@Karl_Buchka I’m deeply inspired by your work, and decided to create one of my own for x31.
I’ve got some questions. I’m wondering what pins you are using from the internal connector. It seems like it only gives one USB and rest are for keyboard rows and colums. Are you using that one USB for running all peripherals? Perhaps there’s a USB hub on the daughter board?
I’m also wondering what that m.2 connector on daughter board is for.
Any advise would be so appreciated. Awesome work, and thanks!
Thank you for the kind words! The only pins I’m using on the input cover connector are for USB, 5V power, and the power switch input.
There is no USB hub on that board. The USB D+/D- lines are run directly to the corresponding pins on the Teensy microcontroller.
The additional USB-A ports and Ethernet port are broken out from one of the left side USB-C ports on the Framework mainboard. Those are routed via a custom 4-port USB hub that I designed.
The M.2 connector is a 1:1 breakout of the M.2 connector on the right side of the mainboard. Since the mainboard is pushed up against the right side of the case, I didn’t have enough room to install the Wifi/BT module. I designed a 7.5mm wide board with an M.2 card-edge interface that flips all the conductors 180 degrees onto a high density FFC cable, which then runs to my input cover board and breaks them back out to the M.2 connector you see.
Let us know how it goes when you get a moment! Absolutely love the work you’re doing here, as someone who has also come from a long line of Thinkpads to using Frameworks now.
JUST saw this and I can only say this is an absolutely amazing project as someone who uniquely used thinkpads a long time ago when they were the greatest laptops around. Resurrecting such notebooks is one of the big contributions of Framework ;). What an amazing work.
I got a 701cs from a customer over a year ago to repair, but it was a total basket case with numerous faults related to the main battery exploding and leaking all over the board. The customer abandoned the machine, so after it sitting in pieces off to the side of my bench staring back at me that long, I decided to try doing something with it, which is when I found this project.
I’ve mostly figured out what I’m going to do for the screen and motherboard, but I’m completely baffled on the butterfly keyboard.
The problem I’m having is with the two keyboard connectors, through some extensive research, I believe it’s called an “interstitial flat flex cable” with a 0.3mm pin pitch. But I cannot find this connector anywhere. I’ve ordered a few sample connectors, and they always end up being microscopic and nowhere near the correct size. After 10 or so failures, I gave up and removed the ones from the old main board, and then ran into another problem, the PCB mounting pins are also not a standard size. I’ve bought several of those FFC/FPC adapter boards from Ali Express, but none of those are the correct pin pitch. It seems to be something like 0.55mm.
I was wanting to know if anyone has a source for those weird keyboard cable connectors, and potentially a generic adapter board that they can sit on? I really want to have to avoid soldering wires directly to the flex cables and permanently alter them. Currently I have a jank setup using an 80 conductor IDE ribbon cable, which just happens to match the pin pitch on the IBM connector. I’d prefer not to use this method, because it takes up too much space. The janky adapter works well enough with a TeensyDuino that I can get half the keyboard working at a time, but it’s not consistently reliable.
The keyboard and trackpoint FFC connectors are from the Molex 52204 series. They are 0.625mm pitch. Molex no longer manufactures these connectors. I purchased new-old-stock from Quest Components.
I have breakout boards for these connectors that fan them out to a pin header. I’d be happy to send you a few if you want. Just DM me your contact info.
I’d love to get a few of those adapters, but since I have a new account, I can’t use the PM system. If you have another way of contact, I’d be glad to pay something for them.
Are the PCB files available? I could get one of the board fab companies to run some of them off.
Also, thanks for the link to those connectors. I’ve been pretty bummed I couldn’t find the right connector after a month of looking around.
I see you’re currently at “29m read time, 2 topics viewed, 21 posts read”
If you just click 3 more topics / threads and scroll through another 9 posts, then you should hit Trust Level 1, and be able to PM. You just need 5 topics viewed plus 30 posts viewed. Understanding Discourse Trust Levels
I never had a 701c but, like so many people, I have very fond memories of owning IBM branded ThinkPads - I think the models were XT21/22 T21/22. I don’t know how much of it is coloured by nostalgia now, but my memory would have me believe these were the best laptops I’ve ever used. They were solid and dependable. I’ve had a Lenovo ThinkPad for the last 10 years (waiting to be replaced with a FW16), but it’s just not the same.
