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******* YELLOW STICKY ET 2 THREAD - FACTORY SETTING OF PSI - REGULAR AND HIGH PRESSURE MANIFOLDS ************
I reached out to Bruce to help shed more light on how our manifolds work - both regular and high pressure HPM models. He responded and I believe answers the questions for our thread. Comments welcome.
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Hi Bruce
Was hoping to shed some light for ET2 owners on our thread regarding how the setting of PSI on our manifolds was done.
A couple of questions.
1) Are the set screws in the manifolds set up differently for different PSI's ?
2) Does setting a higher minimum PSI manifold (i.e. 19 PSI minimum), mean the spindle/manifold (gap) is smaller, tighter. How I came to ask this.
My ET 2.5 which you set up for highest possible psi 19. It continues to dominate over my digital. I also own an older ET2 High Pressure Manifold. I have noticed without air applied, that pushing my spindle through the manifold on the ET 2.5 is tighter, than the spindle going through the older ET2 manifold. The older ET2 HPM will also work with a lower psi, example 7 psi.
Appreciate any information you can provide.
*********************************************************
Chris,
The pressure drop across the set screws define the restoring force and part of the stiffness of the air bearing.
The tolerance between the Manifold Inner Diameter and the Spindle Outer Diameter determines the lifting pressure as a function of flow rate through the set screw. Without a restoring force or pressure drop across the set screw, the bearing will lock up, so you always need a higher air pressure in the manifold housing as compared to the pressure at the surface of the spindle.
The high pressure manifolds have a slightly tighter tolerance between the spindle and manifold, they also use a set screw with more plating to restrict the air flow around the threads to create the increased pressure drop (the difference between the pressure in the manifold housing and the pressure at the surface of the spindle).
It does not hurt to slide the spindle in the manifold bore without air, the resistance you feel may be the surface finish roughness on the hard coat anodizing as well as tolerance.
I hope this helps, thank you very much.
-brucet
*********************************************************
Happy Listening
******* YELLOW STICKY ET 2 THREAD - FACTORY SETTING OF PSI - REGULAR AND HIGH PRESSURE MANIFOLDS ************
I reached out to Bruce to help shed more light on how our manifolds work - both regular and high pressure HPM models. He responded and I believe answers the questions for our thread. Comments welcome.
--------------------------------------------------------
Hi Bruce
Was hoping to shed some light for ET2 owners on our thread regarding how the setting of PSI on our manifolds was done.
A couple of questions.
1) Are the set screws in the manifolds set up differently for different PSI's ?
2) Does setting a higher minimum PSI manifold (i.e. 19 PSI minimum), mean the spindle/manifold (gap) is smaller, tighter. How I came to ask this.
My ET 2.5 which you set up for highest possible psi 19. It continues to dominate over my digital. I also own an older ET2 High Pressure Manifold. I have noticed without air applied, that pushing my spindle through the manifold on the ET 2.5 is tighter, than the spindle going through the older ET2 manifold. The older ET2 HPM will also work with a lower psi, example 7 psi.
Appreciate any information you can provide.
*********************************************************
Chris,
The pressure drop across the set screws define the restoring force and part of the stiffness of the air bearing.
The tolerance between the Manifold Inner Diameter and the Spindle Outer Diameter determines the lifting pressure as a function of flow rate through the set screw. Without a restoring force or pressure drop across the set screw, the bearing will lock up, so you always need a higher air pressure in the manifold housing as compared to the pressure at the surface of the spindle.
The high pressure manifolds have a slightly tighter tolerance between the spindle and manifold, they also use a set screw with more plating to restrict the air flow around the threads to create the increased pressure drop (the difference between the pressure in the manifold housing and the pressure at the surface of the spindle).
It does not hurt to slide the spindle in the manifold bore without air, the resistance you feel may be the surface finish roughness on the hard coat anodizing as well as tolerance.
I hope this helps, thank you very much.
-brucet
*********************************************************
Happy Listening