Scubapro 108HP

[Open Ocean Diver]

Only if seats were near identical.
But it's a really smart idea!

Do you mean in material or dimensions? The orifices are the same.

 

[rsingler]

Do you mean in material or dimensions? The orifices are the same.

Mostly Durometer. How deeply does the knife edge embed in the seat? That will affect the ease with which the poppet backs out enough to start flow. That tiny distance, as you know personally, is a huge difference in cracking effort.

 

[Open Ocean Diver]

My test rig… two magnehelic gauges, one on the mouthpiece side port, and one on the reg inlet-tube, vacuum pump on the mouthpiece inhalation port. When the valve opens the inlet port mag will rise and match the mouthpiece port mag. With this set up I was able to identify the G250V needed more effort to open the valve compared to the 108HP.

Both regulators have been stored with seat saver mechanisms.

 

[Open Ocean Diver]

After testing opening effort (spring compression ) at ambient and finding the balance 109 and unbalance 108 second stage regulators very similar… spring force + seat force without ip force.

I pulled out the kitchen scale… tested spring force and confirmed what I had learned from Robs seminar, spring force is close to half in the balanced verses unbalanced 108 with the same spring with both properly tuned.

However:
108 @ 132ip cracks .9, 110ip 1.2, 100ip 1.4, 75ip 1.5
109 @ 132ip cracks 1.0, 110ip 1.1, 100ip 1.2, 75ip 1.3

I thought the difference in cracking effort with low ip between the two would have been in the range of .7 with similar seat force, being both having the same seats material.

Understanding the lighter spring gives longer life to the soft-seat and spring… but the 108 has a single o-rings. I’m convincing myself simpler is better. Lol

Based on the above I’m thinking Scubapro 108HP is one of the greatest regulators ever built.

 

[rsingler]

Since you're one of the guys that can now flip a seat every 6-12 months and tune your toy nice and light, you're absolutely right!
Alas, the poor folks that need Atomic seat-saver orifices and 3-year service intervals to accomplish the same thing! And who do they bring their regs to for service? The guy who had a three-hour manufacturer's course but actually has to sell wetsuits for a living.
I ain't faulting dive shops. I'll take my local guys over Leisurepro any day of the week. But it's a tough business model.

 

[Open Ocean Diver]

Since you're one of the guys that can now flip a seat every 6-12 months and tune your toy nice and light, you're absolutely right!
Alas, the poor folks that need Atomic seat-saver orifices and 3-year service intervals to accomplish the same thing! And who do they bring their regs to for service? The guy who had a three-hour manufacturer's course but actually has to sell wetsuits for a living.
I ain't faulting dive shops. I'll take my local guys over Leisurepro any day of the week. But it's a tough business model.

Pretty much service at a dive shop is a loss-leader. Shops have no way of measuring how service attracts customers to buy new products. Big box stores if they can’t measure it then in the bean counters mind it’s not a profitable business . Techs either have to sell or be an instructor to really make a living like you say. Performance measurement for a technician is how many regulator sets they do per day.