Form/crush dressing for surface grinder wheel?

Hey guys, I have a custom application and looking for some help on exactly what I need.

I think I'm mainly looking for some sort of form dressing to accomplish this but maybe you guys can help me know if that's correct.

What I'm looking for is some way to dress a surface grinder wheel with a pretty small serration pattern (from the center bottom groove of one groove to the next it's .045")

The purpose is to grind 'jimping' into the spine of a knife blade for the thumb to rest on that will look similar to the below pic

you can either make a tracing template to put on your mag and chase it with a styli that has a diamond on the other end. this is nice because you can scale it for better detail.

crush dressing is a fine method aswell. make yourself a hardened blank and feed it carefully into the rolling grinding wheel. I would not do this on your surface grinder if you can avoid it. we have mounted arbors in the lathe to mount the hubs on to minimize the heavier side load of this task.

Wheels are made special for crushing. A simple crusher can be made on a lathe or with a Grinder. Roll crushers are professionally made and very costly.

A wheel crusher made of mild steel or pre-hard to 48 (for turning on a lathe) or so will hold up very well.

Crushable wheels have a special bond the allows crushing.

Crushing a normal wheel may work but also may break the wheel.

One might find a form dresser diamond and use that t to dress a wheel for the making of a Roll Crusher.
Made in USA Single Point Concave Radius Diamond Dresser 3/8" Shank Diam, 2" S... | eBay

Often a roll crusher is about 3" in diameter and made to roll on a stout bearing, two pillow blocks would do nicely. the wheel is brought to the roll with the long travel locked to the go direction, and with hand-cranking the roll, the grinding wheel is brought down feed into the roll.

Roll dressed wheels hold up very well, better than diamond dressed wheels.

*Oh, and the roll wheel should be left on its own mount and to a line-up mark at the spindle end so it can be taken off and on and still run true.

We used to grind very small blade set-out serrations, likely .012 or so (and some .030 or what). One could never do that effectively with not roll dressing a wheel so doing one full blade with one down feed.

On the other hand, I had to grind teeth on about a 30" radius and a 2, 3, or 4* tilt, each by hand on the SG with loop single setting each of about 15 teeth for a job that took almost an hour for one part. That job did not come often enough to make a proper set-up but when it came it was a stop the lines emergency.

Hi josh623:
You could also use a Diaform wheel dresser to dress your profile into a conventional wheel.
Diaforms are 5:1 or 10:1 pantographic tracers, so you have to make a template.

Best for your needs would be the model that mounts to the wheelhead of your surface grinder and can be left there, all set up.
That way it's super simple to re-touch a wheel as soon as the corners start to wear, without having to strip off the job, mount and align the dresser, dress the wheel, rip it all back off the machine, re-mount the job, realign it and resume grinding.

Look on Fleabay for a used one...nobody wants them anymore so they go for cheap.
Mine cost 500 bucks and it was a twenty grand toy back in the day before wire EDM when every diemaker needed one.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

You could also use a Diaform wheel dresser

Click to expand...

Anyone going this route, get a manual and educate yourself on the various models , sizes, and ratios. And all the parts that should come with the dresser, including diamonds, diamond holders of different configurations including roughing and finish, & duplex. Set up tooling and dedicated indicator(s), diamond protectors to fit the stylus so as not to run the diamond where sideways would cut it out of the stick, and the condition of the flexible linkage straps. (I don't know what they/it are called - pile of flexible spring steel strapping, more or less)

Also, be sure of the perspective if viewing one from photos.
There are 3 different models here including a big one that came in a mahogany case the size of a washing machine. :^)
I was going to mount the over-the-wheel style to my smaller 618 grinder, but then it became my primary surface grinder, so would be in the way 99.9% of the time. Also have a table mount unit for that size (7"or 8" wheel) but have not used it.

Very few I've seen over th eyears on eBay have all the necessary tooling. I have enough diamonds not to need any, but my impression are they are not readily available inespensively?

Implemex - do you use yours?

A form diamond perhaps a 1/32 radius could be set under a wheel, and with raising and lower into the diamond to make a series of 1/32 dents/divots into the wheel. Time-consuming to shape the wheel but likely be an oK method.

I don't see any such diamonds on eBay, but there are some that look like a 60* and a small point.

