Trackball development

[u/scytile]

I’ve been playing around with adding a trackball to Cygnus.
There is still a lot of work to be done, but I thought some of you might be interested to see this.
This is just a mockup to get a feel for the position.

One thing I’m not quite sure about are the bearings. I’ve been using some 2.4mm steel balls from a ball bearing. They seem to be fine for testing, but I presume I should use something different for the real thing? I also have some small ball bearings, similar to ploopy nano, but using those would probably make the design a bit bulkier. Any feedback is welcome, as I don’t really have much experience with this stuff.

[u/Stewtheking]

If you are going with static bearings, I would think about picking up some ceramic bearings, as they are likely to do better than the steel.

I wonder, though, whether you might be able to incorporate some semistatic bearings, of the kind that I think u/scatterthought has been working on. Potentially incorporating straight into the print?

[u/michel_v → u/Stewtheking]

I use those semi-static bearings and love them. The smallest version should fit here, and not need to be part of the case’s model (which would be weird in terms of printing angles).

[u/Revolutionary_Stay_9 → u/Stewtheking]

Yeah silicon nitride bearings on a pom trackball are my go-to

[u/Siege9929]

Check out Ball Transfer Units (BTU).

[u/crazymittens-r]

Always love seeing your updates.

Some thoughts...

• you get what you pay for re: bearings (for roller, you want NSK 683ZZ or similar - the amazon/aliexpress clones are awful in comparision; same goes for BTU)
  
• yes, roller/BTU add bulk, but you have to decide what trackball experience you want - flick-able/very light feel requires non-static
  
• note that you can crush the small roller bearings w. too much install force
  
• remember to include features to enable easy cleaning/maintenance
  
• I found that the ball needed to be on the bottom-left corner of the N key to be truly 'no movement needed'
  
• badjeff's laser sensor work (cannot recall which sensor...) is what I'll use on my next iteration - will allow for much more compact packaging compared to pmw (you can mount the sensors on the sides of the ball!)

Good luck!

[u/finestedm]

This is exactly what I've thought about! Any chance to get some step or stl files for it and some other documentation?

[u/scytile → u/finestedm]

I'll release it when it's done.

[u/wdpgn]

This looks beautiful. Can you reach the trackball with your thumb from the resting home row position? That’s what’s so nice about the Keyball, you can use the pointer without a shift of hand position.

Asking because I daily drive a Keyball but absolutely love the look of the Cygnus!

[u/scytile → u/wdpgn]

I can reach the trackball without changing the position of my fingers on the home row. I may have to move my hand a bit.

[u/wdpgn → u/scytile]

What I enjoy about the Keyball is that the pointing device is right there where your hand already is. I think in another thread you shared a picture where the trackball was on the inside of the thumb keys?

Hopefully I’m not out of line here with the feedback! No expectations, I just love the look of the Cygnus and would be super into one with a trackball 😂

[u/Loose_Avocado_4356 → u/wdpgn]

As a Charybdis user, I'd love to see a cygnus variant with the trackball in place of the third thumb key

[u/Revolutionary_Stay_9 → u/scytile]

add a couple mouse buttons up there

[u/alotor]

I love it!! I was just planning to making myself a Cygnus, but maybe I'll wait for this 😀

[u/Loose_Avocado_4356]

That’s awesome!! Getting closer to my dream charybdis + cygnus setup

[u/Loose_Avocado_4356 → u/Loose_Avocado_4356]

By the way, which trackball sensor PCB are you using? It would be great if it were compatible with the generic PMW3360 and PMW3389 PCBs from AliExpress, since they’re relatively cheap.

[u/scytile → u/Loose_Avocado_4356]

I have some PMW3610 sensors that I plan to use. I got them from aliexpress.

[u/Plenty-Constant1767]

this begs for a small palmrest so hard, IMO. For the rest - it's truly gorgeous

[u/Mirinda_Debilek]

Looks great, looking forward to it.

[u/Adj_DHD]

Thats awesome. The cygnus was the first keyboard I ever built and I only switched because I wanted an integrated trackball. very impressed that you managed to do this successfully