Can the sear be removed from the system? I think so.

[hill160881]

For now I am going to try to get it playable in this configuration and test the efficiency. If there is no gain at all iI will abandon this project as a fun idea. If there is a gain I will start putting all my Ideas into a marker.

[vf-xx]

This is the real danger. If something looses pressure it will go full auto until you turn off the air.


But like that will ever happen,,,,,,, maybe should not have said that .

Maybe add a 1/4 turn ball valve as an emergency cut off? the ones from Palmers are pressure rated and shouldn't restrict flow.

[Dirge]

An ICE Epic works in a similar manner to this concept. The on/off is held in place by a sliding plate. When the trigger is pulled, the plate slides out, allowing the on/off to open. It however does have another on/off that seals the dump chamber when the trigger is pulled.

Just putting that out there (I love this idea).

[hill160881]

the latest video, Much better.

http://www.youtube.com/watch?v=mAsSNB5xc6I

[jade_monkey07]

i would imagine that it could potentially reduce bolt cycle time once the dwell is tuned properly, less friction. maybe new speed record out of a mag? im looking forward to seeing what comes of this.

[snoopay700]

Teacher, i have a question. Did you make something to fill in the void that was previously the dump chamber? You didn't mention it, but if this was to improve efficiency then it would seem foolish not to.

I've toyed with this idea many times, never had the funds to pull it off though, good on you.

[hill160881]

Teacher, i have a question. Did you make something to fill in the void that was previously the dump chamber? You didn't mention it, but if this was to improve efficiency then it would seem foolish not to.

I've toyed with this idea many times, never had the funds to pull it off though, good on you.

Not yet. I am just going to see if it plays. Then get a base line on efficiency, to see what improvements come from a smaller shot chamber then different springs....

My theory on the size of the shot chamber is that the chamber size is not as important as the dwell and spring length on the bolt. The amount of air used is related to dwell and pressure not the size of the shot chamber in this set up. We will see if that is the case. maybe a bit of both.

[hill160881]

Last video until i do an efficiency test.

http://www.youtube.com/watch?v=88TTHmqky8Y

This is another efficiency mod that has shown limited results, but I may as well. I also put two on it instead of just one.

[snoopay700]

Not yet. I am just going to see if it plays. Then get a base line on efficiency, to see what improvements come from a smaller shot chamber then different springs....

My theory on the size of the shot chamber is that the chamber size is not as important as the dwell and spring length on the bolt. The amount of air used is related to dwell and pressure not the size of the shot chamber in this set up. We will see if that is the case. maybe a bit of both.

That's what you'd think, but the thing is that you are seeing two losses in the flow from the on/off to the powertube, and those are the losses due to the sudden expansion of the dump chamber, the second is the sudden contraction. If you can make a spacer that makes it one diameter the whole way, you should see a rise in efficiency.

[p8ntbal4me]

Not yet. I am just going to see if it plays. Then get a base line on efficiency, to see what improvements come from a smaller shot chamber then different springs....

My theory on the size of the shot chamber is that the chamber size is not as important as the dwell and spring length on the bolt. The amount of air used is related to dwell and pressure not the size of the shot chamber in this set up. We will see if that is the case. maybe a bit of both.

When your working with a setup like this involving a sear from EP... dwell effects air efficiency on the size of usage on the LPR related to tank capacity, not the valve.

Your right to assume that the ram and dwell effect the efficiency of the valve when you are relating it to MROF or similar.

If dwell is time on/energized, then we can relate that to the solenoid, ram, and LPR. When you talk about those components in relation to the valve, you need to add in factors of the other components and what they take away from the valve, specifically the on off.

