PDA

View Full Version : Suggestions for HF Tool Grinder Wheels?



retusaf99
07-03-2008, 01:52 AM
HF sent me a flyer with their 6" tool grinder (Item 46727) on sale for $135, along with a 15% off coupon, so I think I'm sold. I know I've read other threads about this grinder, but I'll be darned if I can find them. What I recall is pretty positive, but the supplied green wheels suck.

After using Forrest Addy's diamond wheel to sharpen my carbide-tipped scraper at his scraping class, I'm sold on a diamond wheel on one side. I ordered one from CDCO for $60.

I haven't bought the grinder yet, but can anyone recommend an AO or ??? I've checked ENCO, Travers, MSC, and just get confused. I'm thinking the other wheel is for HSS. I have a couple other grinders that I can use for grinding less precision stuff.

Any advice from the experts?

Heck, while I'm asking questions, Forrest used a diamond paste to charge his diamond wheel. Can anyone expound on use of a diamond wheel with that kind of paste? ENCO has it in a zillion grades. Where do you start?

Doug

lazlo
07-03-2008, 02:36 AM
AO wheels are relatively hard to find for this grinder they're Type 35 Plate Mounted Wheels. J&L Industrial sells an unbranded A46 plate mounted wheel for ~$45 -- it's actually a Norton OEM wheel. Wait for the 25% off sale every three weeks. KBCTools also sells a Chicom A46 plate mounted wheel for ~ $40.

Enco doesn't carry them, and MSC only carries the Norton-branded plate mounted wheels, which are $90 each.

Forrest's "diamond" wheel was a cast iron lap -- you apply diamond paste and hone the scraping tool with it.

A diamond wheel is electroplated with diamond -- you don't need diamond compound.

lazlo
07-03-2008, 02:41 AM
By the way Doug, here's a thread I posted awhile back about mounting Western diamond wheels on the HF grinder, which has 8mm tapped holes. I also mention the Type 35 and D6A2 (diamond) wheels that work with this grinder:

Pinging Forrest: Harbor Freight Tool Grinder Question (http://bbs.homeshopmachinist.net/showthread.php?t=25295)

retusaf99
07-03-2008, 02:46 AM
AO wheels are relatively hard to find for this grinder they're Type 35 Plate Mounted Wheels. J&L Industrial sells an unbranded A46 plate mounted wheel for ~$45 -- it's actually a Norton OEM wheel. Wait for the 25% off sale every three weeks. KBCTools also sells a Chicom A46 plate mounted wheel for ~ $40.

Enco doesn't carry them, and MSC only carries the Norton-branded plate mounted wheels, which are $90 each.

Forrest's "diamond" wheel was a cast iron lap -- you apply diamond paste and hone the scraping tool with it.

A diamond wheel is electroplated with diamond -- you don't need diamond compound.

Lazlo, you are a gentleman and scholar. Thanks very much for your input. I'm venturing into new territory, and greatly appreciate your wisdom.

ETA to just say thank you. (Edit to add)

Doug

macona
07-03-2008, 05:02 AM
Some diamond wheels are resin bonded too, and there is another type as well.

My Leonard grind-r-lap has a copper lap disc that you load with diamond grit or the lapping compound of your choice. Still need to get some. Had the thing for a year and never used it.

wierdscience
07-03-2008, 08:32 AM
Yup,resin boned wheels are better,last much longer,but cost 2x's as much however they are worth it.

Evan
07-03-2008, 08:45 AM
There is also a type of semi-vitrified bond diamond wheel but I haven't seen one, yet. $$$$$

Electroplate diamond wheels are the cheapest and fastest cutting but also have the shortest life. As they are used the diamonds are fractured and the effective grit size becomes smaller.


My Leonard grind-r-lap has a copper lap disc that you load with diamond grit or the lapping compound of your choice

Try it, you will like it. It's the only way to put a mirror finish on a carbide tool. I use a brass lap with diamond dust to polish carbide engraving tools that I custom grind. Even under the stereo microscope they look like mirrors.

GKman
07-03-2008, 12:13 PM
There is also a type of semi-vitrified bond diamond wheel but I haven't seen one, yet. $$$$$

Electroplate diamond wheels are the cheapest and fastest cutting but also have the shortest life. As they are used the diamonds are fractured and the effective grit size becomes smaller.



Try it, you will like it. It's the only way to put a mirror finish on a carbide tool. I use a brass lap with diamond dust to polish carbide engraving tools that I custom grind. Even under the stereo microscope they look like mirrors.

