Automating Screw Turning

So, I’m in the concept stage of building a reconfigurable mold, consisting of an array of 392 half inch square pins located by… 392 screws. The notion is to position those many screws with the AVID via an elastomer held in the spindle, turning the screws via pressed friction or interference, or to employ a threaded collar held in the spindle. This scheme attempts to avoid extensive machining of the screw ends. I wonder if any have or know of folks employing CNC screw placement? I know of one maker who drives nails to create a matrix using their CNC machine. Do contemporary systems offered by AVID feature a reversible spindle? Any insight or reflection would be appreciated.

How about a thread mill? Clamp the pegs “thread up” and cut the threads by spiraling the spindle around them. Can do the holes they thread into the same way, but spiraling down the inside.

The challenge here isn’t threading, but positioning- the “extensive machining of screw ends” referred to altering the screws to accept a socket or driver head to aid engagement with the tool held by the spindle; I was hoping to avoid machining all those parts, so was considering friction engagement. Perhaps I’ve misunderstood your intent.

It sounded like you were trying to make wooden blocks with threads that threaded into holes on the bed. If you’re trying to get the spindle to install those blocks, I have no idea :wink:

You’re basically making a pick and place machine; those use vacuum systems, but I don’t know how easily it would be to grab and install a screw with a vacuum nozzle.

It’s the case of a block with 392 holes, each bearing a screw, the height adjusted to describe a relief.

Spindles are reversible, but Avid’s system might not be set up to correctly handle an M4 reverse spin command. There also wouldn’t be a way to command an angular position to drive a screw in a controlled way. It would just be turning it on at a specified RPM.

One oddball idea would be to create a crank arm to turn screws. Put the end of the arm over the screw and move the spindle in a circle to rotate the crank. The arm would need enough friction to keep the drive head from losing its position between screws. This would be similar to a drag knife in that the spindle is off, the end effector has a non-self-actuated rotation, and the CNC 3-axis motion does the work.