[dosh]

cockerpunk, on 25 March 2013 - 02:45 PM, said:

dosh, on 25 March 2013 - 02:19 PM, said:

cockerpunk, on 25 March 2013 - 01:22 PM, said:

dosh, on 25 March 2013 - 11:56 AM, said:

brycelarson, on 25 March 2013 - 07:47 AM, said:

dosh, on 24 March 2013 - 04:55 PM, said:

The whole "poppets are faster" makes no sense. On both of them the amount of time the valve is open is dependent on where the open point is on the rams stroke. On the spool you have a stem clearing an o-ring which allows the air to flow down the bolt. The time from open to close depends on how fast the stem is moving past the o-ring.

actually poppets being faster makes a ton of sense. How far does a spool valve move to open the valve? At what speed? How how far and fast does a poppet move?

The answers are: along distance, slowly and a short distance, quickly.

The poppet takes less time to move from a closed to fully open position and less time from an open to a fully closed position. Thus, better valve resolution and more efficiency.

Then the problem isn't with the spool valve. The problem is with the engineer and where he is placing the open/close position in the rams stroke, and ram speed. There isn't any reason why the a spool can't have as good of a resolution as a poppet.

If we have two guns with the ram traveling at the same speed on both the forward and return stroke, and both are moving, lets say, 1/8 of an inch past where the seal is going to break, then both will open and close at the same time. Fully open for the poppet will be when the cup seal is at it's max travel from the valve guide, fully open for the spool is when the sealing surface has lost tangent with the o-ring, moved enough to clear the radius, and whatever material is forming the wall of the o-ring groove. You can do that in the same amount of space as a poppet, and since the gas doesn't have to hook three 90* turns you could shorten the dwell below the poppet valve.

sure, if you can move a spool valve as fast and hard a poppit, it will run like a poppit.

so what?

So if there's a current deficiency in spool designs that can be cured then you can build a better mouse trap. You can get an equal or lower reciprocating mass out of a spool so getting the speed isn't a problem. There's a path to building a better mousetrap here.

not really,

so if you make a spool shoot like a poppit, it will have the same type of performance as a poppit (ie kick), so why didn't you just shoot/design a poppit in the first place?

also, the reverse is true, if you slow down a poppit system you can make it operate as inefficiently as a spool, and be much much smoother the traditional poppits, but why would you? it makes no sense.

What if you could make a drop in assembly that gave you the efficency of a poppet without increasing kick? Lighten the bolt, massage how it seals, creative chamfering... I think this might be doable. There is no absolute that says a spool has to be either hard kicking or ineffecient.

[dosh]

brycelarson, on 25 March 2013 - 02:49 PM, said:

cockerpunk, on 25 March 2013 - 02:45 PM, said:

so if you make a spool shoot like a poppit, it will have the same type of performance as a poppit (ie kick), so why didn't you just shoot/design a poppit in the first place?

actually assuming we're talking about a spool scaled like most modern spools we would be talking about a huge increase in kick - since there's so much moving mass when talking about a spool vs a rammer.

Not really. Think about what an Ego is moving. Two chunks of stainless and a peice of delrin compared to an aluminum shaft in a spool gun. The delrin is the largest piece, and it's a little more than half the weight of aluminum per cubic inch, but the stainless is just under three times the weight. Also the delrin is thick walled. There's alot of mass being moved there in comparison to a spool guns bolt, even without looking at alternative materials or design to remove material.

Mass x velocity=force. You can lighten the bolt and speed it up while keeping the same force so the amount pf kick stays the same.

[andrewthewookie]

dosh, on 25 March 2013 - 07:14 PM, said:

What if you could make a drop in assembly that gave you the efficency of a poppet without increasing kick? Lighten the bolt, massage how it seals, creative chamfering... I think this might be doable. There is no absolute that says a spool has to be either hard kicking or ineffecient.

