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Indoor chrony help
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Author:  Petee_c [ Tue Feb 27, 2018 1:29 pm ]
Post subject:  Indoor chrony help

Recently bought a Chrony F1. My backyard is not conducive to air gun shooting, so I a. And setup in the basement.

Having recorded one shot yet. I've tried at least 30x.

The 1st 10x was because I didn't wait for the chrony to be ready. Couldn't figure out how to clear the "Err" code.

I've changed all the bulbs in the ceiling to LED.

I'm using battery powered LED work lights taped to the top of the diffusers, but no readings are coming up.

The one light is advertised as 400lm(very good light)
https://www.amazon.ca/gp/aw/d/B01BT0OXS ... _pop_mb_pd

The other one is a Braun from harbor freight (great light)

https://m.harborfreight.com/390-lumen-m ... 20provided

Can lights be too bright? Maybe COB LED's flicker?

Do I need to turn off the other lights
In the room?



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Author:  Daryl [ Tue Feb 27, 2018 1:39 pm ]
Post subject:  Re: Indoor chrony help

For indoor chronographing, I use light pucks from Canadian Tire. About $5.09, I think. They have a magnet inside the back and I use rare earth magnets from PAuto to hold them on the plastic diffuser panels of the Cronograph.

Click on the picture and it will enlarge. There is tuck tape on the puck as I dropped it and it cracked. The tape just holds it together.

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Author:  HuskyDude [ Tue Feb 27, 2018 2:04 pm ]
Post subject:  Re: Indoor chrony help

I've only had my F1 for a couple of months.
Although it would read very well out side in natural light. It struggled to read any indoors.
I had some 12v LED boards kicking around and wired up a charging/on/off switch in the body of the F1 and stuck magnets to the diffuser panels.
Works very well !!!
Maybe the LED lights you have chosen are not providing a wide enough beam of light across the photocells.

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Author:  Petee_c [ Tue Feb 27, 2018 6:08 pm ]
Post subject:  Re: Indoor chrony help

Messy basement. Will clean it up this weekend.

Got it to work fairly consistently, about 4 out of every 5 shots

Switched to an old single 150w halogen worklight. ImageImage

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Author:  Ace [ Tue Feb 27, 2018 6:50 pm ]
Post subject:  Re: Indoor chrony help

Petee_c wrote:
Messy basement. Will clean it up this weekend.
Got it to work fairly consistently, about 4 out of every 5 shots
Switched to an old single 150w halogen worklight.

remove the diffusers and just place the chrony directly under the path of the light as you have it now
you will get better readings without them you don't need the diffusers the way your using your chrony
just keep the poles in place so you can judge where to shoot your pellets... :wink:

Author:  leadslinger [ Tue Feb 27, 2018 7:07 pm ]
Post subject:  Re: Indoor chrony help

ERRRR is probably because you had the chrony on and turned off a light. Normally just turn it off and on. And goes away. Or it mot reading.

Chrony I found you really need to install the shades all the time. I glued a washer to the bottom, and stuck LEDs puck under.

Image

Seems to work fine and all my lights are LEDs.

Author:  lleader [ Tue Feb 27, 2018 8:55 pm ]
Post subject:  Re: Indoor chrony help

I use puck lights from Canadian Tire attached under the plastic diffusers. I used to get about 20% errors with .177 and about 10% errors with .22. I had the diffusers at the maximum height. I then moved the diffusers down to half height using only the single rods at each corner (like Daryl has in his post above). I only get the occasional error now if I do something stupid with my aiming.

These are the ones I use:
http://www.canadiantire.ca/en/pdp/hd-po ... p.html#srp

They were on sale when I got them quite a while ago.

Author:  Watertown [ Tue Feb 27, 2018 9:26 pm ]
Post subject:  Re: Indoor chrony help

Consider the chrony measures the shadow of the pellet crossing the sensor. Make sure only the light over the sensor shines on the sensor even if you have to add a shade on the other light.

Author:  rsterne [ Tue Feb 27, 2018 11:15 pm ]
Post subject:  Re: Indoor chrony help

Using a single light over the Chrony will cause a velocity error, because the light is coming down at an angle, diverging from the single source to the two sensors.... This will cause a higher than actual velocity reading, that is worse the higher above the sensors you shoot.... This is a real and proven effect, and one of the most common reasons for higher than actual velocity readings....

