ALPS spring surgery

[Chloe]

I shortened the spring in one of the cream ALPS in my Apple Extended Keyboard II and the switch is much lighter now, even lighter than Cherry MX browns. The actuation point is the same. I only cut a little off the spring.

I might do the whole keyboard depending on whether or not I can get used to the slightly stiffer feeling of ALPS switches. If I do, I'll try trimming a little less first to see if I can approximate the Cherry browns.

[lowpoly]

Did you pull the spring to the original length after cutting?

[Chloe]

I didn't. I fitted it as it is in the photo, with the trimmed end going into the stem.

[lowpoly]

And the cap didn't 'sink in'? Does it mean there's usually some pre-tension applied?

[Chloe]

There's no change to the stem height/protrusion. I think the leaf holds the stem up. Initially I thought shortening the spring might not affect the stiffness of the switch, just the force of the stem returning upwards.

[lowpoly]

Thanks.

[Chloe]

I did some activation force measurements using 1p coins and kitchen scales. These measurements are approximate. I've decided to do the whole keyboard as this will give me an idea of whether I will like the red Cherries as they activate at 45 ± 15 cN, but begin at 30 cN. Cherry browns begin at 40 cN. The initial resistance feels lighter in the spring shortened ALPS.

The unmodified cream ALPS - 62 cN.
Cherry MX browns - 42 cN (the datasheet says it's 45 ± 20 cN).
Cream ALPS with spring shortened #1 (see picture in first post) - 40 cN.

I have just tried shortening only a little from the spring and got 60 cN:

[Chloe]

I've just finished putting the keycaps back on the keyboard. It feels so fast now! It's much better than it was before. I didn't really like the feel of the switches as they were.

The only thing I notice now is the shorter key travel.  With the switches being so light it is hard not to bottom out. I think I will prefer the red Cherries because MX switches have longer key travel.

It's taken 2.5 hours to shorten the springs in all the switches. I found it better to do the tasks in steps, working through the keyboard row by row.

Step 1
With the keycaps removed, remove the upper housing and stem from switch. It's possible to do it in such a way that the leaf stays in the upper housing as you remove it. I think if you push the stem towards the switch mechanism it will hold the leaf.

Step 2
Remove springs and trim them. Then replace them in the switch lower housing.

Step 3
Push the stem as far down as you can in the upper housing without the leaf falling out. This helps ensure the spring will fit back into the stem. Place the upper housing over the lower housing and push quickly.  Now test the switch, if it feels like the stem won't go all the way down or the switch is making a scrunching sound you need to open the switch and try again.

I found that if you shorten the springs too much, the spring might not fit into the stem and this can cause problems with the stem not returning as it should. I solved this by stretched the spring out so it fits. It feels the same. I don't think you can go much shorter than I have without having to stretch the spring to make sure it fits into the stem.

[wellington1869]

thats a great mod, switch kitten

[sandy55]

For shortening surgery ( to make it total length for 60cN ), I recommend you to trim 2 turns from the top and 1 turn from the bottom, or 3 turns from the top  keeping last 1 turn in the upper portion of winding with no gaps ( hope you understand what I want to say ).   I would rather trim only 2 turns from the top.

Chloe, You are a good surgeon,and at the same time, an excellent analyst like Ms. O'Brian.

Seems like SGI900829 ( non AT compatible ) uses a shorter spring.
see the bottom of this page.

Also Focus FK-2001 ( real alps/white ) has similar spring.
see attached picture.
from left
Focus FK-2001___10mm
Silitekc WIN______11mm
Acer KB-101A____ 11mm
Omni 102________11.3mm

sandy55

[Chloe]

thats a great mod, switch kitten

Thanks.  

For shortening surgery ( to make it total length of 6.0cN), I recommend you to trim 2 turns from the top and 1 turn from the bottom, or 3 turns from the top  keeping last 1 turn in the upper portion of winding with no gaps ( hope you understand what I want to say ).   I would rather trim only 2 turns from the top.

Chloe, You are a good surgeon,and at the same time, an excellent analyst like Ms. O'Brian.

Thanks Sandy.

I think doing it this way for 60 cN is better because it keeps some of the winding with no gaps on both ends. If the 40 cN springs had this winding on top it might have been easier to replace the stem and switch housing.

60 cN doesn't seem like much of a change but it felt lighter to me. I don't know of a way to measure initial resistance, but I suspect this changed.

[Chloe]

Just a small update.

I've just finished hardwiring the Command keys to Alt because the iMate adapter maps Command to Windows. I removed the Alt keys and switches so now the layout resembles the Model M with a gap between Control and Alt. I also swapped the Caps Lock alternate action switch with a normal one and hardwired it to the Windows key. I already have this remapped in the registry but for some reason it is not working properly for Windows hotkeys.

I'm going to use this keyboard for a while as my main board. I really like the sound and feel of the lighter switches. The cream ALPS in my Apple Extended II have a light clicky sound to them even though they are not true clicky switches. The key placement feels a little different to the Compaq MX 11800 but I am prepared to get used to it. I'm using it without the casing because this way it the keyboard is flat.

[xsphat]

Chloe, your posts read like keyboard erotica. I think I love you.

[itlnstln]

That, and she just does these complicated-a** mods like they were nothing.  Just grab a new keyboard, make some wiring changes, swap a few caps, snip a few springs... all in about 15 minutes.  

[iMav]

Don't make me get out the hose.

[andb]

I decided to try the Alps Spring Surgery Mod too, and am happy with the the results. I used a Zenith ZB-2 with Alps yellows. I've posted comparison pics of a normal spring and the cut spring in the upper housing.

I found the easiest way to get them back in is upside down. As I don't have a special stand for this, my technique involved resting the 'board on my head and snapping the housing in from below. As comical as it must look, I can report excellent results when re-assembling the board.

My impressions? Its great. I really like the light feel. I do find myself sometimes pressing keys while I'm thinking or concentrating on something else. Also, I cut some of the springs a bit too short I think, sometimes while typing fast I hear a bit of a rattling noise under the keycap, which is I think the spring shaking around or sliding. There is no tactile change related to this noise, so I can easily live with it.

I found it tough to cut all the springs the same length. So I used the shortest ones on the pinky fingers. Fortunately they were all usable after the mod.

In the future, I think I may look for a spring company and buy a batch of a spring that exactly fits my needs. I like the light pressure, but I think the ideal situation is to replace the spring with a same length spring, not cutting it down.

That said, I'm happy I did the mod, but would recommend that you do it with an extra set of springs on hand as replacements in case it doesn't work out.

[sandy55]

I found the easiest way to get them back in is upside down. As I don't have a special stand for this, my technique involved resting the 'board on my head and snapping the housing in from below. As comical as it must look, I can report excellent results when re-assembling the board.

An ideal tip for reassembling alps linears;
"holding a stem/housing combo with a magnet".  I learned it through BBS from Qwerters aurthor.  
You may have 2 or 3 of dead 2.5" hard drive in your junk box. you can harvest a magnet from a dead drive. The method is handy. but I do not know if there is any issue of magnetization on springs.

[wellington1869]

An ideal tip for reassembling alps linears;
"holding a stem/housing combo with a magnet".  I learned it through BBS from Qwerters aurthor.  
You may have 2 or 3 of dead 2.5" hard drive in your junk box. you can harvest a magnet from a dead drive. The method is handy. but I do not know if there is any issue of magnetization on springs.

Show Image

thats an interesting tip for sure. I'll have to try it next time. I have some magnets lying around.

The pegcil should come with a little magnet on the other end, lol.