Scubapro naming convention?

[elmo]

As for the naming convention, when I ordered a pair of MK17s with G260s from my then-local dive shop the attendant couldn't understand my choice of second stage. Her assumption was that a larger number meant a better reg, and that the G260 must fit in the line up somewhere between R195 and R295, yet for similar money I could get the A700. Her comment was, "oh I wouldn't go any lower than an R395 myself for a doubles set". I smiled and let her place the order.

 

[BassO]

Hi guys, thanks a lot! I'd like to ask you so many other questions but we would go too much OT...

I will open another thread in th next days, except if @BassO want to continue here

I'm just going with the flow on this one

 

[Angelo Farina]

I am with @halocline. Simplicity always wins.
I am still using my MK5+109s (modified to BA, of course).
I also own a MK10+156, I understand that it is slightly better, but the difference is really irrelevant for my usage.
I suppose that for tech divers a further step above could be a MK10+G250V.
Everything beyond that is a step back, for me, as they become unnecessarily more complex, and loosing the SPEC environmental protection...

 

[axxel57]

Well, I contributed very marginally to the development of the 109.
In spring 1978 I did carry my modified 109 to the SP factory in Casarza Ligure, showing them my modification.
I did cover the metal disc embedded in the center of the diaphragm with a thin layer of low friction plastic, reducing the friction of the contact between the stainless steel lever and the metal disk.
The technicians appreciated the mod, in fact the following year the new diaphragm was released with a low friction plastic disk instead of the metal one.
I was not paid for this (I was 17), but I received a gift pack containing some SP items: a torch, an SOS decompressimeter (bend-o-matic), two repair kits for my two regs (including the new diaphragms), a gym suit, two T-shirts and a woolen cap.

Seems in the US they had to wait a couple of years longer than in Europe for the new diaphragm.......

 

[Angelo Farina]

Seems in the US they had to wait a couple of years longer than in Europe for the new diaphragm.......

For better documenting what happened....
Here is the original diaphragm, in black rubber and with SS metal disc, which was equipping my earliest 109:

Here the second version, in light blue silicon rubber, with the metal disc.
I covered it which a thin layer of low-friction plastic (my one was not Delrin, as later used by SP, but some sort of PVC), using super-glue for making it to adhere to the stainless still. It is still strongly glued on to it, 40 years later, and having been used for a while diving, as demonstrated by the signs left by the lever...

Here the version in two parts (black silicon rubber plus Delrin disc) described in the document posted by @axxel57. Note that the Delrin ring is missing, as it was broken:

And finally the latest incarnation, as used in the latest SP regs, where the plastic disc is moulded together with the crystal-silicon diaphragm:

 

[rsingler]

Simplicity always wins.
I am still using my MK5+109s (modified to BA, of course)

I'm sorry, Angelo. I can't let this one go.
You just disproved your own statement with your parenthetical addition. There's nothing more fault tolerant than a downstream second stage. It doesn't fail shut. If your first stage has a high IP failure, your second is still breathable. Yet, you chose complexity for the improved performance of the BA.
The same is true in choosing an Atomic or SR-2 second (floating orifice), or a Sherwood first (weird force transmitter and two part piston): some factor that improves performance in special conditions may well be worth the complexity.

I will concede that simple designs are more tolerant of poor maintenence, which is all too common amongst our peers. But unless there is a flaw which increases risk (usually not discovered until after a mishap, like Aqualung's ACD shutter valve), I'll take design sophistication with its attendant complexity every time. Even if I need more frequent preventive maintenance.

 

[Boston Breakwater]

Be careful they can be very addictive.

View attachment 617091

Hello. And oh soooo beautiful.
Cheers.

 

[jakehbk]

I've had a brand new Sherwood 9000 1st stage have it's seat collapse into the piston and seen an SR1 seat break apart before it's service interval. Not saying it doesn't happen on other brands, but those two experiences made me a little leery of the newer Sherwood regs

 

[rsingler]

I've had a brand new Sherwood 9000 1st stage have it's seat collapse into the piston and seen an SR1 seat break apart before it's service interval. Not saying it doesn't happen on other brands, but those two experiences made me a little leery of the newer Sherwood regs

Can't argue with that. There's a reason Scubapro and Atomic rule the roost. And Scubapro done good with their latest Mk19/D420! Now if only Atomic would take their superb engineering and design a dry-sealed piston, even the LDS techs would be happy.

 

[BoltSnap]

Sherwood may have had great ideas and dreams of ideal first stages but execution always sucked. SP and Atomic rule indeed.