Parallel grinder?

[Tuba Dave]

Is there a device with two grinding wheels with parallel and opposing (as in facing each other and running in opposite directions) grinding surfaces, where the "gap " between the wheels can be adjusted? I am looking to hollow grind screwdriver tips to .005" tolerances

So far, I have been using one wheel and a rotary table, but would like to know if the process could be faster. Namely presenting the work once to the wheels and advancing until the "tip" matches the "gap", instead of advancing in increments as the faces are alternated 180 degrees

my google searching only brings up cylindrical grinders and machines where the "sides" of the wheels are parallel, not the"faces"

 

[Alcap]

I believe you’re asking about a Double Disc Grinder . The ones I’ve used the wheels came together with the part held in a fixture thinner the the finished part . Not sure but the wheels could be dressed to the hollow grind you’re looking for and the screwdrivers would only travel to a set stop . Here’s a small version https://www.cbmachinery.com/what-is-double-disc-grinding/

 

[Tuba Dave]

Thanks for the reply. I guess to achieve a hollow grind, the flat face of the wheels would need to be dressed in some sort of parabolic shape.

I was wondering if there exists a machine just like that, but where the grinding wheels are rotated 90 degrees, so that the radii of the wheels point towards each other. A double disc grinder has the radii of the wheels in parallel planes.

Imagine feed wheels on a large tree chipper. Two barrels rotating on parallel axes.

I would like to feed a screwdriver into that chipper and hollow grind both faces of the blade at once. The grinding stones would have to resemble cylinders rather than wheels

 

[tq60]

We do this differently.

Place a mounted stone in a drill press.

Put a screwdriver in a small vise that can be placed on the table and moved around by hand, the shaft horizontal, and face vertical.

Now, just feed into the stone, shift side to side to get the desired shape.

We have a Dunmore sensitive drill, 10000 rpm, and work well.

Sent from my SM-G781V using Tapatalk

 

[Tuba Dave]

We do this differently.

Place a mounted stone in a drill press.

Put a screwdriver in a small vise that can be placed on the table and moved around by hand, the shaft horizontal, and face vertical.

Now, just feed into the stone, shift side to side to get the desired shape.

We have a Dunmore sensitive drill, 10000 rpm, and work well.

Sent from my SM-G781V using Tapatalk

That's kind of what I am doing now, but with a vertical mill and a rotary table. I am making screwdrivers with various tip sizes, so the mill table makes it possible to grind both faces symmetrically, and to get precision in the sizing. These are for sale, so freehand is not an option.

I was just brainstorming to see if there was a quicker and easier way

 

[Alcap]

What diameter would the wheels need to be to get the correct grind ? Would a belt grinder with one stationary and one adjustable idler wheel ?