geekhack

geekhack Projects => Making Stuff Together! => Topic started by: infiniti on Tue, 12 August 2014, 23:00:09

Title: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Tue, 12 August 2014, 23:00:09
Spinning off from a discussion on how to relocate the LED from the bottom of an MX switch to the top without physically rotating the switch  (http://geekhack.org/index.php?topic=61422.0), I remember saving these pics before but I don't remember from where.  I just remember that the guy that made them didn't want to make more to sell or something.

So, let's make something together!

The idea is simple enough but I need help:
1. I don't know how to design a PCB
2. I don't know where to have these manufactured
3. While I have the time, I don't know if I can properly run this as a GB


Pictures of the idea:

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/001.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/002.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/003.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/004.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/005.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/006.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/007.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/008.JPG)

DAT ESC
(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/009.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/010.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/011.JPG)

(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/012.JPG)
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: FrostyToast on Tue, 12 August 2014, 23:03:29
You have me interested! The lighting looks so consistent and clean! Might get a full set if I like the colours and the cost is relatively low
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: IvanIvanovich on Tue, 12 August 2014, 23:12:21
Hey that's actually pretty ****ing genius. You could even use 2 color smd led of the same voltage values, ie like blue/green, white/purple, yellow/red... etc. Get really nuts with bi colors so they flip flop colors on lock keys and things.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: FrostyToast on Tue, 12 August 2014, 23:14:28
Getting a PCB made for this would seem to be extremely simple. The main issue is figuring out if you want the buyers to solder the SMD components themselves or have that pre-done.
As someone with no soldering experience whatsoever, I don't feel like doing 200 SMDs.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: mashby on Tue, 12 August 2014, 23:21:56
That's pretty wild!
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: berserkfan on Tue, 12 August 2014, 23:51:04
Getting a PCB made for this would seem to be extremely simple. The main issue is figuring out if you want the buyers to solder the SMD components themselves or have that pre-done.
As someone with no soldering experience whatsoever, I don't feel like doing 200 SMDs.

The idea is extremely good and gets rid of the uneven lighting complaint.

The execution is tough. Exactly; I don't want to solder so many more teeny weeny things on a board already full of teeny weeny things.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: IvanIvanovich on Tue, 12 August 2014, 23:54:35
The best execution of this would be to have them made on flexi so they fit INSIDE the switches, but that would require clear tops.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: Vibex on Wed, 13 August 2014, 00:02:19
These would be really cool, definitely interested in some if this became a GB. :thumb:

The best execution of this would be to have them made on flexi so they fit INSIDE the switches, but that would require clear tops.
This would be awesome too. ;D
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Wed, 13 August 2014, 00:05:59
With sufficient volume, I suppose the manufacturer could solder the SMD LEDs on.

I'm bugging sprit if his manufacturing contacts can do this.  Anyone else I could talk to about making this?

== == == == ==

The best execution of this would be to have them made on flexi so they fit INSIDE the switches, but that would require clear tops.

That's an interesting idea!  It could replace the sticker.

Wouldn't it interfere with the contact leaf inside though?
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: IvanIvanovich on Wed, 13 August 2014, 00:08:01
How so? It would be exactly like a sticker. The only thing I'm not 100% on is clearance for the smd led on both sides. There are ultra tiny smd led though so I'm sure something could be made to work.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: dorkvader on Wed, 13 August 2014, 02:54:31
make sure to go with a very thin PCB. The original in the pics is much thinner than most PCBs, and you'll very much run into clearance issues with keycaps if your PCB is too tall.

I'd be down for a KB's worth! I think this'll much more evenly light a keycap.

Bytheway, I think you usually pick the LED and ship a roll of them (usually 4000 or so) to the fab who will then combine them with the PCB you have. Some places will have common parts on hand, but IDK if they'll have SMD LEDs in that size.

as to fitting inside the switches: could be done, but I'm not sure why you'd want to. It'd make it awfully hard to close, especially with brittle cleartops (great idea with the white top though: also acts as a diffuser.) Not sure about clearance of LED and the switch leaves on the "back" of the MX switch though. You could maybe do one LED on the front and 2 on the sides.

