compound slide setting

[John Rudd]

I know I should know this......and am emabarrased that I have to ask..

But what is the best way to set the compound slide so I can cut accurately a 45 degree angle on some round stock? 

[BillTodd]

Sine bar:

[Chuck in E. TN]

John, I use a combo square. Took the crappy protractor off my mini lathe ages ago.
Chuck

[mklotz]

You don't mention required accuracy so that opens the doors for all sorts of wild suggestions.

My favorite technique is to plop a magnetic back DI on the compound and then fiddle so it reads X deflection for X motion of the slide when run against a piece of smooth shafting held in a collet.

[vtsteam]

My favorite technique is to plop a magnetic back DI on the compound and then fiddle so it reads X deflection for X motion of the slide when run against a piece of smooth shafting held in a collet.

cool.  must remember.

 

[Fergus OMore]

Unless I've missed the question, I'd use a 45 degree lathe tool- and leave the top slide alone.
It results- if you have it sharp enough, a mirror edge which reflects. However , a graver is the fastest-- and most elegant.

Regards

Norman

[Pete.]

The magic number for right angles and 45 degrees is 1.4142. Just remember 'forty one, forty two'. I use it all the time at work for quickly working out rough areas off drawings (at least I did until I discovered you can pull an area off a pdf drawing straight out of the software), and for setting-out.

How you use it is simple. On a 45 degree isosceles triangle (One right angle and two 45's) if you have either short side a size of 1, the hypotenuse will be 1.4142.

So, stick a DI on the top slide and dead square/touching to the tailstock ram, wind the top slide 141.4 thou and adjust the angle until winding it in 141 thou moves the dial 100 thou. You can use any multiplier to gain accuracy.

[Meldonmech]

Hi,
           I use an accurately ground 45 degree tool, and set up the side of the tool to the face of the lathe chuck then lock in position.
                                 
                                       Cheers  David

[John Rudd]

Well, I thought it best to reply to this thread..........

I think by far the easiest solution to set up is the tool method posted by Meldonmech, Cheers David..

Thanks to everyone else but some of the ideas are a little too complicated for my simple brain...Sine bars? Dunno about them....
 I've heard of Mars bars....

I have a dti but it seems a little long winded...

I'm grateful for all the suggestions tabled but for my limited skills Davids method will suffice I hope...

Thanks guys...