With any milling machine you need mass and stiffness, so I decided to make a Genmitsu 3018-pro stiffening bracket.
The template was cut out from a thick-ish piece of cardboard. You can see that I had to extend the template to add the leg that fits onto the top of the side chassis rail.
Using a template is an easy way of constructing parts like this. The left and right hand parts were cut out using the same pattern and then just folded in opposite directions. Once I had a good fit I then marked the hole locations.
The bracket has a number of functions to connect the upright to the side chassis rail, then to connect the upright to the high cross beams and add a brace between the two cross beams.
Hopefully in these images you will be able to see how this adds triangulation between the elements of the chassis.
These brackets were quite easy to make from 1mm thick aluminium sheet.
Finally, just to show how well this now works I machined the website URL into a piece of aluminium. Also using the sprung D-bit to engrave this.
Subjectively the chatter and vibration levels have dropped dramatically and now you can hear the brushed motor quite distinctly.
I made a 6mm diameter brass sleeve with a 1/8″ reamed hole through the centre, thus allowing the carbide bit to slide. I then have a small 2mm hole in the side of the barrel that takes a piece of 2mm brass rod and this stops the tool bit rotating. The D-bit is then loaded from the opposite end and a small spring gives the compliance. The top end then has an M4 internal thread for a grub screw. This grub screw stops the D-bit and spring escaping.