Wat sequence of grit size do you use from rough shaping to final finish?

Evan
07-03-2008, 01:50 PM
Umm, It depends. :rolleyes:

One of these days I will put together a post on sharpening carbide. I have a wide variety of wheels and grinders that I use including unconventional methods (what a surprise).

dp
07-03-2008, 02:06 PM
Hmmm - I didn't get one of those flyers, but if I had I'd go buy one, too. Mebbe I'll stop by the store today and chat it up with them.

retusaf99
07-03-2008, 02:26 PM
Umm, It depends. :rolleyes:

One of these days I will put together a post on sharpening carbide. I have a wide variety of wheels and grinders that I use including unconventional methods (what a surprise).

Evan,

I'd love to see your thoughts on this.

Doug

GKman
07-03-2008, 03:35 PM
Umm, It depends. :rolleyes:

One of these days I will put together a post on sharpening carbide. I have a wide variety of wheels and grinders that I use including unconventional methods (what a surprise).

Like marrying the supplier?:cool:

loose nut
07-03-2008, 06:15 PM
what would the life expectancy of an electroplate style of wheel be. is there anyway to quantify it.

lazlo
07-03-2008, 06:35 PM
Diamond and CBN wheels are electroplated, and they last for years.

Evan
07-03-2008, 09:56 PM
Electroplate retention of the grit is more common for diamond than CBN. Most CBN wheels are resinoid bond, not electroplate.

This is a 10" electroplate diamond wheel. Electroplate weels are easy to identify as the layer of grit is very thin. It is held in place by a coating of nickel that is electroplated over the particles of diamond or, less commonly CBN.

http://vts.bc.ca/pics/diamond1.jpg

This is a CBN wheel, resinoid bond. It is also easy to identify as the layer of grit has substantial thickness, in this case about .25 inch. Most CBN wheels are this type of resin bond.

http://vts.bc.ca/pics/cbncup.jpg


I didn't "marry the supplier". She has only had that job since the mid 90s. It is handy though.

http://vts.bc.ca/pics/wheels1.jpg

Charlie C
07-03-2008, 11:17 PM
When you get your grinder pull of the backing plate and look it over for voids. Mine had a big void in the bore of the plate and a couple more voids out on the plate proper.

I made two new plates as I felt that the plate could be unsafe with the voids and would be unbalanced for sure.

lazlo
07-04-2008, 12:27 AM
Electroplate retention of the grit is more common for diamond than CBN. Most CBN wheels are resinoid bond, not electroplate.

Most cost-engineered (import) CBN wheels are resinoid.

All the big industrial Superabrasives vendors (Norton, 3M, Carborundum, , Bonded, Branson, Unitron, ...) sell both, and nickel electroplated is more common for both diamond and CBN wheels.

In vitrified and resin bonded diamond and CBN wheels, the diamond or CBN particles are buried beneath the resin, so it's a rougher, hotter cutting action. They're recommended for roughing operations and heavy stock removal.

With electroplated wheels the diamond/CBN particles protrude from the nickel matrix, which promotes a freer, faster cutting action with minimum heat generation. Norton recommends electroplated wheels for finishing operations, including finishing carbide.

From the Norton Superabrasives catalog:

http://i164.photobucket.com/albums/u15/rtgeorge_album/Norton-1.gif

lazlo
07-04-2008, 12:32 AM
By the way, since we're apparently doing show and tell, here are a couple of CBN wheels that were in arms' reach. The top left is a Norton CBN electroplated cutoff wheel -- awesome for pre-cutting M42 and T-15 tool steel. The top middle is a Norton Aztec 100 grit resin-bonded cup wheel. The middle right is a Carborundum 150 grit electroplated cup wheel. The bottom middle is some unknown Western 100 grit CBN cup wheel. I think it's resin bonded, but it's hard to tell:

http://i164.photobucket.com/albums/u15/rtgeorge_album/Norton.jpg

lazlo
07-04-2008, 12:43 AM
Here's a good tutorial on the different superabrasive bonding styles and the application segment from Diamant:

http://www.riegger-diamant.com/grundlagen/bindungen.php

Resin bonds

The resin bond is a very versatile type of bond. Its range of application covers far more than half of all the machining tasks for which diamond and CBN grinding tools can be used.

The outstanding features of a resin bond are that it enables large cutting volumes as well as soft and cool grinding.

However, its rate of wear is higher than that of sintered metal bonds.