Great case designs, great keyboard, good IOs, somehow the worst displays they were able to get their hands on XD.
Though I gotta admit as a think-pad fanboy, my favorite laptop case design is probably still the hp 8570w. It’s too big for me these days but it is the nicest mobile workstation build I know of.
The case design is nice, except for the cursed rubber coating that rots away. Unfortunately, Lenovo still uses it.
My 701cs has rubber rot all over, as does my much newer Lenovo X1 Carbon 6th gen.
It can stripped using IPA, which has an effect similar to paint stripper, it’ll make the coating mostly fall off in clumps and sheets without damaging the underlying plastic. The problem is what to replace it with. Rustoleum rubber paint gives you a nice finish, but no idea how long it will last. Enamel paints give you a durable finish, but they’re not the nicest on your hands.
@Karl_Buchka Just curious–I’m making progress on my T25 mod, but I’m increasingly thinking that it might be reasonable to attempt to just print a new lower case rather than modify the stock part (keeping the topcase / palmrest). Can you comment about the rigidity of the base that you printed?
@rednight39 so far I’ve only printed PLA versions of the bottom case and those have been plenty stiff enough. IIRC I’ve printed them with 1mm thick side walls.
Ultimately I want to get it printed on an MJF machine out of glass bead filled PA12. The PA12 has lower modulus of elasticity than PLA, so I expect it to be a little bit floppier.
Now that you’ve uploaded PCB designs, I think this can be a great help for a lot of DIY Framework builders, not just for Thinkpad designs but any case design where space is very limited.
For instance, I am facing a challenge on how to add power delivery and high speed data where there’s a very small clearance for the board’s USB-C ports. I’m not a electronics engineer expert and USB 3.x protocols are a complicated beast to me, so I will be watching this thread even more closely with the design updates that you make. Keep it up!
Thanks, @ccRicers! I assure you that I am just as intimidated as you about USB 3.x. Previous to this I had only ever piddled with USB 2.0. My design doesn’t include any power delivery provisions, so I can’t be of much help there.
Some updates: I’m waiting on some new parts for my 3D printer so I can do a final test print of the case before sending it off for manufacture.
I’ve put in a big push to finish up the USB hub design. It’s now at a state where I’d consider it done. Overall I’m pretty happy with it, but I’m hesitant to push the order button. I’m pretty much entirely self-taught in board design and I’ve never done anything this complex before. I’ve asked a friend who does board design professionally to review it and give me feedback. All the latest design files are in the github repo.
My friend hasn’t had a chance to review the hub design yet.
The Chinese new year added some delays to a board order I put in, so I’ve been waiting on those.
The parts for my 3D printer came in (upgraded my single head Prusa XL to a 5 head), so I got those installed and ran off a full batch of mechanical parts. I’m in the middle of doing (hopefully) a final test assembly of those parts now.
I also did a bunch of clean-up on the CAD side and uploaded all of the latest revisions to the github repo, as well as a WIP high level BOM and some annotations on which hardware goes where. I also uploaded all of my 3D scan data. Files are here: https://github.com/basketofkittens/framework701c/tree/main/Mechanical
Finished up the test assembly last night and I was satisfied enough to hit the order button on a glass-filled Nylon-12 MJF print of the bottom case from Xometry. It came out to just over $200. Should have it in my hands in a couple of weeks. The version I ordered is in the github repo.
I also assembled and tested the “USB U-turn” board that will connect the USB hub to the Framework mainboard. It’s essentially a tiny USB cable that makes a very tight 180 degree turn. The trace lengths on the diff pairs are matched, but since it’s only two layers there isn’t a hint of impedance matching. It’s not my proudest achievement, but it does work. I don’t have a fancy VNA to actually quantify the performance margins. I instead ran some DiskMark benchmarks on an external SSD and hit about 1GB/s consistently, which was the same as the commercial USB-C cable I usually use.