Mortice and Tenon on CNC3020 Engraver

I need to do a lot of mortice and tenon joints if I'm going to do the chair project, and they aren't fun and never look very good in pine, as it's difficult to work with. So can you do them on the CNC3020?

Well, after 3d printing a clamping plate that attaches to the 4th axis mounting bolts on the front of the 3020, it turns out you can do some very consistent nice looking tenons and matching mortices:

These are test pieces, but they are very consistent, totally interchangeable and look nice.  The clamping bracket lets me put tenons on the end of long pieces of wood, I 3d printed it and it's strong enough to hold the work.

In order to get the spindle out in front of the bed of the CNC enough to do the entire tenon, I had to make a spindle extender attachment. I did this in wood as the 3d print was 6 hours or so, I may do a 3d printed one later if I use it much.

This gives me enough extra over the end of the machine to do the work I need for the chairs. I'm a bit concerned that there may be heat build up due to the insulating properties of wood as opposed to the aluminium heatsink arrangement the spindle normally has.

Of course, this is also going to be true if I 3D print a version. I may have a think about a 3d printed cylinder in the existing heatsink and an aluminium clamp attached to it that gives similar heatsinking as the current clamp. I don't think the machining will take too long so I won't be running for extended periods of time, but it may be better anyway.

Perhaps a 3D printed version with holes for ventilation?