I'm basically done with my pneumag now, but I have a problem. There isnt enough room for a QEV in my benchmark. Normally I could drill out a bit more but I have the smav-3 in the way. I've seen other people have their QEV attached to their mpa-3 through a hose, but I can't seem to figure out how they did it. What fitting would I need to do this? Or could I cut off the male end (the output) and tap it for a barb. Would this work?
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I don't reccomend doing that. I doubt there's room to tap a 10-32 there. Go to a hardware store and pick up a nice thin walled 10-32 hex standoff. Basically it will act as a female-female coupler. You'll need some locktite to seal it. I believe Clippard sells them labled as "inline 10-32 female couplers" ... but the s/h is expensive there.Originally posted by wjr
I have about a dozen of them if you cant find one at a store. FYI - QEV's add marginal performance at best with the MSV-1 3way. Your SMAV-3 will vent like a champ if you take off the unused exhaust barb. SMAV-3 seem to vent much better than a MSV-1, so you definately shouldn't need a QEV given that you didn't put alot of hose between the 3way and MPA-3. However, if you find that you're short stroking you can always add one later. -
Off topic, but how light is the trigger with the smav?Comment
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Don't know...never measured one. But intuition suggests:
It is rated at 20 oz for 100 psig input. Pressure to force should be a linear relationship....
To give you an idea of Fabco valves acitvation force...
An MSV-1 runs 16oz @ 100 psig
A stock MSV-2 runs 2oz @ 100 psig
An MSV-2 modified for a frame runs about 5-8oz @ 100 psig
Operating force = (input psig) x (actvation force oz per psig ratio)
*this calculation neglects the minor spring retun force
**The valve should return without the spring - take it out if you want
Next take this activation force and factor in the mechanical advantage of a trigger. Always calculate the trigger pull weight from the mid length of the trigger. This means if the smav is below the centerpoint of the trigger... then you've increased the pull weight and decreased the pull distance. If the the smav is above the midpoint of the trigger you have gained mechanical leverage and lowered the pull weight and increased the pull distance.
Running ULT (about 50 psig) with the smav about 3/4 up the trigger (about 1/4 from the top)... You're looking at a ~5oz (140 gram) trigger pull. Just about walkable if you've got good fingers. Slightly heavier than a stock e-spyder I think.Comment
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How did you get Shortys trigger pull to <2oz?Originally posted by PneumaggerComment
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I used a modified MSV-2 valve with a 5oz @ 100 psig acitvation.
Everyone knows
around 80 psig to operate a Emag on/off (4oz)
And around 40 psig to operate a ULT on/off (2oz)
now factor in the mechanical advantage of a trigger with the activation point 3/4 the way up the trigger (1/4 from the top). This mechanical advantage doubles the output force as well as the input distance.
So, ideally for an RT or Emag on/off your talking as low as 2.0oz trigger pull and for ULT on/off you're looking as low as 1oz.
I achieved 2.1oz with the emag on/off and 1.3oz with the ULT on/off, both of which agree with the ideal calculated values. These values were measured with the gun pointed upward, so the trigger weight was not included meaning the actual trigger pull may be a tad bit heavier due to the non-weight of the trigger.Last edited by Pneumagger; 07-06-2006, 02:31 PM.Comment
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Anyways...
I used a hex nut, and loctite to join the qev and the barb together. I'm surprised it worked though. As you can see in the picture, the nut is very small.
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And corpse, the smav-3 is not very light at all. I hope to someday get a fabco 3 way and mabye a nicer frame...
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so did ya notice any improvement with the QEV? if so how?~E~Comment
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Right now with the way that it is, yes there is improvment. If I removed the barb from the smav-3 and use it for exhaust then it would work better then the way that I have now.
/I know that the qev is underneath the smav 3 and that the smav 3 vents wellLast edited by wjr; 07-06-2006, 09:08 PM.Comment
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I typically always try to get one in there. And to be perfectly honest...it's not worth it to force it in there. Unless your stooting anywhere near 16+ or 18+ CPS, it's more of a luxury then a necessity. Depending on how hard it is to get in there, it may even begin to hurt performance if you have to use entirely too much hose.
Try this MPA setup
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wait a minute, wjr you have left the hose barb on the exhaust of the smav-3?
take it off if you have. carefully. it is a waste of space and restricts the flow. I just assumed everybody knew to take it off.
if you have to use hose to hook up a QEV, your not going to gain squat. basically the two hose fittings and the hose are restriction, before the air ever get through the QEV, so it's a bit pointless in this particular application.~E~Comment
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Originally posted by the electrician
Yeah, I left it on there. I didn't know to take it off until today. But it looks like I'll be able to fit the QEV right onto the MPA-3 if I tap and plug it like Pneumagger did. I'll also remove the exhaust barb from the smav-3.Comment
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Take a look at where the vent hole is on the MPA-3, then think about it. There is very little gained from adding a QEV from my experience. (Although it wouldnt hurt) I have that MPA3 in an Electro-Pnuematic set up, and it cycles at a ridiculous rate even without it. The speed will be determined by how fast you can cycle the switch.
More info here:
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I won't be able to get a QEV on there anyways. This morning I looked and found that even if I tap it like pneumagger did that It wont fit.Comment
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My QEV/MPA combination really only works great for use in a Logic frame without having to mill out extra room to fit a QEV. It would still require cutting on an I frame or RPG frame. Not as much as with normal QEV, but sill some cutting.Originally posted by wjrComment
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