Chrono help

[Drew P]

So I have had one of these Caldwell chrono for a while and it would always give bunk readings and I had pretty much given up on it because I was never confident in its performance. Sun, cloud, indoor outdoor never could make a correlation. Did a search on it and found that there was a bad batch of sensors or something and that they were replacing some models. Called them and was happy that they said yes we will send a new one out to me. Well I got it and set it up last night in the shop and took a shot. Reading said 8609. Well, im fairly sure I’m not pushing this round 8600fps so what the hell?! I’m sick of this because I’m in the city and I can’t just blast away in my shop to no end not to mention it’s a waste and inconvenient.
Are these chronos 207651just garbage or what?

[Traffer]

I bought one from Amazon about 8 months ago and it has functioned without a flaw. I haven't heard of any bad ones until now.

[NoAngel]

I despise those type of chronographs. I've been using a magnetospeed for a few years now. Worth EVERY penny.

[jimb16]

I've got a chrony that gives crazy readings every now and then. I traced the problem to weak batteries! I replaced the batteries and the readings went back to where they should have been in the first place.

[country gent]

Sometimes indoor lighting and or florescent lights have an affect on them also. A thin piece of frosted plexiglass that covers 8" fornt and back and completely over the screesns stops shadows and bad pick ups. I used 1/8" p;exis glass and sand blasted it to give it a frosted effect for a diffuser on my pact professionals sky screens

[Minerat]

Use a paintball gun to check them if you have one. You can shoot them into a trash can in the garage and it would save a trip to the range too. I have a PACT Professional too and if you shoot too low or high across the screens or it is too dim or bright sometimes you get funny readings. Muzzle velocity should be around 300 fps for a paintball gun. ++1 on the batteries too.

[country gent]

I bought several cans of pellets all the same lot number and use these and my rws r1 pellet gun to check the set up on my pact. I now have a Lab Radar and its way better since its not dependant on light conditions.

[Drew P]

Sometimes indoor lighting and or florescent lights have an affect on them also. A thin piece of frosted plexiglass that covers 8" fornt and back and completely over the screesns stops shadows and bad pick ups. I used 1/8" p;exis glass and sand blasted it to give it a frosted effect for a diffuser on my pact professionals sky screensno fluorescents allowed on my property these days. Shop is all led. Haven’t tried this new unit outside yet but man I’m sure disappointed. I’ll put a new battery in it although I think this one is still like new from the troubleshooting on the last unit.
Good idea on the paintball gun, don’t have one tho. Would a B.B. gun work?

[Drew P]

Use a paintball gun to check them if you have one. You can shoot them into a trash can in the garage and it would save a trip to the range too. I have a PACT Professional too and if you shoot too low or high across the screens or it is too dim or bright sometimes you get funny readings. Muzzle velocity should be around 300 fps for a paintball gun. ++1 on the batteries too. they run paintball guns at 300now?! Back when I was a kid, when paintballs were new, I thought we were running them a lot closer to 200 and those would still raise a nasty welt on a young boys back!

[Traffer]

no fluorescents allowed on my property these days. Shop is all led. Haven’t tried this new unit outside yet but man I’m sure disappointed. I’ll put a new battery in it although I think this one is still like new from the troubleshooting on the last unit.
Good idea on the paintball gun, don’t have one tho. Would a B.B. gun work?

Maybe led lights are the problem. I have noticed a high frequency "flutter" or almost a strobe effect when using a dimmer on non dimable leds. I hooked up a dimmer to the non dimable ones by accident and found the curious effect at about 80 to 90% power. It made me think that maybe these things have a non-discernable high frequency flutter when running at full power. I guess you could check it with a high speed camera or an oscilloscope.

[JBinMN]

Good idea on the paintball gun, don’t have one tho. Would a B.B. gun work?


