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Author Topic: Caldwell precision chronograph  (Read 276 times))

Offline Novagun

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Caldwell precision chronograph
« on: May 20, 2022, 05:05:41 PM »
I have just bought Caldwell chronigraph from Amazon  It came to me from Las Vegas . So the label says . It works well in natural light but
I can't get it to work inside my workhop either day or night  i have tried led and incadescent lights and made sure no fluorescent light is running. I have seen the same machine running on you tube with just an ordinary table lamp. Any hints would be appreciated.
« Last Edit: May 20, 2022, 05:13:23 PM by Novagun »
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Offline cosmic

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Re: Caldwell precision chronograph
« Reply #1 on: May 21, 2022, 04:13:58 PM »
I tried the same on my pro chrono.. I bought a light kit and they are infrared... No missed shots..  I bought the Caldwell light kit which is all led.. Let me know if you want the Caldwell lights..
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Offline Novagun

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Re: Caldwell precision chronograph
« Reply #2 on: May 21, 2022, 04:29:58 PM »
Yes please. I would like the Caldwell light kit   The Amazon site says they are not available and will not be for some time.
Trouble is that I am in New Zealand ; far from the USA so cost might be a lot.
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Online mobilehomer

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Re: Caldwell precision chronograph
« Reply #3 on: May 21, 2022, 04:35:08 PM »
Try this, get a sheet of white foam core board. Lay it on top of the diffuser supports and light it from the bottom. Use an incandescent or led laid on the table and pointing up at the board.
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Offline mikeyb

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Re: Caldwell precision chronograph
« Reply #4 on: May 21, 2022, 06:20:24 PM »
These chronographs need to "see" two events (pellets passing over sensors under diffusers). They measure the time between the two optical "blips" to determine projectile velocity.

My suggestion:

Tape a piece of OPAQUE cardboard BETWEEN the two diffusers and then backlight the diffusers (from above) with the brightest incandescent lamp you have (>100W).

The front optical sensors will only see a bright front diffuser and the rear sensor will only see a bright rear diffuser as there will be a dim area between the diffusers. Without the "cardboard shade" the sensors may see both the diffusers and the direct light from the bulb which will confuse the device.

As the pellet passes each diffuser the corresponding sensor will detect the slight light change from ONLY that diffuser and should give a correct and consistent velocity reading. If the unit cannot get a velocity reading under those conditions it may be defective.

My Pro Chrono worked flawlessly with that setup for over three years... until the 500W worklamp burned out.

I then changed to DIY LED backlight for each diffuser and that has been error/miss free so far.

https://www.gatewaytoairguns.org/GTA/index.php?topic=198050.msg156309396#msg156309396
« Last Edit: May 21, 2022, 06:23:35 PM by mikeyb »
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Online Firewalker

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Re: Caldwell precision chronograph
« Reply #5 on: May 21, 2022, 10:53:30 PM »
I have just bought Caldwell chronigraph from Amazon  It came to me from Las Vegas . So the label says . It works well in natural light but
I can't get it to work inside my workhop either day or night  i have tried led and incadescent lights and made sure no fluorescent light is running. I have seen the same machine running on you tube with just an ordinary table lamp. Any hints would be appreciated.

Welcome to 60Hz and chronographs. LED lights that run on 120v are turned on and off 60 times a second and your chrony sees that flicker and you get all sorts of strange numbers. Even with incandescent lighting, a LED fixture in the room will still cause this.

The solution I found was to use LED strips that run on DC power, it works day or night, inside or outside, cheap and easy to do. Just peel off the liner and stick them under the sky screens. I use a battery pack to power them but a transformer or a car battery would work as well.
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Show me your customer service.. Take a new gun off the shelf and have your tech verify that it passes all the quality checks then send it to me. No sir... I don't want a discount or a store credit or a partial refund... I want exactly what I paid for and exactly what you said you were selling me. If you can't do that then stay out of my mailbox with your spam mail.
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Online starlingassassin

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Re: Caldwell precision chronograph
« Reply #6 on: May 22, 2022, 12:45:12 AM »
not to hijack,
but the fx radar chronograph does away with ALL the problems of a regular chrono.

you can chrono in the dark if you wish lol

wish i had got one sooner!! 

something to think about.
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Offline Novagun

