$29.95
 24 x 48 Rack and Pinion, or Leadscrew MachineA sturdy machine with a variety of options. |
Rack and leadscrew machine with aluminum gantry and carriage.
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Construction
This machine was designed to be accurate and solid for a low cost. This was accomplished by using home center materials with stock sized components. The machine was also designed to be built in a modest shop with basic tools. Though not mandatory, a table saw and drill press will facilitate construction. These plans have hundreds of drawings and dimensioned images with detailed step by step directions for the components and their assembly. The 24 x 48 inch cutting area machines have a footprint of 37 x 60 inches, and were sized to use stock sized materials efficiently. The gantry beam is made of a 2x6 board or aluminum channel. The table frame is made of standard 2x4 and 2x6 framing lumber. The gantry uses an uncut 36 inch steel rod for the pinion axle, and/or a 36 inch leadscrew, and/or a 24 inch rack. These options give a gantry axis cutting distance of 24 inches. The other gantry and Z carriage components are dimensioned for stock sized aluminum flat bar, or plywood. The table bed axis uses 48 inch racks and 60 inch pipe rails. These are also stock sizes, and give a cutting distance of 48 inches. Directions are also included for increasing the bed length to use standard 72 inch leadscrews. All rails are steel pipe from home centers. The rails’ bearings are 608 or 1603 bearings, which are inexpensive and easily found. A list of suppliers for the non-home center parts is included. |
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Options
This machine was designed to allow a number of 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 were sized to be interchangeable, so drop in upgrades are possible. Therefore, the machine can initially be built with inexpensive leadscrews and later be upgraded to Acme as need and budget warrant. 
Rack and leadscrew machine with
wooden gantry and carriage. |
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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. Generally there is $130 in pulleys, belts and bearings; the remainder is in home center parts. Racks and pinions are ~$120 for the table bed axis and ~$50 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. The aluminum gantry and carriage version adds ~$185 and gives a more solid machine, which is capable of more aggressive cuts. Stepper and drive packages start at $270. Routers start at $100. |
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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 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 will 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. |
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Scaling
Lengthening the rack table bed version of this machine is straightforward because racks, unlike leadscrews, can be abutted. 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 home center parts and is sized in imperial units. The measures are in fractions of inches, not decimal inches, so carpenters' measuring tools will serve well. 
Printable templates are included.
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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 this machine. 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. They have help forums and documentation. |
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Compliments
Hi, I just received my plan book, and wow. This book is filled with info. I was expecting getting just a set of plans. Nice job. David, Your plans were awesome and it was a pleasure to build and a joy to use. Thanks!!! |
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Clicking the 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. |
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The file size is
15,014 KB (15 MB) The plans are downloaded as one PDF. The file name is 24x48_13x13_plans.pdf |
$29.95
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24x48 Plan
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The13x13, 25x25 and 24x48 digitally delivered as
one PDF. |
The file size is 25,275 KB (25.3 MB) The file name is 24x48_25x25_13x13_plans.pdf |
$34.95
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Three Plans
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All five plans, digitally delivered as one PDF. |
The size is 32,351 KB (32.4 MB) The file name is 5_plans.pdf |
$39.95
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Five Plans
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