Dry Fire Efficiency Test

[jackwood]

Gordon, what do you find surprising about the cocker?

Did you expect it to be better or worse? (More shots with paint than air, or the same number of shots with paint and air?)

The cocker is probably more complicated than the other guns because LPR pressure and "Trigger Pull Rate" (for want of a better term) can all have an effect on the both bolt retraction points, times and rates as well as the bolts ability to resist blow-back.

The "Trigger Pull Rate" will vary massively from shot-to-shot compared to either an electro or the Mag.

Add to that the fact that varying roll-forward of the ball in the barrel on a cocker will also produce varying amounts of blow-back, and it all starts to look very messy.

The last time I plugged a pressure transducer into a cocker valve chamber was probably in early 2001, and I for sure don't have either that data to hand. We didn't tool at this specific problem, so I didn't do with and without paint comparisons of that, either.

ION: Hilltop may have a point. A vastly over-dwelled situation may also, in theory, produce those figures. Even if the bolt is blown back and re-seals the dump chamber buring the ball fire before the dump is empty, if the bolt return air is not re-introduced to coincide with that, then the bolt could pop forward after the ball has been fired and dump the remaining air in the chamber/set up a mild free-flow state (the Ion restricts flow of inlet air to the dump chamber, but does not produce an perfect seal/block).

Jack

[brycelarson]

ION: Hilltop may have a point. A vastly over-dwelled situation may also, in theory, produce those figures. Even if the bolt is blown back and re-seals the dump chamber buring the ball fire before the dump is empty, if the bolt return air is not re-introduced to coincide with that, then the bolt could pop forward after the ball has been fired and dump the remaining air in the chamber/set up a mild free-flow state (the Ion restricts flow of inlet air to the dump chamber, but does not produce an perfect seal/block).

Jack

As I said before - I tend to just leave my electro markers alone - quite honestly, while the perform great the creep me out a bit.

Anyone know what the stock ION dwell time is on the original gun?

Based on people that better understand the potential cycle times of an ION - is that dwell time likely to be severely under or over the optimal dwell time?

[cockerpunk]

Gordon, what do you find surprising about the cocker?

Did you expect it to be better or worse? (More shots with paint than air, or the same number of shots with paint and air?)

The cocker is probably more complicated than the other guns because LPR pressure and "Trigger Pull Rate" (for want of a better term) can all have an effect on the both bolt retraction points, times and rates as well as the bolts ability to resist blow-back.

The "Trigger Pull Rate" will vary massively from shot-to-shot compared to either an electro or the Mag.

Add to that the fact that varying roll-forward of the ball in the barrel on a cocker will also produce varying amounts of blow-back, and it all starts to look very messy.

The last time I plugged a pressure transducer into a cocker valve chamber was probably in early 2001, and I for sure don't have either that data to hand. We didn't tool at this specific problem, so I didn't do with and without paint comparisons of that, either.

ION: Hilltop may have a point. A vastly over-dwelled situation may also, in theory, produce those figures. Even if the bolt is blown back and re-seals the dump chamber buring the ball fire before the dump is empty, if the bolt return air is not re-introduced to coincide with that, then the bolt could pop forward after the ball has been fired and dump the remaining air in the chamber/set up a mild free-flow state (the Ion restricts flow of inlet air to the dump chamber, but does not produce an perfect seal/block).

Jack

ill post my theroys after the discussion boils down to something.

one thing i have learned though this all is to keep my damn mouth shut until someone says what i was going to say.

as far as the trigger pull rate, i was as careful as i could be to get a very rythmic pattern going, becuase i also suspected the mechanical timming issues with the cocker would lead to diffrences. we did our best to keep the trigger speeds identical, with all the guns.

