Sine Protractor

Just completed this sine protractor.

Its simple to use the distance between the centres is 100mm so to set it to desired angle its just the sine of the angle times 100 move the decimal place two jumps to the right.

This is how you set it:-

Zero you digital height gauge on the top of the roller.

For 30 deg the sine is 0.5 so the height to set the roller is 50mm

Then just use it to set your work at the angle

You can obviously work the other way and use it to measure angles.

Stew

I used a Vice I bought  to alter into  a 5" sine vice  very useful 

Edited By Nobby on 11/01/2018 18:55:01

Looks a clever idea Steward, simple, but then the best ideas are often the simplest.

That vice does look useful Nobby

Stew

Hi Stew
Thank you Those gauge blocks you can see i made to save using the best slips are standard sizes for 20 30 degrees etc
I hope you did'n mind me jumping in on you thread your sine protractor is brilliant
Nobby

With Gauge Blocks, you should ALWAYS use a protective slip on each outer end, to prevent wear of the gauge block proper. Two 0.1" protective slips will be much less expensive that a 2" and and a 1"!

Howard

Don't mind at all Nobby in fact you gave me an idea, there's a small vice on our clubs sale table, if its still there I'll buy it if its suitable to be used.

Stew

It's a good idea and nicely presented vise.

I might consider replacing one of those side plates though, looks as though somethings had a good chomp out of the top of the slot?

The gauge of the steel tends to be fairly thin on those I've found.

Michael W

Hi Howard & Stew
You are right Howard the ones in the photo I made out of H&T gauge plate to save using the the best ones .
Stew that would be a good little project as I said i find them useful . I have sine bars angle plates etc but this is good and quick
Regards Nobby

Hi Michael
Yes that side plate was cut down for the original one . Well spotted . i will have to sort that out
Nobby

Hi Michael
Yes that side plate was cut down for the original one . Well spotted . i will have to sort that out
Nobby

The thing i really like about Stewarts design is it doesn't need agauge block set which a lot of people don't have -including me but a height gauge i do have .

I do have a cheap distance block set that the required parts are held together with or mounted on a long grub screw which it is a PIA to use but my suface plate is there along with my height gauge ready to go any time i need it .

Ian

Another way to set a sine bar without using gauge blocks is to use adjustable parallels or a shaper gauge to set he height. Use a mike to set the proper dimension on an adjustable parallel or shaper gauge. Use thatunder theuppe roll instead of a stack of Jo blocks.