R109 lever height

[halocline]

Tex;
Those are the two levers I've always seen, thinking the stepped lever was the older one, and that it had something to do with the size of the tabs on the older poppet. I've never seen the poppet on the right (at least I don't remember), but if you look at the middle poppet in comparison to the new duro poppet on the left, it looks like the tabs on the old poppet are smaller and might match better with the older poppet.

Next for me is to try filing the feet on the big-flat-footed lever to see if that makes it act better on the new poppets.

Now, if you really want to go into extremely questionable behavior, find someone that can re-chrome all the 109s. Couv did one once and it looked beautiful.

 

[Texfrazer]

Now, if you really want to go into extremely questionable behavior, find someone that can re-chrome all the 109s. Couv did one once and it looked beautiful.

Actually, most of the chrome looks fine. There are 1 or 2 bodies that have a bit more corrosion, but most look like they've been well cared for.

I've got some time to work with them this weekend, so I should have some pictures by the middle of next week (if this seems strange, it's because I'm heading out of the country on business on Sunday and will be back late Tuesday).

 

[mkgriesinger]

My guess is that he swapped poppets but did not switch to the far lighter spring used with the balanced poppet. "done this in the past" can also mean "used to know how to do it but forgot".

Generally, the older levers bind on all the new poppets - balances or unbalanced. The original unbalanced poppet in the R109 was very short with a large hole in the poppet rather than a tab to engage the lever. The ball used as a spring pad was replaced with a flat disc and the popper was lengthended to make up the difference with the next iteration of the poppet, but the hole for the tabs on the lever were still large. It has just been the latest poppets that caused the problem.

UPDATE: So i got my R109s back. When i went to pick them up i asked the guy about the spring. He said he used a new spring and it was still breathing hard. I guess it doesn't matter. R109 is still a great regulator.

 

[LeadTurn_SD]

UPDATE: So i got my R109s back. When i went to pick them up i asked the guy about the spring. He said he used a new spring and it was still breathing hard. I guess it doesn't matter. R109 is still a great regulator.

Try a different tech or shop. Not to be too harsh, but it sounds like the current tech is "throwing parts at the problem", and they may be the incorrect parts, or he may be looking in the wrong place for a solution.

My experience with the R-109 is limited to exactly one, but my very limited experience with converting mine to a balanced adjustable was that it also breathed "hard" until I looked a little deeper to figure out what the problem was.

Advice from the "usual suspects" here (and pictures in this thread!) helped me figure out the problem.

In my case, I had suspected the old lever was incompatible with the new poppet, but actually found it was simply a problem with the metal orifice's surface (I discovered pitting that was only seen by my old eyes when I used 10x magnifaction).

After I carefully resurfaced the orifice, I was able to get the cracking effort down to around 1.2" (from about 2.5").

Don't give up on the -109's just yet, you should be able to get them breathing really well.

Best wishes.

 

[Zung]

Good info. One of my G250's have a metal orifice, so I'll look carefully next time I take it apart. Currently, the cracking effort is about 1"; my #1 son uses it and he's not complaining.

 

[halocline]

A G250 set at 1" is going to be right at the edge of case fault geometry free-flow. As long as it's set that way with the adjustment knob out, I guess it's no problem.

 

[Zung]

That got me thinking; I checked my 4 "active" G250, and they're all at the 20mm/.8" range. I looked at Pete Wolfinger's book, and with the example he used on page 88, the CGF is 1.25".

We were diving in the Mediterranean a couple of weeks ago, and the kids've just completed their Jr. AOW this week. Nobody ever complained, not even me.

What gives?

 

[LeadTurn_SD]

Did you apply the altitude correction for the difference between Geneva and sea level?

Just kidding.

That is a good question. I sort of understand the "theory" with CGF.... and have read advice from very smart folks on why you should avoid setting the cracking effort below that magic CGF number or you risk freeflow in certain positions underwater.... But then I read about obvious exceptions like you have, and my head hurts.....

The only logical explanation is that your karma is very good, Zung, and the Scuba Gods are rewarding you with low cracking effort during your current lifetime...

Hopefully one of the smarter folks will have a good answer... until then I like the Good Karma theory.

Best wishes.

 

[redacted]

That got me thinking; I checked my 4 "active" G250, and they're all at the 20mm/.8" range. I looked at Pete Wolfinger's book, and with the example he used on page 88, the CGF is 1.25".

We were diving in the Mediterranean a couple of weeks ago, and the kids've just completed their Jr. AOW this week. Nobody ever complained, not even me.

What gives?

Some explanation may lie in the accuracy of your magnehelic. More with the idea that the in the normal swimming position, you would not be experiencing the worst case CGF condition. Finally, even when you do exceed the CGF limit the leak is probably quite small and the exhaust valve is also providing a little resistance as does your act of exhaling so any leak may not be noticeable.

 

[halocline]

Here's the basic idea behind case fault geometry. Think of the diaphragm as a limiter on how little air pressure can exist in the 2nd stage body. That's because when the pressure drops (like on inhalation) the diaphragm collapses, which pushes the lever, which opens the valve, which allows air into the regulator, which pushes the diaphragm out until the minimum pressure (roughly ambient) is reached and the valve closes.

Okay, now think of the exhaust valve as a limiter on how MUCH air pressure can exist in the 2nd stage body. Whenever it exceeds ambient (roughly), like in exhalation, it opens and allows air to escape until the pressure on the inside of the reg equalizes with ambient and the ambient water pressure pushes the exhaust valve shut.

Now, consider the regulator case in a position where the pressure on the diaphragm is greater than on the exhaust valve, because the exhaust valve is shallower. Let's say for the sake of argument that in a certain position, the exhaust valve is 1" shallower. That means that the maximum pressure in the reg case will be 1" less than the ambient pressure on the center of the diaphragm where it contacts the lever. This means that if it takes less than 1" of pressure to push the lever and open the valve, it will open automatically in this position. Make sense? There is a friction (maybe surface tension?) factor in this, so it's not definite that the reg would open on it's own, but it's possible that it would not stop flowing once opened. That's why a G250 or 109 set very lightly can have flow problems in some positions. As awap described, usually it's a slight flow, more like the reg acts like it's on the verge of flowing. But, if you add the venturi effect of the reg in, you can get a pretty monster flow going, I've experienced it.

The D series have a coaxial diaphragm/exhaust valve so that there is never much difference in depth between the two. This makes them very stable breathers at extremely low cracking pressure in a variety of positions.