Peak aficionados, show and tell!

[Monocrom]

I'm considering jumping in and getting a Logan 17500. I love the idea of continuously variable output, multiple cell configurations, and getting a unique light.

The execution is not as good as the concept.
Outside of Keeppower, good luck finding 17500 cells; today!
I suspect that variation of the Logan is a light that came out 20 years ago.
And Peak just still offers it.
Unfortunately, the Keeppower 17500 is too long to fit the light.

One thing that has held me back previously is reading about the QTC wearing out. Is this a real and common thing, or perhaps just something that requires maintenance?

Quite common. It's not something you can do maintenance on.

I'm imagining it's user choice, but are there advantages/disadvantages to SS, Aluminum, and brass bodies?

You want heft? Something rock-solid? S.S.
You want shockingly light-weight? Aluminum.
Something heavy (with buttery smooth threads) that will patina nicely? Brass.

Does this have some sort of driver circuitry, or is it essentially a resistor (QTC) and a LED? Seems like there must be at least a boost driver to get up to LED voltage from an Eneloop or aliki.

Other members can do a better job answering this question in detail.

Any reason other than personal preference to select Peak over Franz Labs for QTC? I'm definitely more interested in an AA/CR123 form factor than something larger.

For me, it's personal preference. The brand is old, their offerings are Made in America by one 80 year-old man who could retire at any time. Making future Peaks, likely extinct.

 

[sbslider]

When you say execution is not as good as the concept, is this because the QTC is just too finicky?

I actually have no plan to use a 17500 cell, but cr123 or AA/14500. Perhaps just cr123 / RCR16340, and get the simple Logan, very nice form factor.

I think buttery smooth would be good for a twisty light, wish brass was as light as Al.

 

[archimedes]

The Peak seems to use a "semi-regulated" boost driver that is pretty efficient but not extremely flat in terms of regulation. It may not have a buck circuit, but I am unaware if that has been confirmed or not.

The only real driver details I can recall being discussed here were in one my my old threads, linked here ...

I have run into that same problem with a couple of lights. A very few
electronic circuits will not fire on a low voltage input but once lit off
they will run to about 0.8 volts. The cause is most likely the 22 uF
input tantalum capacitor. Also all of the older lights used a 5.0 volt
boost circuit, when we went to the Cree XPG we were able to use a 3.3
volt boost circuit that uses less start up power and is more efficient.

The difference between 1.2 and 1.5 volts when boosted to 5 volts is
really quite a bit on start up. N cell batteries have very small current
collectors internally as compared to the longer AAA batteries.

Curt

The Peak and the Fraz are both very nice QTC-based lights, but take slightly different approaches to this.

I would say the Fraz is more specifically "engineered" to optimize the QTC function, while the Peak uses a simpler straightforward mechanical solution.

 

[Monocrom]

When you say execution is not as good as the concept, is this because the QTC is just too finicky?

Impossible to dial up the exact output level you want. Or, close to it. Unless you want fire-fly mode (in which case you just very slowly turn the bezel until the light just switches on). Or, the very highest setting (keep turning that bezel until it stops). Then there's just whatever that's in-between. Realistically, that's what you get.

I actually have no plan to use a 17500 cell, but cr123 or AA/14500. Perhaps just cr123 / RCR16340, and get the simple Logan, very nice form factor.

I think buttery smooth would be good for a twisty light, wish brass was as light as Al.

I would absolutely email Robyn first before you use a non-17500 cell in the light.
Ask her if those other options will even work in it.

 

[Monocrom]

Took my brand new stock Peak El Capitan (black aluminum with the key-ring top) to work last night. Seriously, it weighs NOTHING! Even for aluminum, I am shocked at how practically weightless this thing is.

Now I'm thinking, for those who prefer a light-weight, single-AAA light on their keychain.... Peak Logan in the very same configuration above would be ideal. Made in America, no annoying logos on the light, and you can unscrew the top section off of your keys while using the light by itself! How awesome is that?....

And, I just talked myself into getting another Peak Eiger. (My other one is brass, with the Peak pressure switch, and a Prometheus clip attached to it.)

 

[lampeDépêche]

Impossible to dial up the exact output level you want. Or, close to it. Unless you want fire-fly mode (in which case you just very slowly turn the bezel until the light just switches on). Or, the very highest setting (keep turning that bezel until it stops). Then there's just whatever that's in-between. Realistically, that's what you get.

I would absolutely email Robyn first before you use a non-17500 cell in the light.
Ask her if those other options will even work in it.

I've been using both AA cells and a CR123 in my new Logan 17500 light.
The CR123 required the Delrin spacer that Peak sells.
Come to think of it, I also ran a AAA in their, using a different Delrin spacer.
The kit includes three spacers, for CR123, for AAA, and for AA, but that last is just a very slim sleeve, and is hardly needed.
Anyhow -- all three cell-types work like a charm. No problems at all. And given that it works with AA for size and CR123 for voltage, it should also work with a 14500, too.

 

[archimedes]

....
I actually have no plan to use a 17500 cell, but cr123 or AA/14500. Perhaps just cr123 / RCR16340, and get the simple Logan, very nice form factor....

....
I would absolutely email Robyn first before you use a non-17500 cell in the light.
Ask her if those other options will even work in it.

I purchased my Logan 17500 when they were first released, specifically for its "multi-fuel" capability, and have successfully used every one of those options.

Except maybe not the 17500, I can't remember if I ever found one of those cells ....

