Infrared Screen Set

[ryan45kim]

can ced's Infrared Screen Set be used with a pact mkIv chrono

[Flexmoney]

I don't know if they would plug in or not. I am doubting it.

[ryan45kim]

I love my pact mkIv timer it’s the only one I’d buy, but I’ve had nothing but inconsistency with the chrono. I’ll set the chrono up get some good readings load up some more test rounds and the chrono will not work, 1st shot 29fps 2nd shot 3692fps ect ( I have a range in my back yard so we are talking 10-20 minutes between strings). I know this is because the sun is moving but it has become a game of random chance, set it up see if it will work today if not try again tomorrow and that’s not right. I’ve tried taking the sun screens off and on, putting a cardboard box over the chrono, putting it in the shade and out in the direct sun but nothing works consistently.

Here are my thoughts,

1) The inferred screens are only replacing the sky screens on the ced chrono, so if the photo sensors are similar the inferred screens should work on the pact chrono also.

2) Maybe building a box for the whole setup, totally cutting the sun out but I think it will still need a light source.

3) Put the inferred system inside the box.

4) Or building a custom light system into a new box.

Last year I came close to not making my power factor at a couple of matches, I do not want that to happen again, any ideas will be greatly appreciated.

[.40AET]

I emailed Greg Lent (aka: the chrono man) and he was kind enough to send me a photo of what he uses at all of the major matches for the chrono station. The hole in the end is the size of a coffee can.

[Flexmoney]

I love my pact mkIv timer it’s the only one I’d buy, but I’ve had nothing but inconsistency with the chrono. I’ll set the chrono up get some good readings load up some more test rounds and the chrono will not work, 1st shot 29fps 2nd shot 3692fps ect ( I have a range in my back yard so we are talking 10-20 minutes between strings). I know this is because the sun is moving ...

I don't think it has squat to do with the sun. In fact, I'd bet money on it. (If you have them in direct sunlight...maybe. But, if the sun is diffused, then readings won't be very much different.)

You likely are too close to the chrono screens. And, you are getting reading from muzzle blast.

My Pact Mk-IV has been run back to back with a CED (boxed w/Infrared)...the setup we used for a Major match. They were always within 8fps of each other...shot-for-shot.

[ryan45kim]

Flex I’ve tried varying the range from the start screen, I’ve tried 6 inches from the start sensor all the way back to 25 yards and nothing will make it work consistently, if it does not want to work there doesn’t seem to be anyway to make it work (also I've never tried to run it in bad weather, rain, snow, getting dark ect) . Maybe it is just my chrono I don’t know the only variable I can think of that I have not tried is altering the light source, (trying artificial light) but if I’m missing something please let me know I just want it to work consistently.

[shred]

Live near any high-voltage power lines or radio towers? Sounds like either an interference problem or bad screens.

[10mmdave]

I love my pact mkIv timer it’s the only one I’d buy, but I’ve had nothing but inconsistency with the chrono. I’ll set the chrono up get some good readings load up some more test rounds and the chrono will not work, 1st shot 29fps 2nd shot 3692fps ect ( I have a range in my back yard so we are talking 10-20 minutes between strings). I know this is because the sun is moving but it has become a game of random chance, set it up see if it will work today if not try again tomorrow and that’s not right. I’ve tried taking the sun screens off and on, putting a cardboard box over the chrono, putting it in the shade and out in the direct sun

but nothing works consistently. 

<{POST_SNAPBACK}>

This is why I bought the CED with the infrared lights.

I sent my Pact unit back 6+ times, always went back to giving flaky readings,

never a note in the return as to what was wrong, they make great timers

I use the lights even outdoors for consistency. I have had some iffy data

come out when the sodium lights are on in the indoor range.

p.s. I don't know that you need a box outside in the sun, I once tried to use my

CED chrono outside with the IR light units but not powered up (long story )

The unit would not register shots, had to take the units off and then it worked.

There is a web site for a guy who is very knowledgeable about the CED

http://www.shootingsoftware.com/chronographs.htm

[ryan45kim]

Shred that’s a good point I don’t think there are any major lines near me (just the one line that feeds the houses on my street no big ones) but I’m going to check. There are several power plants in my area, but I’m at least 10 miles from the closest one.

Dave thank you, I thought I was going crazy, its just nice to know you’re not the only one. Again I love this timer, I’d never buy anything else it does everything I need it to do and more I’m not trying to bash Pact, everyone I shoot with has them and the club I use to run we used five of them for our matches, I just want to find a way to make this chrono work consistently.

I would still like to know if the inferred screens would work with the Pact sensors, from what I have seen the CED inferred screens only replace the sky screens on the standard CED chrono (the CED chrono still uses there standard photo sensors with the inferred screens), so I’m thinking that if I used my Pact photo sensors and put the CED inferred screens over top of them it may fix my problem but I’m getting tired of throwing money around.

