Mag Switch Resistance Fix.. 1/6th stock!

[fivemega]

Please give me a price for a complete setup for this 2D stock mag using your 6AA battery setup. I would like everything needed, including info on fixing the switch.

Thanks,

Please see post #1

 

[vestureofblood]

I realize this is kindof an old thread, but its contents were new to me, and here is what I have found.

I used flat braded copper wire (the radio shack kind) and did the spring mod only. And now my M*g74 doesnt come on. Excellent
Here is why.... I am running it on a 2x 32500 li-ion pack from KD. This light has always been dependable, and would turn on almost without fail on the first click. By now several of us have tried useing philps 5761 and had the experience of nothing happening. But this from my 1274? My theory is that this mod lowerd the resistance enough to have a real world effect on my lights. By lowering the resistance the 1274 now trips the PCB circut on my KD cells. If I give it several clicks, or warm up the bulb with my AW C cells first it still works. I also did this mod to my M*g61 and the result seems to be whiter light? At least thats what it looked like to me.

Just wanted to say thanks again for the helpful info.
If anyone is interested here is a fix for the KD D cell 2 pack problem.

 

[Northern Lights]

Yes, you are tripping the D pcbs. They are not performing as rated. I am in the process of fixing a 5761 lion D MagCharger. I removed the protection and purchased PCBs from Batteryspace.com and rebuilt the protection. I recieved them in the mail today along with the smart charger that will be hooked to the MC cradle. By lowering resistance you raise Vbulb and get more torch lumens. The NTC is supposed to raise the resistance then back off and give back the Voltage but the new NTCs from Ametherm in the SL12 1R010 have not been reaching a steady state with a low resistance as they were originally rated.

The NTC will raise initial resistance and get by the OEM PCB, that is not trip it, but recently those NTCs have had a steady state resistance higher than they did when I first discovered them and I found that they are dropping the Vbulb to a much lower voltage than anticipated. In and emolie powered light the batteries delivered 7.5 Vbulb but the NTC was dropping in steady state the Vbulb to 6.9 Volts! This barely overdrives the 5761, bright but still can get much more lumens out of it if you can get the voltage to 7.3 Vbulb. I have not had much luck in keeping the bulbs from flashing at a higher voltage. I think 7.1 is very safe after soft start.

I believe for the emolie light I have a problem with I will run a resistor to bring the initial voltage to 7.3 Vbulb from 7.5 and use an AW soft start driver to get it up and running. I have about given up on the new NTCs.

By replacing the PCB I can keep the Vbulb up at 7.0 to 7.1 and get 80 or so lumens more out of the bulb than with the new NTCs that I have on hand.

I am experimenting with a handful of new part numbers in NTCs, Ametherm did assist me somewhat and suggested a few substitutes but so far I cannot get the Vbulb that I first stumbled on.

I am quite disappointed in the false rating of the protected D cells. They are tripping on 4-5 amps for the ones I have.

Because NTCs change resistance with temperature by putting them in parallel often you get higher resistance and not lower as would be expected by ohms law. You must experiment. Missionaryman did get them to work in a parallel situation also.

YouR success has inspired me to give it another shot and work up some unlikely mixtures of the NTCs I have on hand.

Nice job on the set up.

I like to fuse my NTC set ups too:

 

[2xTrinity]

I recently bypassed the switch on my 2C Mag 5761 with a mosfet, admittedly with no soft-start.

Before: stock switch. Kiu socket. Resistance-modded tailcap
After: MOSFET handle the current, stock switch drives gate. All else equal.

The mag was as white and bright at <3.9V/cell (open-circuit) as it was before on 4.2V/cell, and required double-clicking, which was never the case before, even with fully charged AW cells. Not surprisingly, it instaflashed at 4.0V/cell.

Based on that, I estimate I was losing about 0.5V at least to the stock switch, which given the 5A draw of the 5761 means the stock C-switch was contributing roughly 100mOhm.

I was quite surprised to see how mcuh difference resistance really made in this case. I was hoping that I would still have enough sag from the batteries themselves to get away with driving the 5761 without building a soft-starter.

 

[vestureofblood]

So if I am reading this info correctly, the next time I put fully charged AW cells in my M*g61, with this new resistance fix I can expect a?

My Mag74 not coming on sounded like a good thing, but flashed bulbs are bad.

Thanks Northerlights for posting the new NTC info... let me know if you find some good ones.

Also NL, if you would be so kind as to give a link or a description of the new pcb you orderd, I think that may help me as well. With the new circut will I have you use a smart charger to keep the batteries from overcharging or will the new pcb quit at 4.2v?

