Tail Clicky Safety Something To Keep In Mind.

I noticed a while back, and should have posted then..

Most DIY lasers built here are controlled with a 'tail clicky' switch
located to the rear of the laser.

When Loading the battery one should keep in mind that there is
potential for an accident in doing so.

Almost all DIY handhelds are set up with case neg- or +.
The switch isolates the neg-/+ of the battery from the body,
and when the switch is activated the neg-/+ is allowed
to pass through the host body and complete the circuit..

This in mind, there are many host bodies with long springs acting
as the contact. Should this spring be bent while screwing it
on, and touch the battery AND the body at the same time, will
allow the power to flow completing the 'loop' and the laser fires.

I figured this may be worth mentioning considering that class 4's
are becoming so common in handhelds.

As we all know, reflections can also damage eyes instantly
with this kind of power, and is something that we should all keep
in mind with activities as simple as changing your batteries...


A simple fix can be performed with any material that protects
the inside of the host body from allowing such contact.

One way would be to put a piece of thin double sided tape on
the inner walls of the host. Anything that creates a barrier
and is somewhat durable will suffice.

Another idea would be to place some heatshrink tubing over
the spring only allowing the tip to be exposed.

Be safe :beer:

If the spring is too long and could cause a short, bypassing the switch, it's a good idea to simply clip and shorten the spring.

Also you could put a dust cap on the end so if it does lase then the beam wont go far

wannaburn said:

One way would be to put a piece of thin double sided tape on
the inner walls of the host. Anything that creates a barrier
and is somewhat durable will suffice.

Click to expand...

I take that "double sided" means the same as "double adhesive"?

It would work, but would cause other problems with battery replacement.
:beer:

Anyway, you are pointing out a valid concern, anything that shorts the end of the battery to case will set off the laser.

Toke said:

I take that "double sided" means the same as "double adhesive"?

It would work, but would cause other problems with battery replacement.
:beer:

Anyway, you are pointing out a valid concern, anything that shorts the end of the battery to case will set off the laser.

Click to expand...

Double sided but with the waxy paper still on the exposed side..
Should have elaborated on that..

I would use this over regular tape as the 'waxy' slippery paper
reduces the friction, and is a little more durable over say
electrical tape.

Others have also used this tape (myself included) to pick up
any slack in the battery compartment of pens to eliminate rattle.

I have accidentally clicked the switch to the "On" position and then twisted the tail cap on, I burned the living piss out of fingers.

Never put your fingers in front while screwing on!!!

I have noticed this many times before and it is a real concern. It does not matter if the clicky is off or not it still completes the circuit. I always screw my tailcaps on with the laser pointed at the floor just in case. Never thought of actually posting about it so good call on the tip.:beer:

A bigger concern is the spring shorting the positive button to the negative case. If you use Li-Ions, always ensure that the wrapper is intact and has no cracks or weak points. If it shorts, you'll notice one end of the light getting very very hot. Immediately disassemble, because you may end up with a pipebomb if you leave it shorting out for too long.

I've had all my flashlights case-negative, but now this laser is case positive, I'm throwing away all of my cells that have noncontiguous wraps.

Some lights come with spring-tensioned contact points instead of springs. I wish I could find more of those.

DTR said:

I have noticed this many times before and it is a real concern. It does not matter if the clicky is off or not it still completes the circuit. I always screw my tailcaps on with the laser pointed at the floor just in case. Never thought of actually posting about it so good call on the tip.:beer:

Click to expand...

I am in the habit now when testing a laser the first time out,
I point under my workbench, load the batteries and look for problems.

Also giving a slight shake, moving the cap etc. is a good idea
before handeling it as a safe device.

Even when wearing goggles, unless they sit tight to your face, there
is room for light to get around them. For instance, if you have goggles
on and the laser turns on unexpectedly, the beam hitting your shirt
can allow reflected light to get around the goggles. While this may
not pose a significant danger, better safe than sorry..

Its best to look for flaws in the first few uses where the beam has no
way of reflecting back to your eyes and is in a controlled situation as
possible. Under a table with a wall on the other side works well for
me, but may not for others...

Also, pointing at the floor is safe for the user, but always keep in mind
pets, and shiny hardwood floors or tile.

BShanahan14rulz said:

A bigger concern is the spring shorting the positive button to the negative case. If you use Li-Ions, always ensure that the wrapper is intact and has no cracks or weak points. If it shorts, you'll notice one end of the light getting very very hot. Immediately disassemble, because you may end up with a pipebomb if you leave it shorting out for too long.

I've had all my flashlights case-negative, but now this laser is case positive, I'm throwing away all of my cells that have noncontiguous wraps.

Some lights come with spring-tensioned contact points instead of springs. I wish I could find more of those.

Click to expand...

Also some good points. I havent had a problem with any of my batteries YET

I can only imagine what they are capable of inside of a sealed metal host body :scared:

That's why I have goggles that sit thight on my face, who knwo what beams you can catch while bending over a setup or in this case unexpected beams.