An Unusual Project

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Rick_B

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I need to make a swivel block clamop for a steady rest - this is the part the locks the top hinged section to the main body of the steady.

I am starting with a steel rectangle 5/8" wide x 7/16" thick by 1-7/8" long. I need to transform the top 1" or so of the rectangle to a 3/8" round for threading. The oem part is a single piece. I can think of two potential ways to do this.

1. chuck up the rectangle in a 4 jaw and turn the stud - lots of interupted cuts that cause me concern. Is this a viable approach? If so I'm thinking a very slow spindle speed and feed and light depth of cut - at least until it gets close to round.

2. the other approach would to drill and tap the top of the block and use a threaded stud with loctite.

Any thoughts on the first alternative - I would like to try that but don't want to risk the lathe, tooling or me :)

Thanks
Rick
 
Put the rectangle in a 4 jaw indicate it and have at at, this is not at all unusual.

I have threaded the corners of square stock, noisy yet easy, square threaded shafts were employed by door hardware manufacturers 100 years ago.
 
Last edited:
Wreck™Wreck said:
Put the rectangle in a 4 jaw indicate it and have at at, this is not at all unusual.

I have threaded the corners of square stock, noisy yet easy, square threaded shafts were employed by door hardware manufacturers 100 years ago.
Click to expand...

Thanks - what about speeds and feeds? Am I right in thinking slow for both? I would be using a HSS insert tooling

Rick
 
As Wreck said - go for it. Don't sweat speeds and feeds too much. Start slow for both, then increase the speed. Once your surface speed (just pretend it is round) is up to about 70 ft/min, then increase your feed rate (you'll probably be done before you get very far).
 
You will only go as fast as you feel comfortable, this will determine your feed an speed.

I personally would run such a small part at 1000/1500 RPM's at .008 IPR for roughing and .005/.006 IPR for finishing depending on surface finish requirements. You do not have surface finish constraints so have at it.
 
Agree with Wreck, here. I would feed a little slower until the interruption is gone, but rpm as fast as comfy. Even though interrupted, there is less tool pressure with the slower feed rate. At the shop I regularly have to make a similar part for a style of vise clamp in the assembly shop. If all else fails, do the drill and tap routine if that is more comfortable for you. It will work just fine as well. (just less fun, in some of our opinions!)
 
Bucking the trend, I see nothng at all wrong with option number 2!
 
Or.....you could start out with round stock and then mill the sides square.
 
You can take all the precautions you choose , but those interrupted cut chips will find their way down the front of your shirt ! And they usually are hot . Wear glasses , shields , hardhats etc . They make for good shop projectiles as you are trying to peel back that shirt ! LOL
 
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