 

[Northern Lights]

So if I am reading this info correctly, the next time I put fully charged AW cells in my M*g61, with this new resistance fix I can expect a?

My Mag74 not coming on sounded like a good thing, but flashed bulbs are bad.

Thanks Northerlights for posting the new NTC info... let me know if you find some good ones.

Also NL, if you would be so kind as to give a link or a description of the new pcb you orderd, I think that may help me as well. With the new circut will I have you use a smart charger to keep the batteries from overcharging or will the new pcb quit at 4.2v?

No, the AW cells sag. No poof but it might shut down the protection unless you have a soft start provision, NTC or driver.

Notice the sag:
Discharge data for Phillips 5761 on AW's new C Li-ion cells

A 2 C-cell light with the AW spacer or an O-ring giving space on the tail cap threads with my snubber
2C Mag Tail Cap mod for AW's "C" cells
and AW cells is a very good handy light, at one point it was the brightest for the smallest. Yes, you do not get all the potential from the 5761 but until we started using A123 and emolie cells it was top dog. Enjoy it.

I am posting tonight on the new PCB mod I did, it is from batteryspace.com. I will PM you, I have a spare.
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=711

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2774

 

[vestureofblood]

UPDATE: So after draining a bit of the overvoltage from my AW cells (down to about 4.09) I slipped the cells ito M*g61 and.... :mecry: there goes a 5761. I am realy not sure what to even do now. I am not liking the idea of having to undercharge the cells each time I use them but removing my new resistance fix sounds like a bummer too. Suggestions any one?

NL thanks. My PM board awaits your message.

 

[Northern Lights]

UPDATE: So after draining a bit of the overvoltage from my AW cells (down to about 4.09) I slipped the cells ito M*g61 and.... :mecry: there goes a 5761. I am realy not sure what to even do now. I am not liking the idea of having to undercharge the cells each time I use them but removing my new resistance fix sounds like a bummer too. Suggestions any one?

NL thanks. My PM board awaits your message.

You need to soft start this mod. Spend the money, its a hobby after all, and get the AW driver and you will have a favorite light!

The only reason I fooled around with AWR, notice the R, drivers and NTCs was to have a plain off and on light. Those lights were used in law enforcement and in real life or death tatics you want the light off and not make a mistake and just dim it of flash it, just on and off, think about it and it is obvious why, otherwise I would put the AW driver in all my incadescents. High, Medium, low and strobe. AW is the best and he is a great friend too.

Using the AW driver/switch combo does away with all the needs this thread addresses. Go for it, you will not regret it.

 

[m1ruf]

Sorry to bring this old thread up again but I have a question: :shrug:

is there a similar switch resistance fix you can do on a C-mag switch?

The switch in my 2C mag only has one spring cup (towards the bulb end), is this normal?

Does the C switch have as much internal resitance as the D switch, or less?

thanks for any answers!

 

[Northern Lights]

Sorry to bring this old thread up again but I have a question: :shrug:

is there a similar switch resistance fix you can do on a C-mag switch?

The switch in my 2C mag only has one spring cup (towards the bulb end), is this normal?

Does the C switch have as much internal resitance as the D switch, or less?

thanks for any answers!

You can do it pretty much the same way and yes, by the design I would say the resistanc is similar because it comes from the friction fit parts and those are the same.
Usually I drill a small hole in the bottom of the slug becow the cam. Open the plastic slot up to the bottom to accomodate some braid in that position and run the braid back around to the ground screw and solder to the plate. If I am using a Pr to bipin socket, I no longer use the factory cam action as it is useless when compared to premium reflectors, I solder the ground to the ground of the Pr to bi pin socket and solder the positive to the positive terminal coming out of the switch. You must be sure to insulate the appropriate wires.

 

[vestureofblood]

Sorry to bring this old thread up again but I have a question: :shrug:

is there a similar switch resistance fix you can do on a C-mag switch?

The switch in my 2C mag only has one spring cup (towards the bulb end), is this normal?

Does the C switch have as much internal resitance as the D switch, or less?

thanks for any answers!

Hello m1ruf,

A C mag is what I did this mod to. Mine had only one cup at the end of the spring if I remember right. I took the cup and roughed up the inside and cleaned it with rubbing alcohol, then put a bit of soldering paste in there and heated it with a propane torch and put the desoldering braid in (after tinning the wire and cup),then just soldered the other end to the switch contact where the spring was touching at the other end. I also treated all the other meal to metal contacts with progold. By doing this I got a huge jump in voltage off my 2x AW C cells. Before the mod I could put fully charged 4.2v cells in and had only one instance where the bulb flashed. After the mod 3.9v was about as hot as I could go without a . I have since overcome this as well using a fix similar to the one NortherLights shows with an NTC to soft start the bulb.