 

[archimedes]

Ahh, @lampeDépêche was quicker to reply

Mine is primarily used as a travel light, given the wide variety of cells it will take, as I pack it along with the little spacer kit tube.

 

[sbslider]

I would absolutely email Robyn first before you use a non-17500 cell in the light.
Ask her if those other options will even work in it.

I'm pretty sure it requires the delryn spacer kit, but others have reported it works with different cell sizes

 

[sbslider]

I've been using both AA cells and a CR123 in my new Logan 17500 light.

Have you found it to be pretty finicky in terms of getting the light level you want?

 

[lampeDépêche]

Have you found it to be pretty finicky in terms of getting the light level you want?

It's finicky on the lowest, firefly levels. On intermediate and high levels, I have not seen it acting unstably, and it has not been a practical problem for use.
This may just be a feature of how percentages work -- if the QTC is fluctuating in its resistance, then the small fluctuations may be more visible in the sublumen level than when you are putting out 100 lumens.

 

[dc38]

Have you found it to be pretty finicky in terms of getting the light level you want?

If QTC based flashlights had a finer thread pitch, it'd be much easier to dial in the precise levels. HOWEVER, that would defeat the durability aspect of the lights...There is one minor gripe I have with my Peaks, the lack of positive contact post centering. They're off-center, and with the larger tolerance of the body tubes, the batteries can shuffle around on the looser (lower) modes, thus changing the brightness with light bumps or shakes. In general use, it isn't an issue, but if you plan to leave it on uber-low sub-firefly levels such as a desk nightlight or tent indicator light, the brightness may change as if on a hairtrigger.

I've been looking for a suitable tail contact substitute spring, as I absolutely detest battery crushers, but so far I have been using a short aluminum dowel to make contact in my Capitan without the QTC, so I've only been using disposables.

So far, I've tried a variety of pen springs, tailsprings from other lights, contact springs from cheap battery holders, salvaged springs from random junk...they're either too springy or too large/small. I imagine a nice firm spring could be shortened and opened at the bottom to fit into the keychain hole for retention, but I don't know where I could get one.

 

[lampeDépêche]

If QTC based flashlights had a finer thread pitch, it'd be much easier to dial in the precise levels. HOWEVER, that would defeat the durability aspect of the lights...

I don't know whether finer threads would be less durable than coarser threads, but it would mean that you would need to twist the head more turns to go from off to full. Right now, there's about 1/4 - 1/3 turn from off to full, so it's no problem doing that with just your thumb and index, after the battery tube is clamped in your ring and pinky against the palm. But if you had to turn a whole turn to go from off to full, then you'd need two hands.

 

[dc38]

I don't know whether finer threads would be less durable than coarser threads, but it would mean that you would need to twist the head more turns to go from off to full. Right now, there's about 1/4 - 1/3 turn from off to full, so it's no problem doing that with just your thumb and index, after the battery tube is clamped in your ring and pinky against the palm. But if you had to turn a whole turn to go from off to full, then you'd need two hands.

True, and from a general practical carry standpoint, that kind of precision is kind of unnecessary

 

[JP031716]

I don't know whether finer threads would be less durable than coarser threads, but it would mean that you would need to twist the head more turns to go from off to full. Right now, there's about 1/4 - 1/3 turn from off to full, so it's no problem doing that with just your thumb and index, after the battery tube is clamped in your ring and pinky against the palm. But if you had to turn a whole turn to go from off to full, then you'd need two hands.

This is how I use mine as well when I'm not using the momentary switch. I find that the output I can get one-handed with my index finger and thumb ends up being adequate and don't mind if I need to crank down that little bit to get those last bit of lumens if I really need it. That's why I really like the size of the Logan 17500 keychain body as I can get a full four-finger grip.

 

[Monocrom]

Mine is primarily used as a travel light, given the wide variety of cells it will take, as I pack it along with the little spacer kit tube.

Off-topic for this one post:
Another excellent travel light is the Streamlight Protac 1L-1AA Dual Fuel model.
Uses a CR123 cell, a 3.0v. RCR123 cell, Single-AA alkaline, Single-AA Eneloop rechargeable, Single-AAA alkaline, and Single-AAA Eneloop rechargeable. (Though it's best not to leave a AA cell inside the light for too long as the spring can become compressed over time, and no longer work properly with shorter cells.)

Though with the AAA cells, you have to be very careful not to bump the light.
I own two of these SL's they work great.

 

[lampeDépêche]

Up above in this thread I expressed some doubts about whether 17xxx cells will fit into the Logan 17500.
I don't have any 17500's yet, but I do have a 17670 from a different venture, so I tried that.

The 17670 slid right into the tube of the Logan 1750 without a hitch. So the 17500 should work, too.

Now I just need to trim down the length of this 17670 a bit so that I can screw the head in. What would you recommend, meat cleaver, or Sawzall?

 

[Monocrom]

Circular saw would be faster, and make a cleaner cut.

 

[lampeDépêche]

Circular saw would be faster, and make a cleaner cut.

Circular saw it is, then.

Of course, I could just get out the old acetylene cutting torch....

 

[Monocrom]

Circular saw it is, then.

Of course, I could just get out the old acetylene cutting torch....

True, but you risk melting the base into an odd shape. Rather than keeping it flat.
If you use it on the other end, you're guaranteed to burn off the nipple.
Last thing you want to do is badly burn off a nipple.