3D printer capable of printing keycaps consistently?

[Eszett]

Dear makers! I'm considerung buying a Monoprice MP Select Mini v2 3d printer to print out my own keycaps. But I'm not sure if the printer is capable of printing consistently the very tiny parts of the stems.. will it turn out to consistent and usable results? Here is a link https://www.monoprice.com/product?p_id=21711 The supported filament size is 1.75mm, that is probably too thick to print stems? Maybe you can recommend me another reasonable priced printer that's better for this job?

[MajorKoos]

Possible - yes. 
Are the results good enough for daily use - IMO no.
The best results I obtained were at 0.05mm layer heights with a 0.15mm nozzle (at those resolutions it can take 2 hours to print a single key), but the stem felt very gritty from the layers.

Cases & switch plates work quite well if you have enough space on the x/y axis.

Not sure if the monoprice printer is accurate enough, what bed adhesion is like or how it handles retractions, but that's an entirely different rabbit hole worthy of it's own thread.  The one I printed these on cost a fair bit more.

[Coreda]

btw the text color after 'I'm considering buying a' makes the rest virtually invisible.

[Eszett]

btw the text color after 'I'm considering buying a' makes the rest virtually invisible.

Sorry, but it's due to the messy forum board software, which doesn't allow me to see the text in raw format mode. I tried to fix the original post, is it better readable now?

[Eszett]

@MajorKoos thanks for the pictures. From that, I can see that even your higher priced printer with 0.05mm layer height and 0.15mm nozzle gives pretty rough looking results. I'm abit turned down :-(

[Coreda]

btw the text color after 'I'm considering buying a' makes the rest virtually invisible.

Sorry, but it's due to the messy forum board software, which doesn't allow me to see the text in raw format mode. I tried to fix the original post, is it better readable now?

Yea. The BBcode editor shows in the raw formatting code for me though; strange.

[Eszett]

Yea. The BBcode editor shows in the raw formatting code for me though; strange.

Oh, just found there is a "toggle view" button on the very right of the toolbar. Got it!

[MajorKoos]

@MajorKoos thanks for the pictures. From that, I can see that even your higher priced printer with 0.05mm layer height and 0.15mm nozzle gives pretty rough looking results. I'm abit turned down :-(

SLA and SLS printers will give much better results - there are a number of makers who sell keycaps on Shapeways which are made using SLS.
FDM printers won't be able to provide the resolution or tolerences needed. 

Personally I wish I'd spent my money on a Nomad 883.  Then I'd be able to make keycaps, PCB's and cases.

[Leslieann]

If you want to do keycaps, you really want a resin printer, and that gets expensive (and messy!) really fast. Some of it is also toxic until cured.
Basically not something you will be doing in your bedroom, you need a dedicated work area, which will get covered in resin.

SLS is no better, the dust gets everywhere, cleanup is a nightmare, and again, the material is quite costly. These are even less home friendly than the SLA machine.

You can however hire someone to do prints from 3d hubs, which is waaaay cheaper than sites like Shapeways. I woudl recommend starting that way and see if you get anything even remotely as good as you want.

[CompileWithStyle]

SLA printer would give you the detail but they are expensive. The filament printers are going to give you a meh result and you'll have cleanup work afterwords.  If you want to print stems and fixtures than they might work but after doing a few rounds of keys the results I've gotten have made me just go back to traditional sculpt and cast with a synth.

[tp4tissue]

IMHO it's doable, but what you would do is MILL the cross out after printing, instead of printing the empty space.

And obviously use solid fill.

The only thing precise enough to do the whole process would be powder printers.. whiiich are half million each.

[Leslieann]

IMHO it's doable, but what you would do is MILL the cross out after printing, instead of printing the empty space.

And obviously use solid fill.

The only thing precise enough to do the whole process would be powder printers.. whiiich are half million each.

Actually there is a $10k benchtop SLS powder printer available.
The problems I mentioned still stand.

Milling most FDM printed parts would probably require liquid cooling to get decent results, meaning a pretty decent high end mill just to mill low end printed, low end caps. If you have that, why print them at all when you could just mill Delrin or something and skip the 3d printer entirely and get something better. Even a cheap, used cnc mill could handle that for not much more than the cost of a printer, sometimes less.