 

[m1ruf]

thank you for all the answers!:twothumbs

I plan on building a ROP with the following parts:

- new 2c black mag
- download mag c-tower
- download mac c-ring
- 2x aw lithium c-cells
- fivemega 8.38mm hybrid mop reflector
- pelican ROP high bulbs

I've ordered two litemania chargers for the aw cells wich automatically shut off completly at 4.2 Volt.
I already have progold and deoxid.
I've also got some thermal grease (compound, non-adhesive) for use between the c-tower and the inner walls of the mag bodytube as well as in between the inner walls of the mag head (bezel) and the outside of the reflector. On both paces there is almost no gab existent without the thermal grease (a fraction of a millimeter) as the parts (reflector and c-tower) have been designed to dissipate as much heat as possible to the flashlight body (away from the plastic parts of the stock switch assembly). With the thermal grease inbetween heat transfear should be quite good, I hope.

I already orderd all the parts.

If I do any of the resistance fixes you mentioned will there be a much greater risk of insta flashing the ROP high bulb?
The light should run as reliably as possible (also for longer periods of time) as I plan on using this as a high power duty light (leo). Primary duty light is a SF 6P with Solarforce Q5 single mode Cree dropin, but sometimes I just need even more light (in rural area, city ambient lighting etc).

I think I'll have to balance the lumen gain I'll get from any resistance fixes (switch, tailcap spring) with the reliability of the light...
I also know a ROP is an experimental light and cannot be as reliable as most production lights but this is just a secondary light so I think I should be fine!

Any thoughts/comments on my project are most welcome!:laughing:

Cheers,

m1ruf

 

[cy]

Just to clarify names... OP is by AWR (andrewwynn) who ripped off CPF'ers to the tune of $15k+, most still have not gotten their $$$ back. http://www.cpfmarketplace.com/mp/showthread.php?t=163465

AW is a super reputable dealer located overseas, who is responsible for some of the finest batteries/products anywhere.

 

[EvilPaul2112]

thank you for all the answers!:twothumbs

I plan on building a ROP with the following parts:

- new 2c black mag
- download mag c-tower
- download mac c-ring
- 2x aw lithium c-cells
- fivemega 8.38mm hybrid mop reflector
- pelican ROP high bulbs

I've ordered two litemania chargers for the aw cells wich automatically shut off completly at 4.2 Volt.
I already have progold and deoxid.
I've also got some thermal grease (compound, non-adhesive) for use between the c-tower and the inner walls of the mag bodytube as well as in between the inner walls of the mag head (bezel) and the outside of the reflector. On both paces there is almost no gab existent without the thermal grease (a fraction of a millimeter) as the parts (reflector and c-tower) have been designed to dissipate as much heat as possible to the flashlight body (away from the plastic parts of the stock switch assembly). With the thermal grease inbetween heat transfear should be quite good, I hope.

I already orderd all the parts.

If I do any of the resistance fixes you mentioned will there be a much greater risk of insta flashing the ROP high bulb?
The light should run as reliably as possible (also for longer periods of time) as I plan on using this as a high power duty light (leo). Primary duty light is a SF 6P with Solarforce Q5 single mode Cree dropin, but sometimes I just need even more light (in rural area, city ambient lighting etc).

I think I'll have to balance the lumen gain I'll get from any resistance fixes (switch, tailcap spring) with the reliability of the light...
I also know a ROP is an experimental light and cannot be as reliable as most production lights but this is just a secondary light so I think I should be fine!

Any thoughts/comments on my project are most welcome!:laughing:

Cheers,

m1ruf

Hello m1ruf,

Im a LEO in Milwaukee and use 2C ROP HOLA lights for my main high power lights. The parts list you have is almost exactly as I have. I LOVE downloads C-Tower as it helps keep my light running cool even at long runtimes. I also prefer using potted lamps as I feel they are more rugged and remain centered during rough use. Dont forget to pick-up a good glass lens. I use UCL and have not had any problems.

As far as the resistance fixes are concerned, I have performed all of them including running a new ground wire. I have NEVER instaflashed a ROP lamp. I run AW "C" cells and charge them with a either a modified WF-139 and or higher quality single LI-ion charger. My ROPs are VERY reliable and have NEVER suffered a failure. Always be sure to clean the lamp with rubbing alcohol after handling. I actually clean mine every time I remove the bezel or about once a month.

Once you have modified a few switches, you will become more confident in your work. All together I have built about 15 ROPs and the vast majority of them going to other Cops.

