Tippmann A-5 Operator Group - View Single Post

MisterMister · #1 (**permalink**) 11-07-2006, 06:40 PM

I’m making this little tutorial for all the RT owners out there who have or will switch between C02 & HPA. If that sounds like something you might experience down the line, read on. If not, it might be good to know anyway.

Now then, let's start off with the basics of how the RT reacts (no pun intended) with the different types of gas.

Typically when people run C02 it's not regulated, and even if it is there are pressure spikes due to temperature and volume changes. That is one factor. The other factor being that C02 is dense. At least more so then air. Both of these factors combine to add a lot of extra backpressure in your marker's system... and as you may or may not know, the RT lives or dies on back pressure (sort of like a turbo, for you car guys out there). That is to say, as far as the RT is concerned, back pressure makes it work. The more backpressure in the system, the wider the "sweet spot" (the area behind the trigger from which the full auto fire mode is triggered.). But I digress...

Let’s say you have a similar set up to me. The marker would include an RT (duh), flatline barrel, & unregulated C02 tank. Lets also assume you have spent some time and C02 adjusting your RT. This is done by turning the screw located above the hand grip. I will refer to this as the "RT adjustment screw". Its purpose is to set how many BPS the RT will fire when the "sweet spot" is reached (it also has a direct effect on how wide the sweet spot is. Typically the faster the BPS, the smaller the sweet spot).

So you have this sweet A5, with a dialed in RT and a FPS velocity set to 275FPS (for the flatline to work properly). All you need to do is THINK about pulling the trigger and you have paint flying out at 12-15 BPS. It works great, no problems what so ever.

Now let's say you buy your self an HPA tank (again, like me). You pick it up at the local pro-shoppe, get it filled, and run home with it to try it out. You get back and hook the HPA tank up to your marker. Without adjusting anything else, you take it out back to try it out. You then find that you can no longer fire at full auto! At most you can get a few quick bursts of paint, but nothing like before. Why and what do you do?!

Why? Because the air in your HPA tank is not as dense as the C02 you were using before... and to top it all off you probably got a regulated HPA bottle, so there isn’t a huge unregulated flow of gas and no pressure spikes. All this adds up to less backpressure. Now you know, but what do you do about it?

First off, you are going to need to adjust your FVA. SLIGHTLY turn your FVA screw CLOCKWISE (this will DECREASE your FPS). Now when I say "slightly" I mean VERY slightly. About 1/10 of a complete turn of the screw should do it.

Next, you will want to adjust your RT adjustment screw. Turn that clockwise till you can’t turn it anymore. Be careful NOT to over tighten the screw, this can and will damage it, and that’s not covered under warranty. After you do this, you should be able to get one shot off, after which the trigger should become impossible to pull again (if it doesn’t you have a leak in your RT system, but that’s a different post).

From there, slowly turn the screw in the opposite direction (counter-clockwise). Do this while you lightly pull on the trigger. Keep turning the RT adjustment screw until you are able to get a shot off. After that point you will want to adjust the screw even slower. Keep unscrewing the RT adjustment screw counter-clockwise and pulling on the trigger till you get a rapid burst of fire. From that point you can fine tune the RT adjustment screw to where you can maximize your BPS rate while keeping an easily hit "sweet spot".

Keep in mind though, that you might not get this on the first try. If you find that your automatic fire is lacking in the BPS department, and no matter how much you adjust your RT's adjustment screw you just can’t fix it, you need to adjust the FVA again.

If that is the case, repeat the last couple of steps. Turn the FVA in another 1/10 of a turn, re-set the RT adjustment screw (turn it all the way in so you can no longer pull the trigger) and then slowly increase the RT adjustment screw until the desired BPS rate is found.

You can keep doing this as much as you like. I found that there is a good deal of performance to be had out of the RT by taking time to fine tune it in this method. Ideally, you should be able to get a decent BPS rate (~10-12BPS) while allowing for a decently wide sweet spot (very easy to hit and keep). You can and will be able to increase these values the more and more you play with the adjustment. You are only limited to your own patience and time (and air) as far as that is concerned.

Also note that you have now adjusted your FVA screw. You may want to check your marker on a chrono to see how much it is off. It shouldnt be TOO far off, so this shouldnt be an issue, but you will want to make sure. Also, if you want to avoid any FPS changes you can add an RVA to compensate for the decrease in velocity.

Anyway, this has been a compilation of all the info I have gathered from my own experiences dealing with my A5, RT and HPA/CO2 bottles. I hope it helps someone else out as well, since I know the RT can be tricky to use properly. I would imagine most people who have problems with the RT and those who "give up" on it, are the same ones who don’t know how to properly adjust it. Let’s see if this can get those people to love their RT as much as I do.

EDIT: As suggested by a member, I am adding this info...

You can also increase your "sweet spot" by doing a couple modifications. First is the "clicky pen spring mod". This involves replacing the trigger spring that comes stock with that from a "clicky pen". if you look in my signature I am giving this mod away free to A5OG members.

Also, you can do the "q-tip" mod. This is more of a PITA then the spring mod. this involves cutting the center "stick" portion of a q-tip to fit inside the trigger spring. This in turn acts as trigger stop, allowing you to simply pull the trigger and hit the sweet spot every time. It is rather time intensive however, since it takes a LOT of trial & error.

You can SEARCH for either of these mods in this forum to pull up more detailed info (with pictures).