BBgun works.
;)

I used my grandboys Red Ryder to test mine, & was trying to figure out things like distance from muzzle & such. That is why you will see so many Errors in the test run below. I use the hookup to my cellphone & then send the data to my laptop to compare the data later when I get home. Here is that Test Run with the BBgun:

Set: 1
Created: 19/09/17 12:30
Description: B.B. test
Notes 1:
Notes 2:
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 0.00
Temp: N/A °F
BP: N/A inHg
Altitude: 0.00
# FPS FT-LBS PF
10 332 0.00 0.00
9 ERROR 2
8 330 0.00 0.00
7 323 0.00 0.00
6 ERROR 3
5 ERROR 3
4 331 0.00 0.00
3 ERROR 3
2 ERROR 2
1 ERROR 2
Average: 329.0 FPS
SD: 4.1 FPS
Min: 323 FPS
Max: 332 FPS
Spread: 9 FPS
Shot/sec: 0.1
True MV: 329 FPS
Group Size (in): 0.00


I had bought it back in late Spring, but only started to use it in the last couple months.
I kind of like mine, but I have not used any other chronometers to know if they would be any better...
It'll do for me & what I do..

G'Luck! with getting your to work for ya.
:)

[Drew P]

Tried the ole pumpmaster on it and no luck. 3 bbs and one pellet but nothing registered on it. Maybe I’ll put a halogen work lamp on it and see if that helps.

[JBinMN]

My test was outside of my garage the day I tried it. Partly sunny then, IIRC, but I was in partial shade from a tree. I have used it a few times since & am going to use it again in the next few days. The days I tried it I was out on some public land near me & it was mostly sunny out with just passing clouds. I have not tried it indoors & likely never will as I do all my shooting outdoors.

I bought the kit that comes with the light bars that would go across where the screens are for low light conditions. I am now wondering if they would help with your indoors situation.. ??? Maybe one of these days I will experiment & try them out in the garage with the grand boys BBgun to see,even though I may likely not ever use them for the "big boys" firearms.
.

I really do hope you can get it figured out as it is a pretty good setup as far as I can tell, & the price was reasonable for my budget. If ya don't have the light kit and want to use it in low light conditions it may be worth considering...

G'Luck!
:)

[lwknight]

no fluorescents allowed on my property these days. Shop is all led. Haven’t tried this new unit outside yet but man I’m sure disappointed. I’ll put a new battery in it although I think this one is still like new from the troubleshooting on the last unit.
Good idea on the paintball gun, don’t have one tho. Would a B.B. gun work?

The led is a big problem for chronographs. The leds are controlled by a PWM that actually flickers the light set intervals to limit the output. That would totally screw with the chrony.

[hermans]

Using your chrono indoors with LED external lighting is not ideal at all.
Constant lighting is vital for consistent results.
The pellet from a BB gun is very small and the unit can most probably not sense the very small difference in light intensity, especially indoors.
If you want to use the unit indoors only, remove the sun shades, and mount a pair of incadescent strip lights directly above the sensors about the same height as the sun shades, I think they are used a lot in RV's. They work off 12V DC, so and you can run them off any battery or linear 12V DC power supply with good smoothing.
This should solve your problem when using the unit indoors - good luck!

[kingrj]

Unless the LED lights are on a battery or filtered supply they will play hell with the crono...The detectors are phototransistors that are coupled to an operational amp set up as a differentiator so it only amplifies high rate of change light intensity....if the led lights are actually pwm (pulse width modulated) controlled then that is the problem indoors...Try it outdoors...I have had great luck using the Competitive Edge Dynamics light screens with a chrono of my own design...The already have the differentiator amps built into the screens and screens cost about $60...They work very reliably for me..

[Drew P]

Ah ha okay. Must be the lighting then. I had heard about the fluorescent issues but not leds yet. Let me do some experimenting and get back with y’all. Thanks.

[hermans]

Please keep us posted on your progress, would like to know if my tinkering with chronographs for the past 40 years is worth anything!

