Cylindrical Squares

[Chuck in E. TN]

I just purchased my first Mill, an HF X2. It is assembled and on my bench, but not trammed. I’m waiting on an order from LMS with a DTI, air cylinder, wiggler and edge finder.
While reading Harold Hall’s “Milling, A Complete Course”, and “Lathework, A Complete Course”, I came across the Cylindrical Square. I want to make a few for use with the mill (I also have a 7 x 14 lathe).
My question is how do I get two or more to the same length the easiest? Un-chucking to measure would negate the squareness.
My idea is to use a carriage stop as a reference.
Hall also says to make the cylinders no less than 3 times the T-slot width. Is this real critical? I don’t have steel round that big.
And last, in the mill book, the cylinders are used to square a casting of an angle block. The Cylinders are shown secured to the mill table, I assume with studs through the center into T- nuts. Is this correct? Neither book mentions drilling the cylinders for studs.

Chuck in E. TN

[sbwhart]

Hi Chuck

Bogstandard did a thread on making squares you'll find it her.

http://madmodder.net/index.php?topic=2175.0

As John showed best to make them from tube that way you have a hole ready made just use what tube you have available.

To get them all the same length you'll need a back stop and as you said lock you saddle.

Hope this helps

Stew

[Chuck in E. TN]

Thanks for the link, Stew, I'll study that.
I have some heavy wall steel pipe (.250") about 1 1/2", will that work? Do I need to make some kind of cupped bush to center the stud?

Chuck in E. TN

[sbwhart]

Hi Chuck

The 1 1/2" pipe sounds OK but don't make the squares over long say 4.5 " max (3* Dia), to clamp them to the table they don't have to be centered on the stud, but the clamp plate needs to locate across the diameter.

A good book that shows the use of cylinder squares is from the workshop practice series No 35 :- Milling a complete course ISBN No 1-85486-232-4

Cheers

Stew

[Chuck in E. TN]

As I said in my origional post, that's where I first learned of them. Read Bog' write up to. As soon as it warms up in the garage, I'm going to make several sets.

Chuck

[sbwhart]

As I said in my origional post, that's where I first learned of them. Read Bog' write up to. As soon as it warms up in the garage, I'm going to make several sets.

Chuck

Whoops   that will learn me to speed read 

Stew

[madjackghengis]

Hi Chuck,
   Truth is, the squares don't need to be identical in length, the real issue is that they be absolutely stable when pulled down to the table with studs, and short enough the facing head can cut your angle block clean without hitting them.  They do need to be be as accurate as you can make them in diameter from end to end, and once you get the angle block brought up snug against them, you can rough tram across the top, so you've got an even depth of cut for the first cut.
    The can also be used on a face plate and the surface of the angle block faced off, if your lathe faces square and doesn't have much tendency to face off with a concave big enough to hurt, or worse, a convex face.  They don't even have to be the same diameter either, just straight, and cut off square to the limits of the machine.  I've got a couple made from pieces of motorcycle fork tube, about thirty five millimeters in dia., ground for accuracy and chromed for show.  They already have nice big holes in the middle of them, and they are ground to within a tenth of a thousandth round and straight and cut off pretty easily.  you probably could get an old fork tube for nothing at a bike shop.
mad jack

[kellswaterri]

Hi all, go to your local friendly car or engine mechanic and obtain a few piston connecting rod pins...these if taken from a same set of pistons ...will all be ground to exact tolerances same as each other...these make for perfect cylinder squares.
All the best for now,
                          John.