[Hilltop Customs]

after thinking about it a little more....the ion using the same amt of air dry firing and with a ball makes some sense if the dump chamber pressure never drops below the residual pressure level(behind the ball as the bolt comes back to a close) because of the unsealed dump chamber design.

immediately after the bolt starts moving forward ion you there is a pressure drop, and the air begins to flow from the reg to the dump chamber....this doesnt stop until the bolt resets and the dump chamber pressure re-equalizes with the reg'd air. Although there is a restriction in flow, I think enough air gets through while the bolt is in motion to keep the dump chamber pressure above the residual pressure, thereby keeping a flow out of the barrel until dwell closes the bolt.

Now if you look at something like the mag on the other hand, the dump chamber is sealed so once you hit a certain pressure difference (in the barrel and in the powertube) the bolt spring applies enough force to push the bolt back, sealing in residual pressure. Now if there is no ball in the barrel, the forces(internal, external and spring) will take longer to equalize....making a mag in essence have a longer dwell when there is no ball in the breech.
longer dwell=more air escapes=lower dump chamber pressure after a dryfire= more air required to fill the dump chamber than a ball fired shot


hopefully that makes sense

[Beemer]

here is the PBN link - http://www.pbnation.com/showthread.php?t=2809760

fun stuff, PBN is worst about this crap.

Was the original thread there removed?? You can post and refer to Tech PB here. Just dont POST ANY LINKS to his or your vids with SWEARING. That guy has a bad potty mouth that is not AOs style.

edit.... Oh ya on a side note and not to be rude but who cares about paint or no paint and air cunsumption? I know I dont.

What I REALLY CARE about is consistency. Get the FPS on every ball at what ever ROF.

At one BPS I have a gun I can get 299, 299, 299, FPS on CO2. Now what will it be at five, ten or fifteen BPS????? Who can chrono EVERY ball at ten or fifteen BPS? Thats FPS on every ball at BPS.

Who has the MOST consistent gun at what BPS?????????

[ThePixelGuru]

Oh ya on a side note and not to be rude but who cares about paint or no paint and air cunsumption? I know I dont.

I was actually quite curious about this. I heard people say that 'mags were less efficient without paint, but they could never prove it to me. Now we not only know it's true of 'mags but most other markers as well.

[GoatBoy]

Was the original thread there removed?? You can post and refer to Tech PB here. Just dont POST ANY LINKS to his or your vids with SWEARING. That guy has a bad potty mouth that is not AOs style.

edit.... Oh ya on a side note and not to be rude but who cares about paint or no paint and air cunsumption? I know I dont.

What I REALLY CARE about is consistency. Get the FPS on every ball at what ever ROF.

At one BPS I have a gun I can get 299, 299, 299, FPS on CO2. Now what will it be at five, ten or fifteen BPS????? Who can chrono EVERY ball at ten or fifteen BPS? Thats FPS on every ball at BPS.

Who has the MOST consistent gun at what BPS?????????

We care about the truth.

So when someone claims an efficiency number by dry firing a marker, we will know how to treat their data.

[jackwood]

ill post my theroys after the discussion boils down to something.

one thing i have learned though this all is to keep my damn mouth shut until someone says what i was going to say.

as far as the trigger pull rate, i was as careful as i could be to get a very rythmic pattern going, becuase i also suspected the mechanical timming issues with the cocker would lead to diffrences. we did our best to keep the trigger speeds identical, with all the guns.

Haha, not going to get caught out by the same thing twice, huh? Now yer learnin', as we say "Up North" here in England......

I know you think you pulled the trigger consistently, but in the systems we are talking about here fractions of milliseconds can make considerable differences. Why do you think the Ego has the Dwell resolution set at 0.1ms? Because we liked it? No, because that is the kind of resolution you need if you want accurately control the valve dwell.
If you were to use an electro cocker then you would have the ability (at least with ours) to set the trigger rate electronically to see how it may alter things in this test. Then like ai said, you would need to try different LPR pressures etc as well. You could go on and on and on with a cocker.

[jackwood]

Gordon, just looked at your last MCB post and I think I see what you were implying with the "surprise" result from the cocker.

