I'm restoring an SA-250 found in a garage sale. I replace the old axe by the msk-250.
The original new composite bushings had about 0.25 mm radial play, even when new, which caused vibration.
I replaced the original composite bushings on my Tormek with 16×22×16 bronze bushings (3 mm flange).
The bronze bushings eliminate radial play, but I still have about 1 mm axial play.(new hole 4mm from shouder drilled).
Geometry of the shaft:
Wheel bore: 12 mm
Shaft: 12 mm → 16 mm shoulder
Wheel is fully clamped against the 12→16 mm shoulder
The 16 mm part of the shaft passes through the bronze bushing
Between the shaft shoulder and the bushing flange, there is a 1 mm gap
This gap allows the shaft to move axially until the shoulder touches the flange.
On the original composite bushings, the 12 mm washers rubbed slightly against the composite flange, so the flange acted as a thrust surface.
With bronze bushings, the flange is harder and not designed for axial thrust, so I cannot use it as a thrust face.
Has anyone addressed this axial play when upgrading from composite to bronze bushings?
What can be considered as normal play, axially and lateraly ?
As read in the Tormek manual the original composite bushings allow about 0.1–0.2 mm radial play and around 1 mm axial play.
Is it normal that brand new msk-250 kit shows higher value (0.25) ?