You should look into thin PCBs and what fabs offer them. I looked into this a little when I was looking into getting a flex PCB done for an M with NKRO, but sadly I needed PCB files to get a quote from anyone.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: Oobly on Wed, 13 August 2014, 03:10:15
I really like the idea of these, but I fear they will foul a lot of existing keycaps. The ones on the board shown are very "square" and it seems they fit fine, but I would be quite concerned about Cherry or DCS caps.

Maybe if you make them the same width on both edges (like the thinner top edge) then bend the legs when fitting them they would work with more keycaps.

I'd love to get a bunch of these for my KBT Pure, they would make the backlighting usable with so many more keycap sets!
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: AGmurdercore on Wed, 13 August 2014, 05:30:58
OMG it love this, if this becomes a thing i am for it 100%!
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: feizor on Wed, 13 August 2014, 06:44:05
Would keycaps be hitting these pcbs as you type?
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Wed, 13 August 2014, 10:47:28
How so? It would be exactly like a sticker. The only thing I'm not 100% on is clearance for the smd led on both sides. There are ultra tiny smd led though so I'm sure something could be made to work.

I realized that there were SMD LEDs smaller than 0603 that could easily fit in the red portion.  I don't think I can hand solder something smaller than 0603.
(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/MISC/IMG_0074_s.jpg)

I think I'll take a pass at trying to make these fit inside the switch.

= == === ==== =====

make sure to go with a very thin PCB. The original in the pics is much thinner than most PCBs, and you'll very much run into clearance issues with keycaps if your PCB is too tall.

I'd be down for a KB's worth! I think this'll much more evenly light a keycap.

Bytheway, I think you usually pick the LED and ship a roll of them (usually 4000 or so) to the fab who will then combine them with the PCB you have. Some places will have common parts on hand, but IDK if they'll have SMD LEDs in that size.

as to fitting inside the switches: could be done, but I'm not sure why you'd want to. It'd make it awfully hard to close, especially with brittle cleartops (great idea with the white top though: also acts as a diffuser.) Not sure about clearance of LED and the switch leaves on the "back" of the MX switch though. You could maybe do one LED on the front and 2 on the sides.

You should look into thin PCBs and what fabs offer them. I looked into this a little when I was looking into getting a flex PCB done for an M with NKRO, but sadly I needed PCB files to get a quote from anyone.

I think I need some professional help figuring this out.

Any volunteers for technical advice and PCB design? ;D

= == === ==== =====

Would keycaps be hitting these pcbs as you type?

Probably and I think it'll need translucent white o-rings (http://www.ebay.com/itm/150pcs-White-Keycap-Rubber-O-Ring-Switch-Dampeners-For-Cherry-MX-Replace-Part-/191233644953?pt=LH_DefaultDomain_2&hash=item2c8669d999).
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Wed, 13 August 2014, 22:46:56
I consulted with GON regarding the technical matters of manufacturing, assembling, and installing these.

The gist of things:

So, when was the last time something seemingly unnecessary stopped me from modding a keyboard? :))

Still loking for a manufacturer and someone to help design. :cool:
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: FrostyToast on Wed, 13 August 2014, 23:42:44
I don't understand how this could be so hard to get aligned with the switch, but how much easier would it be if you put these into SIPs?
Assuming that you had very good tolerances with manufacturing so that every little thing was practically the same, wouldn't this be a walk in the park with SIPs?
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: MOZ on Thu, 14 August 2014, 07:11:58
PCB should be simple enough once the design is set. I do have my doubts on interference with thicker and lower profile keys.

If noone else is willing to, I can do the PCBs.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Thu, 14 August 2014, 10:45:45
I don't understand how this could be so hard to get aligned with the switch, but how much easier would it be if you put these into SIPs?
Assuming that you had very good tolerances with manufacturing so that every little thing was practically the same, wouldn't this be a walk in the park with SIPs?

