1. Ensure that the sacrificial surface is adhered to the milling table
using double-sided tape (video). It may provide a better surface for
which to place the calibrate card. We recommend at least 4 flat
pieces of tape across the length of the sacrificial layer.
2. Position the calibrate card on the table top side up just as if you
were preparing to mill a copper-clad board. Center the card
between the two notches in the milling table. The number “1” on
the card should be towards the lower-left corner of the table.
3. Retract the spindle upwards along the Z axis by clicking the buttons in the “Move
Tool Z” section. Install a small diameter bit once you have enough room to do so. In
this case of calibrating (and this case only) you may find it helpful to not secure the
bit with the bit clamp. engaging/disengaging the motor will hold the bit in place. This
gives you the flexibility to disengage the motor and slide the bit down by hand to
touch the card and check that you’re exactly where you want to be. This will make
more sense in later steps. Not securing the bit with the bit clamp is only acceptable
because we aren’t actually turning the spindle on. Never attempt
milling/drilling/routing without the bit clamp and its bearing in place.
4. Click “Go To Point 1 Setpt” if it’s safe to do so. “Safe” means there’s nothing in the
way of the spindle or table because they are going to move to position the bit near
point 1 on the calibration card. The bit will move once you click “Go To Point 1
Setpt”, to the setpoint marked “1”. It will not position the bit exactly over #1’s
crosshairs, but it will save you time for the next step.
5. Use the “Move Tool X/Y” section of buttons to move the bit in X (left/right) and in Y
(away/towards you) directions. You must position the bit so it’s X/Y coordinates put
it directly above the crosshairs near point #1. It’ll be helpful to control the Z-axis as
well. Don’t go down too close using the Move Tool Z buttons because you don’t want
to accidentally crash the bit into the table and potentially break the bit. Instead, you
can disengage the motor and manually drop the bit during the last ⅛” or ¼”. You can
also manually turn the Z-axis lead screw. Look at the bit from the front and the sides
to ensure it’s centered above the crosshairs. Once it’s centered, click “Store current
location as Point 1”. This will save your measurement.
6. Make sure the bit is fully inserted again and the motor is engaged so it doesn’t fall
out. Make sure there is enough clearance between the bit and the table for the next
move, by using the Move Tool Z buttons or manually turning the Z-axis. Then click
“Go To Point 2 Setpt” to move to the approximate point 2 location of the calibrate
card. In this step you don’t need to center above the crosshairs for point 2. Instead,
simply move the tool left and right to get it directly above the line that connects
point 1 and point 2, going through both crosshairs. This is easier to do because you
only have to move along one axis. Once the bit is directly above the line, click “Store
current location as Point 2”. This will save your measurement.
7. Repeat the previous step for point 3. Again, don’t center over the crosshairs;
position over the line, with the bit near point 3 just like it was near point 2 before.
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