My first ROP

[andyr354]

I bought a modamag 8AA-2D holder, rop bulbs, fivemega MOP cammed reflector, and a UCL. Soldered in a jumper wire on one side of the holder to make it into a 6AA. Did the main fix to the switch by soldering a piece of wick in between the spring cups.

I have 4 eneloops and 2 powerex 2500s in it right now (waiting on more eneloops). It is nice and bright for 10 minutes or so then starts to dip.

Is everyones ROP sort of on the yellow side or am I running into some kind of problem?

I like how bright it is, but it is not very practical using a light for 15 minutes or so then having to charge it for 6 hours. I might use the 8AA holder and 2D mag for an LED conversion and move the ROP to a 4D with sub C bats.

Andy

 

[MikeSalt]

Mine is lasting an hour on 6xD, 2600mAh cells. Brilliantly bright beam right up until the last 5 minutes.

 

[luigi]

I might guess something is wrong.
Mine is good for about 1 hour using six 2500 Energizers.
About tint I don't know it is subjective, does it feel hot if you point it to your skin at about 20 cm ?

Luigi

 

[mudman cj]

You could try doing the tailcap spring fix as well. If the light is old then there could be oxide build up on the strip that makes contact to the pedestal as it is raised and lowered for focusing. Cleaning that strip may also help you out. The strip can also be bypassed by adding a wire. Another thing you could try is adding a 7th cell.

Oh, and you might have a bad cell there. Try checking their voltages after a run to see if they are balanced.

Sub C's will really drive the ROP nicely - with those high drain cells you even have to be careful not to reduce the resistance too much or you can instaflash ROP bulbs.

 

[frosty]

Which bulb are you using? I find my low bulb rather yellow. Whereas somewhat confusingly, the high bulb is much whiter.

 

[andyr354]

It is an older light, around 7-8 years IIRC. After around 10 minutes of runtime my pack drops down to 7.2V and still puts out a good amount of light. I have not put in the low bulb yet, only have used the high.

It does feel hot on my hand. If I hold my hand over the front 5 seconds or so and my skin is pretty uncomfortable.

I should have a matched set of bats here in a day or so and will cycle them a few times and see how it goes.

 

[andyr354]

Mine is lasting an hour on 6xD, 2600mAh cells. Brilliantly bright beam right up until the last 5 minutes.

Are those just alkalines or something else?

 

[andyr354]

After running the light and then testing the bats in my C Crane charger it shows two that are loosing their capacity quicker than the rest. Hopefully cycling them a few times will bring them up to snuff. They are all new bats.

I put the low bulb in last night and went for a walk around the property. It is a very nice amount of light. If it has alot more runtime it will most likely become the primary bulb and keep the high in the tail cap. Might just buy another reflector and put the high bulb in a higher capacity setup like 6 SCs or 6Ds.

Andy

 

[KevinL]

Congratulations on your ROP. Sounds like you need a better charger too. Agreed that 15 minutes is too short.

If you want maximum output (and whitest color, as the filament is being driven at the highest possible temperature), you will need to do all the resistance fixes on your old light, and get top quality cells.

The ROP high bulb is *ABUSIVE* towards cells. I mean it. It's not your walk in the park for the NiMH batteries. At 4 over amps, really closer to 4.15, it REALLY shows up deficiencies in cells that are absolutely not up to doing the job. In fact, my original designs do not even recommend ordinary AA NiMH - I warned against those, I recommended people use CBP1650 high-current cells, not high-mAH cells.

Over time, many have tried other cells. Of course, it is not my right to stop them, I can only advise them, but if they insist on running zinc carbon cells with the high bulb (zinc carbon is even more wimpy than alkaline non-rechargeable), then I don't think I can help very much

For max output, six high current Sub-Cs like Sanyo or GP's high rate offerings are excellent. The Sanyos and GP's claim to be good up to THIRTY amps.. well, I ain't goin' there but it's nice to know they can if I need to

The Original ROP featured on the webpage uses six Sanyo's. Has never missed a beat since day one.

 

[andyr354]

I gotta save up the cash for a string of batts and a pack charger (recomendations?) I guess. I think I will just stick with the low bulb in the 2D-6AA setup. It seems to work pretty nice so far.

I have a C Crane charger for my individual cells. I charged the eneloops with the charger that came in the package with them the first time, looks like it didn't top a couple of them off to well.

 

[cdosrun]

Congratulations on making your first ROP.

