RoboTorch CNC Plasma Torch Tables

RoboTorch Computer Control Torch XY 27" x 42"Table

Table Sizes:
27" x 42"   (65.58 x 106.68cm)
48" x 48"  (121.92 x 121.92cm)
60" x 60"  (152.40 x 152.40cm)
60" x 96"  (152.40 x 243.84cm)

Assembly Manual:  pdf file 

The table's XY mechanism uses radial ball bearings and iron angle stock.  The use of spot welds to replace drilling and tapping locations for screws.  The linear motion drive consists of three stepper motors, one used for the X axis and the other two are synchronized to drive the Y axis at both ends of the gantry.

The rack is a 24 pitch linear gear.  The spur gear has 15 teeth and a mechanical diameter of 0.625".   The spur gear circumference is 1.96425".  Using the EMC-XYYZB controller the step distance for X&Y is 0.004910625".  Using the EMC-XYY-G controller the step distance is 0.000982125".

Production is by creating precision fixtures that hold the anglepieces in place.  Spot welds are made to hold it all together, then thefixture is removed.  Computer controlled tools are required to make thefixtures.

The Bearings ride on the surface of common angle iron.  The Spur Gear is directly attached to the shaft of the stepper motor.  There are three contact points for each rail, two are bearings and the third is the Spur Gear in the linear gear rack.  The weight is supported by allthree.  Because the Spur Gear is one of the supporting load points there is zero backlash because the gear is being pressed into the linear gear rack by the weight of the load.

The gantry is driven at both ends by size 23 stepper motorswhich are synchronized by the electronic motor controller.

The table is made out of 3" square steel tubing with 1/8thinch wall thickness.  It consists of four posts (legs) and four cross beams. There are two 1/4" steel bolts holding each end of the cross beams to theposts.  Sixteen (16) bolts are used to hold the table together.  The XYmechanism is attached by one screw on top of each post.  Each post has a5/8" leveling jack screw and nut, that can be locked into position, to makeup for uneven floors.  The table is extremely strong and rigid.

There is a cap plate welded to the top of each post.  A hole is drilled and tapped in the top ofeach cap plate.  The XY mechanism is attached to the top of each post through a matching hole using 10-24socket head screws.

RoboTorch Pictures Torch Tables Kits Assembly Renderings Parts

Home Page at
Copyright 2016 Dennis Bohlke
Revised 03/12/16