June 24, 2012 Joe Katona 1

Y-axis modification for Hi Torque Mini Mill

June 24, 2012 Joe Katona 2

Y-axis modification for Mini MillFor our mini-mill build, the y-axis travel is limited by 2 factors:1. The Z-axis down stop interferes with the y travel when the stop is in the down position on the Z-

column.2. WATCH OUT!!—when the Z-axis stop is out of the way, or removed, the “Y” travel toward the column

will go far enough to let the ball nut lose its ball bearings.

3. This modification prevents the ball nut issue, allows you to remove the Z-axis down stop (it just gets in the way for CNC anyway), and gets you another 0.75” of Y-axis travel!!

Before After

Disable all of these switches except the Estop

switch

You will add 0.75 inches of Y-axis travel—and the ball

nut will not lose its bearings.

Z-axis downstop limits Y-axis travel

June 24, 2012 Joe Katona 3

Y axis modification for Mini MillThere are 2 component modifications and 1 build modification involved :

Component Modifications:1. The Y Table clearance slot needs to be widened approx .22”2. The Ball nut retainer (the aluminum part that the ball nut screws into) needs to be notched .22” x 1”

deep

Build Modification:

1. The ball nut needs to be screwed into the opposite side of the ball nut retainer

June 24, 2012 Joe Katona 4

Y axis modification for Mini MillThere are 2 component modifications and 1 build modification involved :

Component Modifications:1. The Y Table clearance slot needs to be widened approx .22

This is the stepper motor end of the

Y-axis table

.22” Machined

from this slot

June 24, 2012 Joe Katona 5

Y axis modification for Mini MillThere are 2 component modifications and 1 build modification involved :

Component Modifications:2. The Ball nut retainer (the aluminum part that the ball nut screws into) needs to

be notched .22” x 1” deep

Mill notch .22 x 1” in ball nut retainer

June 24, 2012 Joe Katona 6

Y axis modification for Mini MillThere are 2 component modifications and 1 build modification involved :

Build Modification:

1. The ball nut needs to be screwed into the opposite side of the ball nut retainer

Ball nut is mounted on

opposite side of retainer

Notch faces opposite direction

from ball nut

June 24, 2012 Joe Katona 7

Y axis modification for Mini MillThere are 2 component modifications and 1 build modification involved :

Build Modification:

1. The ball nut needs to be screwed into the opposite side of the ball nut retainer

This shows the ball nut at full stop

in Y- direction

Notice the effect of the notch that has been milled into the ball nut retainer. The set screw that holds this piece has enough length to do its work.

June 24, 2012 Joe Katona 8

Conclusion:

I know this modification will not be for everyone, but the additional .75” of travel, not to mention the elimination of the possibility of the ball nut bearings falling out, makes it worth the time (took me about 1 hour).

Y- travel increases by 0.75” to 5.65”