Twist type Reed Switch- how have you done it?

Hi all,

I'm looking for a bit of advice on building a reed switch for my mag build.

I'm pretty happy with all the electronics side, as I'm using a taskled driver, but I'm having a hard time figuring out how to build something to house the magnet, and where the reed goes.

One idea is to use a ring with a magnet in it around the body of the light. I'm just not sure how to keep it in one place. I don't need the magnet to stay over the reed to keep the torch on, I just want it to not slide up and down the light. Would it make sense to machine a small groove in the maglite body as a locator, but would i be able to get a delrin/plastic ring over the full diameter of the torch to sit in the groove?

Another member had a ring on the end of the tailcap, any idea how to do that?

Any other ideas welcome, I just need a mechanism so that I can press or click the light (short and long press) for the taskled functions.

Cheers

My first full-custom light had a ring. I turned the ring on the lathe, with a groove in the outside of the ring. Then I cut the ring into two semicircles so it can easily go into the groove on the light, then held in place with an o-ring. The tension of the o-ring provides some friction to keep the ring in place. It actually works pretty well. It does tend to collect sand and get hard to move, but it's easy to clean, even underwater with gloves on.

Locations for the magnet...The machined ring is a classic solution, but if you don't have access to machining tools/ability you can use a tubular lanyard and sew the magnet in at exactly the right place for when you hold it against the torch. Like this;

DIWdiver said:

My first full-custom light had a ring. I turned the ring on the lathe, with a groove in the outside of the ring. Then I cut the ring into two semicircles so it can easily go into the groove on the light, then held in place with an o-ring. The tension of the o-ring provides some friction to keep the ring in place. It actually works pretty well. It does tend to collect sand and get hard to move, but it's easy to clean, even underwater with gloves on.

Click to expand...

Had not thought about this one! Clever...

you can also design something like this:
or
the images are from a german online shop that you can find in the sticky "dive ligthing library" thread.

DIWdiver said:

My first full-custom light had a ring. I turned the ring on the lathe, with a groove in the outside of the ring. Then I cut the ring into two semicircles so it can easily go into the groove on the light, then held in place with an o-ring. The tension of the o-ring provides some friction to keep the ring in place. It actually works pretty well. It does tend to collect sand and get hard to move, but it's easy to clean, even underwater with gloves on.

Click to expand...

Could you elaborate a bit?

So the light body has a groove machined around it, right?

And the ring you also machined up to match the groove, then cut it in half, placed it over the groove, then held it closed with an oring around the outside?

dexter9 said:

you can also design something like this:

or

the images are from a german online shop that you can find in the sticky "dive ligthing library" thread.

Click to expand...

That's a huge sticky, having trouble finding it, can you give me the name or a link?

alunatec-shop
not sure if i'm allowed to post links

dexter9 said:

alunatec-shop
not sure if i'm allowed to post links

Click to expand...

Found it, thanks.

My old man had a pretty good idea for it. I'm going to machine a small o-ring groove on the outside of the torch body, and make a ring to sit on the outside. Then make an oring groove on the inside of the ring, and the oring will catch on the groove and keep the ring in place.

If you find it hard to slip the ring over the o-ring, you might want to try using a spring and bb instead. Omit the groove in the ring and opt for a small pit where the spring and bb sit. The bb is what travels along the groove on the light. Then you can also put small pits in the light to act as detents for the ring. Of course, the o-ring option is a lot easier I guess, and the friction from the ring will keep it from inadvertently turning on by itself.

Hi,
I use "PVC plumbing collar" in size 40mm as following pictures show
The magnet is simply glued with epoxy in the original screw hole (the screw used to fix the collar to a wall).



No need of lathe... and cost effective (very few € for a pack of 5 collars, i don't know for other states but the size 40mm is available in France in shop like leroy-merlin or castorama).

It also exist Maglite accesories (with black collar) to fix the mag to a wall or a door. I have glued the magnet on it in a hand grip configuration (look at the fresh thread : Aluminium canister + Mag mod with three SST50)
Ptit Fred

semi said:

Could you elaborate a bit?

So the light body has a groove machined around it, right?

And the ring you also machined up to match the groove, then cut it in half, placed it over the groove, then held it closed with an oring around the outside?

Click to expand...

Yes, exactly. The ring must be fairly thick in both the axial and radial directions. I cut six large scallops in the outside of the ring so it would be easy to work with thick gloves on.

ptit fred said:

Hi,
It also exist Maglite accesories (with black collar) to fix the mag to a wall or a door. I have glued the magnet on it in a hand grip configuration (look at the fresh thread : Aluminium canister + Mag mod with three SST50)
Ptit Fred

Click to expand...

Wow. That would have saved me a lot of time.

semi said:

My old man had a pretty good idea for it. I'm going to machine a small o-ring groove on the outside of the torch body, and make a ring to sit on the outside. Then make an oring groove on the inside of the ring, and the oring will catch on the groove and keep the ring in place.

Click to expand...

As Doc Ed alludes to, it seems to me like this would require precise dimensions, which can't be known precisely without experimentation. A little off one way, it's impossible to assemble. A little the other way, it comes apart when you don't want it to. Maybe there's not even a good middle ground at all. It does seem like it should be very resistant to contamination, which is a problem in mine (though it's easy to clean).

If you do attempt this, please keep us informed about the real-world results. Anything you can add to the knowlege base is good for all!

That looks like an amazing solution ptit. I'll have a look at some local plumbing suppliers and see if I can find something similar.

some are close to the way i use rotating colars and magnet, without lathe
i'll post soon some picture