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Saint_TGM 02-25-2013 12:18 PM

Chrono variances?
 
Shouldn't all chronos be pretty equal in their measurements?

Here's what happened to me. Yesterday, I played at a new field out of town (I was there for a conference, and naturally decided to take a marker in case I got some time to play.) Their chrono was one of the white/grey handheld variety, while my home field uses the large red free-standing variety (Paintball Radar brand maybe?)

Upon my initial chrono at this new field, I was shooting way hot, in the 320 range. The last time I played, I was chroned right at 270-280. That was three weeks ago.

I use a T2, with a Deadly Wind 14" with sizers chosen for a slight underbore to prevent rollouts. The T2 reg is sweet spotted, in the 250ish range (don't actually know the actual output pressure, as it is sweet spotted...) The only variables then, besides location, were different paint (FPO at both fields) and this chrono. The new paint was Valken Infinity, whereas the paint at my home field is DXS, both in the .678-681 range as far as I can tell.

What would account for an almost 50 fps change? Surly not the paint. While different, it was a appropriately sized neither hugely underbored or over bored. The weather was about the same, maybe a little warmer yesterday, but only by maybe 10 degrees or so. The new field has a lower altitude, but only by a few hundred feet. Am I missing any variables?

This all makes me think that the different chronograph was calibrated too low compared to the more expensive and larger variety. Anecdotally, my shots did seem softer, and had less range. Has anyone experienced this? A "bad" chronograph?

This may beg the question, how fast am I really shooting at my home field? Maybe that one is calibrated too hot? How does one accurately calibrate a chronograph anyway?

Thoughts? Other experiences?

super_stanchy 02-25-2013 12:22 PM

most chrono's read differently

i despise the virtue clocks for this.
if it is not held PERFECTLY you could easily be shooting +/-30fps

technically, its all about how you hold it and if anything is interfering with the reading
the virtue clock is too easy to hold wrong and cause problems, but it could be compounded with an inaccurate chrono

thats what i think you are experiencing.

Spider! 02-25-2013 12:36 PM

Chronographs can wander off (usually up), especially the little hand helds.

At scenarios, one will wander off and that ref becomes a punch-nazi because he thinks everyone is shooting over. Worse is at evening turn-down when the paint swells up and people fresh filled their CO2 tanks, so they tend to shoot hot anyway.

It's always best if you can cross check with another chrono. The big reds don't seem to fail high as much as they can get lost in reflections at high temperatures (95+F)

The yellow ones show +/- 2%, which should be common. That's +/- 6 fps just for normal operation.

Handheld Radar Chronograph for Paintball Gun

Nobody 02-25-2013 01:17 PM

as well as fields will intentionally turn up the chrono so that you are under the field limit or limiting the possible people that want to shoot at 300fps(so they are truthfully at 280fps). its a safety thing. just play in the field limits and don't blame anyone for the limits.

uv_halo 02-25-2013 04:56 PM

I'd first look at this thread before assigning blame:

http://www.mcarterbrown.com/forums/a...you-point.html

Most radar-based chronos are capable of their stated accuracy specs and some are more accurate than their specs in general. This is because the tech is so 'old school' there are no patents to prevent anyone from doing it (which is why there are so many manufacturers).

This is something worth investigating- comparing the performance of the various radar chrono's to an optical chrono. I may actually be able to do this one.

One thing I recommend is that it's probably not a good idea to operate multiple radar chrono's simultaneously unless you have re-assurance that they are operating in different frequencies, or have other features to prevent interferrence.

p8ntninja 02-26-2013 01:01 AM

Quote:

Originally Posted by super_stanchy (Post 2635290)
most chrono's read differently

i despise the virtue clocks for this.
if it is not held PERFECTLY you could easily be shooting +/-30fps

technically, its all about how you hold it and if anything is interfering with the reading
the virtue clock is too easy to hold wrong and cause problems, but it could be compounded with an inaccurate chrono

thats what i think you are experiencing.

I can vouch for this. At a tournament I played last June when the Clocks were still fairly new we expierienced some issues. My teammate got penalized twice for shooting hot after shooting under 300FPS over a Big Red. I don't think the field refs were properly trained at using the Clocks.

DoC19K 02-26-2013 01:27 AM

I was at a scenario this last weekend and have one of the X radar hand held ones and it was within +3/+4 of the field chrono when it was chronoin'g a new CCM 6.5 which was constant. It was constant but this difference between the hand held and stationary was my biggest concern bringing it onto the field.

Saint_TGM 02-26-2013 07:42 PM

Quote:

Originally Posted by CJOttawa (Post 2636105)
When used correctly, I've had half a dozen RadarChron (mini yellow) chronos, one big RadarChron ROF, an X-Radar, Big Red, and ToughChrono (big yellow, similar to Big Red) read EXACTLY THE SAME.

Make sure the sensor area is clean, there are no obstructions or other objects (paint, rain etc) to interfere with the signal and even the little handhelds read +/-1fps.

This is kind of what I was suspecting. But I'm still perplexed as to what caused such a huge variance. 50 fps seems like a huge jump to me when the differing factors seemed pretty negligible. Yes, I was shooting different paint, but I adjusted the sizer for a very slight underbore, just like I always do. Would a 200 ft altitude change make such a difference? Am I missing anything else here?

uv_halo 02-27-2013 11:38 AM

Did you already consider where the chrono's were pointing (what was in the back ground), how high up from the ground they are, your (or the refs ability) to position the chrono correctly.

Even something like marker placement can lead to significant variations. Both the big red and, the grey RadarChron need to be 1" back behind the muzzle, with the barrel resting on the bumpers provided and angled correctly (gray model needs to be held perpendicular to the barrel, while the big red needs to be placed level, and the barrel kept level).

Legolas 02-27-2013 12:38 PM

chronos may not be the issue. The guns we shoot are not perfect. They are not as consistent as dye/PE/etc. would like us to believe they are. There are many many variables involved in the system. Screws move. they do, really they do.

This is why it drives me nuts as a player&ref when someone says oh yeah I just chrono'd this thing yesterday/last week/last month and it was right on. :huh::scratch:

I know the above is not what the op is describing, but it is just an example of the way some people think.


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