[golash]

Hi
My Thompson bearings are running rough. I`d like to change them. Has anyone installed new bearing in
the aluminum housing. I am wondering how difficult the removable process will be. I will add blocking to the
gantry and brace from the floor to support the machine. There is a 1 foot section of the 1 1/4 support
shafting I can remove to remove the bearings from the machine. One thing I was hoping to remove the bearing
without removing its aluminum support block. Do you think this is possible. I see a dowel pin. This looks like
a problem.

[golash]

Hi all
I was never happy with the shake I got on the z axis. I spoke with a application engineer at thompson.
They mentioned that there were two types of bearing assemblies for the round shaft. One was made from
plastic and the other was all steel and non-aligning. After removing one assembly from the machine I was
certain the machine had the self-aligning versions. After the change to the new bearings the machine is
much tighter. If I remember correctly the self-aligning version has 5 degrees of adjustment. This causes
a looseness in the linear system. Which translates to a non rigid linear motion system and causes additional
machining marks in the work piece.
If I were making a new machine I would Not use a round linear motion system. I would buy the THK square
rail version.