K-Line low-profile O27 switch question

I have 36 of them.  6 have limit switch issues.  My question is NOT how to do something to fix the issue, I've already had that discussion here.  I would like to buy some of the correct type of limit switch to have on hand in the event that I can't jimmy-up a fix like I've been doing.  I know nothing about limit switches.  Looked on-line yesterday and was shocked at home many types and ratings there are.  I looked for a picture like what's in these switches but came up empty.  I think I identified it as a "snap type" limit switch but I'm not even sure of that.

So my questions are these:

1. can someone identify the exact limit switch that I would need?? 

2. Can someone point me to an on-line source???? 

3. Does anyone have some that they would be willing to sell to me?

As always, thanks - walt

Original Post

Walt, for your purposes, the size and configuration are all that matters, any form factor that fits the K-Line switches will be able to handle the current. Yes, these are snap switches, and you may have to order some samples. The ones K-Line used are Chinese clones of some commonly available switches, so you will find them but with a little effort and assistance with a micrometer or digital calipers.

Have you pulled one and checked with a magnifying glass to see if there are any markings?  That would be a start, anyway.

Rob

Walt - Is this what you're looking for?  

K275-E002Micro Switch for K275 and K375 Switch$2.00Order

I stumbled across these looking for the lamp housings for my K-line switches.  BTW, if you've got 36, it would appear you've cornered the market. I haven't counted but I have at least 12 K-line O27 switches on my layout that's about 10% from being ready to operate.

raising4daughters posted:

Walt - Is this what you're looking for?  

K275-E002Micro Switch for K275 and K375 Switch$2.00Order

I stumbled across these looking for the lamp housings for my K-line switches.  BTW, if you've got 36, it would appear you've cornered the market. I haven't counted but I have at least 12 K-line O27 switches on my layout that's about 10% from being ready to operate.

That looks very similar.  the K-Line's "action bar", or whatever it's called, is plastic not metal.  The issue that it seems that I have on each one is the the "action bar" doesn't make close-enough contact with the body.  The body has a small node near where the "action bar" hinges to the body so I fix it by wrapping one or 2 thin strips of masking tape around the "action bar" near the node and that seems to have fixed all 6 that quit working.

My 36 unfortunately only consists of 11 of the 42" variety, which since I sold off my MTH collection of cars and engines, my new tin-plate trains can't handle the remaining 27" switches.  I still have my PW 2343 and cars so I do get some value out of still having them.

I will see if I can post a picture.  My point and shoot does very poorly on closeups though but I'll try.

thanks guys - walt

walt rapp posted:
[snip]

I will see if I can post a picture.  My point and shoot does very poorly on closeups though but I'll try.

thanks guys - walt

Walt,

When you take a close up photo, make sure that the camera isn't too close. Your camera lens—just like our eyes—has a minimum focal length, if the object is closer than the focal length, it will be blurry. Also, as GRJ suggests, put a ruler in the photo next to the switch.

—Matt

walt rapp posted:
raising4daughters posted:

Walt - Is this what you're looking for?  

K275-E002Micro Switch for K275 and K375 Switch$2.00Order

I stumbled across these looking for the lamp housings for my K-line switches.  BTW, if you've got 36, it would appear you've cornered the market. I haven't counted but I have at least 12 K-line O27 switches on my layout that's about 10% from being ready to operate.

That looks very similar. ..

Yes, these pictured are for the older solenoid activated switches, Walt is looking for parts for the newer motor-driven switches.

Walt, you have discovered that the shimming procedure works for your issue... it wasn't clear in your original post if the snap switches had failed or if there was an alignment issue. Snap switches should be good for about a million cycles, maybe half that for the Chinese clones.

Rob

Here's the best I could do with my little point and shoot.  Yes Matt I found that out a while ago.  I try to zoom in so i can hold it back a bit further but I still have focus issues.

Rob: The fact that 6 out of 36 have had the exact same issue coupled with the fact that my switches are on a Christmas-time only layout, well, the "million or half that" comment isn't matching to my experience with these things.  I know it's the plunger action and not an allignment issue because if I gently push on the 'action bar/lever' the cycle completes.

The first year that this happened we had a very nice discussion on options to fix it.

Below are pictures:

As Always, thanks - walt

PICT0009_F

PICT0092

PICT0121

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Photos (3)

The contact point for these switches is away from the actual switch plunger, so I don't know what you're trying to illustrate on the right.  The arrow indicates where the switch should be actuated by the external mechanical action.

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Photos (1)
walt rapp posted:
Rob: The fact that 6 out of 36 have had the exact same issue coupled with the fact that my switches are on a Christmas-time only layout, well, the "million or half that" comment isn't matching to my experience with these things.  I know it's the plunger action and not an allignment issue because if I gently push on the 'action bar/lever' the cycle completes.

The life rating of the snap switches is for the internal switch operation of the snap mechanism - your issues appear to be all external involving getting the plunger pushed in far enough to activate the actual mechanism - whether it's the arm getting deformed, the switch not being positioned in relation to the cam, cam wear, or a combination.

If the plunger has developed/worn to a point that it actually requires to be pushed in further than the working ones, then that would be an internal failure. Usually, the snap switches fail completely when the the snap leaf inside becomes deformed or broken.

Rob

John, I agree, the CONTACT point for what I am calling the "action bar" is on the extreme right of it which I think can be seen in the closeup that I showed.  The brown plastic part of the switch swivels and pushes the "action bar" down.  But for whatever reason it's just a hair short of depressing the plunger.  That's why wrapping tape above the plunger has been fixing the issue.

Rob: thanks for the info.  These things are frustrating.

so I'm back to my original questions  - how do I know what to buy and WHERE the heck could I get them?

As always, thanks - walt

walt rapp posted:

...so I'm back to my original questions  - how do I know what to buy and WHERE the heck could I get them?

You're still going to need a digital calipers to get accurate dimensions, but going by your pics it is a standard mini DPST snap switch otherwise, but the arm may be a proprietary build/order or hard to find.  Start HERE for a jumping off point.

It may be the trick to use a ST-302 tool or similar to re-form the arms/action bars into position on your malfunctioning units with small gradual adjustments if the actual snap switches are working properly.
st-302

Rob

I don't know Rob, what I'm calling the action arm is thin plastic.  I tried looking at MICRO snap switches on-line and there are hundreds of different ratings, shapes, sizes, etc.  Some had pictures but none looked like what I need.

as always, thanks - walt

RoyBoy posted:

Rob, what is the brand name of that tool or a source of that tool? I have been looking for one.

Anyone that's ever tinkered with pinball machines probably has a set of these.

They're handy as they have all angles, you can reach practically any flat contact and adjust it.  I also still have a couple of the contact burnishing tools.

Contact Adjustment Tools

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Photos (1)
cjack posted:
Matt_GNo27 posted:
ADCX Rob posted:
[snip]

You're still going to need a digital calipers to get accurate dimensions, [snip]

Rob, what's wrong with a dial caliper?

How do those work, solar power?

They work when the batteries in the digital model are dead!

cjack posted:
Matt_GNo27 posted:
ADCX Rob posted:
[snip]

You're still going to need a digital calipers to get accurate dimensions, [snip]

Rob, what's wrong with a dial caliper?

How do those work, solar power?

? but some do.

"Still trying to not shoot my eye out"

 

"Nursing insomnia one railcar at a time"

My aroma therapy? Smoke Pellets.

 





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