O-Ring Design

[rossrov]

O-rings get a fair bit of mention on the forum, so I'm posting some links to explain how they work, and what dimensions and shape to machine the groove for a given O-ring cross-section diameter.

For the vast majority of hobby ROV work, we are concerned with Static Face Seals

http://www.usseal.com/orings/oring_function_2.html

http://www.usseal.com/orings/Glanddimen ... ing_6.html

Getting the two ends of a cylinder grooved is not much work for a general machine shop to do on a manual (non CNC) lathe. They may have to grind a cutting tool to the shape of the groove, but that should only take a couple of minutes.

Some things that will help them, and help you get the job done as cheap as possible are:
You choose the O-ring and figure out the groove dimensions
Supply the machinist with a decent sketch, dimensioned clearly
Keep the cylinder length as short as possible, so the machinist doesn't have to mess about with setting up steadies and other things on the lathe
Stick to round shapes and grooves. Rectangular items and odd-shaped grooves are more time consuming to set up and may involve the use of a mill, which is more expensive

The end caps or viewports you can do yourself without a lathe

[Bubbles]

This is the oring calculator I am using and it is really helpful.
http://oringcalculator.eriksgroup.com