Model M 3D Printed Frame

[pjmelon]

Well time to start on my next project. I bought a 3D printer because I wanted to do more prototyping work.

The goal of this project is:
Full replacement of everything except the buckling spring mechanism in the model M. I plan on rebuilding the frame for the model M out of PETG plastic. I also plan on 3D printing keycaps. I have salvaged a trackpoint from an IBM rubber membrane keyboard. I also plan to 3D print an underlay out of rubber.

This is going to be a trial and error process. The first prototype below is made from red PLA (final version will be blue PETG). One thing I noted was that the mouse buttons are going to work a lot better miniguru style side mounted.

Given the print area is not big enough for a full size beyboard I will also need to learn how to seamless join PETG and other plastic.

[MrNorse]

Firstly, can I just say that I love how much of this you plan to 3d print.

I worked on a project a couple of years back where I printed a case out of multiple sections in PLA.

I'm not sure if PETG has similar properties but PLA has a huge problem of not dissolving easily, so solvent bonds are near impossible, which might mean coming up with fastening points on each edge that could bolt together. Mine were just little mounds designed to fit M3 fasteners and they worked pretty well, except the positioning resulted in some unwanted bowing and flex.

I'm also not sure how much internal space you're working with, so it's possible that option just won't do.

As far as making it seamless, add some epoxy clay in the joins, sand it back, then do a few coats of primer and sand that. I guess that will only work if you want it painted though.
If you intend on showing off the blue PETG, maybe just a regular 5 minute epoxy could work. It'll be messier because the epoxy will have a similar consistency to honey but at least it will dry clear.

Anyway, best of luck. I can't wait to see how it all turns out

[alh84001]

Interesting, You should probably contact lot_lizard, because he seems to have a lot of experience with this kind of stuff. Check out his M remodelling thread.

As for 3d printing keycaps, I have no hands-on experience, but I heard a lot of people mention that plastic used for 3d printing does not handle stress of continous day-in, day-out typing and that keys would crumble or chip relatively quickly.

[Ratfink]

PLA has a huge problem of not dissolving easily, so solvent bonds are near impossible

You must not be using the right solvent. Dichloromethane dissolves PLA readily, so glues such as Weld-onScigrip 16 work great for PLA. Be warned though, DCM is not a solvent to be taken lightly: it's much more harmful than e.g. acetone.

[drevyek]

There are a lot of threads that are really relevant to this, recently. You have the MF thread, with Phosphorglow's resin case; Wodan's thread on foam and damping material for the F/Beamspring; and the o-ring thread on 3D-printing sound-damping.

#D caps can come out well, but it highly depends on material. Getting the sizes correct may prove to be a challenge. Lot_lizard has some mocks/prototypes for MX adapters for BS, which would certainly be worth contacting about. I recall a thread on reddit a while back (may have been here too) of someone who 3D-printed their entire board- case and caps. If you can find the thread, PM them and ask about the durability of the materials; it may be also worth starting a thread specifically about printing caps, to get other's experience on it.

Looking forward to developments on this. Good luck!

[pjmelon]

Well doing more tweaking on the material. Printing a revised prototype out of ABS (had too much issues printing PETG and joining it). Methyl Ethyl Ketone does a very good job of joining and creating seamless welds.

For the keycaps the material is the critical choice. PLA lacks durability while PBS and PETG are more resilient. My plan is not to print the stem but to print slip ons.

Will post pics once I get something printed

[pjmelon]

Well done some work lately and done some design tweaks and printed in PETG. I side mounted the mouse buttons but not sure of the alignment as they are slightly to the right of centre. I also developed a way to seamless weld PETG by using melted ABS and then epoxy coat it on top.

Also worked on the keycaps. The best way to do this is to ABS print the keycap covers and use the original stem.

One thing I need to get hold of is a 3d model of the plastic top plate so that I can 3D print a TPE underlay similar to Phosphor Glows underlay. Can anyone help me here?

[pjmelon]

Ok so progress has been made.

Based on the previous design I 3D printed the frame out of PETG. I used dowel joints to hold everything together and make it all interlocking. I used melted ABS to secure the joints and make the joints less visible. I then used XTC-3D to give the glossy appearance.

For the underlay I designed and measured the key positions and got it 98% accurate.

For the electronics the model M and the trackpoint are both ps2 so I will hide a ps2 to usb converter on the inside.

Next up, creating the keycaps. Here I am going to get creative. 3D printed ABS does not have the durability for the stem but it does for the keycap if I use XTC-3D.

[ohaimark]

That actually looks sexy... I'd print mine in black and green (or red), though. Are you willing to release the files for other people with 3D printers?

[lot_lizard]

Next up, creating the keycaps. Here I am going to get creative. 3D printed ABS does not have the durability for the stem but it does for the keycap if I use XTC-3D.

Wow... I haven't seen this one in a bit. You have come a LONG way. Congrats on great work.


Could I make a suggestion?!? Instead of worrying about the keycaps, could you make an SSK case? The keycaps are in abundant supply. The SSK case, not so much. It would have a much bigger impact.

EDIT: Im not sure where you are located, but depending, I could send you the internals from an SSK to test with. AND... the trackpoint integration you have is lovely

[pjmelon]

ohaimark: will definitely post the files

lot_lizard: my reason for not choosing the SSK case was that I live on the Num pad with finance calculations at work. I also do have plenty of keycaps but what I wanted to do here is have the colors perfect. My plan is to print the keycaps in blue and 3D print letters at 0.4mm thickness in the yellow.

[lot_lizard]

Just curious... what was the cost(ish) for the current print? Assuming its a hollow/shelled print vs solid?

[pjmelon]

I bought a 3D printer so the cost per print is not that bad. It is more the fiddling around with the printer and the iterations involved in the design that are the issue. It took 3 designs for the frame to get it right and about 6 for the underlay.
Having a printer is good because you can iterate and hone in on the right design.

[andresteare]

hi! do you still have de files for the models?

[kbdfr]

Now that's what I call necroposting