P77 - The TKL Pingmaster

[Mattr567]

After seeing dorkvader's 60% mod (https://geekhack.org/index.php?topic=85806.0) I decided I'm going to TKL mod my Pingmaster.

What makes this easier than the 60% mod is that I'm not taking off any chips, so the wiring shouldn't be as intense. What is being cut off are some resistors that link to the middle chip, which is for NKRO. Dork had to remove that chip (as it was in the way) and do a work around with the wiring. Not sure but I think he did end up losing NKRO as a result.




I have an idea for getting around this. I could use a breadboard to recreate the connections to the middle chip and by that way I could effectively USB-ify the Pingmaster as normal since everything is still there. Other and all ideas are welcome. Wiring is the biggest hurtle for this project.

I have plenty of wiring and soldering skills so I do feel up for the task but I'm not sure on where to cut, where to wire etc. After this can serve as a great guide for future people! I have a feeling i'm not the first to come up with this idea, but I am the first to actually try it as far as I know.

The physical cutting part shouldn't be too bad, as long as you know where to cut etc. I only have hand tools on hand (heh) but I know those won't do, a straight line is critical.

Here is the layout i'm aiming for. As you can see it is very reminiscent of the F77. Hence the name P77 I bought an eclipse one so I think they will make for great companions.


Thanks for all the help! I hope for this project to become fruitful

[Mattr567]

What makes the most sense to me is to cut the case first then see how much to cut the plate, or else you risk the metal being too short/long.

The biggest part of the physical cutting is where to cut the PCB, between what solder points etc. I see a couple of options. The volume knob should stay in any case though. Here is a pic for reference:



Where I'm planning to cut the case:


Waiting for dorkvader to reply to my PM but I wonder if I should desolder the whole board and cut the metal plate and PCB separately or do it at the same time.

Hopefully all of you will be gone soon

[Mattr567]

Ok, mapped out all the traces that would be cut and would have to be re-wired. The rest dead end or dont have any use. Plus the actual resistor connections to the middle chip of course.

Also new plan is to cut the resistor area separate and use it as a breadboard, seems a lot easier than remaking it on an actual breadboard.


In the end I will be able to hook it up like a normal Pingmaster Good thing there is a lot of space inside the case! In a way I'm actually bypassing the numpad entirely.

[just_add_coffee]

I can't offer any help, but I'm interested in seeing how this is done.

I'm wondering if ditching the PCB altogether and handwiring to a Teensy might be easier in the long run. It seems like help would be more readily available and problems easier to diagnose.

Let us know how this turns out and how you did it. For science!

[Mattr567]

I can't offer any help, but I'm interested in seeing how this is done.

I'm wondering if ditching the PCB altogether and handwiring to a Teensy might be easier in the long run. It seems like help would be more readily available and problems easier to diagnose.

Let us know how this turns out and how you did it. For science!

I am definitely considering that as well. At the very least it would be a backup plan. What software would I use on the teensy? Any good guides for handwiring?

If I map out all the traces correctly it should work. Its making all the same connections just bypassing the numpad. I need to do a little more work on the cutting line, need to watch out for the diode connections I still need.

[just_add_coffee]

What software would I use on the teensy? Any good guides for handwiring?

There are some handwiring guides in the /r/mechanicalkeyboards wiki. I've never actually followed any of them or done anything like this yet, but they sure seem fairly thorough.

As far as teensy software, the teensy loader and a .hex file are all you'll need.

[Madhias]

Of course there are also all guides from matt3o here at DT regarding handwiring: workshop-f7/brownfox-step-by-step-t6050.html

[Mattr567]

What software would I use on the teensy? Any good guides for handwiring?

There are some handwiring guides in the /r/mechanicalkeyboards wiki. I've never actually followed any of them or done anything like this yet, but they sure seem fairly thorough.

As far as teensy software, the teensy loader and a .hex file are all you'll need.

So I just use the normal TMK hex for the Pingmaster even if its handwired?

Of course there are also all guides from matt3o here at DT regarding handwiring: workshop-f7/brownfox-step-by-step-t6050.html

Thanks.

So I desoldered the Pingmaster in prep for the mod. Didn't take out the switches since it's like impossible. Was worried that with handwired switches they might come off when cap pulling since there isnt a PCB, but this wont be a problem with SKCC.

Now I have to make a choice...

[Mattr567]

As a update to this, its happening! Cutting the case tormorrow. Also its going to be painted industrial grey

So I am keeping the original PCB, and going to rewire the pull up resistors I'm cutting off, using it as a breadboard I'm gonna convert the PCB first before any cutting so i'm not going in blind. Also in prep for cutting the PCB i'm planning to run all the wires I need to and take pictures of each connection individually beforehand so I don't miss anything

I feel like an idiot for tracing all those traces rather than just using a multimeter lol, idk why I didnt think of it

Turns out the Pingmaster case is painted! I didnt know this when I had to wipe off some sharpie marks and it got everywhere

The weird thing though is that unlike the Model F where the texture comes from the paint, the plastic on the pingmaster has the texture rather than the paint so its rather useless! Idk why they did this. The color is the same, just more matte than the paint as you can see here:


Ready to cut


More updates soon!

