Cmore Potentiometer

[mcoliver]

Anybody know if the potentiometer in a cmore (not the click type) is the same one you can buy from any electronics shop? IIRC, a pot comes in linear or another type. Anybody know which one is it?

Thanks a lot.

[Bear1142]

HUH?

I guess that's why I never earned my Aeronautical Engineering degree. You guys don't speak english.

Erik

[EricW]

Pots are either linear or logaritmic. Logarithmic pots are used for audio. I'm 99% sure that the C-More needs a linear. I have not ever seen the guts of a C-more, but it is extremely likely that it is an off the shelf item.

You can probably buy a replacement at www.mouser.com.

E

[Bret Heidkamp]

I researched this one a while back - I have about 10 of them on hand back at home. I'll post the part number for you as soon as I can. It is not a common pot, but digikey and mouser both carry it if I remember.

The little bushings wear out (for me) before the pot fails.

[mcoliver]

I've also been reading up on pots. Eric, I think you're right, it could be linear. A cmore gut is really very simple. You have the pot, the laser module socket (reminds me of the socket we used to use for our LM555 timer IC) and battery terminals. That's it.

Bret, really appreiate if you can post the part num.

Okay, the reason I wanted to know about it is because I'm thinking of repositioning the pot somewhere else and cut the rear end of the cmore. I need it shorter for a modified gun project. And I was thinking a replacement pot (if I screw this one) is far cheaper than getting a Docter.

Appreciate the help guys. Thanks.

Hey, and just for kicks, I think a photoresistor can also be used, right?icky.

[shred]

You have the pot, the laser module socket (reminds me of the socket we used to use for our LM555 timer IC) and battery terminals. That's it.

it is an IC socket the LED module (it's not a laser, just an LED with a tiny tiny hole exposing it) You'll need to leave that where it is.

Hey, and just for kicks, I think a photoresistor can also be used, right?

If you could get a good match on the light curve and resistance. That might get tricky.

[mcoliver]

Duh! Yeah, I meant LED.

[Bret Heidkamp]

It is a CTS pot, 1/8w carb vert. 10K linear part # 296UD103B1N

This is the non-click model.

Digikey page

[mcoliver]

Thanks a lot Bret.

[Tzygä]

Hi !

I need to replace the C-more potentiometer (CTS pot) not the click one.

Thanks Bret let me to know which one it is.

But I was wondering if it is possible to replace C-more non-click potentiometer to the click one. Because I like the click one better. Do I need change anything else and is it possible to only change the switches.

Is anybody knows what is part number for the click switch or which company makes them?

Thanks a lot.

[Dream]

Any body know where to find the click one???

[shred]

The click one is different-- it's a rotary switch and there's a set of resistors stuck down on the circuit board. The circuit boards are different too, so you can't switch a clicker c-more for a non-clicker without replacing the entire circuit board.

Digkey carries something close, but not quite matching the part number on the one I just took apart (Grayhill #56SP30-01-1-12N-F). It would probably work (it doesn't have shaft sealing and you have to set the stops), though it's out of stock and $10 in single quantities: Digikey link for click switch.

Update: Allied has the same part currently in stock, for $11+. We'll see how close it is.

[pmd]

Any body know where to find the click one???

I e-mailed C-More last week and asked if an upgrade was possible - they said:

"The cost of a click switch up grade is $69.00 + Shipping"

[Flexmoney]

How's it look for shortening up a C-more ?

[shred]

How's it look for shortening up a C-more ?

Anything back of the dot module can be whacked.. all you have to do is move the pot or switch somewhere recoil-proof, wire it in and seal up the holes. It would be much easier to do to a non-click model since the circuit board is considerably simpler and the traces end just past the dot socket. Thinking Modified??

Here's a disassembled C-more showing the electrical parts: This one is a clicker, non-click models have a potentiometer where the Grayhill switch is and no resistors on the board.

[shred]

The click one is different-- it's a rotary switch and there's a set of resistors stuck down on the circuit board. Thus, the circuit boards are different too, so you can't switch a clicker c-more for a non-clicker without replacing the entire circuit board as well

Digkey carries something close, but not quite matching the part number on the one I just took apart (Grayhill #56SP30-01-1-12N-F). It would probably work (it doesn't have shaft sealing and you have to set the stops), though it's out of stock and $10 in single quantities: Digikey link for click switch.

Update: Allied has the same part currently in stock, for $11+. We'll see how close it is.

Update: update: That switch does work. It takes some fiddling, a bunch of desoldering and the stem is way too long, but it fits and works. It feels looser than the original one, so I'm putting it to backup/airsoft use for a while until it tests out. Since it's $15 for the switch and shipping, plus a lot of time, I'd suggest sending a clicker back to C-More unless you really want to dink with it. The non-clicks are relatively easy to swap out-- 3 leads to desolder/solder and a little dremel-to-fit on the legs.

[Flexmoney]

Thinking Modified??

Well..that is an idea...

But, more for the Open Glocks. Ejecting brass in the Glocks tends to hit low on the ejection port, then start bouncing around (up). If you have a C-more above it, the brass can hit the C-more. If it doesn't clear, then you can get a jam from the brass getting wedged in between the sight and the slide.

