24 x 48 x 8 Rack and Pinion, or Leadscrew Machine


A sturdy machine with a variety of options.


Rack and Pinion and Leadscrew CNC Machine with Aluminum Carriage and Gantry
Rack and leadscrew machine
with aluminum gantry and carriage.
This solid machine is straightforward to build for a low cost. This is accomplished by using homecenter materials and stock sized components.

  • Uses a full sized router
  • Leadscrew, or rack and pinion X and Y axes
  • Leadscrew Z axis
  • Uses a variety of leadscrews
  • Aluminum or wood for gantry and carriage
  • 2x4 and 2x6 lumber for the table chassis
  • Belt and pulley stepper couplings
  • Printable 8.5" x 11" templates
 
 

Construction

These plans have hundreds of drawings and dimensioned images with detailed step by step directions for the components and their assembly.

The machine can be built in a modest shop with basic tools. Though not mandatory, a table saw and drill press are helpful.

The 24 x 48 inch cutting area machines have a footprint of 37 x 60 inches, and use stock sized materials efficiently.

The table frame is made of standard 2x4 and 2x6 framing lumber. The gantry can be a 2x6 board or an aluminum channel.

The gantry ends and Z carriage are made of stock sized aluminum flat bar or plywood. The gantry uses standard sized leadscrews or racks to give a cutting width of 24 inches.

The table bed axis uses 48 inch racks and 60 inch pipe rails. These stock sizes give a cutting length of 48 inches. Directions are included for using 6 foot leadscrews.

All rails are steel pipe from homecenters.
The rails’ bearings are 608 or 1603 bearings, which are inexpensive and easily found.

Suppliers for the non-homecenter parts are listed.
 

Options

This machine is designed to allow options in materials and drive components.

The gantry and carriage can be made of aluminum or wood.

The X and Y axes can be driven by leadscrews or racks and pinions.

The stepper to leadscrews coupling on the table bed axis can be one long belt with 1 stepper, 2 short belts with 1 stepper, or 2 slaved steppers.

The pulleys for the leadscrew to stepper connections are common sizes, which simplifies upgrades. The machine can initially be built with inexpensive leadscrews and later be upgraded as need and budget warrant.

Rack and Pinion and Leadscrew CNC Machine with Wooden Gantry and Carriage
Rack and leadscrew machine with
wooden gantry and carriage.
 

Building Cost

The price of the table will vary according to the components used.

$600 is a fair expectation for the basic wooden table with All Thread leadscrews. This does not include the spindle-router, steppers, drives and power supply.

The aluminum gantry and carriage version adds ~$190 and gives a more solid machine, which is capable of more aggressive cuts.

Racks and pinions are ~$125 for the table bed axis and ~$55 for the gantry axis.

The prices of the leadscrews and leadnuts can range from a few dollars for All Thread to hundreds for Acme with anti-backlash leadnuts.

Stepper, drive and power supply packages start at $270.
Routers start at $100.
 

Steppers and Speeds

NEMA 23 steppers move each axis. This is a standard size that is available in many stepper and drive packages.

The prototype machines used the Xylotex and HobbyCNC steppers and drives with torque ranges from 269 to 425 oz.in.
Other systems can be used. However, steppers below 269 oz.in. are not recommended. These steppers are pushed to their upper limits on this larger and heavier machine.
The XL belts used in the machine are also pushed to their limits at ~425 oz.in.


The aluminum gantry and carriage can carry a full sized router. However, the steppers will not be able to push the router to its potential. They usually stall before the router does.

The speeds range from 30 inches per minute with hardware store threaded rod, to 200+ ipm with multi-start Acme leadscrews or racks and pinions.
 

Scaling

Lengthening the rack table bed version of this machine is straightforward because racks, unlike leadscrews, can be abutted.
The plans address using 6 foot leadscrews on the long axis.

Widening the machine more than a few inches will increase the weight of the gantry, which will require more power from the steppers. The machine as designed already pushes 300 oz.in. steppers to their upper limits.

Significantly increasing the stepper sizes will load the XL belts, which will cause the belts to stretch sooner. Up-sizing the belts and pulleys will require reworking some of the machine's dimensions, which is not covered in the plans.

Units

This machine uses USA homecenter parts and is sized in imperial units.

The measures are in fractions of inches, not decimal inches, so carpenters' measuring tools serve well.

Template for CNC Components
Printable templates are included.
 
More information about the 24x48 machine.
 
These plans do not include directions for the software and electronics because the suppliers cover this information for their own products.
These plans do give directions for deriving the Step per Inch values that are needed to configure the software for these machines.
The machines were all designed to use NEMA 23 stepper and drive components such as those from Geckodrive, Xylotex and HobbyCNC.
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.
 
Clicking a Buy Now button in the table below will forward you to PayPal via the downloading service.

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.
The 13x13 is included with these 24x48 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.
 
 24x48 CNC Machine
24x48 Rack / Leadscrew
Also includes the 13x13
$29.95
24x48 Plan
Buy Now

The file size is 15,014 KB (15 MB)
The plans are downloaded as one PDF.
The file name is 24x48_13x13_plans.pdf

 

Three Plans
The 13x13, 25x25 and 24x48
digitally delivered as one PDF.

$34.95
Three Plans
Buy Now

The file size is 25,275 KB (25.3 MB)
The file name is 24x48_25x25_13x13_plans.pdf

 

All five CNC plans
digitally delivered as one PDF.

$39.95
Five Plans
Buy Now

The size is 32,351 KB (32.4 MB)
The file name is 5_plans.pdf