PDA

View Full Version : Official Cycle Speed Thread


toothpastedog
09-24-2004, 11:00 PM
Yes, i know there is thread about this already, but it is really jumbled and messy, not to mention spammed up a bit (;)). I think this would be a great sticky subject, but the other thread isn't really sticky suitable; it is long long long... kind of something that would put off the kind of person who would need/want to read it. Here we go:

First off, before you tackle how different things affect cycle speed, you should be familiar with what Internal Weights (http://www.pbreview.com/forums/showthread.php?s=&threadid=252026) are all about.

Okay, now, here we go for real:

PART I

The three biggest things that effect cycle speed are (in any paintball gun):
1-Dwell
2-Pressure (I don't care about input this, input that, I am just talking about the pressure the ram/hammer/bolt is being driven/run/operated at)
3-Wieght

Dwell:
-The dwell (http://pbreview.com/forums/showthread.php?s=&threadid=224024&perpage=20&pagenumber=1), as you all know, is how long the solenoid redirects the air flow to behind the ram, thus causing it to move forward. For every millisecond the solenoid redirects the air behind the ram, the ram is pushed forward, opening the valve, as well as sealing off the breach. The dwell is independent of every other setting in the gun, and is controlled in millisecond increments. if you have a higher dwell, the pressure doesn't go down or anything, and if you have a higher pressure the dwell does go down or anything (unless you reset it, that is why I say it is independent, it stays the same unless some one changes it; I will get to the lower dwell/higher input/lower solenoid input later).

Force=psi=???
-Did you know something, psi is force. Pound per Square Inch. That is directly translated into force. If the ram in an impulse is run at 35psi, it will drive the hammer at about 35psi (34.somethingpsi) and the hammer will hit the valve with about 35 pounds of force.

Cps=Bps=WRONG
-Cps and Bps are two completely different things. A gun can cycle a million times per second but in reality can only shoot 5bps. The only factor that I will deal with that effect cps rates are how much what ever is being cycled mass is. The bps rate depends on the mass of what ever is being cycled, but it also depends on it what ever is being cycled has to hit something or in other words, the force opposing it; i.e. a paintball, or a valve, or ball detents. In our case with the impulse though, we are only concerned with the opposing force the valve, because it is the greatest (the valve opposes with at least 100psi, the ball detents appose with about 2psi, and the balls oppose with >1psi).

Pressure:
-To get a gun to cycle fast, you need to use at least enough force to move what ever is being cycled (in an impulse's case, a bolt, hammer, ram, and bolt pin). The impulse need at least 20psi to cycle fast (i.e. fast = >13bps). There is a determining factor in the impulse though: since the impulse has a valve, which is opened by the hammer hitting it, you need the hammer to run at least with enough force to open the valve enough to get air to the paintball. In other words, the force that is needed to open the valve is the determining factor because there is like at least 100pounds of opposing force holding the valve closed. The force that drives the ram must be more than 20psi. In most cases, around 65psi works marvelously because that will drive the ram/hammer with enough force to get the valve to open just enough to let a bit of air out. So, with an impulse, since the impulse needs at least 20psi to cycle fast, and since you cannot reliably get the hammer to open the valve unless they are driven with air at about 65psi, the pressure/speed thingy isn't an issue with the impulse because an impulse will only shoot if its ram is being run at 65psi, more than it needs to cycle 20cps.

Internal weight:
-This is an interesting one. Short answer: with the WAS board and a rip valve, you want internals that are very light; 800-1000grains. With any other board and the stock valve you want internals that weight about 1200 (no less that 1100) grains (because the heavier the internals, the more force required to move them, and that makes it easier-with the more force-to open the valve). With any board and a rip valve, internals that weight about 900-1200 grains work great because it takes less force to open the rip valve.
-Other things affect speed, mainly the quality of the parts used, the quality of the lubricant(s) used and tolerances, but we don't really need to worry about them.

Overall:
-I could get an impulse to cycle 40cps, but you still want it to shoot effectively though, right? You can never just say: "I just want my impulse to shoot really fast, because that is all I’m worried about" because when you set up an impulse, you always have to consider velocity and pressures. You always need to think about shoot down. here is my answer to your question though, for the fastest shooting (not just cycling) impulse:

Impulse+
WAS board
RIP valve
Stubby Equalizer bolt
Ti drilled "Tulip" Bolt Pin
Drilled aluminum hammer
silk shot ram
HFV/HFA/VFF/DFF
High Volume Valve Cap
Halo B
HPA tank
Very Well cleaned maxflo, ram, and hammer assembly.