Glocksmiths like to lower the ejection port. So far I haven't heard of any of the slides failing in this area, but it does get kinda thin/short under a lowered port...and we are looking to shoot Major. There is other ejection tuning that goes on with them too...

But, shortening the C-more sure would be nice. I've always thought the sight was too long anyway. It seems like a simple design change could take 3/4 to an inch off the length. The switch/pot could be relocated to stick out the back. The switch post would still stick out a bit, but it would be a pretty decent improvement.

?

[EricW]

Shred,

Can you post the top and bottom sides of the PCB? I've always had this yen for a metal C-More for carry that was more compact like Flex is describing. Making the PCB would be a no-brainer if it's as dirt simple as it appears to be from the photo.

Thx,

E

[shred]

Shred,

Can you post the top and bottom sides of the PCB? I've always had this yen for a metal C-More for carry that was more compact like Flex is describing. Making the PCB would be a no-brainer if it's as dirt simple as it appears to be from the photo.

Thx,

E

It's so dirt-simple I can do an ascii schematic for the non-clicker in one line.

Battery+----10KPotentiometer----LED---Battery-

Yes, there is no current limit for the LED when the pot is wide open. I guess they rely on the 1/3N cell not being able to drive enough current at 3V.

Replace "potentiometer" with "rotary 12 position switch and 12 SMD resistors" to get the click version.

The Dot module carrier is an 8 pin DIP socket and the battery terminals are two pieces of metal soldered to the PCB.

It's the optics that do the work, and I don't know anyplace those can be easily sourced.

[EricW]

Thanks! Apparently the internal resistance of the battery is enough of a current limiter.

One of these days, I'm a gonna have me a C-More with a pulse-modulated LED with a CR-123 battery so that I can just leave the sucker on a la Aimpoint. It'd be interesting to know how the dot modules and lenses are manufactured.

[Flexmoney]

I tore my C-more down the other day (which I told myself I wouldn't do...as I like to tear things down to see how they work...then not put them back together after I've extracted the info )

I was already eye-balling some aluminum and my mini-mill. The tough part about making one out of aluminum would be the spring-like lense adjustment that houses the lense. The C-more adjusts the lense housing for windage and elevation, where other designs tend to have the lense fixed and adjust the dot module.

Far easier, it would seem would be to hack off the back of the C-more, then machine a rear cover plate (think Glock slide cover plate) out of aluminum and tap that into the current plastic frame with small screws.

[B.J. Norris]

FYI, C-More does make a Slide Ride with an aluminum body. It was designed to go on AR's, but works wonderfully on my pistol, though it does add about an once and a half of weight. Only comes with the click switch and retails for $340.

[shred]

I tore my C-more down the other day (which I told myself I wouldn't do...as I like to tear things down to see how they work...then not put them back together after I've extracted the info )

you and me both

I was already eye-balling some aluminum and my mini-mill. The tough part about making one out of aluminum would be the spring-like lense adjustment that houses the lense. The C-more adjusts the lense housing for windage and elevation, where other designs tend to have the lense fixed and adjust the dot module.

FYI, C-More does make a Slide Ride with an aluminum body. It was designed to go on AR's, but works wonderfully on my pistol, though it does add about an once and a half of weight. Only comes with the click switch and retails for $340.

I was wondering if Al would be flexible enough or if it would need hinges. Sounds like it is since I've not noticed BJ's scope looking different in casual glances at it.

[shred]

A couple more things---

Note that the potentiometer needs to be able to handle some current-- the little ones won't be happy direct-driving a LED (sadly, nobody makes a high-enough current digital potentiometer yet-- a pushbutton up/down would be cool and could be tiny.

The optics on a red dot is pretty clever-- The C-more is cool because you can actually see the important bits instead of having them hidden in a tube, but it works almost the same (in tube scopes, the entire inner tube moves to change sight-in, in a C-more, only the primary mirror moves.)

The user-end of the scope is built like a small off-axis newtonian reflecting telescope in reverse-- in a regular reflecting telescope, parallel rays of light come down the tube, bounce off a curved mirror and focus in on the focal point. In a red dot, instead, the dot module sits in the focus point, and light it puts out bounces off a red-reflecting coating on the 'mirror' and back out the tube. Then the front of the glass needs to be curved so light coming straight through doesn't get bent and mess up the image.

Aimpoint has a pretty good page: http://www.aimpoint.com/products/why_aimpoint_sights

Saw off everything that's not lens and dot module and flip it over and you've got a C-more.

[shred]

Update: After replacing a defective non-clicker pot with the Digikey potentiometer (it's not quite a drop-in, you have to thin the leads), I found that even at the lowest setting, the dot stayed on. A little head-scratching and disassembly of the defective C-More pot reveals theirs is a somewhat custom unit that goes open at the low end. By carefully disassembling the replacement and scratching off a small portion of the resistive trace, the replacement now works identically. I suspect lifetime may not be as long since wiper wear from the scraped area could become an issue. If you aren't all about desoldering, and dinking with tiny mechanical components, my advice is to send any defective switches back to C-more for repair.