[cyclestart]

I want to machine a bunch (~200 pcs) of 1.4" x 3.5" abs pipe. It's all variations of the pictured set-up.
Currently an independent 4-jaw chuck is being used. It would be more convenient to have something that can self-center and apply even pressure instead of pressure at 4 points.
Any ideas to share ? Preferably low-cost.
Attachment 414812

[LongRat]

For that many I would make an expanding mandrel. Turn an aluminium cylinder to a slip fit to the pipe bore, then split it longitudinally with a number of saw cuts (3 usually works for me to give 6 segments). A threaded hole in the centre on the rotation axis with a countersink, will cause the mandrel to expand when the countersunk screw is tightened. This will give an even pressure to hold the inside of the plastic pipe.