electro pmag help

[captian pinky]

ok guys i have a frame board everything except noid and the mpa3 also this is run with a ult but would like the option of either stock or ult


i need measurements of the mpa3 and how to install it please

and i need help deciding on a noid

these choices are because i have a very tight space to work and can not dremel the frame forward or back because of the type of frame (trying to keep it a secret for now) but i can dremel the sides abit on the inside

choice one is

http://www.airsoldier.com:8080/cgi-bin/mivavm?Merchant2/merchant.mvc+Screen=PROD&Store_Code=AOS&Product_Code=SMC-S070C-SDG-32&Category_Code=SOLENOIDS

choice 2

http://www.airsoldier.com:8080/cgi-bin/mivavm?Merchant2/merchant.mvc+Screen=PROD&Store_Code=AOS&Product_Code=SMC-SY123A-SG-PM3&Category_Code=SOLENOIDS

now when i do this the mpa3 is spring returned right? so is there only 1 hose run from the noid to the ram instead of 2 or am i wrong i do know that lpr hose is run to the noid

also can some one list any parts i may have forgotten

thank you for trying to help

[wjr]

Most people use set screws to keep their mpa-3 in place.

The first solenoid there is rated for only 72 psi. With a ult you would run it at about 60 psi. With a rt on-ff you would more. Many people would agree that it would 72 psi is too low of a rating, so the second one would probably be better.

The mpa-3 is spring returned, so you would just have one hose running to it.

[captian pinky]

what happens to the other hole and what noid would be small enough to fit in a 3cm by 3cm space and also need to know the demensions of mpa3

[the electrician]

you can find the dimensions of the MPA-3 on the clippard website. http://www.clippard.com/store/displa...asp?sku=MPA-3#
look at the drawing link.

I recommend using an s10mm-30-12-2 or a 6 volt model from pneumadyne. you would have to call and order the 6 volt model though.

[captian pinky]

is 72 psi not enought to push the sear with a ult

[the electrician]

it might be, I don't know your exact set-up but a ult limits the recharge rate. so, making an emag, with a ult kind of limits the performance. but if you can live with the resulting rate of fire, then no problem

what is you set-up?

what valve?
what bolt?
if lvl10 bolt, then what spring?

if we can estimate your operating pressure, then we can calculate the force on the on/off pin and then the force needed to push the sear, and come up with an lpr pressure.

[Pneumagger]

go with the smaller noid and 4 AAA's. Make everything internal in a chimera frame FTW.

[captian pinky]

x valve lvl 10 red spring

[the electrician]

so you're recharge rate is probably good enough not to worry about using the ULT.

you're operating pressure is probably pretty high. I've heard of it as high as 600 psi. with the red spring.

so we can use that as a worse case scenario for calculation.

so at 600 psi the force of the ult pin is about 2.86 lbs. the bolt also adds about 2 lbs of force onto the sear.

so a total of about 4.86 lbs estimated force is needed from the mpa-3, not including the 1lb. needed for the spring. divided by the force factor of .11 that the mpa-3 has, that is about 53 psi

so yeah, that little solenoid would work for your application.

[Pneumagger]

so you're recharge rate is probably good enough not to worry about using the ULT.

you're operating pressure is probably pretty high. I've heard of it as high as 600 psi. with the red spring.

so we can use that as a worse case scenario for calculation.

so at 600 psi the force of the ult pin is about 2.86 lbs. the bolt also adds about 2 lbs of force onto the sear.

so a total of about 4.86 lbs estimated force is needed from the mpa-3, not including the 1lb. needed for the spring. divided by the force factor of .11 that the mpa-3 has, that is about 53 psi

so yeah, that little solenoid would work for your application.

remeber, to be quick, it needs to have a larger force then the minimum. 60-70 psi is not out of the question to eliminate short strokes.

[the electrician]

short strokes? he's talking about making an electromag, soo the dwell is adjustable.

I know, what you are saying, but in reality, you will find that it will actually operate the gun at a lower lpr psi than it should work because of the "two stage" pin. BUT it is definitely NOT good to run it that way, it will cause accelerated bolt wear.

I've posted this info before but, basically...
when the mpa-3 acuates the sear when using any two stg pin(ULT or RT), the pin moves quickly at first because of the smaller lower dia. it can push the sear far enough to let the bolt go, but if the lpr pressure is at a dead minimum or a little lower, the pin will seal and then push with more pressure on the sear than before. the sear will then ride on the bottom of the bolt, and scrape the catch edge when the bolt resets, causing accelerated bolt wear.

hard to follow I know, but there it is.

that is why I ALWAYS recommend estimating and calculating the particular minimum lpr pressure needed for a particular set-up. so you can be sure to be ABOVE that. I'm not telling him to set it at that, I'm saying that he could use that solenoid for his set-up.

make sense?

[captian pinky]

so i should be able to use the smaller noid in my application

how does one find out the lpr pressure i have an adjustable lpr and i just don't know how to find its actual pressure

[wjr]

Start with it off and slowly turn it up firing every so often until it the gun fires.

[the electrician]

get a guage, and cap it, then drill the cap for 10-32 threads for hose fittings. make a n inline guage set-up. then you can see exactly what the hell you're doing. you'll know if it's leaking because the psi is too low or too high. you'll know if you are running it at a proper psi. it helps for trouble shooting too.

[captian pinky]

what if i wanted to use a regular on/off what would i do