6D Mag ROP, Heat sinking?

OzzieDoc

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I am putting together a 6D Mag ROP High with NiMH for long runtimes. I've read the master thread and have got all the usual bits like borofloat lens and a range of reflectors both FM and KD in cammed and camless. However I am still unsure if I need to do anything about the bulbholder. There is mention by some of melting bulbholders and also of melting of the solder at the base of the PR bulb itself. Apparently the latter can be prevented by the use of ProGold or similar contact pastes. Others don't seem to have any problems at all and a few have mentioned a mica shield. What is the best way to deal with heat buildup if in fact I need to do anything at all. Thanks.
 

KrisP

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What durations do you plan to use it?

I made exactly the same light with Tenergy 10,000mAh cells and have not had any melting problems. I've probably only run if for a maximum of 15 minute durations though.
 

Cigarman

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Im using a camless reflector from Lightedge and I wonder if, since the back of the reflector presses against the lamp holder, might that transmit some heat from the lamp? I have run mine for about 10 minutes as well but have never come across any melting issues.
 

Illum

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Im using camless MOP from fivemega here, unless you kept the existin lens and not a borofloat or UCL I dont see any way for things to melt or overheat...then again it depends on your runtime
 

jwl

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The solder blob on the back of my ROP HI bulb softened / melted enough during a run test that it lost contact after it cooled down. Keep in mind that is was running of over an hour and fifteen minutes. Didn't ruin the bulb, just needed to reform the blob on the back of the bulb.
 

OzzieDoc

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Thanks for the replies so far. I looking for it to run about an hour at a time.
 

Illum

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The solder blob on the back of my ROP HI bulb softened / melted enough during a run test that it lost contact after it cooled down. Keep in mind that is was running of over an hour and fifteen minutes. Didn't ruin the bulb, just needed to reform the blob on the back of the bulb.

erm...your lamp my have leaked if the blob melted, but can't say for sure...but theres that explosion hazard
 

jwl

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erm...your lamp my have leaked if the blob melted, but can't say for sure...but theres that explosion hazard

Maybe that is the one that exploded..:sssh:.....I did have one explode but that was because the bulb touched the side of the hole in the reflector while running, it had been on for 5-10 minutes. Its been a while so I can't say whether or not the one that had the bulb melt (partial) is the one the went :poof:, but maybe that was it....
 

Illum

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Maybe that is the one that exploded..:sssh:.....I did have one explode but that was because the bulb touched the side of the hole in the reflector while running, it had been on for 5-10 minutes. Its been a while so I can't say whether or not the one that had the bulb melt (partial) is the one the went :poof:, but maybe that was it....

if your lamp clouds, DON'T USE IT, this is one of the prettier examples of a disaster waiting to happen [not an ROP]...I've heard worse
https://www.candlepowerforums.com/threads/133305
 

SuRgE

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Would there be any additional issues if a 5761 bulb were used? I have a 6D Mag lying around and was thinking of installing a Boro lens, 10.5mm FM reflector, high temp socket, and 10000mah Ds. I would keep the charged cells to total no more than 7.8volts to prevent flashing. Wouldn't run it for more than 5 minutes at a time.

Think it would work?
 

OzzieDoc

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Would there be any additional issues if a 5761 bulb were used? I have a 6D Mag lying around and was thinking of installing a Boro lens, 10.5mm FM reflector, high temp socket, and 10000mah Ds. I would keep the charged cells to total no more than 7.8volts to prevent flashing. Wouldn't run it for more than 5 minutes at a time.

Think it would work?

The difference here is you are using a high temp socket whereas I was still considering the original plastic bulbholder. I know a high temperature replacement is available on CPF (Mag C tower) for a C cell M#glite but I haven't seen a high temperature conversion for a D cell.
Any further suggestions or comments regarding my original question or am I good to go as is for an hours runtime.
 

OzzieDoc

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Thanks jwl. However Kiu's sockets are bi pin and the ROP bulb is PR based. The MagCtower on B/S/T is a PR based solution for C cell but isn't made in D cell as far as I can tell. Perhaps because it isn't necessary?. Surely someone out there has run a D cell ROP high for an hour and can tell me if there is actually a heat buildup problem.
 

jwl

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Thanks jwl. However Kiu's sockets are bi pin and the ROP bulb is PR based. The MagCtower on B/S/T is a PR based solution for C cell but isn't made in D cell as far as I can tell. Perhaps because it isn't necessary?. Surely someone out there has run a D cell ROP high for an hour and can tell me if there is actually a heat buildup problem.

I'm aware that the ROP is PR based (I have a 6D and (2) 2D cell ROPS. I pointed out the KIU socket as an alternative to the ROP bulbs. There are similar bi-pin bulbs that either compete with or exceed the output of the ROP bulbs. (One such bulb is the Philips 5761)

I have run my 6D ROP HI for over an hour. Other than the solder blob on the bulb deforming there we no ill effects.:thumbsup:
 

gratewhitehuntr

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Right behind you with a 6D Mag623 !!
Been there, done that !!!

I have some Tenergy 10K mah D cells that have only been charged and discharged (only completely on my smart charger with discharge function) fo about 2 weeks of use.
I 'm sure I could be convinced to sell some of them. I have 12 !!

My advice however is to avoid the D cells solution and pick up some Emoli cells.

Run 4 of those in a 6D and it drops 1 1/2 pounds and will drive the 35 watt IRC to shame the hell out of the ROP and 5761.

I blew 4 ROP HI bulbs running fresh D cells and a whole fistful of 5761 bulbs.

The only safe way was to run a dummy and only use 5 cells.
With 6 I was holding 7.8-7.9 under load OF A 12V 100 WATT. (fresh cells, would hold up about 10 mins and then dropped SLOWLY)

I have run the ROP HI for 2 hours continuous before it just fizzeled out and the 5761 for about 3 hours (man thats a lot of heat !!) with no ill effects.

I have also run the Osram 64623 for 15 minutes at 14.8+v and couldn't touch the area around the switch.

The 35 watt IRC is a nice trade off and is quite bright (look it up) without burning stuff (my hands).
The 50 may be ideal, if I ever get one.
 

OzzieDoc

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Thanks for those extra suggestions and I intend to get around to them eventually. It's just that I have a stack of D cells, both NiMH and NiCad, a bunch of ROP bulbs and the neccessary lens and reflectors. Wouldn't hesitate to just trial run it until something dies except that I'm in Australia and everything like Maglite switch replacements etc are just plain hard to get or outrageously expensive.
 

gratewhitehuntr

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Right behind you with a 6D Mag623 !!
Well I never did manage to blow a ROP LO bulb but I :poof:ed a few Hi ones figuring out that they couldn't take fresh cells.

I eventually developed a system for not burning the 5761 bulbs.
I would run the same cells for two days and then change four of them and leave two old ones.

Two more days I would do it again, always rotating the old cells.
This worked FAIRLY well but still managed to burn a few.

Eventually I got really frustrated and decided to look for a better solution.

I came up with Emoli cells and IRC bulbs.
 

jimjones3630

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The contact on ROP HO bulb may have melted because of too much resistance in the curcit. Many people have ROP HO that don't melt bulb contact.

Part of the answer to your question "what do you need to do if heat build up becomes a problem in your mod" I'd think would include do you want to risk ROP bulb failure from decreasing the resistance too much? If so, then could try 5761 but 6 cells solution which also can be too over moded, resistance reduced too much and start flashing 5761. Then your are left with wa1111, or changing batteries and going with IRC
 
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