Sintered metal bonds

Sintered metal bonds can be divided into two main groups: bronze bonds and steel bonds.
In special cases, bonds made of hard materials are also used.

The higher mechanical stability and thermal load capacity of sintered metal bonds gives them a greater resistance to wear than offered by resin bonds. This is utilized especially in connection with grinding tools for profile grinding jobs and in the machining of materials which exhibit a strong abrading effect, such as glass, ceramics, etc.

With the exception of brittle bronze bonds, sintered metal bonds yield lower material removal rates than resin bonds do.

Electroplated bonds

In the electroplated bond, the grain-on-grain abrading medium is embedded on a substrate by a metallic deposit in a galvanic bath.

As a rule a single-layer coating is used, however, a multilayer coating is also possible where feasible.

In the case of the single-layer coating, the abrasive grains protrude out of the bond by approx. 1/3 of their size.

http://www.riegger-diamant.com/images/aufbau-bindung.gif

The main characteristic features of diamond and CBN grinding tools with electroplated bonding are:

- Exceptional gripping capacity,
- High cutting capacity,
- Manufacture of complex profiles,
- Manufacture of tools with micro dimensions,
- Repeated use of substrates.

Evan
07-04-2008, 02:59 AM
Most cost-engineered (import) CBN wheels are resinoid.


That may be so. My wife doesn't sell imported wheels. Virtually all the CBN wheels she sells are resin bond by request of her customers. They are made, including custom orders, here in BC. They most definitely are not "cost engineered". The occasional request does come in for electroplated CBN wheels until the customer finds out how much they cost compared to resin bond. They are available if the customer wishes.

[edit]


All the big industrial Superabrasives vendors (Norton, 3M, Carborundum, , Bonded, Branson, Unitron, ...) sell both, and nickel electroplated is more common for both diamond and CBN wheels.


In the real world the sawmills in western Canada buy almost exclusively resin bond CBN. Norton BTW has many of their wheels made offshore.

Swarf&Sparks
07-04-2008, 12:34 PM
I use mainly HSS tooling on a 9 x 20 lathe.
Looking at (maybe) a high-end cup stone, CBN.
Will it do the occasional touch-up on carbide?

Any recommendations within those parameters?

lazlo
07-04-2008, 12:39 PM
It's pretty decent grinder if you treat it as a kit and do the mods that several here have suggested. Turning the backs of the aluminum wheel mount castings really improves the balance, as does turning the shaft spacer concentric.

The "green" wheels that came with mine were sh!t. They're some kit of white abrasive with green paint sprayed on it, and they were wildly out of balance out of the box. If there are any masochists who want them for the price of shipping, I have two brand new wheels.

If you're looking for something to touch-up carbide, one of those cheap diamond hand-laps will leave a much nicer finish...

Swarf&Sparks
07-04-2008, 12:52 PM
Know what you're saying Rob, and I have something a little better than a cheap diamond hone (though I have a few of those too)
The main beast is a DMT mono-diamond 300x50 :)

I have a decent bench grinder, and I'm looking at doing a "Sir John" for small carbide and HSS tooling.

Is there a compromise?
Diamond is not going to last on carbon steel, I'm inclined to go for CBN.

Dental diamonds I have in abundance, they are effectively disposable.
Likewise dental carbide burs (RA)
Nice for shaping very small form tools, but I'd like to grind 1/4" to 1/2" HSS and "touch up" small carbide boring bars etc, to a good edge. (read, cut 316 SS)

retusaf99
07-04-2008, 12:55 PM
The more you guys post, the more confused I get. Did I do OK ordering the CDCO wheel?

6" Diamond Grinding Wheels - Type D6A2C
http://www.cdcotools.com/index.php

I can't make a link work.

Doug:confused:

lazlo
07-04-2008, 01:03 PM
The more you guys post, the more confused I get. Did I do OK ordering the CDCO wheel?

You're set Dave -- that's what you wanted.

While you're waiting for the wheel to arrive, get yourself some M6 x 20mm (length) flat-head socket screws for it. The diamond wheels use the smaller set of holes in the mounting plate, and they're tapped Metric.

Lowes and Home Depot don't have them (at least, the ones in North Austin), but Ace Hardware carries the M6x20mm.

lazlo
07-04-2008, 01:06 PM
I have a decent bench grinder, and I'm looking at doing a "Sir John" for small carbide and HSS tooling.

Is there a compromise?