[MajorKoos]

IMHO it's doable, but what you would do is MILL the cross out after printing, instead of printing the empty space.

And obviously use solid fill.

The only thing precise enough to do the whole process would be powder printers.. whiiich are half million each.

Actually there is a $10k benchtop SLS powder printer available.
The problems I mentioned still stand.

Milling most FDM printed parts would probably require liquid cooling to get decent results, meaning a pretty decent high end mill just to mill low end printed, low end caps. If you have that, why print them at all when you could just mill Delrin or something and skip the 3d printer entirely and get something better. Even a cheap, used cnc mill could handle that for not much more than the cost of a printer, sometimes less.

I spent a lot of time trying to print keycaps on my Ultimaker 2.
Using 40 micron layers and a 0.15mm nozzle with ColorFabb NGEN gave me the best results, but they were never perfect.
The walls of the stem were never perfectly even (layers) so they grate a bit in the switches and there isn't any slack to make them thinner to compensate.  Overheating the part is also a big issue when printing something that small.  The horizontal orentation of the layers also makes the stems tend to shear along layer boundaries. 

In the long run I think I'd have been better off with something like a Carvey or Nomad 883.

[vvp]

You can print Cherry MX keycap stem with an FDM printer just fine. It only needs a different stem design. Make stem base as 5x6.6 mm rectangle with the cross inside. Print in ABS. Pour acetone into the cross (up to about half of the cross volume). Let it soak for about 5 minutes. This softens the plastics. Insert the keycap on a switch. This forms the cross nicely. Pull it out of the switch. Let it dry for about an hour. The stem is done. It will hold well.

[MajorKoos]

You can print Cherry MX keycap stem with an FDM printer just fine. It only needs a different stem design. Make stem base as 5x6.6 mm rectangle with the cross inside. Print in ABS. Pour acetone into the cross (up to about half of the cross volume). Let it soak for about 5 minutes. This softens the plastics. Insert the keycap on a switch. This forms the cross nicely. Pull it out of the switch. Let it dry for about an hour. The stem is done. It will hold well.

Got some example photos of the stem?

I'm not a fan of the square stem approach because of how the outside of the stem rubs against the inside of the switch housing.
Even with acetone smoothing it's more friction than I care for.

[vvp]

Just make the stem square but still small enough so that it does not rub. I do not have rubbing problem. It may depend also on how wobbly the switches are. Anyway I typically just buy some cheap keycaps and do not print them. I doubt you cannot design a square stem which would not rub when you print it with 0.35 mm nozzle or smaller ... really the only possible rubbing place is at the two locations where the cross is near the rectangular opening in the top switch cover. And there is enough space there. The example bellow was printed with 0.5 mm nozzle. I often print with 0.75 mm nozzle now since it is quicker. And when I need thin walls I cheat and tell slicer to use 0.5 mm extrusion width at the walls.
I just wanted to chime in that is is possible to print usable stems. I thought that it would not possible in the past too but then I got the idea that I do not need to design them the same way as they are on the injection molded keycaps.
Here is the example of the stem on a printed keycap:

Here is how the stem is actually designed.

Notice that the "rectangle" is thicker around the cross. As the plastics cools, the thicker part will shrink and the final printed stem wall looks nearly planar.  The cross is small just after printing (again because of shrinking while it cools). But the acetone will soften it and you can press the cross opening to have just the right side by forcing the switch stem into keycap stem while it is soft. Then pull it out and let it solidify.

Maybe play with the dimensions of your rectangular stem a bit. I'm sure you can find the right one for your 3D printer ... so that it does not rub.

[MajorKoos]

It may depend also on how wobbly the switches are.

Pretty much. 
Not really an issue with Cherry, but on my Zealio boards these tend to scrape a bit near the bottom of the stroke if I'm a bit off center on the press.

[vvp]

Try to make it thinner at the places it scrapes. Probably it will be at the top and bottom cross ends. It does not matter if the size will be slightly smaller and the stem will not fit. When you soften it with acetone then you can form the cross opening fine by pressing it on a switch. If it is still not helping then it may be a lost cause with Zealio switches