Image

The Chrony measures the time it takes for the pellet to cross the light path from source to sensor.... With a single lamp, the path is shorter than the Chrony is calibrated for.... so the velocity calculated is higher than it should be....

Bob

Author:  Ace [ Wed Feb 28, 2018 1:03 am ]
Post subject:  Re: Indoor chrony help

bob you may be correct if its a single light (like a light bulb) yes i can see that...
but in my case i put my chrony under 4 foot length light tubes with the chrony running the length of the tubes
and i rarely get error's if do its because i didn't shoot directly over the sensors...and i don't use the diffusers

Author:  Doc Sharptail [ Wed Feb 28, 2018 3:19 am ]
Post subject:  Re: Indoor chrony help

It doesn't take much output to get my F-1 to read.

Usual indoor set up is 15-W incandescent "night lights" taped to each diffuser.

Usual cause of repeated error-1 or error -2 is a dying 9-volt battery for me. Those batteries can last deceptively long, and then do a nose dive when they do go dead.

I have the most trouble with it in bright, direct overhead sunlight. One fix for that is to move the diffusers closer in over the projectile path. The only time I can get away without the diffusers is outdoors under bright overcast...

-D.S.

Author:  Petee_c [ Wed Feb 28, 2018 9:46 am ]
Post subject:  Re: Indoor chrony help

rsterne wrote:
Using a single light over the Chrony will cause a velocity error, because the light is coming down at an angle, diverging from the single source to the two sensors.... This will cause a higher than actual velocity reading, that is worse the higher above the sensors you shoot.... This is a real and proven effect, and one of the most common reasons for higher than actual velocity readings....

Image

The Chrony measures the time it takes for the pellet to cross the light path from source to sensor.... With a single lamp, the path is shorter than the Chrony is calibrated for.... so the velocity calculated is higher than it should be....

Bob
That's why I have the cardboard shade between the 2 sensors in my setup. But it likely will change as I experiment more with it.

Readings look ok. My daisy 953 with cupmod is getting 475-480fps with rws hobby pellets. That's inline with what other people seem to be getting.

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Author:  pelsby [ Wed Feb 28, 2018 11:51 am ]
Post subject:  Re: Indoor chrony help

As to the single point light source . I had to check my calendar to confirm it is only Feb 28 and not April 1 . BHAAAAAAAAAA . If you were using Two lasers a a light source your theory may be valid .The slots above the sensors are engineered as to permit only light from overhead to enter and mitigate any angular effects .I have included a pic of the light pattern of a single led for representation only and as I see it it has almost 180 degrees of radiation .I have always used two overhead lights in my setup and get few errors .Incandescent light bulbs have given the best results florescent lighting has never worked and I am still experimenting with led's . Just my 2 cents .

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Author:  rsterne [ Thu Mar 01, 2018 12:49 am ]
Post subject:  Re: Indoor chrony help

Ace, my comment was directed at the OP, who posted a photo of a single light over the Chrony.... I noticed the shade between the diffusers, I guess they are lit brightly enough to work as intended....

pelsby, you may choose to not believe me, but I have seen videos of guys doing exactly as I stated.... One extreme example had the path of the pellet closer to the single light source than the sensors.... and the guy was getting over 1500 fps with an MRod.... The light source may be spread out, but the light that the sensor sees will be travelling in a straight line from source to sensor.... unless you use a mirror to change the direction, of course....

I use the original indoor lighting kit with my Chrony, with incandescent bulbs.... and it is 100% rock solid and reads the same as outdoors....

Bob

Author:  pelsby [ Thu Mar 01, 2018 9:15 am ]
Post subject:  Re: Indoor chrony help

I am sure there are many video's of chronographs reading higher than the real velocity .This is a common phenomena when the sensor shields have been shot and the slot loading of the light source has been compromised . If the slot loading were included in rsterne's diagram the function of the slot loading of the light source will be apparent . The synopsis is if you have shot you crhony and it still functions it may no longer be accurate if you have changed the light path to the sensor . The sensors are not at the top as per the diagram they are well below the slot where the light enters .This crhony may still work but it is no longer accurate .For exactly the reasons portrayed by rsterne's illustration .

Image

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