Here is a note on dressing a diamond wheel. I have never done that and think it would waste a lot of a wheel.
A form wheel can be made of steel, perhaps aluminum can be coated with diamond to make a special shape diamond wheel.

Crushing a crushable aluminum oxide wheel is an easy process and a guy with having a lathe or surface grinder to make a roll should have no problem making a roll... even a single indent roll could be made and used, figure 5 minutes for each indent so rolling the wheel would take more time. A horizontal mill arbor spacer might be an OK roll material source.

Form crush dressing of diamond grinding wheels - ScienceDirect

I don't think you can make close serrations with a Diaform wheel dresser.. but the diamond made for the Diaform could be used to incremental step at cross feed and make your needed wheel form. your down-feed at .866 times the amount of cross travel should work, and considering how much flat you want on the top of your form.

Trig it out, or just make a drawing at 5 or 10x scale and you can see and measure the form.

likely best to run the diamond wet making indents to an AO wheel.

You may be able to grind a flat on a 60* point diamond with using a diamond wheel at down and cross travel. But that is a tricky grind and so you might pop out your diamond or indent your diamond wheel...and it depends on how hard your wheel diamonds are. XX better not chance trying that.

Hi stephen thomas:
You wrote:
"Implemex - do you use yours?"

I used mine a grand total of a dozen times and then I got my first wire EDM.
I also have an Optidress that suffered the same fate.
But yeah, it's complicated and cumbersome when you're first learning it (but it gets much easier as you practice a bit).
Doing form work on the wire is so much easier and not so messy too.
Also, you make a great point about getting every goodie when you get the unit...they are hard to come by as separate items.
I did find a place that still supplies diamond points though, and yes they are EXPENSIVE.

michiganbuck, you wrote:
"I don't think you can make close serrations with a Diaform wheel dresser"
You're correct, there are some limitations on what you can sneak into with your diamond.
The standard way to overcome that is to form every alternate vee on the wheel and shift it one pitch after you grind the first set of vees.
Not as nice as having every vee on the wheel but still a whole lot better than having only one vee.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Another wheel form dresser is the Grazale Tracaform. You grind a form/shape and then the tracaform follows that form and moves the diamond to follow. I will try to post a photo when I get a chance to do so.

Like the Diaform the Tracaform would not be great for a close /small serration, but better for perhaps a 1/16 or larger radius and continuing to a form/shape, or an angle.

Yes likely to soon sell that along with my Fluid Motion dresser, and my slide dresser(homemade).

I can't find a Tracaform on the internet so I guess it is a rare bird, but the Fluid Motion is on the net.

Does the OP have creep feed?
Do you (OP) have a sense of how often the wheel will need dressed (without creep feed and the perfect wheel, coolant, feedrate combo?)

While i've never made or used one, i agree with Michigan that a crush feed system, set up on the end of the grinder for use as necessary in process, is probably going to be most practical. Crush dressing also makes the sharpest most open effect on the grinding wheel grit, too.

smt

CBN plated wheel?

You can buy a formed dresser that's been electroplated with diamond grit as well. You just stick it on the mag chuck and run the wheel back and forth across it while downfeeding until you've got your form. Alternatively you can set the top of the form dresser at the same height as your workpiece top and just feed the wheel down while the table reciprocates. The shape of the formed dresser will be mirrored in the parts. When you stop seeing sparks you're finished. I forget the name of the company. This seems the best option to me if you want quick and easy, as well as fairly long lasting.

A CBN electroplated formed grinding wheel would work well too though I think that would cost a bit more than the formed dresser. A crush dresser makes more sense if you're doing high volume and many parts at a time.

On a diaform lets just ignore the time and problems to make this template.
How long to carve it in a wheel. Great idea at a dollar fifty or maybe up to five or ten bucks per hour.
There as so many money loosing ways to do this. Have been there but at least I got it done so some feel good.

Found it on eBay
This is what I am talking about.
Roll Type Grinding Wheel Dresser Machinist Tool Maker Box Find Surface Grinder T | eBay

It is a rare bird and with having a roll form you should buy it. (I should buy it)

Copy-paste this to eBay to find a good wheel for grinding a form (if you might wish to change it.)
Bay State 7x1/2x1-1/4 9A100-L5-V72 Orange Grinding Wheel (GW037-E-1)
It is another rare bird, wheel.

