After using my CNC machines to create 3 dimensional art for an art show I wanted to add a fourth rotational axis to ease in the production of 3 dimensional objects and parts. I decided to add the 4th rotary axis to my Taig CNC Milling machine since I had just upgraded to a 5 axis’ controller and had a matching stepper motor. A rotary table used in conjunction with a mill allows a machinist to produce virtually any part he can design. The only limits are size, not complexity.
Using a 4th axis rotary table greatly reduces the amount of time and complexity that it takes to shape an object. Without a rotary table you must devise a registration system and are forced to reposition the object several times during the milling process. The precision that a rotary table provides also ensure uniformity and high quality in components.
I could have bought a cnc ready sherline rotary table but I decided that I’d rather get a table locally and build a stepper motor mount for it myself since half the fun is in the build. I decided to go with the Soba 4-inch rotary table (part# B2424) from Busy Bee tools down the highway in Mississauga. While I was there I also picked up the matching 4-jaw, 3 1/4-inch chuck (part# B2710) and Tailstock (part# B2424).
I wanted to design a mount that would let me return the table to its original state if desired. I used a CAD program to design the mount so that it could be dropped into place and secured with 4 set screws around the existing shaft collar.
The mount is 2-1/4 x 3 x 3 inches and constructed with 1/4-inch thick aluminum. All 4 of the parts were milled on my Taig milling machine with the new controller and stepper motors. I’m always amazed at the amount of precision and accuracy of that taig mill! The rotary shaft is 10mm in diameter so I ended up drilling out two 3/8-inch shaft collars to 10mm. The shaft collars are used to take up the extra space since I wanted to leave the shaft at its original length. I used a 3/8-inch flex coupler drilled to 10mm, a rubber spider and 1/4-inch shaft flex coupler from Princess Auto to mate the rotary shaft to the stepper motor.
Rotary axis with 4-jaw chuck attached.
Stayed tuned for my next blog post where I’ll show the rotary axis in action attached to the Taig mill.
Karl P. Williams