[taylorswiftttttt]

removed

[Mattr567]

What saw will you use?

A hacksaw.

[Wingklip]

Maybe you could save it for a numpad lol. Keeping the original off cut and enveloping it in some custom shroud of plastic, 3d printed then painted

[seebart]

Great project, I love the name "P77". "Pingmaster" is so negative. Looking foreward to your updates!

[Mattr567]

Well, the deed is done! The cut is pretty straight, but sanding will fix any little errors.




Threw the plate in to see how it looks:




Next up is the plate! Gotta re-locate that stand off when its more put together


All the parts ill need Time to start sanding!

[Mattr567]

More progress! Got the case pretty much perfect, and cut the plate to size!

Final cut:


Case:


Now waiting for some epoxy to come as well as some 24 gauge wire for the PCB.

Another thing to do is find IBM Industrial Gray spray paint

[Wingklip]

A little too eager there on the cutting my boy xd

Make sure you epoxy that keyboard nicely

[Mattr567]

Well started to epoxy but it dries really fast and I only managed to do the little gap piece I needed. Lesson learned, and no harm done

Before sanding:


After sanding:


Its perfectly flush and smooth, ready for paint. You won't be able to see the gap Have some more epoxy on the way so I can do the rest.

[Mattr567]

So yeah, I did it It fits together just fine, and looks so amazing!

Details:




Keycap clears the case perfectly

[just_add_coffee]

Looking good, Mattr567! Thanks for the update!

[Wingklip]

Looks like a really tricky job to get uniform. To get the best results I think you need to sand down the case and then repowder coat it

[Harshmallow]

Great job man! That's gotta be a lot of work, but I'm sure it's rewarding. BTW, my Model F AT top case is painted/textured the same way - I've tried describing it to others but I'm not sure how common it was. I'm going to scratch off all of the paint with my fingernails one of these days as the plastic underneath is the same color.

[Wingklip]

Great job man! That's gotta be a lot of work, but I'm sure it's rewarding. BTW, my Model F AT top case is painted/textured the same way - I've tried describing it to others but I'm not sure how common it was. I'm going to scratch off all of the paint with my fingernails one of these days as the plastic underneath is the same color.

Hope to high heaven you aren't serious

[Harshmallow]

Great job man! That's gotta be a lot of work, but I'm sure it's rewarding. BTW, my Model F AT top case is painted/textured the same way - I've tried describing it to others but I'm not sure how common it was. I'm going to scratch off all of the paint with my fingernails one of these days as the plastic underneath is the same color.

Hope to high heaven you aren't serious

Why wouldn't I be? It's already peeling off in many places. I wouldn't do it if it wasn't already damaged.

[Wingklip]

What the hell..... I've never seen bad paint on ANY IBM keyboard

[Harshmallow]

What the hell..... I've never seen bad paint on ANY IBM keyboard

Well I could take a photo to show you, but it's really just a case of someone rubbing away the bottom portion with their wrist over years of use - then the paint started peeling/flaking off. Since the plastic is textured and also beige, it would look better if the paint were just removed completely from the top panel at this point.

[seebart]

What the hell..... I've never seen bad paint on ANY IBM keyboard

Actually some of the surface is rubbed off on my Beamspring Displaywriter in two positions where the user would have rested his/ her hands / arms. I don't have a picture of it now.

[Mattr567]

What the hell..... I've never seen bad paint on ANY IBM keyboard

Well I could take a photo to show you, but it's really just a case of someone rubbing away the bottom portion with their wrist over years of use - then the paint started peeling/flaking off. Since the plastic is textured and also beige, it would look better if the paint were just removed completely from the top panel at this point.

Regular 91% isopropyl alcohol took the paint right off the P77 case, so you could scrub with that and it should come off clean.

Hasu shipped my converter (yeah I bought one lol) so when that arrives I can get to PCB cutting and re-wiring!

[Wingklip]

What the hell..... I've never seen bad paint on ANY IBM keyboard

Well I could take a photo to show you, but it's really just a case of someone rubbing away the bottom portion with their wrist over years of use - then the paint started peeling/flaking off. Since the plastic is textured and also beige, it would look better if the paint were just removed completely from the top panel at this point.

Regular 91% isopropyl alcohol took the paint right off the P77 case, so you could scrub with that and it should come off clean.

Hasu shipped my converter (yeah I bought one lol) so when that arrives I can get to PCB cutting and re-wiring!

WHAT?! NANIIIIIIIIIIIIIIIIIII

[Mattr567]

WHAT?! NANIIIIIIIIIIIIIIIIIII

Lol. I just didn't want to deal with converting it, with all the wiring ill have to do to it already Its something I know that will work as well as being compact and external (although I know people have made their own external converters).

[Wingklip]

WHAT?! NANIIIIIIIIIIIIIIIIIII

Lol. I just didn't want to deal with converting it, with all the wiring ill have to do to it already Its something I know that will work as well as being compact and external (although I know people have made their own external converters).

I managed to make my own using a pro micro and some ancient DB9 Cable I had.

But seriously though, the paint rubs off using alcohol? unheard of