I carry a 2C ROP HOLA on my duty belt. In my duty bag I have another 2C ROP and a 3C M@G85 for back-ups. I use ONLY AW"C" cell Li-ion batteries. All of my lights are equipped with a modamag magclickie tail-switch. This switch is made for AW's "C" cells and does not require an extension to accomodate the extra lengeth. (I persoanlly prefer tail-switches on all of my duty lights). At the beginning of the shift I turn the stock mag switch on and activate the light via the tail-switch.

Sometimes I will carry the 3C M@G85 for duty but prefer the shorter length of the 2C. The M@G85 throws quite a bit more light than the ROP with almost an hour of runtime. A 3C M@G85 may interest you after you build a ROP or two.

Good Luck,
PAUL
Milwaukee, WI

 

[vestureofblood]

+1 for what EvilPaul said. I too have the FM new gen reflector with the C tower heat sink, and the AW cells. However even with the 5761 bulb which I believe is a bit hotter than an ROP, I only use the thermal grease between the tower sink and the body. Its your light and you do what makes you happy, but it seems to me that the thermal grease anywhere else will be unneeded and will just be a mess, it seems it would also increase the chance of getting it on a nice reflector (cleaning can damage the finish) or the bulb. I don't know how familiar you are with hotwire so, I will again reaffirm what EP said about cleaning the bulb with alcohol and a cue tip or toilet paper. If you get oil from your fingers or thermal grease on it the oil will heat up so hot it can explode the bulb, ( i had a wa1185 blow up and gash the reflector, its somthing i'll not let happen twice). Any way good luck.

 

[Northern Lights]

I never used thermal grease in any of the 5761's I have built and they see some run time as I use them in the hot desert, LEO also.
The latest two 5761 I have gotten right up to the flash point finally. They run as hot as they will ever get.

The ROPs I never flashed, it is a stout bulb. If you look here:
http://i61.photobucket.com/albums/h75/pike444/bulbs/3854-HROP.jpg
From
They take up to 8.5 volts, we are under driving them as discused in the thread:
Destructive Incan Bulb Tests - Updated 6/22/08 (Info Added)

The 5761 is also pretty stout and runs a long life aslong as you stay under the flash point.

 

[vestureofblood]

Edit: nvm

 

[m1ruf]

Hey all, thanks for all the useuful info an advice!:goodjob:

Great to see some other people in the same profession using a similar setup.
In my last post i forgot to mention that I of course ordered some Borofloat lenses, too!
Thanks for reminding me not to touch the hotwire bulbs and to clean them with isopropyl etc. I always take care with my other lights and never touch the bulb or inside of the reflector, batterie contacts etc.
But with these high power incan bulbs you've got to be extra careful!

Good that you mentioned maybe not to use the thermal grease between the reflector and the inner bezel walls, I'll follow this advice for now, as I already made a mess when putting the thermal greased C-tower-switch back into the light ( I used too much grease and the excess grease smeared all over the inner body tube; took me half an hour to clean it out again; I can only imagine what it would do to the inside of the reflector, or even the bulb!)

Anyway this will be my first hotwire build. So far I've done the c-tower installation + the switch resistance mod. Now I'm anxioussly waiting for the rest of the parts to arrive (lens, bulbs, batteries, chargers) so I can fire my first ROP up!:devil:

 

[Jarski]

Sorry for bumping this old thread. I tried to do that spring mod, but I failed to do it. I tried with my 30w soldering iron, but it didn't fit in the cup and I didn't anything to attach them to keep them in place. So, does this mod make noticeable difference with ROP?

 

[vestureofblood]

Sorry for bumping this old thread. I tried to do that spring mod, but I failed to do it. I tried with my 30w soldering iron, but it didn't fit in the cup and I didn't anything to attach them to keep them in place. So, does this mod make noticeable difference with ROP?

Hi Jarski,

When I did this mod I added the piece of braided copper wire to the center of the spring, but to do it rather than the soldering iron I used a pencil torch. I roughed up the inside of the cap a bit and put a little flux in there and held it with some pliers. Then I cut a small piece of solder and dropped in. I held the cap over the torch until it melted and stuck the braid in and let it cool (touched the bottom to a piece of ice). IMHO this by itself made a noticeable difference for my M*g5761 project. With this and some progold on a 5761 bulb it raised the VF to the point I had to make a soft start to keep from ing the bulb. With an ROP I dont think blowing the bulb will be an issue (if you are using 2x li-ion or 6x nimh) since the flash point is higher for this bulb.

If you don't have a torch, you could probly use a stove burner, I think either a propane or even setting it on an electric would probly do the trick.