Were my expectations too high for RoP?

Snow

Enlightened
Joined
Apr 3, 2005
Messages
479
Location
Kansas City
Okay so I finished my first ever Mag hotwire last night, a RoP. Here's my setup:

Maglite 2D
Odd Mods 6AA-2D adaptor
6x Sanyo Eneloop AA
Fivemega cammed MOP reflector
Borofloat lens
RoP low and high bulbs


I fired it up and although it's by far the brightest light I own, it didn't "wow" me. People always say stuff like "Every time I turn on my M6, I smile" and whatnot. Well this should be as bright as an M6, right? I dunno, I guess I just expected to be amazed. I will admit, at night, this bad boy will go for miles and has a ton of useful spill to boot. I guess for $100 I expected a glorious fire-starting hotspot.

I measured today with freshly charged Eneloops and got 8 volts, 1.93 A on low, and 4.11 A on high. Any ideas? Is it just my elevated expectations? Is it the MOP reflector? After seeing some beamshots where the hotspot looked way more intense than mine, I thought maybe I should have gone with LOP. Any input is appreciated.
 
Have you used it outdoors yet? If you haven't I suspect you'll have a different opinion afterwards.

I have hotwires much brighter than my ROP HI, yet the beam produced by it's HOP reflector, a perfect balance of throw/flood, still puts a smile on my face when I power it up outside.

I only trust beamshots when comparing lights or reflectors.

Cheers,
Gary
 
Yeah I used it on a brief hike last night and even on low, it was very impressive. I just feel let down again now that I'm indoors comparing it to how bright everyone else's look online. Stupid, I know.
 
I had the same impression when I built my 2C ROP Hi about a year ago. Turned it on indoors and was underwhelmed. I also knew there wasn't any problem with resistance either, adn the bulb wasn't getting any brighter because the color temperature was pretty close to my 3500k room lights.


However, it has grown on me, and is now my second most used light. High output, compact (jacket pocketable), good runtime (40 mins), focusing action that is actually useful (try grinding down the cam with a dremel so that it is about half the slope -- now it won't defocus the bulb too far and you won't see "donut holes).

Indoors, it isn't very impressive, however, in total darkness it is quite impressive. I was once out camping with a guy carrying a 3D maglite, stock, with half dead batteries. He was definitely impressed at how much light was coming from a 2C. He commented that it was like holding a lightsaber... he specifically said that the 2C flashlight is roughly the same size as an official replica lightsaber that he owns :D
 
Snow -

I'm a little suspicious of that battery adapter. I'm not familiar with it. The ROP draws higher amps than a Mag85. In the ~40W HotWires the ROP runs the highest amps that I know of. Resistance will eat high amps. If that battery holder has a lot of resistance the ROP lamp won't be very impressive.

What is bright has a lot to do with perception. I don't know what you are used to seeing. I'll pick on 2XTrinity (He knows a ton about all kinds of lights). He's seen a lot of lights and built a lot of lights. I would imagine that a ROP might be a real yawner for him. The first time I fired up a Mag85 on my elevated patio I was wowed by it then became concerned that it would draw unwanted attention from the local PD.

I'll try to give a little perspective. A ROP should look like a very good incandescent motorcycle headlight only a little whiter. My ROPs are brighter and whiter than any of my neighbors' incandescent automobile lights.

Are you measuring under load? Here's what my little 3C ROP running Intellect 1400 2/3 A batteries measures.

4.30A and 8.09V at start.
4.28A and 7.93V at 10 seconds.
4.15A and 7.85V at 30 seconds.
4.12A and 7.73V at 1 minute and settled down.

If that 4.11A is sustainable under load you're doing well. But how you go 8V has me wondering about the measurement technique. If this is your first HotWire and you aren't smiling about it I think there's something wrong.
 
Hello Icebreak,

The intellect cells will outperform eneloops by a fair margin, as they are designed for RC cars (20 amps give or take). So your results are undoubtedly above average. Not to mention, the mag switches in the C bodies are of better quality than D bodies, (lower resistance there). It has been my experience that the ROP high on eneloops is a nice light, but nowhere near as white or bright as bulbs in this class can get.

