[Jay Smith]

This is the first time posting. I have been a member for almost 2 years reading and gathering info about CNC projects. I currently have a 4 x 8 table with the add on 4 axis that will do 6" turnings.

I would like to start by commenting on the many manufacturers who I contacted and asked to build a rotary 4 axis table. Not one company offered to build because it was a one of a kind, so I started posing the question that If I could give them a parts list to sell me then I would build it. then I got the reply we do not sell kits. These responses are what has made me the DIY person I am today. I have recently started my 4 x 8 rotary 4 axis build. I wanted to talk about the pros and cons with the build and the hurdles that may arise during the process. I felt that I have received so much information from reading other peoples posts that I needed to pay it forward.
Thanks in advance to any and all who will give advise and make this a successful build. I will post pictures along the way to help give a visual of what is going on.

Jay

[awerby]

How high is your Z axis? To be able to cut even halfway to the middle of a 6" workpiece mounted on your bed, you'd need a tool that sticks out 3", so you'd need more than 9" of Z height to clear the stock.

[Jay Smith]

I do have about that much height. my problem was that I could not turn large pedestal's or table legs. they did not have the depth to the center but were larger in diameter. some of the pieces I will be making are 15" round, and only need a small amount removed. I have ordered my Hiwin linear rails and the z was about 400mm. I was a little taken back when I got the invoice for all the rails and blocks to match. I got all the holes drilled and tapped for the X and the Y axis, long day.

[Grant Nicholson]

How high is your Z axis? To be able to cut even halfway to the middle of a 6" workpiece mounted on your bed, you'd need a tool that sticks out 3", so you'd need more than 9" of Z height to clear the stock.

I get your point, but 4th axis work doesn't have to cut all the way through. I would like to be able to produce sculptural work within a 12" envelope, and even 2 inches of relief would offer plenty of carving possibility.

[Grant Nicholson]

How did it go? I would really like to construct my own 4th axis machine. I don't need a table bed - just x down the length, z for depth, A for turning. It would accept a 12" diameter.
I use CNC professionally every day, but haven't built one. Can you buy a board and steppers/servos that work together out of the box and add them to a physical structure on rails?

[asuratman]

just x down the length, z for depth, A for turning. It would accept a 12" diameter.

You want to build the one like this :