Peak lights with QTC

[gustophersmob]

Does anyone have experience using Peak, or any othe similar twisty lights) with QTC pills?

How well does it work adn do you find it useful?

I've got some QTC on the way, but just want to get some opinions.

Thanks! 

[NutSAK]

I carry a Peak with QTC every day.  I have Eigers, an El Capitan, Logan, Pacific AA, all equipped with QTC and they work VERY well.  The #8 Eiger is especially good with QTC and 10440 Li-Ion.

According to Kurt, Peak's engineer, there will be Peak bodies available with QTC built into them soon.  He puts the pills in a brass & delrin sandwich inside the body to increase durability of the pill.

[gustophersmob]

Thanks Terry, this is what I was hoping.  I'm tempted to wait on the peak QTC bodies to be ready, bt the sale on the Narrow #8 HAIII El Cap at RMSK is also tempting...   

[gustophersmob]

Terry, one more question, if I may.  Do you have any QTC pills in Peak lights with the momentary switch?  If so, does it work well?

[NutSAK]

Terry, one more question, if I may.  Do you have any QTC pills in Peak lights with the momentary switch?  If so, does it work well?

The spring under the negative contact piston will have to be replaced with a solid piece to use QTC with the momentary switch.  The spring isn't stiff enough to put the proper pressure against the QTC.  This would be fairly easy, you could just replace the spring with a length of brass rod from a hobby store.  This would give the switch a stiffer feel, of course.  It has been done by CPF members and they report that it works.

[gustophersmob]

Good to know. I will have to try that when my new Peak and QTC gets here.

Thanks again!

[Mr. Whippy]

I've waited all day, hoping someone else would ask, so I wouldn't look like a dolt, but...

What's QTC?

[gustophersmob]

I've waited all day, hoping someone else would ask, so I wouldn't look like a dolt, but...

What's QTC?

It stands for Quantum Tunneling Composite.

The ones we are talking about are like little pieces of rubber (Basically) in 3x3x1mm squares (looks like someone cut a bicycle tire inner-tube into little pieces) that conduct more and more current as pressure is applied.

They work based on a principle of quantum physiscs that electrons can act as waves under certain conditions. 

This link explains it better than I can:  http://www.peratech.com/qtcmaterial.php

The end result for flashlights is that you can take this little piece of rubber-like material and put it in series with the battery.  As you twist the head, more current will flow, which basically can turn a single mode twisty like a Peak into and infinitely variable output light. 

Hopefully that makes some sense! 

[NutSAK]

Here is another link that provides a good basic description: http://www.practicalphysics.org/go/Resources_18.html

It basically works like a variable resistor.  The QTC material has virtually infinite resistance (perfect insulator) at rest, but as the material is compressed, the resistance goes lower and lower until it has very little resistance.  So, with the head loose on the flashlight, there is no output, but the more you tighten the head, the brighter the output becomes.

[gustophersmob]

My QTC came today! 

It is very cool, and works quite well in my #8 Eiger and Matterhorn.  They are now both infinitely variable

The only issue is that the o-ring is slightly exposed on the Eiger when off, and very exposed on the Matterhorn.  They are both pocket bodies, so there isn't much I can do.

Since I have many extra pills, I am going to see if it is possible to thin one down a bit so the head can seat a little lower.

It seems like I have to crank it down fairly hard to get what appears to be full power.  Hopefully this won't prematurely wear the aluminum threads.  Since the #8 Eiger is so bright anyway, I will likely keep it at less than full power just in case.

[NutSAK]

I use nano-oil on the threads... no problem getting to full brightness w/QTC regardless of metal.  Mine are lugged or keyring bodies, and the oring is still covered when a 1/2 turn past off....  Maybe you can sand down the positive connection on the head a bit?  ...not sure if  that's a good idea...  Keyring seems to be the best solution since the negative post can be adjusted out if need be.