See: Shocker Eigenbolt

[cockerpunk]

dosh, on 25 March 2013 - 07:14 PM, said:

cockerpunk, on 25 March 2013 - 02:45 PM, said:

dosh, on 25 March 2013 - 02:19 PM, said:

cockerpunk, on 25 March 2013 - 01:22 PM, said:

dosh, on 25 March 2013 - 11:56 AM, said:

brycelarson, on 25 March 2013 - 07:47 AM, said:

dosh, on 24 March 2013 - 04:55 PM, said:

The whole "poppets are faster" makes no sense. On both of them the amount of time the valve is open is dependent on where the open point is on the rams stroke. On the spool you have a stem clearing an o-ring which allows the air to flow down the bolt. The time from open to close depends on how fast the stem is moving past the o-ring.

actually poppets being faster makes a ton of sense. How far does a spool valve move to open the valve? At what speed? How how far and fast does a poppet move?

The answers are: along distance, slowly and a short distance, quickly.

The poppet takes less time to move from a closed to fully open position and less time from an open to a fully closed position. Thus, better valve resolution and more efficiency.

Then the problem isn't with the spool valve. The problem is with the engineer and where he is placing the open/close position in the rams stroke, and ram speed. There isn't any reason why the a spool can't have as good of a resolution as a poppet.

If we have two guns with the ram traveling at the same speed on both the forward and return stroke, and both are moving, lets say, 1/8 of an inch past where the seal is going to break, then both will open and close at the same time. Fully open for the poppet will be when the cup seal is at it's max travel from the valve guide, fully open for the spool is when the sealing surface has lost tangent with the o-ring, moved enough to clear the radius, and whatever material is forming the wall of the o-ring groove. You can do that in the same amount of space as a poppet, and since the gas doesn't have to hook three 90* turns you could shorten the dwell below the poppet valve.

sure, if you can move a spool valve as fast and hard a poppit, it will run like a poppit.

so what?

So if there's a current deficiency in spool designs that can be cured then you can build a better mouse trap. You can get an equal or lower reciprocating mass out of a spool so getting the speed isn't a problem. There's a path to building a better mousetrap here.

not really,

so if you make a spool shoot like a poppit, it will have the same type of performance as a poppit (ie kick), so why didn't you just shoot/design a poppit in the first place?

also, the reverse is true, if you slow down a poppit system you can make it operate as inefficiently as a spool, and be much much smoother the traditional poppits, but why would you? it makes no sense.

What if you could make a drop in assembly that gave you the efficency of a poppet without increasing kick? Lighten the bolt, massage how it seals, creative chamfering... I think this might be doable. There is no absolute that says a spool has to be either hard kicking or ineffecient.

it does if the forces needed to operate the parts at the required speed/force mean you have that kind of kick.

the best idea is to combine the two systems, alla pressure controled poppits or tweak the systems, like the new LV1 ego, or the above mentioned shocker eigenbolt, which helps the dynamics of the shocker valve.

[brycelarson]

dosh, on 25 March 2013 - 07:23 PM, said:

Mass x velocity=force. You can lighten the bolt and speed it up while keeping the same force so the amount pf kick stays the same.

Kinetic Energy = 1/2m*v^2

The speed matters more than the mass.

So, the short answer is that it's design dependent. Here's an example - let's say that a spool has twice the mass but moves half as fast. Let's say 10g for the poppet and 20g for the spool. If the spool moves 100 m/s and the poppet moves 200 m/s then the force calculations are:

Spool E = .5*.02*100^2 or 100 Joules
Poppet E = .5*.01*200^2 or 200 Joules

So, when doubling the speed and halving the mass the energy involved is doubled.

Spools are smooth due to slow movement.

[cockerpunk]

well there are also impact issues, the poppit tends to hit a harder stop on each end (or at least the front, valve, end), but a spool has to hit a stop on each end too, so again, there isn't much to play with there. so when you talk about speeding up a spool bolt to get the valve open faster, you eventually have to stop it again (when the bolt is closed), requiring some kind of stop.

