Dead centers are funny sometimes.....
First, they do NOT want to be "tight". They want to be "there", completely in the center feature, but they don't want to be pushing the work towards the chuck. Only carrying the horizontal loads from the tool.
How do you not ruin one? Don't ask me......
How have I ruined them? Go ahead, ask me.....
Putting work in that had a drill hole, without bothering to add the center feature (the taper/chamfer from a center drill). A sharp corner does not leave enough bearing surface Oil, grease, or any antiquated lubricants that a few of are lucky to have can do the job, but you need some surface area for them to "float" the parts, eliminating the metal to metal contact.
Cutting a center feature FIRST, and THEN facing the end of a part, leaving a burr inside the center hole. Same problem as above.
Putting the center too tight. It took me a couple of those centers (well, recutting my center a couple of times) to figure that out. If there's no room for the part to "float" on the lubricant, then it won't. And then you've got metal rubbing.
Letting the part get too hot. Among the stuff I can get easily are some pretty gnarly steel shafts. They get HOT if I'm taking more than a few passes. I find that if there more than a few inches long, I need to keep an eye on that, and back the center out and place it properly one or two times as the part warms up, or I'll be cutting the center again.
I kind of like dead centers. I think mostly because I'm a neanderthal or someting, because NOTHING that I do requires that kind of precision. It does take some practice and "feel" to not do damage to them. I bought a small tin of "lead substitute" at some point. It's not spectacular, but it works. EP grease works, Way oil , motor oil, and sulfurized cutting oil, maybe not so much so.
First, they do NOT want to be "tight". They want to be "there", completely in the center feature, but they don't want to be pushing the work towards the chuck. Only carrying the horizontal loads from the tool.
How do you not ruin one? Don't ask me......
How have I ruined them? Go ahead, ask me.....
Putting work in that had a drill hole, without bothering to add the center feature (the taper/chamfer from a center drill). A sharp corner does not leave enough bearing surface Oil, grease, or any antiquated lubricants that a few of are lucky to have can do the job, but you need some surface area for them to "float" the parts, eliminating the metal to metal contact.
Cutting a center feature FIRST, and THEN facing the end of a part, leaving a burr inside the center hole. Same problem as above.
Putting the center too tight. It took me a couple of those centers (well, recutting my center a couple of times) to figure that out. If there's no room for the part to "float" on the lubricant, then it won't. And then you've got metal rubbing.
Letting the part get too hot. Among the stuff I can get easily are some pretty gnarly steel shafts. They get HOT if I'm taking more than a few passes. I find that if there more than a few inches long, I need to keep an eye on that, and back the center out and place it properly one or two times as the part warms up, or I'll be cutting the center again.
I kind of like dead centers. I think mostly because I'm a neanderthal or someting, because NOTHING that I do requires that kind of precision. It does take some practice and "feel" to not do damage to them. I bought a small tin of "lead substitute" at some point. It's not spectacular, but it works. EP grease works, Way oil , motor oil, and sulfurized cutting oil, maybe not so much so.