You expected the Cocker and 'Borg to produce similar figures because they are both poppit, right?

Nooooo, not going to happen. Completely different in every way. Just because they both have a knock-open valve does not mean they work in anything like the same kind of way.

[drg]

I think the point of dryfiring to try to get efficiency is so you can get a number without shooting paint and the associated expense. Personally I just keep track of the balls I shoot over the course of a tank during a normal day of play, but I guess people tend not to run their tanks dry when they have all-day air.

[luke]

lol

You said "uumm" 23 times, in a span of 1 minute 42 seconds of tape. On average that is every 4.435 seconds.

[cockerpunk]

jack, im with you 100% percent.

i know without a timming system you can't possibly pull the trigger in a perfet rythm. even with a timing circut, its easy enough to simply measure the time better and all of a sudden your .1 ms resolution is worthless aswell. hell, at work here we bore holes out to .000001 inch resolution, and before i worked here i though +/- .001 in was a tight tollerence.

what i was saying is that i was not rapid firing, then slow shooting for the other test. clearly, that would have an effect that we could see.

yes, i was surpized by teh cocker, yes, but i think i know what is going on now that we have the test data.

[GoatBoy]

So, anyone else run any of their own testing yet?

The field was quiet this weekend, so I decided to run my own tests.

http://spreadsheets.google.com/pub?key=pq_qLVoBwi8hx5Mocq7tBOw

I used a digital scale to measure results.

The HPA results were a little more exaggerated than yours, particularly at the high end.

The CO2 results, on the other hand, were just bizarre. This is the exact same gun used for the HPA test; just the air source was switched out (and I did rechrono to 300fps; today there wasn't much difference). I ran this test twice and came out with the same results.

The only really unusual thing about my setup is that I removed the valve pin from the AIR, and I'm using the Palmer's Stabilizer to perform regulation. Again, same configuration for all tests.


I'm planning to do the same thing with some blowbacks; I have a Spyder coming in a few weeks. I'm more interested in the "low end" gun performance than "high end".

[Hilltop Customs]

GoatBoy, I'm just curious as to what you are interested in finding out with these tests?

your co2 data is very interesting. Its very much like the ion data, counterintuitive.

Seeing all your data in g's makes me wonder the weight difference between an empty air tank, a full air tank and the weight where the remaining air pressure no longer functions the marker properly.

[GoatBoy]

GoatBoy, I'm just curious as to what you are interested in finding out with these tests?

I've never trusted anybody elses data or general rules of thumb (except for, say, Tom Kaye).

The dry-fire thing was just to see if I could see something similar to what cockerpunk got.

The paint tests were to give me an idea of how my guns really operate. I feel I've been lied to enough by other paintballers, so I want my own data now.

Overall, I want to see if some of my calculations make sense.

Seeing all your data in g's makes me wonder the weight difference between an empty air tank, a full air tank and the weight where the remaining air pressure no longer functions the marker properly.

That can actually be calculated.

I just happen to have air in my nitro duck 45ci tank today, and it had a little over 1000PSI according to the gauge (and by the way, I trust my digital scale way more than my little paintball gauge). I threw that on the scale. Then I emptied the tank out and threw that on the scale.

Approximately 1050PSI @ 45ci = 1246g
Empty tank = 1179g

So 1050PSI at 45ci is about 67g.

If I plug in all the Boyle's law stuff that I used earlier, I get 3215ci of air released, which should weigh about... 68.1g. Actually, the tank didn't empty out; there was still 45ci of air inside of there, which was like 0.95g, subtracting that gets about 67.2g.

So my math appears nearly dead-on; the error involved is probably ... my reading of that stupid gauge, and the extra volume added or taken away by the regulator (since that plugs into the tank technically).

If you want to calculate the weight of the tank when your gun stops functioning, then you just pick a PSI and use the equations. Conservatively, on a mag, I'd use about 500PSI as the point where the marker starts feeling bad.