3/4” Short, Will It Bite Me In The Butt????

Howdy all, this is my first post here. If it doesn’t belong here mods please send it to its proper place.

I’m fixin to pull the trigger on an Avid custom machine purchase. The Y axis will be 5,880mm (19.29 feet). Yes it’s large. 400mm for the home/resting area at one end, and the other end will be reserved for a rotary axis. Between the two will be 16.667 feet so that I can have one sheet of plywood being cut while I’m off loading or reloading another.

I’m starting off with a 5x5 machine, then adding on to get to my end point. Because I’m adding on the build will be in two phases. (There’s a question coming soon, I promise).

The 5/5 kit has linear rail and gear rack for 1900mm, so I’m going to have to purchase 3980mm of each for phase two. That is 156.69 inches. They sell the gear rack in 52” sections. So that’s three of them, just .69” short of what I need.

Here’s the question……… I’m planning on the rotary axis on the end of my unit. The way my mind works it would seem like when using that all of the cutting on that axis would be right in the center of that axis. It calls for a 360mm space to mount it, so half would be 180mm.

Is there a reason why it would need to go past half way on the rotary axis to make a cut (since the highest point on something round would be exactly in the middle). If it wouldn’t then that .69” wouldn’t matter because it will never cut over that far. Or am I going to have to purchase and cut one more piece of gear rack just to cover that .69” space?

Your thoughts please?

Thanks everyone. Look forward to your responses and learning from y’all!

Hughie McMillan
Columbus, OH, USA

How are you going to handle the safety aspect?

These machines move fast. A simple software error or toolpath error or just not zeroing your work co-ordinate system right one day could see the gantry flying at you when you are loading / unloading.

The commercial machines that do this have serious safety features.

Rotary axis: if you want to do true 4 sided machining you want to be able to go past the midline.

For just round objects you can stick to midline.