Thanks everyone!
@Kerrin: What is a CofC drawing? Probably a section view? In the post where the picture with the non return valves are, you can see three of the steps of machining those plungers.
The machining sequence:
1. Machine the diameter on both sides
2. machine the O-ring groove, depth is in about 0.8 times the O-Ring string diameter, width is around 1 to 1.2 times. It is important that the inner diameter of the o-ring is smaller than the guiding pin. That way, the o-ring is slightly pre-loaded and does not want to get out. If you use an o-ring which has a bigger inner diameter, it will want to fold at one point (due it's under pressure) and that would avoid the valve from closing tight. (I used O-rings with 4mm inner diameter for the guiding pin which has 4.8mm.)
3. machine one or two slots on the top side to let the water flow through the outlet channel (to prevent the valve blocking the bore when lifted)
4. plunge-mill the water grooves on the valve guiding extension.
In the attachments you can see a setion view of the clack valve.
The lift of the valve is limited to 1mm. The guiding pin has in about 0.1 to 0.2 mm less diameter than the guiding bore so it does not get stuck. The lenght of the guiding pin is in about like its diameter.
The outer diameter of the plunger is 7.5mm and the big bore of the valve cavity is 8mm in diameter (machined with an endmill)
@Shopshoe: No worries there about work - its fun for me and therefore I am enjoying to make another movie
Cheers Florian