I have the Mag 3C setup (6xIB1400) and always smile when I turn it on. I keep it in the door pocket of my car and have used it in 'anger' at an accident already. For a light of its size, the output is incredible but I only get about 20mins runtime. If yours will make newspaper smoke in a couple of seconds (with the HOLA) then it is doing what it should be IMO. I would love to convert my 6D (also in the car) but I would get pretty fed up trying to keep the cells topped off in that light as well.

My regulator arrived for my Mag85R and that is an incredible light as well, it can set newspaper alight (better than just making it smoke in about 30 seconds.

Good luck, but you might have better experience with the high-drain type cells as Kevin suggested. I think the Eneloops are meant to be quite good though.

As for chargers, I use an Ansmann ACS 410 (4-10 cell) pack charger for my cells. It will plug straight into the bottom of the FM battery holders and I use magnetic leads for charging the sub-c cells. It isn't tremendously fast (700ma charge) but I haven't had cause to question it so far and it was quite cheap £16.

Andrew

 

[MikeSalt]

Are those just alkalines or something else?

Oh yes, forgot to add NiMH

 

[andyr354]

I tried lighting some kleenex on fire with mine, no go, no smoke. I don't thing my cells have enough umph or the slide in the head has to much resistance. I forgot my DMM up in my tool box at the shop again so I still haven't checked it.

The eneloops were sort of a compromise though. I kind of wanted a light that could set a few months and still have good brightness if needed. So the LSD they offer was nice.

Andy

 

[Icebreak]

I don't think it's a good idea to run different types of batteries. I don't know the difference in chemistries but surely eneloops must be somewhat different. I only run exact same groups of cells; batteries...chemistry...manufacturer...capacity.

Battery Shootout shows that Titanium 1800 AAs do well. CBP1600 AAs can handle it. Eneloops don't look that good at above ~2 amps according to the graphs in the Battery Shootout.

A properly overdriven ROP high should be a very nice white. cdosrun knows what I'm talking about because he has a Mag 3C 6 X 2/3 A as discussed in Post #4 of the ROP sticky. I don't know why it is not popular. It is truly impressive.

Anyway, I think you'll see very different results when you get 6 identical cells running. Good luck and let us know how it is going.

 

[andyr354]

I got the 6 matched cells in a yesterday and have been running it with them. They are brand new cells so from what I have read it takes a few cycles to get them up to full capacity.

I did try some newspaper this evening. I can get smoke but no fire. It doesn't discolor the paper so I am not sure what is smoking... the ink?

Andy

 

[cdosrun]

Andy,

with the newspaper, the trick is to find a reasonably dark area (like a picture) and hold the focus of the beam on a spot for a few seconds, I haven't tried in earnest to actually light a fire with the ROP but I don't think it is that easy; much easier with the Mag85. If it isn't smoking within 3 or 4 seconds, it probably isn't turning out what it should be. You have the same reflector as I do and the advantage of the UCL lens (I have the borofloat, less likely to crack under the heat load as I keep it in the car - UK).

If, after a couple of charge cycles, you can't really smoke paper well (the first couple of seconds don't show much sign of it but after a few more, you should start to see holes appearing) then have a go at a few of the low resistance mods. With the D-cell maglites, the positive contact is a spring, you can lower the resistance by soldering some desoldering wick from one end to the other. The same can be done to the spring in the tail cap and also the lamp holder itself.

If you have the time and money, you could try making the 3C model, mine has no low resistance mods and is still pretty impressive, as Icebreak said, they aren't popular but I really don't know why.

Alternatively, you could try measuring the current running through the lamp. If you have a decently low resistance ammeter, you can measure and post the results. Everyone here could probably give you a more quantitative appraisal of your ROP then.

As for the whiteness of the beam, as Icebreak said, it should be a really nice white (not quite as white as my Mag85R) but don't try to compare it to an LED.

Good luck, I hope you can get it sorted.

Andrew

 

[andyr354]

OK, borrowed a Fluke 112 at work for a few minutes.

At initial touch it was drawing 3.94A, after a minute or so it seemed to stabilize around 3.78A. This is with a set of freshly charged batteries that had set for a day.

After running the light for around 5 minutes the pack of 6 bats measured 7.84v

I did the resistance fix on the tail spring and the switch spring but not the slide. Holding the meeter to the outer part of the bulb holder and the base of the battery tube where the tail cap contacts it I get 2 ohms. So looks like I need to address the slide.

Would pulling one strand out of say a 12g copper wire work for wrapping around the pin on the slide?

Andy