Mk19EVO/MK17/Mk11 Balance Chamber O-ring

[rsingler]

As discussed previously here
Scubapro O-ring Sizes
my custom order of EPDM Duro 90 orings that  might match the 01.050.317 in the new Mk19EVO has just arrived from Precision Associates Inc.
They are sized at 1.905mm C/S x 2.591mm ID.

Hooray!

The Min Order Quantity plus the custom run for an o-ring not in stock anywhere that I could find in the US set me back a couple hundred dollars.

They're available for anyone trying to create homemade Mk11/Mk17/Mk19EVO service kits using
Scubagaskets diaphragms
(SG10.117.107 205) or
(SG10.705.119 375)
and HP seats
(SG10117209 8500)
and o-rings from wherever you source your orings. This balance chamber o-ring was the one I couldn't find anywhere.

In the thread above, I had provisional orders from
@abeck70
@L13

These o-rings are available for anyone interested at $7 for 10 o-rings if you are in First Class Mail territory, or US$6.40 plus postage anywhere else. With a little luck, I'll recoup a bit of the cost of this experiment, lol!

DIY Forever!!

 

[runsongas]

shouldn't these be thin enough you could just tape them into an envelope with a first class letter stamp rather than as a parcel? you lose the tracking, but for something this small and cheap, its a big difference in shipping

 

[rsingler]

Exactly. 60 cents shipping taped in an envelope, and 60 cents per oring. A custom run of these puppies was expensive!
My profit = 40 cents per person minus gas to the post office maybe minus whatever PayPal fee exists for $7. NapaScuba doesn't get Friends and Family free transactions.

It's the DIY satisfaction that I like. It ain't for money.

Of course, now that they've made the custom molding run, they likely have also added thousands in stock at PAI.
The standing MOQ is $60 for orings at that company, and these're probably 18 cents apiece now that they're in stock. Somebody had to go first...

For future reference:
Precision Associates, Inc
precisionassociates.com
Item: 75-102 23911

 

[runsongas]

i'm surprised you had to resort to a custom run, would have figured someone would have had something suitable between oringstore, marco rubber, sterling seal, etc.

 

[rsingler]

Tell us if you find it!
Who wants to pay 60 cents apiece?

Unfortunately, ~1.9mm C/S is only found with the near-extict Parker 5-series (1.88mm) and the JIS B2401 series.
Unfortunately, JIS B2401 doesn't include 2.59mm ID. The closest, a P3, is 2.8mm ID, and is too loose on the shaft of the poppet.

I really tried, but am happy if you find one!
As with not a few Scubapro oring sizes, it's...WTH?

 

[Johnoly]

Tell us if you find it!

I rep a custom injection molding company overseas (not orings). We do some very small runs of 25-100pcs of small parts in 1 cavity molds. Although it all depends on final tolerances (.001 is a huge difference from .0001) just the mold cost can be $5k up to $30K before you even hold one acceptable part in your palm. When doing the machine run setup, we typically throw awary 40-50% of material as we calibrate the mold temperatures, humidity, moisture, air temp, cycle times, release compounds and so many more variables. So many people look the final small product in the palm of your hand and say 'This costs HOW MUCH!!”. Especially with soft flexible items, not much can be 3D printed and yet still meet the above tolerances to work correctly.


@rsingler - I feel your pain and just wanted to explain to other readers WHY it costs so much for custom small runs. And that's just if you can find a molder to accept your custom work order cause it's a PITA!.

 

[BoltSnap]

Why go through this trouble and not buy original parts from original vendor SP?

 

[grantctobin]

Why go through this trouble and not buy original parts from original vendor SP?

Combing through a recent dealer price list probably answers that.

 

[-JD-]

Why go through this trouble and not buy original parts from original vendor SP?

Because here in the USA, SP says:
"No parts for you!, unless you are an authorized dealer "
"And dealers ... 'No Parts for Them' if you want to remain a dealer"

Basically, unless you have a good friend who is an authorized dealer and is willing to quietly uninventory some pieces or buy on the import market you are SOL if you DIY.

And yes, then there is the significant cost difference compared to equivalent aftermarket parts, when available.

 

[James79]

Why go through this trouble and not buy original parts from original vendor SP?

Sourcing consumable parts from other sources also increases the odds of a given reg being maintainable even after the OEM quits supporting them.