17 x 20 Tables

These plans are no longer available. The 25x25 is similar but simpler.

Overhead leadscrew CNC tableThese two 17 x 20 tables were the first ones for which plans were developed here at Solsylva.

They were designed to use home center materials, and to be solid enough to support a trim router.

The rails are made of a single10 foot joint of gas pipe with no waste. Standard sized 3 foot long threaded rods are used for the leadscrews.

These machines do not require a base; therefore, they can carve patterns in any size of stock, including floors.

Dual Leadscrew Table
The X leadscrew of the version shown above is placed over the gantry and carriage.

The other model, shown on the left, uses dual leadscrews with one on each side of the gantry.

The Z carriage was designed to be compact, so it would permit clearance for the overhead leadscrew. This compact Z is unusual, and may be handy for other applications. However, the lack of Z travel makes bit changes inconvenient with thicker stock.

The overhead leadscrew is also an unusual element for DIY CNC machines. It requires a short Z travel and introduces the same racking issues as an under-table single leadscrew.

The newer 25 x 25 machine is somewhat similar to the dual leadscrew 17 x 20 table. The 25 x 25 is designed to be simpler, use fewer parts and tools, and to more easily permit upgrades to Acme leadscrews. The 25 x 25 has a larger cutting area while using the same length of leadscrews as the 17 x 20 dual leadscrew machine.


The dual leadscrew version of the 17 x 20 machine costs around $45 more to build than the overhead leadscrew version because of the belt and pulleys required to drive the two leadscrews.

The dual screws increase the rigidity of the system, and permit a trim router to be pushed harder than the overhead leadscrew table permits.

These prototypes when powered by the HobbyCNC 200 oz.in. system can rapid at 30+ ipm.

Larger steppers and drives also can be used, of course. The Xylotex 425 oz.in steppers do not deliver enough high speed torque unless they use Dampers.

The image on the right shows the table with casters.
These can be attached to an end-plate and the table can be rolled out of the way for storage.

These plans do not include directions for the software and electronics. This information is covered by the recommended software and stepper suppliers.
These plans do address the Step per Unit values needed to configure the software.

The machines were all designed to use the stepper and drive systems from Xylotex and HobbyCNC. The recommended software is Mach3 or TurboCNC.

These suppliers work with the Do It Yourself market, and supply documentation and help forums for their products.

................................