[Larry Gibson]

Also, when you set it up how far from the muzzle is the start scree? Your errant readings in 1st post sound like muzzle blast interference.

[JBinMN]

My light set came in the kit, but below is the light set at a couple of places, if ya don't already have them & want them. Or, don't want to make some yourself as was suggested above.
Just posting about it in case you, or someone else did not know about them for some reason.
:)

https://www.amazon.com/Caldwell-721111-Chronograph-Light-Kit/dp/B00HX46M0I

https://www.midwayusa.com/product/101504606/caldwell-chronograph-light-kit (< Currently OOS/backorder Ok aat this one.)

G'Luck!
:)

[swheeler]

I'm pretty sure I saw on here where someone was using LED lights hooked to the sky screens on his chronograph for indoor, or low light shooting, said it worked great?

[vzerone]

http://www.competitionelectronics.com/product/indoor-lighting-system/

They say they have to be infrared LED's.

[swheeler]

https://www.youtube.com/watch?v=BAleLVbFmh0

[fredj338]

You do understand that most chronos are designed to use the sunlight to provide the shadow for the skyscreen to read? You need special skyscreens for indoor readings. The Labdar units do NOT use skyscreens & can be used in any light. Really good units nut expensive.

[vzerone]

You do understand that most chronos are designed to use the sunlight to provide the shadow for the skyscreen to read? You need special skyscreens for indoor readings. The Labdar units do NOT use skyscreens & can be used in any light. Really good units nut expensive.

Yup they are designed for infrared light. That doesn't mean they don't work at all with another source.

[Drew P]

I'm pretty sure I saw on here where someone was using LED lights hooked to the sky screens on his chronograph for indoor, or low light shooting, said it worked great?
THere are several ways to use leds and in their basic function they are all DC and smooth light that I’d guess is ideal for anything like these chronos. However, the implementation of them in our homes means they need to be able to use AC power and how they deal with that can happen in different ways. One way is to actually let the polarity reverse 60 times a second. This is not great and means the lamp is lit 1/2 the time, as it turns on and off. at 60hz you can almost not detect it as a human eye. However they do “flicker” a little. Now, to a photo type equipment like a chronograph well heck I can see it being a big problem. Now, I know my shop led lights are not flickering like that, but I don’t know exactly what they look like to a chronograph.

However, my previous testing with this was in all conditions, mostly outdoors, varying ranges and ya know, if you are so doubtful of the equipment readings then it really makes it a useless tool even if it is correct 50% of the time. I need to be able to use it, once, for one shot and have an expected and reliable reading. If it can’t do that then it’s really just a waste of plastic and time to me. But, I’m not giving up just yet. It’s just weird because when something works intermittently I can usually figure out some sort of pattern and that leads to discussion and solutions or at least work-arounds. But this tool has left me just stumped. I’ll play with it this weekend outside if I get a chance.

Hey the company told me that shots in the (?) portion of the shooting window would produce the best results but I forgot where he said to focus shots. I think it was in the lower 1/2 of the window, nearer to the unit (carefu!) Can anyone verify this?

[Mal Paso]

Light reflected from the ground can sometimes cancel the bullet shadow from the skyscreen. Dillan reloading suggests a dark blanket spread on the ground under the chronograph.

I took it a step further putting 2 sheets of black plastic against the skyscreen wires. Worked in almost any light.

Bullwolf put 2 Amazon battery LEDs on his screens with great success. Post #20 https://www.google.com/url?q=http://castboolits.gunloads.com/showthread.php%3F255234-Shooting-Chrony-F1&sa=U&ved=0ahUKEwjt6LLOur_XAhUO8GMKHaH2BckQFggIMAI&client=internal-uds-cse&cx=partner-pub-6216953551359885:1942134700&usg=AOvVaw366eslN_DjWIy50CvcruBj

[Drew P]

Also, I’ll add that the reason I chose this model was it was the cheapest chronograph available. I was able to shake 90$ free for the tool. Much more than that and I’d probably be ******** about not having a chrono instead of how crappy the cheap chrono I have is. So, maybe I deserve it. I figured if it does it tells me the speed that seems all I need. And actually the app is pretty nice. Anyway just mentioning the reason I selected this one instead of another’s more expensive unit.

