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HWooldridge
05-18-2006, 12:23 AM
This is a small kink but might be helpful to someone in the future.

I had the need to put some 90 degree points on quite a few 1/4-20 hex head bolts that were 2 inches long. This had to be done quickly plus I did not want to grab the bolt threads in the lathe chuck so I ran a nut about half way down the shank, then chucked both head and nut in the 3-jaw, leaving the threaded end protruding. This works pretty well to center the shaft and the nut obviously cannot turn since it's locked. Of course, both head and nut must have the same dimension across the holding surfaces, e.g., a 1/4 bolt and nut both use a 7/16 wrench so I wouldn't do it with a non-standard size.

For my purpose, a rough point was sufficient so I spun the part in the lathe and used a right angle grinder to make the point. An added benefit to the nut is that it cleans the threads when the bolt is removed.

IOWOLF
05-18-2006, 03:26 AM
I hope you covered your ways.;)

HWooldridge
05-18-2006, 11:09 AM
I washed them down afterwards with cleaner.

pcarpenter
05-18-2006, 12:19 PM
I had a discussion with a guy in charge of a shop here at work when I saw him using a die grinder with an abraisive wheel to clean up spinning stock on the lathe. I mentioned the abraisive dust on the ways and he proceeded to tell me it didn't matter if they were kept oiled. How do people think this way?

Clover compound is silicon carbide in a petroleum (grease) base....used specifically as an abraisive. I think if I said to someone "hey...I have this bag of abraisive I am going to go sprinkle all over your lathe" they would hopefully stop me. We do the same while working on them and don't bat an eye sometimes. The ways on a modern lathe may be harder that much of the machining swarf that ends up on them...but not harder than these abraisives.

Cleanup is one way to approach it, but that doesn't happen until the job is done which often involves working the carriage back and forth and getting some abraisive underneath.

What works for me are a couple of pieces of black rubber floor mat/stair tread stuff you can buy at the hardware store. I just keep them hanging over the back of the chip guard on the back of the lathe for quick access to tuck under the chuck before grabbing any abraisive to use on the work in the chuck. The stuff is flexible, but has ribs which help to keep the grit on the mat. When done, they just go over to the trash can with a chip brush and all the grit goes with them.

CCWKen
05-18-2006, 06:36 PM
I "bag" the whole darn machine now. The only thing sticking out is the chuck, tool post and handles. I started doing this after a nasty encounter turning a load of cast iron. Grinding is worse. You might as well be poring sand over the machine and adding oil. :rolleyes:

HWooldridge
05-18-2006, 07:56 PM
Well, the point of my providing the info was intended to illustrate that adding a hex nut to a bolt would allow firmer work holding - but it has turned into a discussion about grit on lathe ways. All good points but not what I was trying to convey.

TGTool
05-19-2006, 10:27 AM
I've also used the chucked bolt and nut as a threaded mandrel to hold an internally threaded part that needed some operation - machining off a nut for instance to make a thin locknut or facing a parted-off piece. You can set whatever thread length you need to have protruding, and the nut (right at the chuck) serves as a stop. They can't be relied on for good concentricity, but fine for knock-off operations.

Russ H
05-20-2006, 07:11 AM
I use hex stock, mark side/ edge that is in contact with #1 jaw.
Then drill and tap while in 3 jaw chuck. Takes care of concentric problem
Russ H