Scubapro 109 Poppet

[redacted]

Before you start to modify your poppet you should try and get a precise measurement of the overall length so that you can replicate it. I have found in my poppet experiments with the BA poppet that a few thousandths of an inch make a huge difference in lever height and adjustment range. You may need to fabricate an entirely new head for the poppet if removing material to get the proper length results in the head coming off as in couv's experience.

I would think that there is some room for adjustment between LP seat thickness and orifice position without disturbing the critical lever height. But if the position of the poppet feet that engage the lever starts changing, then it will not take much to cause problems.

 

[halocline]

I'll probably get strung up for saying this but I'm starting to realize "One-O-Nine means Nickel-and-Dime". Many of the ones I have purchased used needed a significant expenditure on parts to be brought back to tip top shape.

I've never spent as much as $100 on one between buying all the parts and the reg itself; usually about half that. Consider the cost of the new A700 (maybe $350?) and it starts to make sense.

For whatever reason, I have found in my limited searching that old conshelfs seem to be more expensive on ebay than the 109s...go figure. I wanted to get a metal conshelf 2nd to use as an octo for my PRAM, but I've never been able to find one at a low price. I guess the last thing I need is another regulator, anyways.

 

[NotSure]

I made a quick belt sander cross section of a BA poppet so I could see exactly what we are dealing with and it looks like any modification will be a real challenge. The head of the poppet popped off even before I was half way through. It appears that the brass head just snaps on the plastic body with a compression fit of some kind. The seat itself is very thin so even if you just tried to glue a new seat on the end you would probably have to remove more material then I would be comfortable with given the compression fit. If you do try to solder on the brass head you should definitely remove it from the poppet first and epoxy it back on when you are done. I think someone with a metal lathe and brass round stock could easily make replacement heads for these poppets that would fit standard seats, but with access to a machine shop what couldn't you do.

 

[NotSure]

I tried to make a rough prototype of a new 109 poppet head in my garage with some old aluminum round stock I have and got mixed results. I think I successfully showed that it can be done, but at the same time proved to myself that I don't have the tools or level of precision necessary to make a functional replacement poppet head. The plastic end of the poppet is shaped such that a pressed fit is easily achievable and a small groove machined inside the metal head to capture glue would assure that the new head would never come off. I also think it would be a good idea in addition to a pressed fit on the seat side to cut a dovetail grove around the base of the seat hole to allow the seat to expand once pressed in allowing a lock fit. If anyone with a machine shop would like to make a few of these and sell them on Ebay as the Kevorkian poppet head I will take two.


Seat Side


poppet side


poppet head


Kevorkian Poppet

 

[Couv]

Herman is probably the man to contact. He likes projects like this.

 

[NotSure]

Herman is probably the man to contact. He likes projects like this.

I'm not sure if making new poppet heads is even a good idea. The main problem I see is that many would not have the patience/skill needed to remove the old head without damaging the poppet. Even gluing the new head on would require a level of skill and knowledge of adhesives. Even if you could make perfect poppet heads for $5, the risk for them getting into unskilled hands is just too great. If you have the skill to make them yourself then go for it, the rest of us should just pay $30 on Ebay.

 

[Couv]

..... If anyone with a machine shop would like to make a few of these and sell them on Ebay as the Kevorkian poppet head I will take two.....

I was responding to the above part of your post. Herman not only has the skill and tooling, but may have other ideas on how to approach the problem.