5th axis and Auto Tool Changer

[coolman]

Is it possible to have both the 5th axis and the Automatic Tool Changer (ATC)? This is for a DIY system. Since the ATC sits on top of the spindle making it taller/longer, rotating the spindle is not possible since the spindle and ATC is too long. Does anyone have any ideas on how to pull this off on a DIY project?

Thanks,

[JFettig]

You can change the position of the tool rack, I saw a gantry 5 axis machine with auto tool changer, the tools sat toward the back at 90 degrees, the head turned strait back and put the tool in using the x axis to push it into it. Its definately possible and a lot of the bigger 5 axis machines I have seen have auto tool changers.

Jon

[spoiledbrat]

Coolman, I am trying to build one of these heads myself.
What I have found is that right angle reduction units run about $1200 apiece, and advertise 3 ' (minutes) of backlash. 10:1 reduction. With a 22 inch spindle, assuming we rotate it from the center, the 3 minutes of backlash becomes .0095 inches of tool movement.
They do have more precise reductions (<1 minute backlash), but only in the inline format. Cant have a motor sticking out the side, can we?

My question for you is: Does anyone sell shorter,more compact spindles with the taper fixture for ATC installed? I would like to find a 5HP spindle, less than 10 inches long, with tool-holder fixture installed.

[coolman]

spoiledbrat,

I am a novice at this stuff (my hobby) and I do not know a place to find a combo spindle and tool changer with a shorter length. I like your design.

What are right angle reduction units? What is the advantages of a right angle reduction over using a stepper motor directly connected (no gears) to the swivel unit? What are the advantages to a 10:1 reduction unit?

The one problem I see in using your method for my CNC is that the gantry or y-axis will be in the way when the spindle rotates. What would be a good solution to this problem?

I was thinking of building a hobby/cheaper version of the tri-tech 5th axis head which allows the spindle to be stationary and the head unit can swivel. But this project is not as easy to build as your idea.

Thanks,

[spoiledbrat]

A 10:1 reduction accomplishes two things.
1. Torque is multiplied by 10, holding the spindle against any resistance
2. Using a 4000 line encoder, you end up with 40,000 "indexes" or positions.

I think....