Using Host as a Wire

[HydroSean]

So I noticed on several flashlights they connect the negative end of the battery from the spring to the entire laser host and use the host as a wire to connect to the negative end of the lamp. My question is this how I should do it if I am using two series feilong 32650s connected to an sxd driver set to 4.5 Amps?

 

[Sta]

This is definitely possible.
What I'm thinking of doing with mine is to put a spring at the tailcap (like with flashlights), then solder the negative wire of the module to the inside of the host. Thus, the laser will be case negative.
That takes care of the negative.
I believe the positive side can be accomplished by adding a battery contact board, insulated from the edges, in the middle of the host. It will probably end up being something like a coin. Then a wire can be soldered onto it and connected to one leg of the switch. Positive end of the module goes to the other leg.

That should work. What does the inside of your host look like? Is it all raw unanodized aluminum?

 

[HydroSean]

This is definitely possible.
What I'm thinking of doing with mine is to put a spring at the tailcap (like with flashlights), then solder the negative wire of the module to the inside of the host. Thus, the laser will be case negative.
That takes care of the negative.
I believe the positive side can be accomplished by adding a battery contact board, insulated from the edges, in the middle of the host. It will probably end up being something like a coin. Then a wire can be soldered onto it and connected to one leg of the switch. Positive end of the module goes to the other leg.

That should work. What does the inside of your host look like? Is it all raw unanodized aluminum?

So you don't think I'll get electrocuted then? Lol I'm just double checking because it's 4.5Amps of current. The inside is black anodized aluminum so I'll have to etch some away to make a solid contact most probably.
I've custom made the positive battery contact board with some blank PCB board, a stone grinder, and some thin gauge wire. It fits into the host nicely.

 

[Sta]

So you don't think I'll get electrocuted then? Lol I'm just double checking because it's 4.5Amps of current. The inside is black anodized aluminum so I'll have to etch some away to make a solid contact most probably.
I've custom made the positive battery contact board with some blank PCB board, a stone grinder, and some thin gauge wire. It fits into the host nicely.

Nope, you definitely won't get electrocuted. While the current is high, the voltage isn't large enough to get through your skin. Besides, the metal of the host is a path of much lesser resistance. But that anodizing needs to be removed.

And would you be able to make me one of those contact boards too? I don't have the equipment to do it myself. I'll be willing to pay you for it, just name your price.

 

[diachi]

So you don't think I'll get electrocuted then? Lol I'm just double checking because it's 4.5Amps of current. The inside is black anodized aluminum so I'll have to etch some away to make a solid contact most probably.
I've custom made the positive battery contact board with some blank PCB board, a stone grinder, and some thin gauge wire. It fits into the host nicely.

There's not enough voltage to electrocute you - or even shock you. Current is what kills but you still need enough voltage.

Make sure your thin gauge wire is thick enough to handle 4.5A

 

[HydroSean]

Nope, you definitely won't get electrocuted. While the current is high, the voltage isn't large enough to get through your skin. Besides, the metal of the host is a path of much lesser resistance. But that anodizing needs to be removed.

And would you be able to make me one of those contact boards too? I don't have the equipment to do it myself. I'll be willing to pay you for it, just name your price.

Sure just pay for shipping, I'll make you the first one free what diameter do you need? Btw it will be blank nonconducting and with a bunch of small holes in it.

Here's what the ones I made look like with the spring for the negative terminal and the 20 AWG wire for the positive.

BTW the inside diameter of my host is 1.320 inches but when I made the board exactly 1.320 inches it would not fit in. I had to make it roughly 1.280 inches for it to fit in...

 

[Sta]

Sure just pay for shipping, I'll make you the first one free what diameter do you need? Btw it will be blank nonconducting and with a bunch of small holes in it.

Here's what the ones I made look like with the spring for the negative terminal and the 20 AWG wire for the positive.

BTW the inside diameter of my host is 1.320 inches but when I made the board exactly 1.320 inches it would not fit in. I had to make it roughly 1.280 inches for it to fit in...

Thanks so much. I think all the Ultrasabers hosts are 1.32 inches; would you be able to make me a negative and a positive identical to yours?

I'll PM you my address.

 

[HydroSean]

Thanks so much. I think all the Ultrasabers hosts are 1.32 inches; would you be able to make me a negative and a positive identical to yours?

I'll PM you my address.

Yeah sure, the negative board I made is smaller so it would fit in the smaller ID end cap, but I can make yours the same diameter as the positive if you want.

 

[Benm]

Why not just use the laser host as the conductor for one of the battery terminals?

This has been done for ages in flashlights and it works pretty well in most cases. The only time it gives you problems if you have a diode with it's case connected to any of it's input pins.

Most laser diodes on the market nowadays are case-isolated so it doesn't matter if you tie the host body to any of the battery terminals.

A notable problem here can be 808 nm pump diodes that often have the anode connected to the case. This offers some design challenges and they are often solved by a system where the batteries go in 'the wrong way around', that is connecting battery positive to case. This design is fairly common to low cost dpss green laser pointers, and the standard for ones that run off 2 aaa cells or such.

 

[HydroSean]

Why not just use the laser host as the conductor for one of the battery terminals?

This has been done for ages in flashlights and it works pretty well in most cases. The only time it gives you problems if you have a diode with it's case connected to any of it's input pins.

Most laser diodes on the market nowadays are case-isolated so it doesn't matter if you tie the host body to any of the battery terminals.

A notable problem here can be 808 nm pump diodes that often have the anode connected to the case. This offers some design challenges and they are often solved by a system where the batteries go in 'the wrong way around', that is connecting battery positive to case. This design is fairly common to low cost dpss green laser pointers, and the standard for ones that run off 2 aaa cells or such.

yeah as of now I am going to connect the negative end of the battery to the inside of the host and also connect my driver to the inside as well, effectively using the host as a wire. thanks for the reassurance

 

[Sta]

Yeah sure, the negative board I made is smaller so it would fit in the smaller ID end cap, but I can make yours the same diameter as the positive if you want.

Yeah, I think with my host it has to be the same as the positive. So please make them both the same diameter. :thanks:

 

[HydroSean]

Yeah, I think with my host it has to be the same as the positive. So please make them both the same diameter. :thanks:

Okay I'm making them now, I can send them out tomorrow morning

 

[HydroSean]

Here they are, fresh new custom battery pcb connector board. I figured you might want to see them before I send them out.

now its time to have a few beers :beer:

 

[Sta]

That's great, thanks so much! I would +rep you but I must spread some around first. Somebody please +rep HydroSean!

 

[Antharak]

That's great, thanks so much! I would +rep you but I must spread some around first. Somebody please +rep HydroSean!

All set
Ed

 

[10fenny]

I've always used the case of my hosts as a path.. didn't really think there was any other way.. it's like a car.. everything metal on the car is neg/ground(unless it's an mg..some are "case pos").. as a mechanic I always laugh when see people running pos and neg to there fog lights or other accessories... if you have issues with this working it's usually some anodizing or paint on the threads or other contact points