Then, again, make sure everything is always clean with dow33, set your input to 140psi (+/- 5-10psi), set your dwell to the lowest setting while still shooting 280fps or so over the chrono. Oh yes, the impulse with all those parts I just described could cycle about 26bps really. IMO, an lpr would help your cycle time go down (meaning the gun can shoot faster), but you need a good lpr that can sustain 25+ cps/bps. All those parts are not necessary to get you impulse fast as hell. You could have an impulse shooting 20bps with a brass hammer, a voodoo bolt, and the stock bolt pin; those parts are just for the perfect impulse ;).

What lpr’s will be able to sustain high rates of fire (>20bps)?
-Pretty much any lpr out there will work fine, but look for properly working scm's, and i have found sonic lprs to be extremely fast recharging.

Does it make a big difference if I buy a drilled or round ti bolt pin?
-As long as it is made from titanium, it doesn’t matter… those 5 grains aren’t going to matter much…

toothpastedog
09-24-2004, 11:01 PM
Part II

Our good rep from EPBO, FOM's 2cents:

Your Solenoid pressure has a great deal to do with how fast your gun will cycle. I see a LOT of realy tricked out Impulses which will not shoot over 17 shots a sec, simply because they are running too low of an LPR pressure.

While it is not written in stone, with anything around "normal" interal weights, I would recomend you try to keep the the LPR pressure within about 60 psi of the valve pressure.

From a pure "rate of fire" issue, I would NOT recomend dropping below about 100 PSI on the solenoid. I normaly run a lot higher LPR pressure-- about 140.

Unless you go to VERY heavy interals, I don't think this will have any major effect on your rate of fire. I did have one gun come in here that they had tapped the holes in a rat hole hammer and added long set screws (to make the hammer VERY heavy) with a slick shaft and with a very heavy bolt. shooing over a shot counter, I could not get this gun to shoot 15.5 per sec. We dropped a ND hammer assembly (with rat hole) in and the gun jumps up to 23 per sec!.

Too light an assembly would only be an issue if it caused you to use a LOT of dwell to get up to speed.

From a pratical stand point, I have not seen dwell effect rate of fire until it gets over "10"- and then the effect is very small. Ofcourse when you get REALY long dwells, you are not only slowing the cycle rate, but you are almost certanly loosing some of the "push" you get from recoil to start the bolt back.

I have seen a number of guns be limited by TOO LIGHT of a return spring on there trigger. While I see some that can shoot a gun realy fast with a super light return, I personaly shoot a lot faster with a little heavier retutn and a bit more travel. This is one of the resiona I love "reverse" magno triggers and do not like "atracting" magno triggers.

I know it SEEMS counter productive, but realy TRY using a bit longer "stroke" and a bit more return pressure.

FOM

How do i set my input pressures and dwell?
-Use a rock-o-meter, or stick a gauge on the back of your impulse. Normally though, you should just go by feel and adjust it by... I feel like I've said this 1000's of times...

This is for the stock valve... for RIP valve do what is in the parenthesis....
Go to the chrono and

-set input to 150psi (110psi)
-set lpr output to max/150psi (120psi)
-adjust dwell till the gun shoots 300fps (set dwell till it shoots 280)
-raise input to 200psi (raise input to 130-150psi)
-lower lpr's output till the gun shoots 280fps-299fps (same)

-Do not forget that this is definitely not set in stone, and varies a bit from impulse to impulse, even those with the same parts, so be ready to fiddle... around with you impulse that is...

-FOM's Input on lprs, etc:
Most players don't know or care what the exact solenoid pressure is. You can easily check the pressure by unscrewing the littl silver plug on the back of the gun and screwing in a pressure gague. This does present a problem in that you can't remove the hammer assembly without first removing the gauge. a slightly better solution is to mount a 90* fitting and then put the gague in the 90* elbow.

But all that is just informational. (it that a word? I'm sure it isn't spelled right if it is <G> ) The plain fact is most players don't care what that pressure is, just as long as they don't get shoot down.

I know the tendency for many is "give me the EXACT numbers and let me set it that way"- but every gun is different and what works best on one gun may not work best on another. In general you will do something like toopaste indicated, the shoot the gun as fast as you can and see if you can hear any "shoot down" if you do, simply increese the LPR pressue and decreese the dwell and try again.

I know there are some users out there that want to set a new all time word record for lowest pressure on the planet- but I got to say, there are no real pluses in going to the lowest pressure you can get. In general, you will slow the gun down and use more air.

