Needed a pony reg, was this a good purchase? (older MR12 off ebay)

[LeadTurn_SD]

OK, so what I gather is the Mares directions and most of the special tools were designed to walk idiots through the process and leave the reg safe to use.

I played around with the Abyss a bit just to get a feel for the adjustments while the old parts are still in it. I was adjusting the nylock with a pair of pliers as my oddball 5.5mm nut driver hasn't arrived yet. When it shows up I will have to go through the process correctly and see how it goes.

It sounds like your directions are pretty universal for the Mares 2nd stages actually. I've got the hang of the MR22 and probably the MR12 1st's, once I have the 2nd's down I think I can fix most Mares regs with minimal if any instructions...

Having the nut driver should make a world of difference. You need to be able to turn the nylock nut in very tiny increments.

Regarding the Mares manual, I think you are correct. I believe it was written for the "lowest common denominator" shop monkey who might potentially take cold hard steel to soft marine brass. It will get you in the "ballpark" and produce a "safe" result, but sadly will often produce a mediocre result as well... these 2nds will breath like a dream if tuned properly; like a dog if they are not.

The basic tuning procedure works for all two adjustment 2nds. The goal is always to end up with the lowest cracking effort, longest lever travel, and lowest pre-load on the spring that is stable. The same applies to balanced barrel poppet 2nd's as well, but you often just have orifice depth to work with.

Good luck with those regs. They should work well once you get them tuned.

Best wishes.

 

[Fishpie]

I believe the removable orifice came in with the 2 HP port model.

 

[84CJ7]

Cool, thanks guys. The MR12 has arrive and is in pretty good shape but I saw for whatever odd reason another seller on ebay had just the stripped body for an MR12 with the DFC port (not removable seat though) for $14 shipped so I snagged that too just for the hell of it. I will need to tear this thing apart since the HP seat is obviously in questionable condition judging by the IP behavior (IP creeps down a bit as it locks up among other things), so I can just build it off the DFC body. Might put a older 200 bar din connector on it at the same time and shrink this thing down a bit more even.

Concerning my IP gauge I question that it might be reading a bit high (its new) so I may bring it to a shop and see if they are willing to compare it to one of theirs.
I may also just buy that inline tool before I go nuts fiddling about with these things.

Something in your tuning instructions confused me, you said to set the orifice where it should be, and then about step 7 you make it sound like I should adjust the orifice to make up for the lever being too high when I put the diaphragm on, doesn't that mess up the work previously done? I would think I would want to set the lever height if the orifice is already set but the lever is making it hiss when i put the diaphragm on.

 

[Fishpie]

.....your new dfc body with the removable seat may well come that way, with the seat removed.

The inline tool will only help with 2nd stages that have an adjustable orifice which your IV does not have.

 

[LeadTurn_SD]

.... Something in your tuning instructions confused me, you said to set the orifice where it should be, and then about step 7 you make it sound like I should adjust the orifice to make up for the lever being too high when I put the diaphragm on, doesn't that mess up the work previously done? I would think I would want to set the lever height if the orifice is already set but the lever is making it hiss when i put the diaphragm on.

Sorry, I think my poor wording is making it way more difficult than it really is. And this is for your Abyss, not your IV... it applies to 2nd's with adjustable orifices. And your Proton 2nd has a removable plug opposite the demand lever that allows adjusting the lever height with the front cover/diaphragm in place... the Abyss (at least the older ones??) need to have the front cover / diaphragm removed to adjust the lever height...

Anyway, back the the Abyss: The Mares manual instructs you to set the lever to a specified height based on the model of the 2nd stage, using a special gauge.

I don't do that.

I want the lever as high as possible, just short of "fouling" the diaphragm, and the orifice turned in just deep enough to stop the leak... with the understanding I am then going to need to tune the reg from this "starting point".

My starting point is different that what Mares suggests. I am starting from an unstable, "too hot" tuning point, and gradually increasing the cracking effort (and adjusting lever height as I do this) until the reg is "stable", but still breathes well.

At this initial setting I am suggesting, the reg will hiss again when you put the diaphragm on. The cracking effort is usually too light for the reg to be stable, and the lever is several mm too high (which is why it leaks when you put the diaphragm on)... turning the orifice clockwise simultaneously increases the cracking effort and lowers the lever.

You will usually need to adjust the lever height again (several times, probably, as you tune the reg)...

You do need to go back and forth with the orifice depth and lever height until you find the "sweet spot", but the adjustments should be fairly small.

It is much easier with an inline tool, but the first several years I was tuning my regs I did not have one, and it was fine (just more tedious).

Sorry, I hope I'm not confusing you even more. It really is not hard, I think the way I'm describing the process is what is making it seem difficult.

Best wishes.

 

[84CJ7]

Fishpie the spare body is one of the intermediate models with the DFC port but still having a fixed orifice. I wouldn't mind if it was removable and had come without it though as they are only $11 for the new type orifice that you are supposed to use with the new HP seat:
http://www.subzero.cat/biblioteca/i...HP_Poppet_Seat_-__46186216_-_Update_Jan30.pdf
I am assuming from the reports of others that the new tri material seat will seal fine to the old shape hard seat as well, though obviously it was updated for a reason. I would assume that the non removable seats are the same shape as the older style removable seat.
In hindsight I probably should have just bought a newer one to start with instead, but this will all work out it looks like and I won't be too far in the mud by the time its all together and working.

