Another Factory F/A, Now with a Cyclone
Got my hands on an F/A this week, to the detriment of my winter quarter textbooks :rolleyes: I didn't have too much time to play around with it, much less tear it down and clean it up. I did get to gas it up and have some much needed trigger time. It's got quite a leak down barrel until it's cycled, and scared the crap outa me on full auto, it cycled faster than my SMG. I also think the sears need adjusting since when the bolt is foward, it's darn near impossible to cock it. I'm starting this thread so Ive got somewhere to post pics and ask questions during the restoration.
To start this out, what happens if the sear pistons need new fluid? How would i change the fluid out properly, and what kind of fluid would i use? Does it even use fluid, or is it just an air shock? Is the spring oil I saw in the YouTube videos a special oil, or will Hoppies #9 work for lubeing the spring?
I don't know too much about the F/A's, but I'd love to get one sometime. I think I remember reading that you should use ATF(auto transmission fluid) for the shock fluid. If it's cycling faste than a SMG then there's something wrong with the shocks, probably just no oil. I remember playing against someone using a F/A the first time I played at a real field, he could adjust the ROF between about 5-15bps. I would think any oil/lube would be fine on the spring, something thicker like pure lube or dow33 would probably be best. Hopefully someone that has actually used one of these guns will chime in with some answers.
You want ATF fluid. get a shallow pan about 3" deep. Take the shock assembly off (remove the sight cover, then remove the 2 screws under it and slide it off the front. Don't need to tear the gun down to do this). Unscrew the brass screws all the way, and push the rear pistons out from the front with a small punch. Make note of which screw goes in which side, as they are not the same. Oil will leak out. Submerge the shock body in ATF, and let it sit for a while so there's no air in it. Helps if you shake it around a little bit to get all the bubbles out. While it's still submerged, push the plungers back in from the rear. This is the part that you have to futz with a bit and may need to do a couple times. If you push them in too far, you don't have enough space filled with fluid to give you the pressure resistance, if you don't push them in far enough, it's REALLY hard to get the shock assembly back on the pistons and it may not fire in Semi. I have the best luck with getting them just below flush. Once they are in, still submerged in fluid, screw the brass bits back in, holding the pistons in place from the back. Take the assembly out, and dry it off. Slide it back on the rail and screw it down. From there, you adjust, per the manual (link below). Get it to fire in semi first...then start adjusting the RoF screw for auto. It can be really touchy, and you will probably have to experiment a little bit with getting the right amount of fluid in the chambers. Mayvik helped me out a lot with mine.
Schools out, and I've finally got some time to get this thing shooting. I tore her down today and cleaned everything. Some pretty scungy old paint in just about every conceivable crevice and corner, plus the hammer was pretty corroded. I blasted and polished that, maybe that helps the cycling and cocking issue some. I did notice that the top sears don't engage at all. I unscrewed one of the brass adjusting screws and almost no oil leaked out, so I'll have to get some transmission fluid. Thanks Riot for the tutorial on that one. I had no idea what you were talking about before I tore the F/A down, but now I get it.
So I rebuilt and re-oiled the dual shock mechanism. I did manage to find the right amount of oil such that I can both mount the housing and fire semi-auto. I was even able to tune it to shoot at a controlled semi-auto rate . . . for about five shots.
I took a video of the problem. It starts out just as I wanted it to; a nice slow ROF. You can see the gun cycling in the video (the air compressor in the background prevents you from hearing it). It starts out slow, picks up speed, and eventually goes to just the hammer bouncing uncontrolled. I can adjust the ROF screw a bit, and again it will start slow and work its way to uncontrolled full auto. Eventually I'm going to run out of adjustment.
My best guess is that I've got an oil leak somewhere? Or did I possibly not fill it correctly in the first place?
VID_20120612_182627.mp4 video by aglover_1991 - Photobucket
GOT IT! After replacing all the non-redundant seals on the pistons and screws in the shock mechanism, and re-oiling it, she cycles great. I ordered a new detente, main spring, and spring guide just to replace the more worn parts. I also made a new front bolt just because the old one was beat up. I really need to find a GoPro so I can take a video on the field with it.
Ok, I finally managed to get a video of me on the field with the F/A. Unfortunately, I set the GoPro up pointing a little bit downward. Fortunately, that mistake lead to a great diagnostic shot of some feeding issue I was having.
It seems like the loaded was getting a little bit stuck and wouldn't fully load paint into the breach. You can see it in the first clip of the video. It gets stuck several times in both semi- and full-auto. Oddly, the F/A doesn't always crush the half loaded ball; instead the valve train just stops ON the ball and needs to be reset. While not as bad a break, its still really annoying and frustrating to have my unicorn gun so close to being fully operational.
Anyone have any ideas? I took the loader apart and inspected everything inside it. It all seemed pretty normal, no parts out of place nor anything obviously broken, with the exception of the spring being a little bit bent around the center shaft. I tried to get a good picture of it, but this was the best I could manage;
I got sick of the standard hopper misfeeding and didn't want to try and source a new spring to attempt to fix it, so I did this;
I cut down and radiused a 98 custom cyclone adapter plate;
Drilled out a cyclone cup for 10-32, lined up to coincide with the 1/4-20 clearance holes on the body.
This is the biggest problem Ive found so far;
On an A5, the cyclone cup sits right up on the breech, so that the cyclone paddles hold the paint in the breech and prevents it from partially rolling back into the cup.
On the 98, the cyclone is mounted "up stream" of the breech, so gravity rolls the ball into the breech after it leaves the cup.
On my ghetto mounted F/A, the cyclone is offset from the breech by the thickness of the adapter, and is NOT uphill of the breech. So if I hold the F/A slightly sideways and a ball rolls back into the cup, I'm almost positive Ill chop a ball.
Work Completed 4/21/13;
Installing 1/16" line like this didn't get the cyclone to cycle. Not enough air flow I guess.
Shooting the gun holding it tilted to the right so that a ball partially rolls back out of the breech produced this result;
And swapping the 1/16" banjos with 1/8" banjos produced this result;
Overall it does work, but as you can see in the video, if theres no paint in the breech then the cyclone doesnt cycle. To fix this I'll probably drill and tap the body for the banjo fittings. First I'll fix the partial feed issue.
I think I fixed my problem;
With a zip tie :p
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