Thicknessing blanks

Can anyone help on this subject. I have some cast acrylic pen blanks that I want to alternate and stick back together. I have cut the blanks into as close as I can get to on the band saw and using a disc sander smoothed the banks. What I am trying to do is thickness the blanks down to the same size and machine an almost perfect hole in them. My problem is that the blanks are not an accurate thickness being done by hand. How can I machine them down to a good thickness if the original blanks are not all of the same thickness to start. As far as I can see Easel will allow you to machine from the top down. Is it possible to take the ‘Z’ axis zero from the base and then move it up and machine down from there? Sorry if this sounds a little confusing but I’m fairly new to this. Thanks in advance for your guidance
Allan (UK)

Yup :slight_smile:

Say your blanks have a thickness of 6-8,5mm.
Zero the bit off the waste board (Z zero) then jog up 9mm
Move bit to center of your design (hole) without moving Z, only X & Y
Use this as Easel Home Position (Work zero)

Define the hole to be CNC’d 9mm deep.
Then carve, some may be a little “air work” before actual carving will happen but all will be made to full depth.

Here are a couple more alternatives to think about. I like to generate alternatives and choose the best one.

This pen blank thicknessing process may be done on a drill press. If you have a drill press, you could attach a drum sander to it and clamp down a fence to sand the acrylic to size too.

A router sled with a straight bit would make fast removal to a piece of acrylic held in place below it.

Here is an alternative to do it without using Easel.

The Universal Gcode sender is a way to run your x carve without Easel.

You could create the gcode in easel, save it to a file, and then just zero your bit to the thinnest piece of acrylic and machine them by jogging or creating a program to move back and forth over them.

For hole drilling, I’d create a drill press fixture to hold the part vertically and drill down with a twist drill.

This is what I thought. The hole is not a problem because that can always done on a secondary program. It was just getting the blanks a fairly accurate 10mm thick. The actual blank size is only 20mm square so it would not take long to machine them to the correct thickness.
Thanks for your prompt reply

Hi Marty
Thanks for your response. The blanks are only 20mm square (jig made to machine them) so trying to use a sanding drum or router would not be feasible. I think I will go with zeroing off the base and jogging up a set thickness and then getting it to machine to the required depth. The hole drilling again will be done on the mill as it needs to be very very accurate in diameter. Thanks for your reply