[rwmagnus]

I emailed Greg Lent (aka: the chrono man) and he was kind enough to send me a photo of what he uses at all of the major matches for the chrono station. The hole in the end is the size of a coffee can.

<{POST_SNAPBACK}>

What chrono is inside that box? It looks like a CED but it has 4 screens on it is that correct?

[Flexmoney]

ryan45kim,

I thought you were asking if the CED lights and sensors would plug into the Pact.

Now, I understand that you just want to use the CED's as a light source.

I don't know if that would work or not. If I ever get out with my chrono (Pact Mk-IV) when somebody has their CED's out...I'll check.

rwmagnus, they often run two CED chronos, back to back.

[BigDave]

I also had a problem with inconsistent chrono results with my PACT MkIV. What I found out that helps is:

1) When shooting a pistol, 4-6 yds behind the chrono is a good distance

2) Place a target in front of the skysreens. This will block any powder residue that will give false readings and it will give you a consistent aiming point so that the sensors will "see" the bullet at more or less the same place with each reading. Shooting off a rest or sand bags also aids here.

3) Angle the screens so that no sun is shining in the sensors (gotta disagree with you here Flex$). Direct or indirect. There is nothing that says these screens have to be pointing straight up, either. They will work on their side and I'd bet upside down, too, but haven't tried it (but I do think it is one helluva idea). There needs to be light so the sensor can pick up the projectile moving across the "white" background of the skyscreen, but just keep it directly off of the sensors.

I spent a lot of time pulling my hair out setting up an AP load that I was confident that would pass chrono at Bianchi and our State and Regional Matches. Sensor placement and light are very, very critical to accurate readings. If not, why would G. Lent use a chrono coffin?

[ryan45kim]

Thanks for the replies guys, I like the idea of turning the sensors upside down (wish I could say I thought of that) I will give that a try, between work and setting up my rifle and shotgun for three gun, I haven’t had any time to play with my crono, but this is definitely something I’m still working on, any suggestions will be appreciated.

Ps. No power line anywhere nearby.

[kevin c]

I also have a Pact chrono. It works fine, at certain times of the day, and it does seem to be sun related. There's also a chance that it's power line related, but maybe for a different reason than radio interference. The high voltage lines running over part of our range are up on 60' towersl, and, or course are there all the time, so I don't think that the interference should change with the time of day, if it's from the lines.

What does change is the angle of the sun. It might be what Big Dave was saying - light directly on the sensors - but the worst of it was when the sun was shining down directly THROUGH the power line, perhaps some shadowing or diffraction effect.

Anyway, I end up chrono'ing later in the day, or under cover, if I want consistent readings.

I keep meaning to try the chrono-on-its-side trick...

[ryan45kim]

Well I had yesterday off and decided to do some chrono work I’ve been putting off, the results were the same as always it worked about 1/3 of the time.

The only time I could get it to work consistently was when the sun was behind the clouds.

Unfortunately turning the sensors on there side did not work for me; neither did turning the whole unit upside down (sensors facing down instead of up).

I guess I’m going to start drawing up a design for an enclosed box with its own lighting system, any ideas guys?

[.40AET]

CHRONO COFFIN DIRECTIONS

NOTE: I EMAILED GREG LENT FOR SOME ADVICE ON BUILDING A CHRONO COFFIN AND HE WAS KIND ENOUGH TO SEND ME THE DIRECTIONS AND A PHOTO. Thanks again Greg. The Following is Greg's reply:

Hi Kirk

No problem...and thanks for the interest. It's always easier to get folks off on the right foot than correcting problems later on...

Attached is a jpg of one of my boxes.

The dimensions are either:

2'X2'X6' (min)

or

2'X2'X4'

Use the shortest box if you're just running 1 chrono.

The longer ones if you're running 2 like we do at tournaments.

Be sure to have the access door on the side for easy access to the equipment.

For lighting, if you have CED's, they have an accessory IR lighting system that replaces the existing sun screens.

OR

on standard CED's or any other brand with a standard sky screen, mount 40W display case bulbs either directly over each sky screen or attach them to the top of the screens. 40W bulbs work for most chronographs.

Be sure to have the access door closed, an entry hole in the box about the size of a 1-lb coffee can (this shields the units from blast too) and cover the exit to keep extraneous light out too (a small exit hole is a good idea too along with a target for a point of aim).

Have the holes several inches above the sensors to avoid hitting them.

Also use a designated operator. Don't let everyone shoot his gun over the equipment...it'll get blown-up.

Let me know if I can be of any more help.

Greg

[ryan45kim]

.40AET thanks for the reply, I think I’m about to build a box (as soon as I get some free time). And please send my thanks to GREG LENT for his development of the coffin and being nice enough to share his experience.

Again thanks for the help guys.

[.40AET]

My pleasure. I'll tell you, I picked up his email from an article he wrote for Front Sight. I sent him the question and he sent me back a very detailed answer right away. He's a good guy in my book. He works a lot of Big matches, you can thank him when you get there.