24x48 Rack/Leadscrew Video
This 30 second video shows a cut being made in a piece of 2x8x20 inch southern yellow pine with the 24x48 Rack/Leadscrew machine.
The bit is 1/2 inch diameter, and the cuts are 1/2 inch deep; the feedrate is 100 inches per minute.
Video compression causes the movement to appear uneven; however, the router is moving smoothly and the quality of cut is good.
The vibrato-tremelo sound of the bit carving the wood indicates that the speed is approaching its upper limits at this depth and width of cut. Cutting across the grain adds extra loads that cause chatter.
The version of the machine used for this video has an aluminum gantry and carriage. It uses racks and pinions on the long table bed axis, and 3/8 inch 5 turn per inch Acme leadscrews with Delrin anti-backlash nuts on the gantry and Z axes. These plastic leadnuts can contribute to chatter since they are flexible.
The machine is powered by the HobbyCNC 305 oz.in. kit. Xylotex systems performed similarly.The machine used around $700 in materials, not including the HobbyCNC components and router.
These plans do give directions for deriving the Step per Inch values that are needed to configure the software for these machines.
Mach3 and TurboCNC are popular controller software options. Other software and motor suppliers can be used.
The above vendors work with the Do It Yourself market and have help forums and documentation.
You do not need a PayPal account to use a credit card with PayPal.The Digital Download page gives more information about downloading the plans.
These plans are also in the Three Plans set, which includes the 13x13, 25x25 and the 24x48.The plans are also in the Five Plans bundle, which includes the 10x9, 13x13, 18x24, 25x25 and 24x48.