The battery adapter he is using is made by me, the resistance is negligible, the current handling capacity for the adapter is probably 20+ amps.
 
Snow -

I'm a little suspicious of that battery adapter. I'm not familiar with it. The ROP draws higher amps than a Mag85. In the ~40W HotWires the ROP runs the highest amps that I know of. Resistance will eat high amps. If that battery holder has a lot of resistance the ROP lamp won't be very impressive.

What is bright has a lot to do with perception. I don't know what you are used to seeing. I'll pick on 2XTrinity (He knows a ton about all kinds of lights). He's seen a lot of lights and built a lot of lights. I would imagine that a ROP might be a real yawner for him. The first time I fired up a Mag85 on my elevated patio I was wowed by it then became concerned that it would draw unwanted attention from the local PD.

I'll try to give a little perspective. A ROP should look like a very good incandescent motorcycle headlight only a little whiter. My ROPs are brighter and whiter than any of my neighbors' incandescent automobile lights.

Are you measuring under load? Here's what my little 3C ROP running Intellect 1400 2/3 A batteries measures.

4.30A and 8.09V at start.
4.28A and 7.93V at 10 seconds.
4.15A and 7.85V at 30 seconds.
4.12A and 7.73V at 1 minute and settled down.
 
Yeah that measurement was under load.

Anyway, after messing around with it some more tonight, I am wowed. Standing in my completely dark kitchen and pointing it at the ceiling, it looks like I flipped a light switch. It will light up my entire backyard with ease and keep going across the next street over.

I think part of the issue might be the reflector. It is a little diffuse compared to an LOP or a more throwy light. With some bright LED lights like my L4, L1, etc., it can be hard to look right at the spot when it's shone on a wall. My ROP isn't like that. I guess maybe that is also a factor of incandescent vs LED.

Anyway, I am pretty sure it is running normally, I just think maybe the hyperbole in some people's descriptions made me think it would be a religious experience to fire one up. After messing with it in a completely dark park, I am a lot more impressed with it. It has a nice combination of throw and spill.

(Not to mention, it makes my dad's Fenix T1 look like a Minimag. :D)

Thanks for the opinions, guys. And thanks to mdocod for the battery adaptor. :)
 
I had the same underwhelming experience with the ROP I recently built. I think it's just a matter of expectations being too high.

Mine doesn't hold a candle to my H4 motorcycle headlight. It's a little brighter than a Tigerlight but not as bright as a Surefire M4.

Mine measuress 3 amps from Energizer 2500's. I haven't found any Eneloops locally yet. I didn't know that Mag C's had lower resistance switches than Mag D's.
 
I just did a test of my ROP high bulb on 6 eneloops in one of my adapters, fresh off the charger the open circuit voltage of the pack was 8.91V, current across the tail-cap was 4.40A settling to 4.34A after about 10 seconds. This is on an unmodified mag D switch.

I would suggest giving the eneloops a few cycles, seems like mine got better after the first few cycles.. Also, the quality of the charger in question can have a big impact. I use an Intillipeak 4-8 cell pulse charger set to around 300mA for balancing the pack, or around 1-3 (depending on my mood at the time) amps when I want it charged up faster.

You might experiment with the pack a little, snug down that nut a little more if you have it kind of loose. Just be careful not to over-tighten and crush those cells.

------------------------------

edit in:
Stingray... serious you are only getting 3 amps across an ROP high? That would account for a MAJORLY underperforming ROP.... Something seems to be out of whack with that number... By my calculations, the only way to drive an ROP high at 3 amps, is at about 4.5V give or take. At which voltage the output would be a dim orange glow of a few lumens.
 
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A CHE (Calibrated Human Eyeball) detects brightness logarithmically. Add ten lumens to a one-lumen light, and it'll seem like a big jump. Add thirty lumens to a 180L light, and you probably wouldn't notice any change.

