Crossover bolt and springs experiments

[FlightMedic938]

The Automag bolt test will have to wait but I ordered a TechT MRT Pro Series Tipx bolt last night and hopefully that’ll be here soon so I can wrap this thing up.

I did more trigger work recently. The return was too strong with the larger magnet behind the trigger lever. I swapped places of the larger and smaller magnet and it felt ok but then the return wasn’t strong enough. Tricky. When I say return, I mean the return of the trigger lever, not the trigger itself. It’s weird. The trigger lever (sear) is basically an extension of the trigger itself. It’s like tuning 2 separate triggers.

Anyways, for those of you that have Crossovers you may have noticed that the trigger could definitely be more responsive in mech mode. Sometimes you may even experience shoot down. That’s not really from the trigger but the trigger lever not resetting all the way and catching the trigger pin before it’s seated fully in the valve core.

So I’ve got a magnet under the trigger itself, next to the trigger pin housing (?) and that magnet helps the trigger pull by snatching the trigger lever once it’s broke free from the magnetic field of the magnet(s) behind it. There are 2 magnets behind the trigger lever. One is flat and rests partially over the valve assembly housing screw and the other is the cylinder style magnet that was in my broken adjustment arm. It’s encased it plastic and sits on top of the flat magnet.

These 2 magnets return the trigger lever back to rest very quickly. Aside from making the trigger feel a lot better I have a theory that it might help prevent damage to the trigger pin by quickly getting the lever out of the way so the pin doesn’t slam against it.

You can’t see it but there is a small magnet in the trigger spring recess on the trigger itself. It’s opposing to the large flat magnet under the trigger. This helps with actually trigger return (not trigger lever). It’s much better than the stock trigger spring on both pull and return of the trigger. Then there is the stock trigger adjustment magnet at the far end, on the trigger itself, at the top. I adjusted this to the point the trigger landing (the part thats under the trigger lever) is touching the lever. The trigger adjustment magnet also acts as a trigger return magnet.

So 5 magnets all in all. I re-polished up the points where the trigger contacts the valve assembly housing. You can see where I did it by its silvery appearance. There is a lot of metal on metal contact with this trigger and, in my opinion, polishing those points makes for a much better feel and performance.

The trigger landing and the trigger lever were also re-polished. Focusing mainly on where the landing and lever contact each other. I also shaved off that last little bit that was poking out from where I cut off the part of the trigger that I wasn’t using anymore. Then to top it off, a little Mississippi silver on the sides to keep those pins from walking out.

Here is a video of me just messing with the trigger. I’m doing it left handed so it’s not all that great but at the end you can see the lever really moving good when I’m walking it.




https://youtube.com/shorts/QMJvaqfww...yioNk6X5uzsb7-

[FlightMedic938]

It’s a no go. The Tipx bolt has a very slightly smaller ID and the stem is huge compared to the Crossover stem which would require boring out the ID of the Crossover powertube.

I’ve read that Phenom and Tipx can swap between bolts with some minor modifications but it looks like the Crossover powertube is too different in dimensions to join the club. Automag bolts I assume wouldn’t work as well just by looking at them now but I could be wrong. I bet though, that Automags could use Phenom and Tipx bolts. Not much of a benefit of using the Tipx because of the large stem I would think but I don’t have one to test it out anyways.

So I’m going to try and make lemonade out of lemons and bore the ID of the powertube and machine the OD so it’s a nice fit. I decided to overbore the ID so more air can get around the stem. I’m more than halfway done so it shouldn’t take long.

The Tipx is 7g lighter than the current bolt which may or may not make much of a difference. The thing I’m curious about is that it travels half an inch (roughly) shorter than the current bolt. By my measurements it still barely makes it past the part that most Tippmann barrels have that is large bore to account for bolt travel. Will the lighter bolt, faster cycle speed, and lighter spring make a noticeable difference in performance, is what I’m asking myself.

[FlightMedic938]

Nope not going to do it. Just losing interest working on this power tube. Arthritis is acting up and I’m getting pissed. I know it can be done but honestly it should go to a professional machinist. So if you have a Crossover and want an aftermarket bolt but can’t get your hands on the TechT one you’ll have to get a Phenom, NOT the Tipx, and probably send the powertube to a machinist to match the bolt to the tube. Get the bumper from researchpb and I highly suggest putting a bumper down the body. The bumper for the Emek is a perfect fit. This’ll prevent breaking the bolt especially if you are running a lighter front bolt spring. You might have to adjust your bumper stack slightly since the front bolt travel on the Crossover is a fixed distance and you’ll be reducing bolt travel with the Emek bumper. You want enough room in the breech for a paintball to load easily.

