Apeks XTX lever height

[buddhasummer]

I have some XTX second stages both were cracking at 1.5" out of the box. Tuned them down to 1". Using the lever height setting tool to set the lever as per manual I noticed that the lever then sits quite a bit past, lower, than the point of screwing in orifice until leak stops.

I'm wondering if Apeks designed the tool so it sets the lever on the low side to prevent in between servicing issues, i.e they set conservatively?

Is there any reason I'm missing that prevents me from setting lever height as one would on a G250, G260, 156BA etc? screw in just until leak stops? and then use the micro adjuster to fine tune cracking?

Cheers

 

[sh1513]

I've never found any issues when using the Apeks AT20 or AT20F setting tools with the GAS / NO GAS, then fine tuning the cracking with the micro adjuster.

I don't see any reason why you can't do it as you suggest by setting it just until the leak stops and fine tuning, that's how I would do it without the setting tool. As long as it doesn't leak or free flow you're good to go.

 

[Pao]

I usually just set it flush with the top of the case then use the microadjuster to set cracking effort to 1.25 or thereabouts. This usually works for me. I have the go/no go tester but don't usually use it.

 

[buddhasummer]

Thanks guys, that's what I was thinking but just wanted to be sure I wasn't missing something. There is quite a difference in lever height between using the setting tool vs screw in orifice until leak stops, I was surprised. On a G250 that difference would be noticeable but I guess the micro adjuster on the XTX compensates for that.

 

[Pao]

If your'e not comfortable with that height difference, you can adjust the lever height until it just rattles a teeny bit when you shake it.

 

[buddhasummer]

I've tuned one using the lever setting tool and one using the screw just till leak stops method. I'll take them for a dive and compare.

 

[buddhasummer]

Update:

I could tell no discernible difference between either tuning method. I guess the micro adjuster makes all things equal. Cheers.

 

[Macan]

Update:

I could tell no discernible difference between either tuning method. I guess the micro adjuster makes all things equal. Cheers.

On both method, is the 2nd stage free-flowing (as it should) when the purge is rapidly cycled and mouthpiece facing up? Using the "no tool method" (adjusting the metal seat until it hiss and backing off slightly), I find that that the 2nd stage does not free flow at all.

 

[rsingler]

Been watching this thread and holding off. I feel the need to jump in. IMO, the seat setting tool should be thought of as just a "rattle stop" gauge. But you can do just as well setting the diaphragm in place after sealing the orifice under pressure, and then lowering the lever with the orifice until the diaphragm is no longer dangling from the lever (and maybe 1/2mm lower if you like). Then screw on the case and see if you can get a light enough cracking effort by backing out the microadjuster. If you can't, then back out the orifice a touch (which now puts pressure on the diaphragm plate inside the case as the lever rises, and completely eliminates rattle). If this works for you, then take a sight across the case rim when the lever is where you like it under pressure. You don't need no stinkin' gauges!

The problem with the lever height gauge method is that it compensates for inadequate lever clearance in the case by potentially putting more pressure on the seat, and creating a deeper ring/groove over time. With the G250, we would seal the orifice (+ 1/12 turn), and bend the lever if it didn't position correctly under the diaphragm. With the G260, that need went away, because you could create lever height with the orifice, and lighten pressure on the seat with the microadjuster. The XTX is theoretically just like that, but using the tool is (IMO) a very coarse way to adjust the orifice. I believe that the XTX has less room for lever height than the 260, but a shade more room than the 250, with its very flat diaphragm. So just do it by feel. Seal the orifice plus 1/12 turn and see if you can get it to crack where you like. If it rattles, then that's telling you the lever is too low, but backing it out makes it more prone to freeflow if you've only added 1/12 orifice turn past sealing. If it doesn't rattle, then lever is either perfect or jammed up tight against the diaphragm. Either way, if you can get your desired cracking effort with the microadjuster, you're alright, though potentially at the cost of more lever friction against the diaphragm.

If the ideal position by the above tests yields the same height as suggested by the gauge, great. But I'll bet not. The gauge is too coarse a measure.

 

[StefinSB]

On both method, is the 2nd stage free-flowing (as it should) when the purge is rapidly cycled and mouthpiece facing up? Using the "no tool method" (adjusting the metal seat until it hiss and backing off slightly), I find that that the 2nd stage does not free flow at all.

Just working on my first xtx50 and that is exactly my problem right now.