The HF grinder with a diamond wheel on one end, an AO on the other. That's how mine is set up.
I bought a 3M diamond wheel on Ebay. The D6A2's got for between $50 and $100. If you don't want to do Ebay, CDCO's diamond wheels are around $60, and they're apparently pretty decent.


Diamond is not going to last on carbon steel, I'm inclined to go for CBN.

You're not supposed to use CBN on carbide, but Bill Pace mentioned that he accidentally used a CDCO CBN wheel on carbide, and the wheel and the carbide were both fine. YMMV.

Swarf&Sparks
07-04-2008, 01:09 PM
Don't use diamond on carbon steel unless you're running coolant.

Swarf&Sparks
07-04-2008, 01:11 PM
sorry, cross post
my last was to retusaf :o

retusaf99
07-04-2008, 05:12 PM
Cubic Boron Nitride (CBN)....Learn something every day. Is this a somewhat recent material development, or am I just out of the "cool stuff" loop? Would the wife like this better than diamonds?;)

Lazlo, begging your indulgence, but I went to J&L and started sorting thru 497 pages of grinding wheels....ACK!! Please, sir, give me a catalog # or something to narrow the search. What's maddening is the photos are very generic. (Yup, these are grinding wheels that might look like this, but maybe not.)

If anyone has a reference/link for grinding/abrasive wheel technology, it would be much appreciated.

Thanks guys!!

Doug

Swarf&Sparks
07-04-2008, 05:23 PM
retusaf, Im sure Evan will chime in at some stage here.
He's just across the road from you, in BC :D

Frankly, I'm as confused as you.
One thing I'm sure about, from experience, is you don't use diamond on steel (carbon) unless you regard the diamond as disposable, or use flood suds.

DICKEYBIRD
07-04-2008, 06:03 PM
Here's a link to the one I bought for my HF grinder. Don't expect it to be any straighter than the ones that come with the grinder.

I machined a stub adaptor, chucked the HF adapters in the 4 jaw and trued them up before installing the J&L wheel. It was worse than the original wheels and I had to true it up considerably with a diamond dresser. Works good now. Others here have said this is true of many grinding wheels.

http://www.jlindustrial.com/CPW-14210H/SEARCH:KEYWORD/product.html

Bill Pace
07-04-2008, 06:20 PM
Yes, I DID have a brain fart, and did some 20-25 carbide EM's using CBN ... there was certainly no change in the cutting ability to give me a clue as to the boo-boo. To clarify, this was on a tool & cutter grinder, not the HF carbide grinder. I have both a diamond and CBN 5" cup wheel for the T&C G and they are very similar in appearance and I just sat down without checking which wheel! Afterwards I examined the CBN with a loupe and did some HSS EM's and ---- well, no change!

As for the CDCO wheels, The diamond cup on the T&CG, and plate backed one on my Delta carbide grinder are theirs, while the CBN cup is off ebay. The CDCO wheels are giving me excellent service, I've used both quite a bit and I'm just blown away with the way they handle carbide (the CBN does the same with HSS!) and --- NO MESS!! And at the prices the Chinese vendors like CDCO are getting on both the diamond and CBN (the CBN is still a bit pricy) its much easier to have them in the home shop.

Re CBN, I havent seen one offered in the plate backed version for the HF type carbide grinders, have any of yall seen one? I hate to use an AO type wheel anymore with the grit/mess they put off

dp
07-04-2008, 06:58 PM
HF sent me a flyer with their 6" tool grinder (Item 46727) on sale for $135, along with a 15% off coupon, so I think I'm sold.

Just got back from HF with a grinder in the trunk. Thanks for the heads up on the special!

lazlo
07-04-2008, 08:34 PM
Here's a link to the one I bought for my HF grinder. Don't expect it to be any straighter than the ones that come with the grinder.

http://www.jlindustrial.com/CPW-14210H/SEARCH:KEYWORD/product.html

Yep, that's the one I ordered. Wait 'till the next 25% off sale at J&L, which should be next Monday.

Evan
07-04-2008, 10:21 PM
Grinding cobalt bonded carbide with CBN will sooner than later put a glaze on the wheel. It then must be dressed hard with a silicon carbide dressing stick which will remove the glaze and some of the CBN grit. I do it from time to time and the wheel loading isn't too bad if all you use it for is very light finish grinding. Don't try grinding carbide to form with a CBN wheel though.

retusaf99
07-05-2008, 12:52 AM
Just got back from HF with a grinder in the trunk. Thanks for the heads up on the special!