[dosh]

[quote name='cockerpunk' timestamp='1364318053' post='3182576']
well there are also impact issues, the poppit tends to hit a harder stop on each end (or at least the front, valve, end), but a spool has to hit a stop on each end too, so again, there isn't much to play with there. so when you talk about speeding up a spool bolt to get the valve open faster, you eventually have to stop it again (when the bolt is closed), requiring some kind of stop.


I've been thinking about what you guys have been saying, and without getting actual weights and speeds it's hard to come to a conclusion. I pulled the bolt out of my Ion and the bolt and rammer out of my Etek3. I'd say off hand they should be fairly representative of both families.

The Ion bolt felt just a little lighter then the Etek assembly, not much, but perceptible. That makes sense when you think about what both have to do. The spool valve just has to slide back and forth. The poppet has to transfer energy at the end of it's stroke to overcome the spring and air pressure against the cup seal. The poppet needs to weigh more and move faster.

If you guys have a source for weights and cycle speeds you can share I'd appreciate it. I've been trying to find something solid and it's been a fruitless search.

[benzy2]

While speed is more important, you could find a happy middle ground. If you equal poppet marker speed but use 1/3 the mass, you'll end up with 1/3 the energy. If speed is a big key to efficiency, running something like an eigenbolt or an L7 type ultra light bolt should keep kick at a fraction of an equally speedy poppet type marker with ram, bolt, and bolt pin all being tossed around. From there, use some of the better design features to quickly close the valve and you ought to see nearly equal efficiency numbers while still being a far softer cycle than a typical poppet.

[Punisher068]

Wonder how a closed bolt spool valve would fit into this question?
http://www.mcarterbr...ed-version.html

[Danny D]

dosh, on 27 March 2013 - 12:00 PM, said:

cockerpunk, on 26 March 2013 - 12:14 PM, said:

well there are also impact issues, the poppit tends to hit a harder stop on each end (or at least the front, valve, end), but a spool has to hit a stop on each end too, so again, there isn't much to play with there. so when you talk about speeding up a spool bolt to get the valve open faster, you eventually have to stop it again (when the bolt is closed), requiring some kind of stop.


I've been thinking about what you guys have been saying, and without getting actual weights and speeds it's hard to come to a conclusion. I pulled the bolt out of my Ion and the bolt and rammer out of my Etek3. I'd say off hand they should be fairly representative of both families.

The Ion bolt felt just a little lighter then the Etek assembly, not much, but perceptible. That makes sense when you think about what both have to do. The spool valve just has to slide back and forth. The poppet has to transfer energy at the end of it's stroke to overcome the spring and air pressure against the cup seal. The poppet needs to weigh more and move faster.

If you guys have a source for weights and cycle speeds you can share I'd appreciate it. I've been trying to find something solid and it's been a fruitless search.

I cant speak for the etek, but the Ions bolt weight has nothing to do with the actuation speed. I have tried the L7 bolt, stock ion, firebolt and redz bolt with several variables. The only one I found to be significant enough to warrant its price is the QEV in terms of bolt speed.

The numbers:

Critical dwell values with QEV:
Stock - 8ms
Firebolt - 8ms
Red - 8ms
L7 - 7ms.

The only difference is 1ms with the L7. Compare that to the 15-20ms difference that a qev provides, It is clear that bolt weight is of minimal importance, and instead it is the exhaust that determines the speed of the bolt.

[Broccolidwarf]

cockerpunk, on 25 March 2013 - 07:49 PM, said:

dosh, on 25 March 2013 - 07:14 PM, said:

cockerpunk, on 25 March 2013 - 02:45 PM, said:

dosh, on 25 March 2013 - 02:19 PM, said:

cockerpunk, on 25 March 2013 - 01:22 PM, said:

dosh, on 25 March 2013 - 11:56 AM, said:

brycelarson, on 25 March 2013 - 07:47 AM, said:

dosh, on 24 March 2013 - 04:55 PM, said:

The whole "poppets are faster" makes no sense. On both of them the amount of time the valve is open is dependent on where the open point is on the rams stroke. On the spool you have a stem clearing an o-ring which allows the air to flow down the bolt. The time from open to close depends on how fast the stem is moving past the o-ring.

actually poppets being faster makes a ton of sense. How far does a spool valve move to open the valve? At what speed? How how far and fast does a poppet move?

