4th axis servo controlled rotary table build

Hi everyone,

I am getting ready to build a 4th axis for my CNC mill. I should be getting the rotary table in the mail in about a week. I will be posting pictures as I go along .

The rotary table is one from eBay. It is of the 8" variety. I believe the brand is CME.

The servo and drive is from Leadshine and is 400w.

Here are a couple pictures of the servo and drive:

 

The belt and the pulleys finally came in. Here is the design for the bracket. Pretty straight forward.

 

Started making chips!

 

Some more chips!

 

Some more chips!

My machine is running a software controller provided by Jim Dawson. His software is also 4th axis capable, so I intend to try that capability out with this build.

 

Working the backside.

 

Working the backside.

Cleaned up.

 

4th axis pretty much finished up. I still have to run it in and put it under some machining stress to see if the setup will actually hold. The next project will be making a mounting plate for the 4th axis so I can actually mount it at mid-point on the Y-axis travel.

Here are some things I learned doing this project:

1) It's probably best to use a 4 jaw chuck when boring holes in things that require a set amount of tension or backlash like pulleys and gears. when I rotate the shaft of the 4th axis, I can push down on the belt and notice that a few spots have more tension. Fortunately it is not enough to cause extra drag in those spots, but If I was off anymore, I probably would have been taking a one way trip to destination screwed.

2) incorporating some kind of tightening mechanism would have been a big help. Pulling on the servo to get the belt tight while trying to hold an Allen wrench in the hex socket hole and drive my electric impact gun from the other side is not fun.

Overall, I am happy with the results.

 

Looking good !

 

A short video:

 

I need to bump up the acceleration a little bit. It uses about 90deg of rotation to get up to speed.