-In other words, obviously, FOM is right. You cannot get the lpr's output/the force that the bolt will possibly hit/chop a ball, like you can a cocker's-because a cocker's hammer hits the valve via a spring, and thus has enough force to open it all the time, while you need to have at least an operating pressure of XXpsi for you impulse cause it requite XX amount of force to open the valve...


...oh yeh, the reason this wasn't just one big opst was because it was too long...

Dwell Time Info
-The Correct Dwell Time Info

Originally posted by Toothpastedog
The Stock Cricket board has a Dwell range of 4-14 milliseconds and is adjustable in .25 millisecond increments. This allows you to fine tune your Impulse.

beeps=dwell time (in milliseconds)
0 (the lowest)=4
1=4.25
2=4.5
3=4.75
4=5
8=6
12=7
20=9
28=11
36=13
40 (the highest)=14

IwAnNaShOoTyOu
09-25-2004, 05:10 AM
sticky.:tup:

toothpastedog
09-25-2004, 08:17 AM
don't really have a good reason to post this bit of info here, but i have one last thing to add:

brass is heaveir than any other material used in an impulse (aluminum, titanium, stainless steal). next comes stainless steal, harder and less plyable but a good bit lighter. next is titanium, yes ti is heavier than aluminum, and it is also not as strong as stainless steal-it is kinda like the mid wieght. finally we have aluminum; not anywhere near as strong a stainless steal, but not as plyable as brass.

Azn_Boy
09-25-2004, 08:18 AM
Originally posted by IwAnNaShOoTyOu
sticky.:tup:
:agree:
if this is a sticky wont this be like your 8th or 10th 1

toothpastedog
09-25-2004, 08:20 AM
11th one i have written myself

TIPPY NIKY 98C
09-25-2004, 10:40 AM
ok i got a question. When u have the rip valve is the lpr max 120? i wasnt sure sry if this is a stupid question.:paranoid: :paranoid:

Awhislyle
09-25-2004, 12:17 PM
Well if you expect this too clear up anybodyts questions, maybe you should explain to them what preeusre you are talkign about and why thats the only one that matters

toothpastedog
09-25-2004, 03:52 PM
Originally posted by TIPPY NIKY 98C
ok i got a question. When u have the rip valve is the lpr max 120? i wasnt sure sry if this is a stupid question.:paranoid: :paranoid:

not a dumn q; no it is not, unless your input to the rip valve is 120psi when the lpr's output is at its max. Awhislyle; i didn't really understood what you said i should do about the pressure issue.

limpyimpy
09-26-2004, 01:26 PM
TPD U da man, Thanx, but one more question how does one know when he or she is shooting X BPS. U know why I asked this, the little red crono is not very accurate when shooting 14 plus BPS.

Is a halo dump a good way to measure BPS or sustained BPS.

I hope I am not driving u crazzy with this halo dump thing.

I just had a brain fart, another way of finding out BPS is to film or record your self shooting gun and pull the sound clip into adobe premire or abobe aduigy, or any program that will let u see the sound spectrum in a time line. All u have to do is count the spikes in the waveform in one second and that would give u CPS or BPS.

I think the above method would be very accurate.

toothpastedog
09-26-2004, 03:07 PM
there are different types of chronos, some work better than others. you just need to find one that gives you a good reliable reading... which is actually more accurate than a halo dump test, and a lot cheaper and easier than a recording...

Dark Master
09-26-2004, 03:28 PM
I smell yet another sticky....:P

Calebd2
09-27-2004, 09:44 AM
Sorry for the delay. Darn hurricanes. :rolleyes:

Added. Good work.

toothpastedog
09-27-2004, 02:54 PM
coo, god must hate you guys... either that or something logical like physics must be creating em'...

master_chadwick
09-27-2004, 05:07 PM
Good job mike.....:o as usuall;)

toothpastedog
09-27-2004, 05:15 PM
by the way, i used your trigger frame sticky as a reffernce today, not to shabby yourself!

master_chadwick
09-27-2004, 05:20 PM
haha thanks. but its dwarfed by your stickies.:D

toothpastedog
09-27-2004, 05:28 PM
aw shucks... :P

toothpastedog
10-13-2004, 04:26 PM
updated...

Awhislyle
10-13-2004, 04:43 PM
Nice:)

Dark Master
10-13-2004, 04:48 PM
I love you TPD:love:.......:P

lol.Thanks for the great info.:tup:

toothpastedog
10-13-2004, 06:13 PM
heh heh, i should never fully rely on any one other than myself :P , well, now it is updated with the correct dwell time info...