A NEW SINE PLATE

[KACHINKOO]

GENTELMAN
I HAD ANOTHER OCCAISION TO USE MY SINE PLATE TODAY AND GOT FED UP WITH THE WHOLE
PRECISION END OF THINGS. MOST OF WHAT I DO WITH A SINE PLATE IS TO THE NEAREST DEGREE, GIVE
OR TAKE HALF A DEGREE. I DECIDED TO MAKE MY OWN "ANGLE RODS" OUT OF .875 S.S. 316 ROD.
I FIGURED THEIR HEIGHT FOR A 5 INCH SINE BAR BASED ON .5, 1,2,3,4,5,10,15,20, DEGREES FROM
THE HANDY SCIENTIFIC CALCULATER. GOT THEM ALL JUST ABOUT DEAD ON. MY QUESTION IS, DOES ANYBODY
ELSE USE THIS METHOD?THANKS, DAVE

[John Stevenson]

At last - a member of the real world.
Good idea Dave.
I have a sine plate but I can't remember the last time in 20 years that I used it.
I've got a nice tilting and swivel vise with graduations I trust and if I need to check I also have a decent combined level and protractor.

J&L also sell a set of tapered packings starting at 1 degree. You can stack these to get virtually and angle you need either by addition or subtraction depending on how you stack them.


I'm a firm believer that sometimes this precision thing gets far tooo way out of hand in the home shop.

[Thrud]

Sure. Why not. You used to be able to buy a notched plate that was marked with the angle you get from a 5" sine bar. I think KBC still has them.

There are also 1" diameter rods threaded in ecach end to screw trogether with setscrews. These are accurate to around .ooo1" and good enough fo most stuff. Sort of a poor man's gage blocks (even if they do cost more than a Euro gage block set).

I use my rotary table for most of that stuff unless accuracy is important then I dig out angle blocks or gage blocks and a 5" sine bar.

[snorman]

Finding build up for a sine plate is easy if you keep a calculator handy like I do. Just find the sine of the angle desired and multiply by the size of the sine plate. (usually 5 inch) It's quicker than using Machinery's Handbook all the time and you get the good feeling of figuring it out for yourself. :-)

[msrm]

What is the angle rod method?
I've only used the [email protected]" and then
stacked up the gage blocks.

[Thrud]

MSRM
You make a rod about the length of the gage stack you need and mark the angle it will make on it - same, same.

[JCHannum]

I use adjustable parallels and a micrometer to set up when I use sine plate. Usually use a tilting table though.

I agree about the accuracy part. I think a lot of aspiring HSM's may be put off by this. It is necessary to learn what is important, and must be correct to a gnat's hair, and what can be allowed to run a little loose. Usually most of our projects can be on the loose side unless fit of two parts is involved. Even then, they can be made to fit each other, not mine to yours if you know what I mean.

[halfnut]

Aren't those angle fun. I've got a sine bar I have used a few times when things needed to be dead nuts, I think the last time I used it was to make an angle block I didn't have.

I use those angle blocks quite a bit. I've also made up some specials for jobs we do regularly, combined parrellel angle block gizmos, work good.

I love having a level milling machine, I use the spirit level of my protractor head a lot for setting angles in mill vice. I'd say around 1/4 degree accuracy, fast and easy.

[msrm]

thrud thank you

[Thrud]

Msrm
I must have got lucky as to what you were asking - you are welcome.

Halfnut
Bevel protractor - never thought of that one. Use mine to check angles but never used it to set them. That would work just dandy too. Never even occured to me. Good Idea.

Everyone:

As has been stated before, getting anal with accuracy has its place. Home projects are rarely critical. Proper project design can reduce the need for high precision as well as completetion time on projects. Some subassemblies may require higher precision but most do not.

When you are trying to make money from your machine time is important and chasing "tenths" when all your customer need was a pretty "weight" is mindless.

Common sense. Use that first. Then, if you feel like getting fancy - what ever grabs yer snappy!

I happen to like playing with blocks (ceramic, not steel - but I have both) - because I deprived of them as a child...