Yes, you still need to find crushable grinding wheels, perhaps a PM guy can help or call Radiac. I don't know if Radiac makes them but if not they will give you a source.

*The fellow selling the dresser may have some used crushable wheels.

One trick to grinding the likes of a roll is you take a small amount from each notch for the whole row, and go back and pass again, that way the first and last are not highly different from wheel breakdown.

That's more or less what i was thinking of, as well.
My DoALL manual lists table mounted units, and describes their use.
They offered both powered and idler types as options.

One set up shown for production has a crush roll dresser and roll on each end of the table outside the magnet.
One end was the master, the other end the working roll.
WTTE: "after about each 100 wheel dressings with the working roll, the wheel should be dressed on the master roll, and used to regrind the working roll" There's also verbiage elsewhere about if production is really high, you might need a "grandmaster" roll to re-dress the master roll, from time to time.

DoALL notes (without other stipulation) that only vitrified wheels can be used, whether Al or Si oxide. They suggest 120 grit minimum & up, but that is largely based on how sharp the corners need held. They suggest oil coolant for grinding with crush dressed wheels. Both conventional downfeed, and creepfeed approach to grinding the work are mentioned; though the assumption is that either way the increment/advance is by means of autofeed.

stephen thomas said:

That's more or less what i was thinking of, as well.
My DoALL manual lists table mounted units, and describes their use.
They offered both powered and idler types as options.

One set up shown for production has a crush roll dresser and roll on each end of the table outside the magnet.
One end was the master, the other end the working roll.
WTTE: "after about each 100 wheel dressings with the working roll, the wheel should be dressed on the master roll, and used to regrind the working roll" There's also verbiage elsewhere about if production is really high, you might need a "grandmaster" roll to re-dress the master roll, from time to time.

DoALL notes (without other stipulation) that only vitrified wheels can be used, whether Al or Si oxide. They suggest 120 grit minimum & up, but that is largely based on how sharp the corners need held. They suggest oil coolant for grinding with crush dressed wheels. Both conventional downfeed, and creepfeed approach to grinding the work are mentioned; though the assumption is that either way the increment/advance is by means of autofeed.

Click to expand...

The same or very similar is in my Brown & Sharpe grinder's manual.

Wow thanks for all the responses everyone!

stephen thomas said:

Does the OP have creep feed?
Do you (OP) have a sense of how often the wheel will need dressed (without creep feed and the perfect wheel, coolant, feedrate combo?)

While i've never made or used one, i agree with Michigan that a crush feed system, set up on the end of the grinder for use as necessary in process, is probably going to be most practical. Crush dressing also makes the sharpest most open effect on the grinding wheel grit, too.

smt

Click to expand...

I'm not sure what a creep feed is so I guess I don't... I have a Harig 618 if that helps. I'm thinking I want to stay from crush dressing though, as I'm not set up for that and I'm not sure what grit and resin would be necessary to support such small peaks.

CarbideBob said:

CBN plated wheel?

Click to expand...

I've looked into this and it's about $400 which I am totally willing to do, however, I wanted to stay away from a plated wheel because I'm really not sure how long it would last. The abrasive would seem to strip out of the peaks much quicker than the rest of the form, and I wouldn't be able to re-dress but would have to send it out for re-plating.

eKretz said:

You can buy a formed dresser that's been electroplated with diamond grit as well. You just stick it on the mag chuck and run the wheel back and forth across it while downfeeding until you've got your form. Alternatively you can set the top of the form dresser at the same height as your workpiece top and just feed the wheel down while the table reciprocates. The shape of the formed dresser will be mirrored in the parts. When you stop seeing sparks you're finished. I forget the name of the company. This seems the best option to me if you want quick and easy, as well as fairly long lasting.

A CBN electroplated formed grinding wheel would work well too though I think that would cost a bit more than the formed dresser. A crush dresser makes more sense if you're doing high volume and many parts at a time.

Click to expand...

