Help with adding 2nd micro switch to La Marzocco Linea Mini

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
blondica73
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#1: Post by blondica73 »

Hi all,

I built most of the assembly to mod my Linea Mini to do true preinfusion and I need help adding a second switch to be activated by a supposed modified paddle. Any suggestions?

Thank you
Christian

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Jake_G
Team HB

#2: Post by Jake_G »

You have two options.

1:
Mount a new switch that is mounted towards the center of the paddle stroke and is triggered earlier. Been a while since I really scrutinized the real estate in there, but I think it could be done with relative ease.

2:
Mount a second switch right on top of the current switch using longer screws and add a second bump on the paddle arm to trigger the switch earlier.

I have a model of a cam extender that clicks onto the paddle arm to trigger the stock switch earlier, and I'm certain it could be gently modified to trigger a switch mounted above the stock switch at mid-stroke and allow the stock switch to do its thing (although you want to trigger the stock switch early and trigger a second switch later, right?)

Anyway, should work just fine.

If you want to email me some height dimensions for a second switch stacked on the stock one, I can make the changes to the extender.

Cheers!

- Jake
LMWDP #704

blondica73 (original poster)
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#3: Post by blondica73 (original poster) »

Jake_G wrote:
I have a model of a cam extender that clicks onto the paddle arm to trigger the stock switch earlier, and I'm certain it could be gently modified to trigger a switch mounted above the stock switch at mid-stroke and allow the stock switch to do its thing (although you want to trigger the stock switch early and trigger a second switch later, right?)

- Jake
Thanks Jake.
Here's the theory of operation I'm envisioning.

No flow
1. Paddle to the right
- stock switch - off
- new switch - on or off

Restricted flow
2. Paddle in the middle
- stock switch - on
- new switch - on

Full flow
3. Paddle to the left
- stock switch - on
- new switch - off

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Jake_G
Team HB

#4: Post by Jake_G »

So I'd suggest using the N.C. contact on the new switch and stack it atop the factory switch for ease of installation.

My snap-on adapter extends the cam on the paddle to the rear so the stock switch activates early in the stroke. We can trim that down to trip wherever you like in the stroke, such as halfway.

I can add a copy of the factory cam up above to trigger the new switch at roughly the same point the factory switch does now, which will open the N.C. contact and turn it off.

I'll mock it up and upload a pic later today to illustrate the idea.

Cheers!

- Jake
LMWDP #704

blondica73 (original poster)
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#5: Post by blondica73 (original poster) »

Thank you, Jake.

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Jake_G
Team HB

#6: Post by Jake_G »

Here's a mock-up with some switch bodies I found from Mcmaster:



The top left quadrant shows stock paddle geometry with the switch.

Lower left shows how the cam extension mimics the left paddle position at the center to trigger the stock switch earlier, then the next image shows an isometric view of the raised section that triggers the new switch with the paddle all the way to the left, just as it triggers the stock switch currently.

And finally the obligatory isometric view of the extension itself. It slides over the paddle arm after removing the the fascia and the "knob" of the paddle and latches down over the back. No fasteners needed. All you'll need is longer screws to secure the new switch.

Cheers!

- Jake
LMWDP #704

blondica73 (original poster)
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#7: Post by blondica73 (original poster) »

Looks great, I'm ready to try it out.

blondica73 (original poster)
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#8: Post by blondica73 (original poster) »

Jake_G wrote:Here's a mock-up with some switch bodies I found from Mcmaster:

image

The top left quadrant shows stock paddle geometry with the switch.

Lower left shows how the cam extension mimics the left paddle position at the center to trigger the stock switch earlier, then the next image shows an isometric view of the raised section that triggers the new switch with the paddle all the way to the left, just as it triggers the stock switch currently.

And finally the obligatory isometric view of the extension itself. It slides over the paddle arm after removing the the fascia and the "knob" of the paddle and latches down over the back. No fasteners needed. All you'll need is longer screws to secure the new switch.

Cheers!

- Jake
I tried it out; however, with the cam extension installed the stock switch is already triggered.
Paddle - right



Paddle - middle



Paddle - left


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Jake_G
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#9: Post by Jake_G » replying to blondica73 »

Sorry about that!

Is the switch triggered in the middle position without the extension?
LMWDP #704

blondica73 (original poster)
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#10: Post by blondica73 (original poster) » replying to Jake_G »

Yes. No worries, thank you for your help.