Really technical question - revamping old LVL7's

[spsantos]

Ok, my minimag is now 10 years old (SN 5829), after more than 5 years, last weak i played my first game since then. Changed to compressed air.

I love this marker to much to give it a go, and with all those electronic, etc markers around, it still behave like a charm, but I believe I can make it better without buying extra parts.

I have access to latest technology milling and lathe machines (my home town is a world major producer of moulds for plastic/alluminium industry).

I have already tweaked the on/off to pull down the trigger weight, redesinged the PF plug to get a better ball feed rate, now i (think) need to increase valve recharge rate.

How to increase the valve recharge rate? and thats what I ask:
Tips, blueprints/Cad desings of valves.
Any technical info about airflow ratios would be welcome, to sum it all up, any information that could lead me to a working solution is welcome.

I'm also available to freely test feasable ideas you guys may have.

I understand that maybe this post may bring more questions than answers, but at the moment, i'm just starting the modifications and I don't have any accurate results to give so far, but I'll always welcome any feedback.

Last but not least, even if I come up with a good modification, it's not my intent (not even my business) to make money from it, I have much else to worry from ;)

[trains are bad]

search for posts by 'the electrician'

all I got to say

[PumpPlayer]

I have a mag that was given an ingenious trigger job. You will need an 1/8" drill, an 1/8" dia x 1/2" spring, a 1/16" hex head set screw and the appropriate drill and tap. Here is what was done to make the trigger darn near hair-light:

The stock carbon fiber frame is very versatile and can be cut, drilled and tapped easily and holds up well. The 1/8" hole is drilled vertically from the top just forward of the passage hole for the valve screw. You want to drill in far enough to hold the spring, but not all the way through the frame. You are trying to place the spring just under the aft portion of the trigger sear, pushing it up. Adjust the height of the spring by cutting to where the on/off will seal correctly under the slight pressure of the spring. This will drop your trigger pull down to a few ounces if done correctly. I have not measured it, but I would guess around 5 to 6 ounces is about right.

The next thing to be done is to put in a trigger stop using the set screw. Make sure that you take the grips off for this procedure. At the top end of the backstrap of the frame, you will notice that there is a portion which, at the most forward point of the backstrap, there is no interference from the framing inside and the bottom portion of the sear travels back and forth. The idea is to drill through the back of the frame, tap the hole and insert the set screw to stop the travel of the trigger sear. When finished, put the marker all back together and adjust the position of the set screw. Use a little bit of loctite to keep it in place. Screw the set screw all the way in and pull the trigger. The marker should not fire as the set screw prevents the sear from traveling back far enough. While holding down the trigger, slowly unscrew the set screw until the marker fires. Give the set screw another 1/4 to 1/2 turn out and make sure the marker fires reliably each time.

The mag that I have that has this modification was bought used and I did not do this myself. I will be performing the procedure on any carbon-fiber frame mags I have in the future. (my other mag has a benchmark frame, so all I did to it was the spring, not the set screw) If there is enough interest, I might post a picture, but as I don't have a camera, it's not easy for me to do.

Another tip: It's also possible to make the pull lighter without drilling any holes. There is a passage on the forward portion of the trigger that a spring can be inserted vertically in order to make the pull a bit lighter. Unfortunately, you need to remove the trigger safety in order for the trigger to work properly if you do this. I would not recommend the procedure as I'd rather be safe than fast.

As for increasing the recharge rate of the valve, do this: If you've seen the 8-hole modification for the regulator body, do that first. Stock, there is a single hole for gas to pas from the regulator to the on/off. By drilling more holes, you increase the cross-sectional area for the gas to flow through and thus cut down on resistance. I won't go into detail here because there's plenty of info out there on this. Also, if you HPA tank has an adjustable regulator, try decreasing the output pressure slightly. Not enough to give you shoot-down, but enough so that the regulator essentially has 'less work to do'. It'll give you maybe another shot a second. Stock, however, your first major limitation is the trigger. Focus on that first. Regulator second and ball feeding speed third. In fact, a stock mag with the long feed neck has almost no use for a motorized hopper: the long feed neck works great to keep balls in the chamber by itself.

Keep in mind you're still only looking at 8 to 10 balls a second if you really suck out everything it can give you. (the major limitation being the single trigger) If you mod it with some aftermarket parts and really tweak it, you can get more, but that's not what you're going for. Personally, I think 8 bps is plenty fast enough for anything, especially if it's an accurate 8 bps. A little bit of aiming is better than cranking out 18 bps any day.

[Scott Hudnall]

search for posts by 'the electrician'

all I got to say


Ditto that......I'd check electrician's threads....some pretty amazing stuff.

regarding recharge rate on the classic valve, I think i've read in multiple places that it can recharge 16 times per second without shootdown?

My old mag is in the 5000 serial # range, still my main gun, and still has the original on/off assembly. Intelliframed the thing last season and it shoots as fast as I can crank the trigger......(no, I don't make claims as to ROF, nor do I believe the other boasts regarding 20 bps ROF....come on, now......)

[trains are bad]

I would also suggest that you not listen to anything pumplayer said. Some of it is very wrong.