On another note. The regulator spring for the PE SL3 reg is a drop in for the Crossover. Not a big upgrade by any means but it is a lighter spring and if you are dropping your OP via lighter front bolt, lighter front bolt spring, and volumizer I theorize it’ll give you better consistency.

I’m still convinced the stock spool spring is too stiff for this marker. That and the sluggish return of the trigger lever is what, IMO, is bending trigger pins. I fixed the trigger lever return by placing a magnet behind the lever. This won’t work if you running electronics because you’ll throw the whole Hall effect balance off.

I shimmed the Emek spool spring with a small O ring but this time I placed it in the spool cavity where the spring rests. I also filed down the lip on the spring post so the spring goes over it completely with another o ring shim. It seems it improved concentricity but like most of my experiments it’s anecdotal at this point. I’ll know soon when I get some air but until then this post is done. Failed on my part but maybe somebody else will have better luck

Also, even if are running electronics, place a small magnet on the body and under the front on the trigger, next to the stock magnet in the valve assembly (which is used to adjust the trigger.). You don’t have to superglue it or anything. The magnet in the assembly will keep it in place. Really helps the trigger return and gives the trigger a cleaner break. Remove the trigger return spring or at least cut several coils off. Don’t place a magnet under the trigger near the trigger pin. It really wasn’t doing much of anything. A magnet isn’t needed in the spring recess on the trigger either. I noticed an improvement with a small circular magnet next to the magnet in the assembly and a magnet behind the trigger lever. Those were the best 2 spots I found.

[FlightMedic938]

Stock spring and SL3 spring

[Trbo323]

It's a no go. The Tipx bolt has a very slightly smaller ID and the stem is huge compared to the Crossover stem which would require boring out the ID of the Crossover powertube.

I've read that Phenom and Tipx can swap between bolts with some minor modifications but it looks like the Crossover powertube is too different in dimensions to join the club. Automag bolts I assume wouldn't work as well just by looking at them now but I could be wrong. I bet though, that Automags could use Phenom and Tipx bolts. Not much of a benefit of using the Tipx because of the large stem I would think but I don't have one to test it out anyways..

Crossover was gen1 flex valve and they refined it a bit for the tipx /phenom which was Gen2. I was never told what exactly changed but was told there were changes.

Nope not going to do it. Just losing interest working on this power tube. Arthritis is acting up and I'm getting pissed. I know it can be done but honestly it should go to a professional machinist. So if you have a Crossover and want an aftermarket bolt but can't get your hands on the TechT one you'll have to get a Phenom, NOT the Tipx, and probably send the powertube to a machinist to match the bolt to the tube. .

This is basically where I got to with mine. I got frustrated by the amount of work I would have to do to MAYBE make it better and it was a lot of work that I felt like tippmann should have done from a design point of view and found these things could be better through R&D.

The big one that really frustrated me was the ASA and how there was no simple way to plug the transfer tube without tippmanns little block mount. Hell tippmann themselves didn't even bother to fix that with the upgraded crossover. Players wanted to have a on/off ASA and rather than give them that tippmann made an inline on/off that pushed the tank further back and used the same asa

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[FlightMedic938]

The Tipx and Phenom came out before the Crossover but I get what you’re saying.

I agree. The trigger and trigger lever need bearings on the pins. I don’t think that would’ve been hard for them to do. The spool and spool spring should’ve been lighter with a taper in the ID of the powertube on the spool side. I’m confused on why the spool has to travel like a 1/2” inside the powertube before it seats and why there isn’t a taper inside the powertube to reduce friction before it seats.

A way someone could block the gas line would be to plug it on the firing valve assembly itself and remove the gas line all together. Some JB Weld would do the trick I think. The bottom line mount is standard I think right? I could be wrong.

If you sealed the cavity in the firing valve you could then run whatever ASA you wanted with an external line to whatever reg you want in place of the foregrip. On the XVR anyways. I’ve read that on the standard Crossover there is a screw that needs to be machined out in the foregrip cavity so it can connect to the air channel going to the firing valve. The XVR doesn’t have that screw so it’s just an open channel connecting the foregrip cavity to the firing valve assembly.