P60 drop in question

Jvvjvv · Mar 13, 2015

Just started "building" my first flashlights, SF C2's. I got two drop ins........(one high end)..... and one not so much. The high-end one dropped right in and fit nicely without the spring. Worked great!

The other one was loose without the spring.....(up and down).... and wouldn't seat on the rim on the body with the full spring, so I cut the spring to where the head would fit flush. It didn't work. I then wrapped the base with copper tape......(that came with the unit)....... and it works fine, without the spring. Not very Hi tech.....

.... the only thing holding it from going up/down, is the "force" fit from the tape.

What is the spring for?

These lights have been around for a long time.......(so do not want to reinvent the wheel)..., but, it just seems to me, that the reflector rim should not be tight against the glass.....(no gasket or O ring).???

Thanks...Jack

scs · Mar 13, 2015

Jvvjvv said:
Just started "building" my first flashlights, SF C2's. I got two drop ins........(one high end)..... and one not so much. The high-end one dropped right in and fit nicely without the spring. Worked great!

The other one was loose without the spring.....(up and down).... and wouldn't seat on the rim on the body with the full spring, so I cut the spring to where the head would fit flush. It didn't work. I then wrapped the base with copper tape......(that came with the unit)....... and it works fine, without the spring. Not very Hi tech..... .... the only thing holding it from going up/down, is the "force" fit from the tape.

What is the spring for?

These lights have been around for a long time.......(so do not want to reinvent the wheel)..., but, it just seems to me, that the reflector rim should not be tight against the glass.....(no gasket or O ring).???

Thanks...Jack

Hi, Jack.

My understanding is the pill, the part that screws into the reflector, needs to make contact with the flashlight body to complete the electrical path. This is done either through direct contact or via the spring. In the first case, your drop-in is probably designed for a SF host and therefore, its contour fits snugly into the head, and its pill makes direct contact with the body. In the second case, the drop-in is probably for a generic p60 host, and when inserted, its pill does not make direct contact with the body. Adding the spring should have worked though, so I don't know why it didn't.

I think the reflector is actually butting up against a ledge on which the lens sits, not directly against the lens.

scs · Mar 13, 2015

With a couple of my drop-ins I find that if the pill is pushed up against the bottom of the reflector with too much force, the drop-in doesn't light. Perhaps that's what happened when you put the spring on. That's my best guess.

Jvvjvv · Mar 15, 2015

scs.......thanks for the replys. Just watched a couple of videos showing the "best" way to install a drop in. It showed using aluminum foil wraped around the unit, untill you get a "press" fit. As with most things,......... more that one way.

Is there a schematic anywhere of the surefire current path and the reflector/bezel/body association?
Jack

DellSuperman · Mar 15, 2015

scs said:
With a couple of my drop-ins I find that if the pill is pushed up against the bottom of the reflector with too much force, the drop-in doesn't light. Perhaps that's what happened when you put the spring on. That's my best guess.

It could be a short that is causing the light to not light up. See if you can cover ur solder joint with some form of insulation to prevent the short...

Jvvjvv said:
scs.......thanks for the replys. Just watched a couple of videos showing the "best" way to install a drop in. It showed using aluminum foil wraped around the unit, untill you get a "press" fit. As with most things,......... more that one way.

Is there a schematic anywhere of the surefire current path and the reflector/bezel/body association?
Jack

Yeah, by apply layers of aluminium foil u are creating an electrical & thermal pathway from the pill to the reflector to the flashlight host..

scs · Mar 16, 2015

Jvvjvv said:
scs.......thanks for the replys. Just watched a couple of videos showing the "best" way to install a drop in. It showed using aluminum foil wraped around the unit, untill you get a "press" fit. As with most things,......... more that one way.

Is there a schematic anywhere of the surefire current path and the reflector/bezel/body association?
Jack

Jack,

I've never seen a schematic. Picture the electrical flow starting at the + terminal of the battery. It then goes through the spring, soldered to the bottom of the pill, then through the circuits, across the terminals of the LED, back into the pill body, into the neck of the body, down the body, into the tailcap spring, and finally the - terminal of the battery. Don't know if I'm 100% right though.

scs · Mar 16, 2015

DellSuperman said:
It could be a short that is causing the light to not light up. See if you can cover ur solder joint with some form of insulation to prevent the short...

DellSuperman,

I've looked into that and the solder joints are clear of the body.

scs · Mar 16, 2015

Some say by wrapping copper or aluminum tape, or aluminum foil around the straight portion of the reflector only, clear of the pill, the contact spring is no longer needed. I've tried that and it didn't work, so I'm thinking the pill itself needs to make contact with the body.

DellSuperman · Mar 16, 2015

scs said:
DellSuperman,

I've looked into that and the solder joints are clear of the body.

I was referring to a possible short with the reflector...
Since you said that it only happens when you tighten the pill & reflector, that is one of the possibility.

DellSuperman · Mar 16, 2015

scs said:
Some say by wrapping copper or aluminum tape, or aluminum foil around the straight portion of the reflector only, clear of the pill, the contact spring is no longer needed. I've tried that and it didn't work, so I'm thinking the pill itself needs to make contact with the body.

Hmmm, that actually worked for me..
However given that you are using a Surefire host, you don't need that external spring at all...
I used to apply copper tape around the reflector but i have now used a soda can strip.
Its a much neater way without all the adhesive problems.

Jvvjvv · Mar 18, 2015

SCS.......thanks for the verbal walk-thru.........I have a schematic in my head now. The pill must touch the body. Seems like the upscale pills are "self" contained............they have their own built in lip than rests on the body and the reflector is imbedded in the pill. The less expensive one has the reflector sitting on top of the pill and on the body , as I see it......I am "assuming" that some of the reflectors are plastic???

i just ordered another upscale unit and a couple of real cheapys.....

Jack

DellSuperman · Mar 19, 2015

Jvvjvv said:
SCS.......thanks for the verbal walk-thru.........I have a schematic in my head now. The pill must touch the body. Seems like the upscale pills are "self" contained............they have their own built in lip than rests on the body and the reflector is imbedded in the pill. The less expensive one has the reflector sitting on top of the pill and on the body , as I see it......I am "assuming" that some of the reflectors are plastic???

i just ordered another upscale unit and a couple of real cheapys.....

Jack

Perhaps you can let us know what are the brands of dropin that you have purchased & we can advise you better.

P60 drop in question

Jvvjvv

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scs

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scs

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Jvvjvv

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DellSuperman

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scs

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scs

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scs

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DellSuperman

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DellSuperman

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Jvvjvv

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DellSuperman

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