Pass Along MW
April 08
Steady Rest Accuracy
by Jack Johns
was asked to re-machine the centers, in both ends, of four 4" diameter x 50" long hardened rolls. The ends were plugged and soft, so they could be machined. The tolerance was .0002" TIR on a dead center.
I set up a roll in the usual way, using a four-jaw chuck and solid steady rest jaws. After cutting the center and checking it, it ran out .0015" TIR.
An older machinist saw that I was having difficulty and explained that the chuck jaws were deflecting the roll, even though I had indicated the roll very accurately. He told me to place a ring of 3/16" diameter brass or other soft metal wire around the chuck jaws, making sure the wire ring is square with the chuck to prevent deflection. The results were very good; I received a number of sets to do!
Please do us a tremendous favor and forward this e-mail on to your machining friends!
Are you not a subscriber to MACHINIST'S WORKSHOP ? Visit us at www.homeshopmachinist.net and request a no-obligation issue, or call and request it at 1-800-447-7367. Tell them you received an e-mail from a friend!
Your friend thinks you’ll enjoy MW, or you wouldn’t have this e-mail!
We hope you enjoyed this e-mail tip, brought to you by your friends at Machinist's Workshop.
To unsubscribe to these pass along tips just send this email message.