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Yep - It’s tiny - many push on the ADV for sealing that end. My point is that the restoration force in Mack truck springs cannot make corrugated metal seal - I think we align on that - so the in situ claim is lost on me …
Fram Endurance Flashlight Test in canister
- Thread starter Glenda W.
- Start date
I doubt they are "designed to leak". In the engineering world, there is a design with specs and drawings, and then there is manufacturing that is supposed to build to those specs and drawings. If the manufacturing engineers and workers can't build it right, it may not perform as designed. I've seen this many times ... the best design and drawings will result in a crap product if it can't be made to the engineering specs and drawings.
You completely didn’t read or forgot my previous posts
The test specs advertised maybe be with an early design and production, and as time goes on the manufacturing QA goes south. We have already seen examples where the leaf spring stamping quality is different on the same make/model as time went on. Just like forming louvers, on the same make/model, some are great and then others are messed up. Manufacturing QA can change for all kinds of reasons.
If the drawing doesn’t control that region then it’s not on manufacturing
My post was about this. My comment about the connection between the engineering design and the manufacturing QA is valid based on this.
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We can't see the engineering drawings, so nobody knows if the drawing shows or specs that a non-flat and ripply stamped leaf spring is "part of the design". I doubt it is, because we have seen differences in the leaf spring quality on the same make/model of filter.
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Yeah - this looks like a change made in a stamping machine and potentially the metal. Steel has gone up in the last couple years …
The rubber ADBV adds very little to the "spring" action in the system. Look how thin the ADBV is where it's actually compressed between the end cap and base plate.
Yes, it's been conclude long time ago that ripply non-flat metal-to-metal seals don't work well. Hence the root cause of this leak gap being discussed.
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The ADV is resilient - doubt it adds any recoil at all …
You might be surprised what sheet metal manufacturers allow for tight radia and spring back and ripples-so unless it’s specifically controlled the only control might be default dimensional control on the feature.
Could be +/- 0.020 or 0.030” good lord hope not 0.050”
I’d imagine it’s a manufacturing defect. It’s only seen on the champ lab made filters. The fram made ultra/titanium leaf springs are smooth and seal with no gaps even with the end cap seal deletion.
If the filter engineer isn't caring about the leaf spring seal, then who knows what was speced. And if the design engineer did spec some requirements for the leaf spring stamping, but the manufacturing engineer fell on his face to produce the speced leaf spring, then there's a disconnect between engineering and manufacturing. It happens all the time throughout industry, I've seen it many times in my job. Obviously, when Fram designed the OG Ultra they were very focused on the leaf spring sealing design.
What are the chances that the drawing says it should be warped and rippled, and then manufacturing makes it flat and smooth.
There has to be a spec and drawing for the leaf spring in order of it to be manufactured.
Here’s a new style Fram ultra leaf spring from another members c&p. There’s got to be a spec to manufacture. But yes we don’t know what the drawing shows.
That’s a whole different shape - right? I agree I bet the feature is controlled in that one- and the tool surface in the die when forming in the punch press holds it flat right there
Appears to be the same sheet metal but much better forming.
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