Just one week after ordering they have arrived in California, shipped air mail from U.K.
I just ordered 10 pcs of qtc. I will keep 3 and will sell the other 7. I paid ~£12 including shipping so I will offer them for $2.50 ea including postage conus or $2 ea + 50 cents postage if you want more than 1. Post here and send pm if you want any but do not pay until I get them and ask for payment.
I’ll take three…
And I'll take four. :D
3 gone 4 left. I have no idea when they willarrive as I was quoted 5-40 days shipping. This is why I won’t ask for payment until I get them.
Look above you, I'll take 4.
Wow, okay. All gone. Are you thinking what I’m thinking Scaru?
Yes, yes I am. :D Not sure of how it will work but I hope it will.
I’m watching Match’s mechanical to see how he’s doing it but I’m thinking of a copper disc sandwich with a foam ring to hold the qtc pad. That or 2 depopulated driver boards back to back to fit in a pill.
Eleven minutes; well done.
Guess I should have bought more. Here is a link to the site I used(good for small orders) and here is a link to a site with a lower unit price but a higher minimum order(better for large/group buy orders)
… but you might not have ordered enough. QTC is pretty bad for getting squished and deformed. (Hint: try to avoid anything like shear.)
Thanks, I figure I have at least a few weeks to lurk over Match’s shoulder or anyone else I can find who is using them.
I've used them in a couple of builds now but the longevity is not very good. Even 100% direct squeeze and no turning/shear/angle and they still don't last me longer than a good month in a edc style light.
I've sold off one unit to a friend of mine and gave him 10 pieces of QTC with it. He went through them all in less than 6 months and has bought a mega load of them now. (He used mindsetsonline and just added enough QTC until he was above minimum order price. I can not remember how many that is but it is a lot.
I wish they could invent a more durable material with more linear current profile. This generation is behaving somewhat like the current rises exponentially. And I cannot get any linearity into the feel of it.
Perhaps if I find a screw with a small enough thread pitch, something like 1/10 mm pitch would perhaps do the trick.
I do hope your designs are better than mine because it is cool to have a infinitely variable loss free flashlight with a forward clicky for signalling.
I’m hoping to use spring compression as force control rather than thread pitch. Is there any spec on conductivity/Nm?
None that I've found. I stopped searching about 6 months back though.
But here is the funny thing:
Because there was no data I tried making my own. My mod idea was based on scavenging threads from a micrometer so I took a mikrometer and isolated it's prongs electrically with tape.
Then superglued some copper plate with wires soldered on taps to the tape.
Then started squeezing and recording the current it let through hoping to make a repeatable controller. Or at least get a good idea for one. But here is the point: I could not make it repeatable! I tried and tried and recorded series of series of data but none were repeatable.
In the beginning (new qtc) each series is close enough to the previous one that it resembles it. But at it was squeezed repeatably it's repeatability vanished. When they get squeezed hard they become similar to a short. But do this even once and they alter electrical profile and the point of becoming a short moves around. And even that point is not repeatable from new qtc piece to new qtc. In the end I gave it up. I've actually designed a poor mans qtc holder thingy that lets you add it to any light that does not have a spring in the driver end. And it works okay but you wear the threads and the system has no linearity or repeatability.
I'll see if I can fashion one and take some pictures as I do not have one with me. Ohh. And you need to mod the light so that it has no springs in either end too. And you get squeeze marks in your batteries from when you get eager to get the last lumens out. I've destroyed a few batteries that way. Or the protection circuit anyway.
I'll get back to you...
EDIT: For clarity. And I found something out. I have not bought any QTC for this trip as I've stopped using my QTC controlled work flashlight. Sorry.
Bumped for edit.