RE: [CAD_CAM_EDM_DRO] Bridgeport SeriesII air assisted knee

Sean,

Welcome to the Series II self help group here on CAD_CAM. There are a few of
us so you are not alone. I have one on my side of the 2 car garage. Her name
is Bridgett.

We discussed the air assist system a while back and the conclusion I reached
of how it works is as follows


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OK, so it is turned sideways and you get my crappy ASCII art. The base is to
the left. The screw shaft has a piston on the bottom of it and it acts like
the shaft in an air or hydraulic cylinder. The ball nut is actually in the
position at the top of the cylinder where the seals would be on a normal
air/hydraulic cylinder.

I have no actual verification that it is constructed this way, but looking
mine over I can't come up with any other way that would work with what I
see.

Bridgett's leaked pretty bad at first, but after I ran the table up and down
the full travel a few times the leaks pretty much went away and I don't hear
much air at all coming out any more. Just in case you are interested I run
about 60 psi on the knee with the normal hobby sized items on the table.

Tim
[Denver, CO]

> -----Original Message-----
>
>
> I have a Bridgeport Series II milling machine with an air assisted knee.
> When air pressure is applied to the base of the knee it leaks very
> rapidly. My question is what is in the base casting and how does the air
> assist system work? I am currently using the mill without it as it hasn't
> worked since I purchased it. Will feed rates be higher with the air?
> Thanks
> Sean