I'm thinking you are right... I would love to find a formed dresser that I could just mount on my chuck, run it back and forth under the wheel to dress it, and be ready to go. unfortunately from what I've read the form dressers are all wheels that spin (similar to ebay link below) so as to not strip the grit out of the one contact area on a static form dresser.

michiganbuck said:

Found it on eBay
This is what I am talking about.
Roll Type Grinding Wheel Dresser Machinist Tool Maker Box Find Surface Grinder T | eBay

It is a rare bird and with having a roll form you should buy it. (I should buy it)

Copy-paste this to eBay to find a good wheel for grinding a form (if you might wish to change it.)
Bay State 7x1/2x1-1/4 9A100-L5-V72 Orange Grinding Wheel (GW037-E-1)
It is another rare bird, wheel.

Yes, you still need to find crushable grinding wheels, perhaps a PM guy can help or call Radiac. I don't know if Radiac makes them but if not they will give you a source.

*The fellow selling the dresser may have some used crushable wheels.

One trick to grinding the likes of a roll is you take a small amount from each notch for the whole row, and go back and pass again, that way the first and last are not highly different from wheel breakdown.

Click to expand...

Thanks for looking that up! Something like this looks exactly like what I'm looking for. But I'm thinking I want a form dressing wheel that can spin and grind the shape into the abrasive wheel... but it sounds like what you posted is for crush dressing based upon what you said about me needing a crush wheel (even though it looks like it would be for form grinding dressing) - is that right?

Pic for everyone:


Even if I don't get this one, I think this is what I'm looking for. I could have a custom form wheel made - but the abrasive compatibility is what I'm not sure about. I use some radius'd 120 grit bonded CBN wheels by Global Tooling, which actually is a really hard bond and has lasted a long time for me.

You see the serrations on the back of this blade.
Clearance Moulder & Planer Knives – Global Tooling & Supply.

Those are what we ground at Cutmore Tool back in the 60s for various mill cutters .. on high volume sometimes hundreds even thousands.

High accuracy and very fast to grind with a roll crusher set-up..*and not an expensive special wheel.

OP said:

I'm thinking I want to stay from crush dressing though, as I'm not set up for that and I'm not sure what grit and resin would be necessary to support such small peaks.

Click to expand...

Then he said:

Thanks for looking that up! Something like this looks exactly like what I'm looking for. But I'm thinking I want a form dressing wheel that can spin and grind the shape into the abrasive wheel... but it sounds like what you posted is for crush dressing based upon what you said about me needing a crush wheel (even though it looks like it would be for form grinding dressing) - is that right?

Click to expand...

There's some confusion going on here.
The eBay unit shown is for crush dressing, can even be used with steel rolls you make yourself on your lathe with a form ground plunge tool. Crush dressing makes a far sharper working wheel than one that "grinds" in the profile, or even a diaform type.
Your concerns about the lightness of the Harig do have merit. It would be good to add tape inside any wheel you try crushing (or around the dedicated arbor), to minimize the wheel's ability to shift on the arbor under the pressure.

Either the grinding wheel, or the dressing wheel can be "powered" including armstrong actuation like the eBay item. DoALL manual suggests "250 - 300 rpm" though they don't parse that to roll size or wheel size. (example in manual is suggested aprox 6" crush roll dia, but the book is for grinders with 8" through 12" dia wheels). Emphasis is to not skid the wheel - Make contact & add pressure quickly, dialing it in as the parts turn, and then finish with another few .001's downfeed, and crank a bit longer. Just don't flat spot the dresser roll. The ebay unit seems ideal for us small shops to experiment, because it is completely under operator control, and you can "feel" what is going on, without any opportunity to over speed it or risk other uncontrolled mayhem while on the learning curve.

smt

PS

I'm not sure what grit and resin

Click to expand...

As has been stated - NO resin. Vitirified only. Grits finer than 120.

You can research the grit vs corner profile, since that is well established, whether the op includes diamond dressing (conventional R & A dresser, Diaform, optidress); or superabrasive blocks or rolls like the plated forms you mention, or crush dressing. It's the same grit spec for a given corner, regardless your method to dress it. The only difference is that "cutting" the form into a wheel by any of the diamond/superabrasive methods mentioned makes a dull cutting tool because diamond actually cuts the softer Al oxide grit. Crush dressing (& "crackerjack" dressing) fracture the grit into shape leaving an array of mostly sharp points to grind crisply with less heat.