[vzerone]

THere are several ways to use leds and in their basic function they are all DC and smooth light that I’d guess is ideal for anything like these chronos. However, the implementation of them in our homes means they need to be able to use AC power and how they deal with that can happen in different ways. One way is to actually let the polarity reverse 60 times a second. This is not great and means the lamp is lit 1/2 the time, as it turns on and off. at 60hz you can almost not detect it as a human eye. However they do “flicker” a little. Now, to a photo type equipment like a chronograph well heck I can see it being a big problem. Now, I know my shop led lights are not flickering like that, but I don’t know exactly what they look like to a chronograph.

However, my previous testing with this was in all conditions, mostly outdoors, varying ranges and ya know, if you are so doubtful of the equipment readings then it really makes it a useless tool even if it is correct 50% of the time. I need to be able to use it, once, for one shot and have an expected and reliable reading. If it can’t do that then it’s really just a waste of plastic and time to me. But, I’m not giving up just yet. It’s just weird because when something works intermittently I can usually figure out some sort of pattern and that leads to discussion and solutions or at least work-arounds. But this tool has left me just stumped. I’ll play with it this weekend outside if I get a chance.

Hey the company told me that shots in the (?) portion of the shooting window would produce the best results but I forgot where he said to focus shots. I think it was in the lower 1/2 of the window, nearer to the unit (carefu!) Can anyone verify this?

The infrared light kit from Competition Electronic has an adaptor that changed the AC current into 24 Volts DC so the AC cycling doesn't affect it. They also tell you that you can wire two 12 Volt batterys together to operate it.

[Drew P]

Light reflected from the ground can sometimes cancel the bullet shadow from the skyscreen. Dillan reloading suggests a dark blanket spread on the ground under the chronograph.

I took it a step further putting 2 sheets of black plastic against the skyscreen wires. Worked in almost any light.

Bullwolf put 2 Amazon battery LEDs on his screens with great success. Post #20 https://www.google.com/url?q=http://castboolits.gunloads.com/showthread.php%3F255234-Shooting-Chrony-F1&sa=U&ved=0ahUKEwjt6LLOur_XAhUO8GMKHaH2BckQFggIMAI&client=internal-uds-cse&cx=partner-pub-6216953551359885:1942134700&usg=AOvVaw366eslN_DjWIy50CvcruBjthat makes a lot of sense. I may try that. Takes portability and setup time down a notch tho

[JBinMN]

Source:http://www.btibrands.com/wp-content/uploads/2014/05/chronograph-and-kit-master-instructions.pdf

From the Operation page(5/8):



2. Position the unit 10 to 15 feet in front of the muzzle of a firearm or
if using with a bow, at least one full arrow length in front

3. Align the Chronograph:
a. Height, so that the projectile travels through the center
of the shooting window
b. Tilt Angle, so projectile travels parallel to the top surface of the housing
c. Left/Right, so that projectile is in line with housing

From the Tips page(7/8):


1. Understand the flight of your bullet
will be lower than your sight picture.
Most scopes are mounted 1.5” higher
than the centerline of the barrel.
Always aim higher than the middle of
the shooting area.
[Note: There is a pic to the right on the page that shows the "window" described above]

2. Avoid low light conditions, such
sunrise and sunset. During these
times the extreme low angle of the sun
can cause added variation due to
reflections and low levels of light. Use
of optional light kit will improve
function in these conditions.

G'Luck!
:)

[Larry Gibson]

Again, when you set it up how far from the muzzle is the start screen?