Better explained: you have a gap on your mpa3 between the ram and sear. You need some gap for pre-stroke and travel. This is a decrement value to your efficiency of the solenoid sear and lpr. You haven't even pushed on the pin yet to shut the air off and your already loosing battery life, air, and time.
Now the ram starts to push on the sear, so technically your dwell is your setting value PLUS pre-travel. Do you have a spring in the mpa3 still?
If so we need to figure friction. Obvisouly frictionless would be nice but probably not going to happen. Since the on off pin has enough pressure to reset the ram you are going to loose more time in your dwell value due to the mpa3 spring where the solenoid needs to supply enough air to push the ram plus spring friction. Keep in mind that compression and friction increases as the ram extends. Your dwell value is value PLUS spring compression now.
At this point, you haven't even fully cycled a shot yet....

See where this is going?

I think once you figure out what you want to do with the setup Hill, you should revisit the ram and solenoid. Your loosing a lot of time right there and that is what we are talking about when we all say "efficiency ". Personally, I would use a 4-5 way solenoid because they vent the fastest over soneloids without internal QEVs. Adding QEVs to a 4-5way would speed it up that much faster and drop the extra compression you are getting internally from the spool in the solenoid body.

Did you ever pick up one of those 3way solenoids I linked you to couple months back? The ones with the larger coil?
If you are okay with loosing battery power some, you can use a larger coil solenoid and drill out a vent hole for the body to act as a QEV. I know you had your heart set on a smaller 3way to save space. This may be one answer for you.

Could you take some pictures of the internal setup or make a nice diagram in MSpaint so we can see what the cycle looks like from LPR to valve?

[hill160881]

I will lay all the parts out in an expanded format so everyone will see how it is put together and I will try to do a diagram if I can figure it out I use a mac and there is no paint

I kinda follow what you are saying. Yes there is still a spring in the mpa3 so the pressurizing of the ram is slowed by it. But I could not get it to work without it. I tried and without more input pressure it wont cycle without a really long dwell.

I am going to devolumize it after I play it tomorrow.

[hill160881]

Keep in mind the components being used were just used due to there being easily acquired. I am only in this for $50 and a sear that was no good at this point

Once I see if there are any gains I will look for better components for this application.

Edit:OOPS, I left it charged all night. Power on.......pull trigger...........pop.


Edit: If I could get it to run at 750 pis input pressure it would be better on the efficiency as well.

[MAGpie]

Little late in on this discussion, but do you know what surprises me most about this: That no one thought of it earlier... Think about it, PumpMag. The sear's ONLY function in a pumpmag is to hold the bolt back to overcome the wave-spring... The logical next step should have been, well, the sear has no real purpose then in other configurations... Well, apart from preventing the degassing fart when the air pressure is too low.

Wow... sometimes innovations is just so simple, it is missed altogether.

Nicely done Hill.

[hill160881]

First off, The POS camera died before the first video and wont turn on anymore. Time for a real video camera.

A day of testing, 4000+ rounds and some surprising numbers, but not way better. With the gold bolt spring it did not want to crono over 250. With a slightly longer grey spring it cronoed fine.

The most noticeable differences were the accuracy difference between the two markers, and how much smoother the reverse mag shot. The reverse mag is one of the most accurate markers I have ever shot, I played 3 rounds on a hopper and two pods. I never shoot this little amount. It stacks way better at longer distances than my insert marker.

All test were with the same paint and barrel. I rounded all # to the nearest lower pod but none of the setups got into the next pod really.

Reverse Ego mag/level 10- Full 68/45- 1280+- rounds at 285ish

Ego mag/level 10- Full 68/45- 1080+- rounds at 285ish

Ego mag/level 7- full 68/45- 1120+- rounds at 285ish

If the bolt were lighter and the shot chamber were smaller I think I could get another 100+ rounds or so. I also need to try other on off pin lengths, to try to use the plugged level 10 bolt I have . So some tinkering will settle it and it will take its place as my workhorse marker due to its amazing accuracy at longer ranges.

[hill160881]

After the day I put a .007" shorter on off pin in and crono problem solved. I was having a hell of a time with the different spring lengths, pressure from the LPR, and pressure from the valve to get it to crono but no longer. It was the pin.

A quick video to show the progress.

http://www.youtube.com/watch?v=6waaxqAjF7k