18 x 24 Fenders


Overview and G-Codes

The top rack axis bearings are covered with CNC cut fenders. These help to deflect chips and keep stray items from being pinched by the bearings.

Quality plywood usually works better than solid wood since the fenders are thin and can split along the wood's grain.

The fenders use the same code for each side of the machine.

Fender for 18x24 machine
Fender for bearing.

The fender's g-code is linked at the bottom of this page.
 
The g-code is for 3/4 inch thick stock that is cut with a 1/4 inch straight bit.

The top of the stock is Z at zero, and the bottom of the cut carves into the bed at −0.8 inch (negative 0.8 inch).

A spoil board that is secured underneath the stock is recommended.

The two holes are plunge cut with a clearing retract, but they still may smoke with the straight bit.
Fender in stock
Tabs hold fender in stock.

The code includes tabs that keep the piece in the stock. Arrow in image. Cut the tabs with a knife after the CNC job is completed; prying the piece free may split the work.
 
The codes have been simplified to only use G01 moves. All arc and circular motion is broken into short line segments. This is done so the codes can be used with basic controller software.

These short segments will cut more smoothly with constant contour activated. (G64 in Mach)
The first few lines of the code may need to be deleted with TurboCNC.

Disclaimer: These codes have been tested on my CNC systems and have worked well.

You assume all risk and responsibility when using them.
 
G-Code           18x24 Fender G-Code