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Re: Caldwell precision chronograph
« Reply #7 on: May 22, 2022, 03:58:33 AM »
Well it works. Pretty cool here today so I retreated to the workshop and made a light wooden frame and glued so opaque oven cooking paper to it. Shining 3 x 100 watt bulbs onto the paper over the light sensors and it worked on the bench in the daytime.
Thank you for your suggestions, they worked.
Radar chrony. Might be a bit exspensive here in the antiodes .
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Offline Hoosier Daddy

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Re: Caldwell precision chronograph
« Reply #8 on: May 22, 2022, 08:32:48 AM »
Glad you got it figured out.
Just out of curiosity, may be relevant or not...
Over there in New Zealand are you 240v 50Hz?
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Online Firewalker

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Re: Caldwell precision chronograph
« Reply #9 on: May 22, 2022, 10:10:30 AM »
Glad you got it figured out.
Just out of curiosity, may be relevant or not...
Over there in New Zealand are you 240v 50Hz?

Its the sine wave that messes with the chrony, the actual Hz doesn't matter. DC provides a constant stream to the LED's, AC provides light 60/50 times second.
  • USA, MN, Mille Lacs
"If I spend my hard eraned money on an airgun, especially a mid to high end airgun and it has any issues whatsoever, I'm boxing it up and sending it back where it came from. Nope, nope, nope... don't say you fixed it and send it back to me. I didn't buy a refurb and I don't want a refurb back.
Show me your customer service.. Take a new gun off the shelf and have your tech verify that it passes all the quality checks then send it to me. No sir... I don't want a discount or a store credit or a partial refund... I want exactly what I paid for and exactly what you said you were selling me. If you can't do that then stay out of my mailbox with your spam mail.
That's part of the problem with retail these days.. We, the consumer settles for whatever shovel full of stuff they feed us.
Shame on us for that."
-Bill

Offline Hoosier Daddy

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Re: Caldwell precision chronograph
« Reply #10 on: May 22, 2022, 10:16:18 AM »
Yep,
 I was wondering if the change of Hz from 60 here to 50 there was making it more prone to error.  ::)

But then I also thought Light Emitting Diodes were the solution because there didn't flash 60/50 times a second...
My Caldwell light kit has an AC to DC transformer and thought it would be the solution.....  shows what I know.
« Last Edit: May 22, 2022, 10:20:29 AM by Hoosier Daddy »
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Offline Robert 5mm

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Re: Caldwell precision chronograph
« Reply #11 on: May 22, 2022, 01:05:41 PM »
I have had good luck with the free Harbor Freight light ( two ) held with elastic strap to the sunshade.

https://www.harborfreight.com/144-lumen-ultra-bright-led-portable-worklightflashlight-63878.html
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Offline mikeyb

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Re: Caldwell precision chronograph
« Reply #12 on: May 22, 2022, 01:06:23 PM »
Glad you got it figured out.
Just out of curiosity, may be relevant or not...
Over there in New Zealand are you 240v 50Hz?

Its the sine wave that messes with the chrony, the actual Hz doesn't matter. DC provides a constant stream to the LED's, AC provides light 60/50 times second.

Yes and no... there are exceptions.

Sine wave and PWM light pulses will mess with a chronograph reading.

FL light bulbs flicker A LOT actually at 120Hz (=2x60Hz) but most folks eyes don't notice. Incandescent HOT filament bulbs ALSO pulse at 120Hz but the THERMAL TIME CONSTANT of the hot filament is very large so the optical flicker is actually VERY SMALL. I've not had any interference from any incandescent bulb while using my chrono.

LEDs on steady DC diet are also GOOD! However, some "dimable" LED systems chop the DC into a PWM voltage/current to dim the LEDs. THAT high frequency pulsing of the LEDs looks continuous to our eyes but can provide even more interference than FL bulbs to optical electronics like chronographs.

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Offline Novagun

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Re: Caldwell precision chronograph
« Reply #13 on: May 22, 2022, 05:10:09 PM »
We are 230 volts at 50 hz. I thought that the incandescent filament didnt know that and didnt have time to cool off between current oscilations so steady light. Now after reading this thread I know different .
The important thing is that I didnt know and the opaque paper works well. Bit of a bugger really because I have found some guns a little tired.
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Offline Hoosier Daddy

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Re: Caldwell precision chronograph
« Reply #14 on: May 22, 2022, 05:52:29 PM »
BUT.... now you know it.
That is the Beauty of a Chrono.
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Offline Novagun

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Re: Caldwell precision chronograph
« Reply #15 on: May 22, 2022, 06:48:43 PM »
Woops duplicate post.


« Last Edit: May 22, 2022, 07:14:54 PM by Novagun »
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