On the topic of the MR12 IV 2nd and parts, after taking it apart it shares WAY more parts with the abyss than I was expecting. The O rings are mostly wrong because of the plastic body and seat, but the rubber seat, the main diaphragm and I think the exhaust diaphragm and from the looks of it all the internal metal parts are identical to the Abyss 2nd. The exhaust tee started to rip in half when I went to take it off, so I am just going to leave it alone and I think I will flip the rubber seat, clean things up and throw it all back together as everything seems to work well diaphragm wise. It only has one O ring in the whole 2nd and that was a static one in between the poppet and metal hose attaching part and I don't have another that size so I will just reuse it. I have hose O-rings so that means zero parts are needed to put the 2nd in service with the seat flip.
I will still need to order an MR12 rebuild kit and tri material hp seat, I have a spare new 1st stage diaphragm already.

On the topic of abyss reg adjustment I think I get what you are saying. I was forgetting how tangled up the lever height adjustment and spring preload are in that design so I was assuming that lever height would be adjusted to suit after the adjustable orifice was set.

---------- Post added June 30th, 2014 at 03:21 PM ----------

Played with tuning the Abyss again. MR22 1st IP stable at 145.
I ended up with about 7/8" inches of cracking depth (just washes over back of main body) or 2mm of travel on the purge button before it starts to even faintly hiss. Does the depth in the water above diaphragm on that test equate directly to inches of cracking pressure?
I don't really trust the shake the regulator and listen for a click test anymore because it would randomly not click at all no matter what I did, and then suddenly start clicking clearly without changing anything so I went round and round at one point and couldn't figure out why it was sometimes super loud and other times nonexistent despite adjustments that would do the opposite. Now with it pressurized I sometimes hear the faintest of taps (not consistently) when I shake the crap out of it with the purge button held still but not pressed. Its definitely on the tight side for lever height I think though with the purge button working at 2mm I think its probably good enough.

I will definitely be getting the inline tool for next time (might actually get it and redo this anyways). The newest abyss model has an adjustment port on it like the proton does from the pictures I have seen, that would have made things a whole hell of a lot easier as well though its easier for tiny lever height tweaks to do it from the orifice end actually since it moves the lever a lot without being enough of an adjustment to throw anything else way off from what I was seeing.
My first go round I had everything set perfect with 4 1/2 turns out but it gave me 1/2" of cracking depth which I thought a bit more hot than I felt safe with, though it breathed quite wonderfully. The Mares diagram for setting it in water without a gauge shows it just under the mouthpiece opening which is like 2 1/4" which would work absolutely like crap. I have no idea why even conservatively they print it like that.

 

[84CJ7]

So as an update I have worked through the MR22/Abyss/Proton without issue.

I also did a simple seat flip on the plastic "IV" second stage of that MR12 and everything else was reusable though I changed the hose O rings. After comparing parts it is a plastic abyss in every way except the non adjustable plastic orifice, everything else is identical in size and shape and hardware. Someone at a shop told me that would possibly make it a Navy. I have no idea and its not really critical so long as an abyss kit and an odd fat O-ring for the orifice will service it.

Down to the MR12 and I ran into an oddity that has me confused. I got a newer "DFC" mr12 body because the original 1st stage body isn't labeled DFC anywhere, and I was under the impression that it was a pre DFC design, but now that its all apart there is clearly a second hole from the diaphragm chamber to one of the LP ports. Also when I look into various LP ports two of them of them have a smaller opening inside (unrelated to DFC, new body has them too). I also notice that the DFC hole under the diaphragm is slightly smaller than the main hole in the center wheras both are the same size on the newer body. It appears to be chromed inside so I don't think it was user drilled later. The newer body also has the center hole stepped down to not much larger diameter than that tiny pin that runs through the center of the regulator wheras the older body has a straight large bore hole all the way through, dunno if that was part of the DFC change but as the hole is mostly plugged with a metal plunger it shouldn't matter.

Going left the ports are blank spot, LP larger hole, HP, LP smaller hole (across from blank), LP larger hole unlabeled DFC, LP smaller hole (across from HP port).

The new body has one extra LP port which I don't need, and has the labeled DFC port across from the HP port so I would have hoses going in opposite directions (using regular pressure gauge) which would be inconvenient for a pony setup.

The old body has the "DFC" port placed so it only has one port between them which would be a better angle. I had bought that other MR12 body with the labeled DFC port thinking it would be a nice cheap upgrade, and now I wonder whether or not I need it.

Both of these lack the venturi tube the MR22 has inside the DFC port, maybe those were never used on the 12. It actually looks like any non DFC MR12 could be made into a DFC on any port simply by tossing it in a drill press and putting a hole in it. Obviously one of the large bore LP ports would be preferred.

Perhaps those more familiar with the 12 could chime in, is this actually an unlabeled DFC port on the older body?

EDIT: Put the MR12 back together with its original body for the better hose routing using the DFC like port for the 2nd stage. I set it to 10 bar and adjusted the lever as low as I could get it though it still doesn't have a click when shaken and its so far out I'm not sure the nylon on the nylock is even fully engaging.
It breathes amazingly well and I cranked the IP up to 15 bar and it never free flowed. This is almost irritating as the more expensive stuff I have doesn't even work this well. Didn't bother to check the cracking height in water as there is no adjustment so it is what it is.