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Recently I found myself needing a pushrod seal.
first, these things do not cost much at all, so
consider buying a ready made one.
But I was impatient, so I thought up a way to make one myself.
The idea is to squash an o-ring between two flat surfaces.
I used washers the same size as the o-ring.
One washer was glued against my endcap (because the
endcap itself had a rough surface and would not seal).
My endcaps are flat, by the way. This trick will not work on
Robbe endcaps.
Around this washer I drlled three holes, taking care not to
pierce the endcap.
In these holes I glued threaded rod (M3 size).
Now the o-ring can be put on the glued washer, and the
second washer on top of the o-ring. The stuff is held in place
by the rods.
Using three nuts, the upper washer is forced down.
This causes the o-ring to expand to the outside but also to
the inside, sealing off the pushrod. Be sure to sqeeze
evenly !
An alternative is to drill all the way thru the end cap
and install an o-ring at both sides.
Another possibility is to use bolts instead of threaded rod,
but I failed to tap a proper thread in one of the blind holes.
hence the glue...
Edited By raalst on 1142693137
first, these things do not cost much at all, so
consider buying a ready made one.
But I was impatient, so I thought up a way to make one myself.
The idea is to squash an o-ring between two flat surfaces.
I used washers the same size as the o-ring.
One washer was glued against my endcap (because the
endcap itself had a rough surface and would not seal).
My endcaps are flat, by the way. This trick will not work on
Robbe endcaps.
Around this washer I drlled three holes, taking care not to
pierce the endcap.
In these holes I glued threaded rod (M3 size).
Now the o-ring can be put on the glued washer, and the
second washer on top of the o-ring. The stuff is held in place
by the rods.
Using three nuts, the upper washer is forced down.
This causes the o-ring to expand to the outside but also to
the inside, sealing off the pushrod. Be sure to sqeeze
evenly !
An alternative is to drill all the way thru the end cap
and install an o-ring at both sides.
Another possibility is to use bolts instead of threaded rod,
but I failed to tap a proper thread in one of the blind holes.
hence the glue...
Edited By raalst on 1142693137
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