I didn't consider using SIPs to line up the leads.  That should indeed make things easier.

== == == == == ==

PCB should be simple enough once the design is set. I do have my doubts on interference with thicker and lower profile keys.

If noone else is willing to, I can do the PCBs.

That would be great MOZ!  As far as design is concerned, it just needs to sit on top of the switch like this:
(https://dl.dropboxusercontent.com/u/20523800/GH%20Pictures/2014-07-15b%20LED%20Mod/007.JPG)

Yeah, it probably will be of no use if used with thick keycaps but it's mainly to provide even distribution on backlight keycaps or thinner keycaps.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: Melvang on Thu, 14 August 2014, 11:10:47
I might be interested in a couple.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: nubbinator on Thu, 14 August 2014, 22:33:08
PCB should be simple enough once the design is set. I do have my doubts on interference with thicker and lower profile keys.

If noone else is willing to, I can do the PCBs.

I have serious doubts as well.  It's a cool idea and I'm sure there has to be a better way.  My mind is just blank on it.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: Findecanor on Thu, 14 August 2014, 22:54:03
make sure to go with a very thin PCB. The original in the pics is much thinner than most PCBs, and you'll very much run into clearance issues with keycaps if your PCB is too tall.
Yep. It would work with OEM profile keycaps but with Cherry profile which has less clearance, it would shorten the key travel. And forget about using O-rings to dampen bottoming out.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Fri, 15 August 2014, 10:04:24
I believe it is time that I begin to experiment with some plastic card and copper tape to make a proof of concept.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: margo baggins on Fri, 15 August 2014, 12:03:24
if you need any help with assembly happy to build those little guys if that helps anyone.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: damorgue on Fri, 15 August 2014, 12:36:45
Posting to find my way back. It looks interesting, the only thing which worries me a bit is the height, especially when the LEDs are placed in the middle where the reinforcements of most caps are placed.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: dorkvader on Fri, 15 August 2014, 22:47:07
if you need any help with assembly happy to build those little guys if that helps anyone.
Same here.

Posting to find my way back. It looks interesting, the only thing which worries me a bit is the height, especially when the LEDs are placed in the middle where the reinforcements of most caps are placed.

I was thinking about that, I wonder if sourcing 4 LEDs would be better: you could make it dimmer and place them just off the center to avoid that.

Or maybe three LEDs. Two can go in the back avoiding the keycap support (and maybe have a small cut in the PCB to get more clearance) and one can be mounted upside-down in the front, with a hole over it.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: Oobly on Sat, 16 August 2014, 03:29:43
4 LED's sounds good, in the corners. Would give a very consistent backlight. The brightness should lower per LED due to having current limiting resistors. The current through each of the 4 should be 1/4 of what was going through the single "normal" LED. I think this would make ANY keycaps look good  :D

Personally, I don't care about orings, I trampoline mod all my boards.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: infiniti on Sat, 16 August 2014, 04:09:26
Apparently copper tape is proving to be harder to come by than I expected.  I'll probably order some from Amazon if I can't find anything by Wednesday.

'good to know there's a lot of you interested in helping assemble and stuff! :thumb:
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: FrostyToast on Sat, 16 August 2014, 19:37:50
I would only go for more than 2 LEDs if it doesn't drastically increase the cost. If it's a do it yourself sort of thing then it should be fine as I can just solder 2 on assuming you can run these in parallel.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: Oobly on Mon, 18 August 2014, 03:15:08
For those who like to torture themselves, you could superglue 4 LEDs to the corners of the housings and them wire them together with magnet wire... LOTS of work, but would look pretty darn good.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: heedpantsnow on Mon, 18 August 2014, 07:33:53
Cool!  I'm interested, though I have no skills to add here...
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: 0100010 on Tue, 19 August 2014, 14:06:49
PCB should be simple enough once the design is set. I do have my doubts on interference with thicker and lower profile keys.

