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Thread: Solenoids, dwell times and stuff and a ghetto E.P. frame folly. Well in theory.

  1. #1
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    Solenoids, dwell times and stuff and a ghetto E.P. frame folly. Well in theory.

    I'm thinking of doing this for something to do, I know it will work (sort of) but without be able to set dwell times for the solenoid it'll probably be a disaster. The idea is to do away with the Fabco MSV-2 and replace it with a micro switch with a lever. Screw the rod to the lever mimicking the MSV-2 and bolt into the same position. Then, wire a 9 volt battery with a resistor to the micro switch and then onto a Spyder solenoid as they're dirt cheap. Plumb in a QEV and an mpa-3 and see what happens!

    This is what I think will happen.
    1. It will work fine.
    2. It will work fine until I start rapid firing at which point it will probably short stroke as there is no way to control the time of the solenoid turning on or off, (Dwell) as it it will be on until you release the trigger. A tiny timed relay would probably sort the short stroking out if there is such a thing. This is the smallest relay I've found so far.

    http://www.semitek.cz/tyco/rele/agastat/md0.pdf

    That said it might work better than a Pneumag.

    Any thoughts?

  2. #2
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    talk to spider…he did something similar to wat your wanting to do. here is a link to his thread:
    http://www.mcarterbrown.com/forums/c...control-4.html

  3. #3
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    Hey thanks for the link, I knew I'd seen something similar before. It does make me think...

  4. #4
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    its all good man!!!

  5. #5
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    Ok, so I've been doing a bit of investigating into doing a full EP frame as well and it seem there's a few things I'd need. It seems that some boards have caps on them whereas some don't appear to have one fitted. Would I still need to fit a cap if the board doesn't have one?

  6. #6
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    i would PM spider or P8ntbal4me about the electric stuff…or Mann or Loguzzzzz or Renie or Hill or Athomas

  7. #7
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    Quote Originally Posted by need4reebs View Post
    i would PM spider or P8ntbal4me about the electric stuff…or Mann or Loguzzzzz or Renie or Hill or Athomas
    Cool thanks again, I'll do that!

  8. #8
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    For a capacitor, the easy thing to do is look at the board that usually drives the solenoid you are using and try to match the voltage and power.

    If not that, then you could use a datasheet from the solenoid manufacturer. If not that, then a datasheet from a comparable solenoid of the same service or specs (if printed on the side).

    Then there's just bread-boarding or circuit-scribing a test setup and checking for function on the low side of operation and heating on the high side of usage.

    If you are using a rifle stock or your own frame, you can use lots of stuff (ala Flatliner). If you are trying to use a regular frame, it's hard to cram everything in there without a lot of planning.

    Your relay asks for a high voltage (24vdc) and is also an on-delay. You need something around 5V rating (depending on your available circuit voltage), as you will be firing a short pulse into an inductive load (whether it is a relay or solenoid).

    You basically need two time delays of one sort or another (digital, analog, or self limiting circuit). One is how long the solenoid is charged, the second is how long to wait until the system will be ready to fire again. It doesn't matter if it's an EM or EP mag, you still need a minimum of two in order to avoid chuffing. You could probably get away with a circuit that will dump a capacitor into a solenoid to fire it, as opposed to actually controlling dwell. It just needs to release the sear immediately after tripping. The problem with using caps to limit themselves is that the timing changes as the supply voltage varies. If you go to voltage regulation, you might as well use a timer chip.

    There are a lot of trade-offs to be made. I think Hill made one of the first EPs with the SMC-70 and a UTB(?). Not the first EP, but using the SMC-70. I think that became his sleeper (maybe he had two; they were many months apart iirc).

    But yes, EPs are pretty nice and chuff-less. I still play with mine, and I think dukie still has his wrath frame conversion.

  9. #9
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    I've decided to make my own EP frame I think it'll work out better for me. I bought I Spyder E Trigger to mod but after looking at it I think I could do just as good a job with a Chimera frame rather than destroying the Spyder frame. I'll just sell it on I think.

  10. #10
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    Just as spider hinted on: you need a timer to control the dwell. And if you are going to put the work into that circuit, you would be better off using one that already exists to do the hardware and software work for you.

    UNLESS you just want to try it,.... Then "it's all good"

    But spider is correct. Most questions asked about dwell with solenoids rarely look into the timing issue with the total voltage dump versus the timing that occurss with the reset of the valve and sear.

    If you: used a micro switch, cap, battery, voltage reg., and a relay to dump the charge,.... Your dwell would be based on the speed of your fingers. And as you have pointed out,.... Your marker would chuff all the time.

    Would it work? Yes. Would it work the way you want it to? No.

    What I would do in your case is to get some bread boards from JAMCO or whomever and tests your circuit outside the frame. Bread boarding is a very cost effective way to use PCB parts that you can move and place with your fingers and test with little to no cost if you are "learning".

    Packages for components such as SIP AND DIP work great to learn with.

    So lay your gun on the table, trouble shoot your circuit outside the gun,... And test it as you modify the circuit.
    You should be able to power it on, move things around and try it out. No soldering......
    _______________________
    Jai "P8ntbal4me" Menard

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