The answers are: along distance, slowly and a short distance, quickly.

The poppet takes less time to move from a closed to fully open position and less time from an open to a fully closed position. Thus, better valve resolution and more efficiency.

Then the problem isn't with the spool valve. The problem is with the engineer and where he is placing the open/close position in the rams stroke, and ram speed. There isn't any reason why the a spool can't have as good of a resolution as a poppet.

If we have two guns with the ram traveling at the same speed on both the forward and return stroke, and both are moving, lets say, 1/8 of an inch past where the seal is going to break, then both will open and close at the same time. Fully open for the poppet will be when the cup seal is at it's max travel from the valve guide, fully open for the spool is when the sealing surface has lost tangent with the o-ring, moved enough to clear the radius, and whatever material is forming the wall of the o-ring groove. You can do that in the same amount of space as a poppet, and since the gas doesn't have to hook three 90* turns you could shorten the dwell below the poppet valve.

sure, if you can move a spool valve as fast and hard a poppit, it will run like a poppit.

so what?

So if there's a current deficiency in spool designs that can be cured then you can build a better mouse trap. You can get an equal or lower reciprocating mass out of a spool so getting the speed isn't a problem. There's a path to building a better mousetrap here.

not really,

so if you make a spool shoot like a poppit, it will have the same type of performance as a poppit (ie kick), so why didn't you just shoot/design a poppit in the first place?

also, the reverse is true, if you slow down a poppit system you can make it operate as inefficiently as a spool, and be much much smoother the traditional poppits, but why would you? it makes no sense.

What if you could make a drop in assembly that gave you the efficency of a poppet without increasing kick? Lighten the bolt, massage how it seals, creative chamfering... I think this might be doable. There is no absolute that says a spool has to be either hard kicking or ineffecient.

it does if the forces needed to operate the parts at the required speed/force mean you have that kind of kick.

the best idea is to combine the two systems, alla pressure controled poppits or tweak the systems, like the new LV1 ego, or the above mentioned shocker eigenbolt, which helps the dynamics of the shocker valve.

I just watched the efficiency test TechPB did on the LV1, which I must admit was pretty disappointing for a poppet (7 pods if I remember correctly?).

Am I correct in assuming the poor efficiency, is directly related to the lever design meaning it takes far longer to open and close the valve now?

- and.... if I am correct, how could the design be improved, while maintaining what appears to be a very smooth shot?

(btw, just to be clear, It is the first ever Ego I seriously considered purchasing.... because it is fantastic from an ergonomic perspective, and seems to shoot very smooth..... but I need better efficiency to be able to make that choice)

[andrewthewookie]

He was also using the heavier ram, and was probably overboring as well.

[Cookybiscuit]

If you think about it efficiency tests are not really indicative of efficiency, stupid as it sounds. Take for example the fact that the SL8R got 14 pods, and I think the Victory got 7 too. It just seems like theres so many factors that go into it (other than the gun) that its pretty hard to create a standard.

[Egomaniacal]

Broccolidwarf, on 23 April 2013 - 09:06 AM, said:

Am I correct in assuming the poor efficiency, is directly related to the lever design meaning it takes far longer to open and close the valve now?

- and.... if I am correct, how could the design be improved, while maintaining what appears to be a very smooth shot?

(btw, just to be clear, It is the first ever Ego I seriously considered purchasing.... because it is fantastic from an ergonomic perspective, and seems to shoot very smooth..... but I need better efficiency to be able to make that choice)

The LPR on the LV1 is going to have a significant impact on efficiency (Jack has told me via PM that the LPR on the LV1 actually has an adjustment range). By tweaking the LPR, proper ram choice and dwell, I have little doubt it can be made quite efficient.