If noone else is willing to, I can do the PCBs.

I have serious doubts as well.  It's a cool idea and I'm sure there has to be a better way.  My mind is just blank on it.

Could you just not direct wire the LED, using stiff wire bent into a square shape?

EDIT : ipotato pic of a bent paperclip plus some photoshop example :

(http://s3.postimg.org/4gx6z8vf7/dual_led.jpg)
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: bpiphany on Mon, 25 August 2014, 08:35:58
PCB should be simple enough once the design is set. I do have my doubts on interference with thicker and lower profile keys.

If noone else is willing to, I can do the PCBs.

I have serious doubts as well.  It's a cool idea and I'm sure there has to be a better way.  My mind is just blank on it.

Could you just not direct wire the LED, using stiff wire bent into a square shape?

EDIT : ipotato pic of a bent paperclip plus some photoshop example :

Show Image
(http://s3.postimg.org/4gx6z8vf7/dual_led.jpg)


 :thumb: Like for creativity and perfectly sufficient potato pic.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: FrostyToast on Tue, 26 August 2014, 20:15:01
PCB should be simple enough once the design is set. I do have my doubts on interference with thicker and lower profile keys.

If noone else is willing to, I can do the PCBs.

I have serious doubts as well.  It's a cool idea and I'm sure there has to be a better way.  My mind is just blank on it.

Could you just not direct wire the LED, using stiff wire bent into a square shape?

EDIT : ipotato pic of a bent paperclip plus some photoshop example :

Show Image
(http://s3.postimg.org/4gx6z8vf7/dual_led.jpg)


I would prefer to have the LEDs in parallel, but that might not even be possible with a pcb
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: dorkvader on Tue, 26 August 2014, 21:22:46
I would prefer to have the LEDs in parallel, but that might not even be possible with a pcb
That is indeed possible with a PCB.

It is in fact not likely to have the LEDs in series, as (for blue, white, etc.) LEDs with a Vf over 2.5, they cannot be powered in series by a 5v supply.

Also the picture show two LEDs in parallel. I'm not really sure what you're getting at.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: FrostyToast on Tue, 26 August 2014, 21:46:05
I would prefer to have the LEDs in parallel, but that might not even be possible with a pcb
That is indeed possible with a PCB.

It is in fact not likely to have the LEDs in series, as (for blue, white, etc.) LEDs with a Vf over 2.5, they cannot be powered in series by a 5v supply.

Also the picture show two LEDs in parallel. I'm not really sure what you're getting at.

So they are...
Well I guess we have to see which is more easy to make and manufacture.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: dorkvader on Tue, 26 August 2014, 23:11:44
So they are...
Well I guess we have to see which is more easy to make and manufacture.
You mean series vs. parallel: you can do either one equally easily with a PCB, but only parallel makes sense in this case.

Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: bpiphany on Wed, 27 August 2014, 00:41:40
Actually parallel loading LEDs is not always a very good idea. You really should have one resistor in series with each LED. Read up on thermal runaway if you want to know one reason why. Keyboard LEDs aren't usually driven very hard so this may not be a big issue here. Even if two LEDs probably won't break (as long as none of them does) there can be other side effects. A slight difference in forward voltage across the LEDs can lead to a big difference in brightness.
Title: Re: MX LED Mod -- an idea that needs a PCB
Post by: dorkvader on Wed, 27 August 2014, 08:47:09
Actually parallel loading LEDs is not always a very good idea. You really should have one resistor in series with each LED. Read up on thermal runaway if you want to know one reason why. Keyboard LEDs aren't usually driven very hard so this may not be a big issue here. Even if two LEDs probably won't break (as long as none of them does) there can be other side effects. A slight difference in forward voltage across the LEDs can lead to a big difference in brightness.

Yes, the main reason I recommended it is that we are giving each LED less than half it's rated current so if one fails we won't have an issue.

If you're worried about brightness levels, you should be hand-matching your LEDs anyway.