900L or so "sounds" like it should be amazingly brighter than an L4 or similar light, but really isn't. It is definitely noticable, of course, but it isn't "OMG my room is on fire." Very few flashlights will compare favorably with something so supposedly simple as summer sunshine, often leading to an underwhelming hotwire experience. Keep that in mind when inspecting wow-lights.

That said, my very first hotwire was an LK12. :)
 
is it possile that a 1.5-2C discharge is too much for the poor AAs?

Have You tried with larger cells, just out of curiosity?
Or with another kind of battery (lead, Li-Ion)?
 
Snow,
I have just gone through a similar build to you.
I found that the ROP bulb 'fogged' up the reflector every time I used the light
so I dropped the ROP in favour of Bi Pin bulbs. (WA1111 and 5671)

I then had some problems in getting the resistance out of the circuit and found LuxLuthor's article ( link below ) to have really helped me understand what was really going on.

http://www.candlepowerforums.com/vb/showthread.php?t=186405
 
Something doesn't seem right here. :thinking:

You say your pack measures 8V under load.
8V / 6 cells = 1.33v per cell under a 4 amp load.

In Silverfoxes tests, the Eneloops sagged to under 1.2v per cell with a 4 amp load.

How exactly did you measure the voltage under load?

Now I don't claim to be the "master of the multimeter" but those numbers sound high to me.
 
Very few flashlights will compare favorably with something so supposedly simple as summer sunshine, often leading to an underwhelming hotwire experience.
Few people realize just how intense direct summer sunshine is, it's in the nighborhood of 100,000 lux. That's about three orders of magnitude higher than typical indoor lighting. So that means to light up a single 10 square-meter room to solar intensity, you'd need a million lumens. Not going to happen in a flashlight anytime soon. Even assuming a 100% efficient light source, you'd need about 3kw of power to make that happen. In reality, we will probalby never see a light source more than 75% efficient, which would mean dealing with many kilowatts of waste heat.

If you're going to design a light for maximum throw though, you really can't have too many lumens -- consider that if you're going to look at a target, the amount of light you'll need to be able to see it will be proportional to the 4th power of the distance. That's because light going from your flashlight to the target diminishes as the inverse square, then the light reflected back also diminishes as an inverse square.

I found that the ROP bulb 'fogged' up the reflector every time I used the light
so I dropped the ROP in favour of Bi Pin bulbs. (WA1111 and 5671)
One solution to this is to either "bake" the ROP lamps in the oven. I've actually simply underdriven them with the glass removed using a power supply to break them in (if they are underdriven, they will still heat up and vent, but you won't lose a lot of lamp life)
 
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Something doesn't seem right here. :thinking:

You say your pack measures 8V under load.
8V / 6 cells = 1.33v per cell under a 4 amp load.

In Silverfoxes tests, the Eneloops sagged to under 1.2v per cell with a 4 amp load.

How exactly did you measure the voltage under load?

Now I don't claim to be the "master of the multimeter" but those numbers sound high to me.

Sorry, I was unclear. The amperage was measured under load, the voltage I just measured on the bare battery pack.
 
I fired it up and although it's by far the brightest light I own, it didn't "wow" me...

...I measured today... ...4.11 A on high. Any ideas?

Sorry, I was unclear. The amperage was measured under load, the voltage I just measured on the bare battery pack.

OK. If you look at Lux Luthor's tests on the 3854H, you will see that 4.11 amps corresponds to just over 6.5V at the bulb.

Since your Eneloops were "fully charged", six of them should have delivered at least 7.2V under load.

This means that you lost at least 0.7V in the battery holders, spring, switch and contacts, and, note carefully, your meter's burden voltage.

And again, according to Lux's tests, resistance fixes alone should see you a lift in lux from 64 to about 90-ish, depending on state of charge. Why? Because the voltage at the bulb can theoretically lift to very near the on-load battery voltage, if you do all possible resistance fixes.

I'd start with a FiveMega or mdocod battery holder.
 
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