Has anyone made a Brake Dresser?

[Janderso]

I’m going to grind some Norton stones so they become precision tool room stones.
There are a few videos out there on how to do it.
Bob Korves and I, (using his B&S surface grinder) ground my precision stones. They are great.
I purchased a 7” x 1/2” diamond wheel for my Surface grinder From Shars.
The TIR is about .008”, it’s kind of fussy to measure.
Solid Rock machine cleaned up a wheel by grinding low carbon steel and using a dressing wheel. All diamond and CBN wheels need to go through this process for best performance according to several articles I read by the manufacturers.
The beauty of A Brake dresser is You can control it. The wheel runs slower by a controlled braking method.
They run over $500.
I think it would be an interesting project
here is a Norton brand.

Norton

 

[ErichKeane]

I actually did this. I made 3 pairs, and all are currently seeing heavy use in 3 different shops.

I bought the 10" diamond wheel from Shars, I didn't bother to measure the runout and just got to grinding. I DID do a practice stone (Zoro sent me a broken one, so I ground on it a while) where the wheel 'ground in'. My stones, like everything I cut on my B&S, ended up with a slight 'ripple' pattern on them, but it is sub-tenth.

The stones themselves are great for what I used them for a scraping project. I found it nicer/better than the surface plate for that purpose once I got closer.

 

[Bob Korves]

I purchased a 7” x 1/2” diamond wheel for my Surface grinder From Shars.
The TIR is about .008”, it’s kind of fussy to measure.

Are you still messing with that wheel, Jeff? I would have sent it right back to Shars for a replacement, and kept doing so until I received one close enough to massage to near zero runout. The one I got from Shars was .002" out, and it took some time to get the wheel dressed round and with a flat face, but it is possible. Keeping it round and the face flat in use is also something that needs constant attention with how it is used. I am also interested in a brake dresser, but have never even seen one, much less used one. In online videos, they sure seem like the answer to dressing diamond wheels...

 

[projectnut]

What is it that you are doing that requires a stone precision ground to the sub tenths? I am considering purchasing a diamond wheel for sharpening carbide end mills. I'm looking at either a General Industrial Diamond or one from 3M which bought out GID back a few years ago. According to their spec charts the runout is within .001". I would think that would be close enough at least for the application I am considering.

 

[Janderso]

but have never even seen one, much less used one. In online videos, they sure seem like the answer to dressing diamond wheels.

Click on, "Norton" at the bottom of this first post.

 

[Janderso]

What is it that you are doing that requires a stone precision ground to the sub tenths? I am considering purchasing a diamond wheel for sharpening carbide end mills. I'm looking at either a General Industrial Diamond or one from 3M which bought out GID back a few years ago. According to their spec charts the runout is within .001". I would think that would be close enough at least for the application I am considering.

Good question, I know these CBN and diamond wheels run from the $100 - $800 range for the 7" size. I'm sure there is a quality difference.
Watching Solid Rock machine, Robin Renzetti and many others, they all need to be conditioned before use.
Bob was lucky finding a diamond wheel with only .002".
If 3M is stating .001" then I should have gone that route. One thing though, the CBN wheels run >$500 and the diamond are >$275.
I was trying to keep this project down to earth.
If I use this wheel for anything else it is going to need to be round.
Bob, you are right, I should probably try to send it back. I've used it now so I don't know what their response will be.

 

[ErichKeane]

Click on, "Norton" at the bottom of this first post.

So it seems to me that this braking dresser is just a spindle that resists being spun by the diamond wheel (plus a specialized wheel)? I would think you could do this by making a mount for a DC motor with a wheel on the end (it actually doesn't have to be that accurate, since you can move it forward/backward, and only the 'high' spot matters), then hooking the leads to a resistor. This would turn it into a brake.

 

[Janderso]

So it seems to me that this braking dresser is just a spindle that resists being spun by the diamond wheel (plus a specialized wheel)? I would think you could do this by making a mount for a DC motor with a wheel on the end (it actually doesn't have to be that accurate, since you can move it forward/backward, and only the 'high' spot matters), then hooking the leads to a resistor. This would turn it into a brake.

The accuracy must include a perfect 90 degree approach to make the cut.
It appears the dresser grinding wheel turns in the same direction of the wheel to be dressed but must run slower to do it's work.
There are some pretty poor DIY wheel dressers on Youtube.

 

[ErichKeane]

The accuracy must include a perfect 90 degree approach to make the cut.
It appears the dresser grinding wheel turns in the same direction of the wheel to be dressed but must run slower to do it's work.
There are some pretty poor DIY wheel dressers on Youtube.

I don't really think thats true, if it isn't perfect it becomes a single-point dressing tool (just like a diamond dresser). I would contend that EVERY SINGLE one of the brake dressers is actually this Presumably, the stone wheel would eventually wear away until it was a perfect surface anyway, since the high spot would be worn away constantly.

As far as the running slower in the same direction, thats exactly what using a DC motor + resistor would do, the dresser would gain its rotation from the main wheel, but would be slowed down by a brake.

 

[Janderso]

I don't really think thats true, if it isn't perfect it becomes a single-point dressing tool

Erich,
What I am trying to describe is you want to form the cutting edge to be flat against the entire working edge.
I'm trying to understand your point.
Thanks,