Your errant readings in 1st post sound like muzzle blast interference.

[nitroviking]

I'd never heard of the Lab Radar before seeing the posts about it here, so I just did a quick search on it..... Never before have I been so tempted to spend $500 that I cant really afford than right now, I'm putting that on the must have list for sure. Very nice

[Traffer]

Yup, I believe that the Lab radar technology will eventually take over this industry. In the mean time, some of us can only afford the current cheaper units. (which were nearly science fiction 30 years ago).

[Drew P]

Again, when you set it up how far from the muzzle is the start screen?

Your errant readings in 1st post sound like muzzle blast interference.ive tried all distances from 10-30’, although thisfirst shot on the new unit was maybe less than 10’

[Larry Gibson]

Ok, if the errent readings also occurred outside I'd suspect something is wrong with the crono and would send it to maker for repair or replacement.

[Messy bear]

Most units work best outside in cloudy or hazy conditions it seems. Take it out and find out for sure. I have used many different brand's but all work outdoors in those conditions IIRC. Hope you get it going cause they are a useful tool.

[Mal Paso]

In overcast conditions some units work better with the sky screens off.

The optical type chronographs uses two photo sensors to start and stop a timer that displays that time as feet per second. They are usually fairly accurate.

We wouldn't have half the problems if we just shot Jacketed Bullets. LOL A lead boolit, polished by the bore, is Shiny Silver, like a mirror and reflects light which sometimes cancels the boolit shadow.

After you eliminate muzzle blast whatever you can do to increase the contrast of the boolit's shadow helps reliability.

[swheeler]

In overcast conditions some units work better with the sky screens off.

The optical type chronographs uses two photo sensors to start and stop a timer that displays that time as feet per second. They are usually fairly accurate.

We wouldn't have half the problems if we just shot Jacketed Bullets. LOL A lead boolit, polished by the bore, is Shiny Silver, like a mirror and reflects light which sometimes cancels the boolit shadow.

After you eliminate muzzle blast whatever you can do to increase the contrast of the boolit's shadow helps reliability.

Drew, from the sounds of this you are going to have to start powder coating!:kidding:

[JBinMN]

Used my Caldwell Ball. Chrony today in cloudy skies, outdoors & it worked fine. I am thinking that yours is having issues with that indoor lighting.

Please let us know what ya find out.
:)

[lwknight]

I'm pretty sure I saw on here where someone was using LED lights hooked to the sky screens on his chronograph for indoor, or low light shooting, said it worked great?

There are different type power controls on leds. A buck/boost regulator used with batteries will be a smooth pure light. The PWM is the cheapest and most common regulator. Even battery powered leds probably use PWM unless they are a higher end product. The ones that run from a constant power supply will have a P.W.M. controller . The PWM actually measures the pulse width to control output.
This will totally mess with the chrony.

Have you even been behind a car and cut your eyes one way and saw multiple tail lights for a second like the old party strobe. That is what most leds are doing.

[Landshark9025]

I love mine. I did get some funky readings and called them. They sent a new one- but truth be told I'm not 100% sure it wasn't the battery. Although I think I tried that. This weekend I used it outside- in the rain. Not a downpour but an alternate between misty haze and light sprinkles with large drops. A lot of false readings as the rain would trip one sensor, but not the other. Once I weeded those out I was left with solid data.

I didn't use the screens this time.

I usually set mine about six feet from the muzzle, but I'm also only using it for 9mm.

[smoked turkey]

In response to the comments about muzzle blast interfering with the chronograph & giving erroneous readings, I too have experienced that situation. My problem was not the distance from the sky screens, but from the muzzle blast of the rifle (in this case) being too close to the computer that receives input from the screens. I had always placed the computer on my shooting bench. I solved my problem by putting the computer inside a small Styrofoam box and set it on the ground at the foot of my shooting bench. Evidently this muzzle blast is no longer an issue as my unit now functions near 100%.