type of typewriter did the coil springs come out of and what is their diameter?

zrrion · 25 Apr 2018, 05:37

They are ~1 cm in diameter and came out of a Smith Corona XE 5000 which uses Mitsumi switches. The caps use a cross mount that should be compatible with a bunch of Mitsumi stuff.

green-squid · 25 Apr 2018, 07:13

These new old stock Pingmasters on eBay are very tempting to buy, but the shipping costs are in the sky!

How are the switches? Are they better than SKCL greens?

xxhellfirexx · 25 Apr 2018, 08:42

If Alps SKCC green switches are too light for you, you should try Alps SKCC cream switches in the Apple M0110 keyboard, which are slightly stiffer. Loose switches are available on eBay if you want to go down that path.

zrrion · 25 Apr 2018, 08:43

I haven't tried SKCL greens actually so I couldn't say, but these have a rather high actuation point so they are very easy to accidentally press. These are smooth and the slight tactility you get after actuation is pretty nice.

The beeper on mine works and I like that it gives me audible feedback so that I have a better idea as to when I've accidentally bumped keys. The speaker in the board doesn't have any sort of noise reduction/filtering so there is often an audible hiss/buzzing over the speaker even with the volume off. It is especially bad if I have my phone charger near the board. This could be solved with a ferrite bead or a filtering cap or something similar but I haven't gotten around to adding one yet. There are some short clip-in feet that come with the board but imo they are too short and don't angle the board enough for my taste.

Every key can be put on upside down if you want except the keys with stabilizers, so no meme space bar. I personally miss having a big-ass enter and a long backspace, so I've set it up to have 2 backspaces right next to each other, and 3 enter keys in a group but that's down to preference. Not sure what else to put there though. I also haven't figured out how to get the double zero key to output 2 zeros so it currently functions as a second zero key.

EDIT: I've thought about cream, but I'm looking to be as gentle with this board as possible so I wouldn't swap out the switches. I would like to get a board with them at some point though.

Blaise170 · 25 Apr 2018, 15:03

I love the Pingmaster, though I sold my first one a couple of years ago. I just bought another one but admittedly I haven't taken it out of the package yet as I don't want to ruin a NIB vintage board like that. I actually had an Apple M0110A with Cream SKCC as well as a TI-99/4A keyboard with them and I think they are nice, but unfortunately the PCB was broken on the Apple and the TI-99/4A was missing caps (I didn't really want to handwire it without a case anyways). If you are interested in Creams I have a bunch of loose switches as well as the plate+switches from the Apple.

seebart · 25 Apr 2018, 18:15

Interesting mod! Where are the springs from?

ScottPaladin · 25 Apr 2018, 22:10

seebart wrote: Interesting mod! Where are the springs from?

zrrion wrote: They are ~1 cm in diameter and came out of a Smith Corona XE 5000 which uses Mitsumi switches. The caps use a cross mount that should be compatible with a bunch of Mitsumi stuff.

Also, those hand drawn legends have got a strange charm.

SpacemanToby · 26 Apr 2018, 14:44

green-squid wrote: These new old stock Pingmasters on eBay are very tempting to buy, but the shipping costs are in the sky!

How are the switches? Are they better than SKCL greens?

I think the overall experience of the SKCL keypress is a tighter and more enjoyable experience. I love how smooth SKCC switches are, but they have a sort of floaty quality to them that keep them from being my favorite.

snufflecat · 29 Apr 2018, 21:01

Does anyone know how tall are the springs? I'm curious to see if I could order a batch of springs on ebay or something, instead of having to rely on finding an old typewriter to salvage.

seebart · 29 Apr 2018, 21:18

Well OP should know...

SpacemanToby · 29 Apr 2018, 23:29

I actually have a bag of those springs sitting around from a different Smith Corona typewriter I salvaged. They're like 1/2 in tall. You're welcome to them if you want.

Blaise170 · 30 Apr 2018, 01:23

These can also be found on many Keytronic foam and foil boards which are worthless otherwise.

snufflecat · 30 Apr 2018, 12:50

SpacemanToby wrote: I actually have a bag of those springs sitting around from a different Smith Corona typewriter I salvaged. They're like 1/2 in tall. You're welcome to them if you want.

Thanks! I'll keep you posted if I 1) have the need and 2) can't find any online.