# Mystery Sine Bar



## Susquatch (Apr 13, 2022)

I got this with a bunch of other tooling as part of an estate buy. It's a hinged sine bar. But the top piece is a bit of a mystery.






The top piece is aluminium and it is a precision slip fit to the top of the sine bar. But it is not held in place in any other way than at the sides. There are no screws to hold it at the sides.

However, it does have a tight slip fit pin on the top of it. The bottom of the pin is not machined. It is just rough. The top of the pin has wrench flats on it. The pin hole is drilled at a slight There is also a set screw on the slider that can hold the pin in place if desired. Why you would ever want to is a mystery to me.

There is no matching part. It cannot be used as a vise.

What the heck do you folks think it's for?


----------



## Darren (Apr 13, 2022)

angle dresser for a surface grinder? does the pin have a diamond nub in it?


----------



## RobinHood (Apr 13, 2022)

X2 what Darren said.


----------



## Darren (Apr 13, 2022)

I'd say it's missing a handle or lever though. Fingers awfully close to the wheel as is


----------



## Susquatch (Apr 13, 2022)

@Darren & @RobinHood 

By George the pin does look like it has a wheel dressing diamond in it! 

6 beers for each of you on me! 







So what does this missing handle or lever look like? I don't like the general idea of my fingers awfully close to the wheel...... 

And as luck would have it, I'm closing in on a potential surface grinder..... A few more weeks of patience...... 

How is this thing used?


----------



## Brent H (Apr 13, 2022)

Something like this:





You may have some modifications to do.


----------



## Dabbler (Apr 13, 2022)

I'd install a set screw in the side of the aluminum block, to secure the diamond while dressing.  it can then be removed, and the part can be ground.

great video @Brent H

@Susquatch  Do you have a surface grinder?


----------



## Susquatch (Apr 13, 2022)

Brent H said:


> Something like this:
> 
> 
> 
> ...



Thanks Brent! Bet you will never guess where I got that thing...... 

Modifications are us!


----------



## Susquatch (Apr 13, 2022)

Dabbler said:


> I'd install a set screw in the side of the aluminum block, to secure the diamond while dressing.  it can then be removed, and the part can be ground.
> 
> great video @Brent H
> 
> @Susquatch  Do you have a surface grinder?



There is already a set screw there to secure the diamond dressing bar. 

I do not have a surface grinder yet. But I am first in line for a small one that is coming up for sale soon. It's not a totally done deal quite yet. But I am highly optimistic. I still have to look at it. Patience is a virtue. It's definitely not a grouchy old man moment around here.


----------



## Brent H (Apr 13, 2022)

@Susquatch - looks like it worked out fine for you. I only have one guess, but then you would have to kill me - so I choose to remain silent


----------



## PeterT (Apr 13, 2022)

Stefan has a neat one


----------

