Flat Stock Calibration
Secure the stock between two rotary axis by using the ER32 collets or rotary vices.
Make sure that both rotary axis dove tail clamps are secured to the backside of the dove tail bed.
- Home Z over the middle of the part
- Swap over to a extruder tool and jog down until the nozzle is right over the stock
- Jog to the edges of the stock in the y direction and use the M208 command to set the y limits.
- Jog the toolhead over in the -X direction until the motor is about to hit the rotary axis, this is the new x min limit, record. Repeat this for the X positive direction
- Use the M208 command to set the new x limits (i.e. M208 X35:130)
- Jog the z axis up and switch back to the probe
- Jog the x over to the x min and touch off the probe from the stock and record the z value, repeat for the x max.
- Use the silver thumb screws on the rotary vice to adjust the part in the z direction, repeat step 6 until the Z value is within ±0.05 mm (i.e. the example stock needs to be raised by loosing the top thumbscrew a bit and tightening the bottom thumbscrew) (Pitch of the thumb screws is 0.7 mm one full rotation is move the stock 0.7mm)
- Probe the top surface of the stock on both sides of the y axis and record the z values. Adjust A by ±0.01 until both sides are equal.
- Save the A axis position in a WCS (i.e. G56), this is the A offset, and change into it.
- Jog the tool head up so that it is clear of the part and rotate the A axis to 90
- Now probe the front and back sides of the stock. Find the position of the (green) center line by ind the position of the 2 sides and dividing by 2. This is the y offset for the WCS.
Round Stock Calibration
If you have round stock, the above method will not work. (Or if you are confident that your part will be contained within the volume of your stock, and you give yourself plenty of feed high out of CAM.) There is a simpler method of finding the centerline of the A axis.
The rotary housing, an accurately-millied aluminum part, fully defines the center of A-axis rotation. By locating the edges of the housing, you can determine the center of the axis.
First, probe the top of the housing. This position should correspond to Z=41mm. (So do NOT use the "Set to current" button in the WCS table. You will need to manually type in the WCS Z position so that the current position, when that WCS is active, is 41mm.)\
Next, probe the front edge of the top section of the housing (see image below). This edge is at Y=-25mm. NOTE: consider the radius of the probe (1mm). If you are unsure of the direction, jog the probe UP and in +Y by 1mm, then set the WCS position there.