Hi Dennis,

I like to think that's why we come here. Thanks to all that have pointed me in the right direction for the grinding wheels. (Well, maybe not right for everyone, but at least a direction that has worked for others. I can't ask for any more.) I'll wait for the J&L sale and see what happens!

Thanks much guys!!

Doug

ETA : Man, that's like a dollar a pound. Wish they were made out of burger or pork sausage....Ummmmm...

retusaf99
07-06-2008, 11:26 PM
Here's a link to the one I bought for my HF grinder. Don't expect it to be any straighter than the ones that come with the grinder.

http://www.jlindustrial.com/CPW-14210H/SEARCH:KEYWORD/product.html

Dickeybird,
I'm not familiar with the 46K grit designation. Looks like you can get any grit you want in AO as long as it's 46K. I'm used to 60,120, 180, etc, and I think the K refers to hardness. But a quick google doesn't provide any help.

Any pointers here?

Oh, and I can't break the J&L catalog code. What the heck is "GC" price each, versus "39C" price each? (I don't mind asking stupid questions with this group.)

(You have to go out to the J&L catalog link, page 1371, that Dickeybird kindly provided, and look at the wheels.)

Doug

dp
07-06-2008, 11:34 PM
Anyone got hints for a good single and multi point wheel dressing tool for these things? I've used the Sioux valve grinder style dressing diamond nib and that works great, but haven't seen the equivalent for something like this except from Baldor.

lazlo
07-06-2008, 11:46 PM
I'm not familiar with the 46K grit designation. Looks like you can get any grit you want in AO as long as it's 46K. I'm used to 60,120, 180, etc, and I think the K refers to hardness.

That's right: 46 Grit, K (medium) hardness. That's pretty coarse, but it's the only grit that's easily available.

I picked up several of the Norton ToolRoom 32A Type 35 wheels in 60 and 80 grit from Grainger when they were clearancing them out -- they were around $30 each. I posted about the Grainger clearance here but didn't get any responses :confused:

From ShopSwarf's excellent machinery reference page:

http://shopswarf.orconhosting.net.nz/grindwheel.gif

retusaf99
07-06-2008, 11:50 PM
Anyone got hints for a good single and multi point wheel dressing tool for these things? I've used the Sioux valve grinder style dressing diamond nib and that works great, but haven't seen the equivalent for something like this except from Baldor.
I don't have any great tools, yet....but I'm thinkin'.

I have a couple chunks of 80/20 aluminum extrusion with triple tracks (4.5x1.5 thick?) . I know it's not cast iron, but if you're doing fine work, and not hogging stuff...

Lazlo,

That's what I was looking for! Thanks!

I apologizie for borrowing this from another forum, and would be happy to credit the author, Jim, but couldn't find a referecnce.

Rich-in-WA wrote...

> Anyone know of a good online source for Norton white aluminum oxide
> grinding wheels? In particular I'm after an 80 grit 7"x1" wheel. I
> think the Norton code might be 38A80-H8VBE (but this might not be the
> right dia). I've seen 6 and 8 inch wheels in some of the popular
> catalogs (Lee Valley, Rockler, etc) but none in 7-inch. I'm fitting
> these to a Baldor 7306 7-in, slow-speed grinder. I tried sourcing
> these locally, with no luck so far.

MSC (www.mscdirect.com (http://www.mscdirect.com/) ) and McMaster-Carr (www.mcmaster.com (http://www.mcmaster.com/)) both sell
them. Look for toolroom grinding wheels. The Norton code does not include
the wheel size, width, or hole diameter. You have to specify those when
ordering. Norton's grading code breaks down like this:

38A = abrasive type (38A is white aluminum oxide abrasive)
80 = grit (80 is the coarsest "fine")
H = grade I.e., hardness (H is the hardest "soft")
8 = structure (lower numbers have higher grain density [1])
V = bond type (V is vitrified)
BE = a Norton symbol designating a bond modification

[1] The structure number runs from 2 to 28, but 8 is near the middle of
the range {2,4,5,6,8,12,16,19,25,28}.

The size is specified as wheel Diameter x Thickness x Hole diameter
(DxTxH). You might want a 7 x 1 x 1-1/4 (but see below). You will
probably need a bushing to fit the wheel on your arbor, but 1-1/4 is the
most common hole diameter, so the wheels are less expensive and more
readily available.

The wheel type gives its geometry. You probably want a straight wheel
(type 1 or O1).

I haven't seen a type O1 size 7 x 1 x 1-1/4 in the 38A80-H8VBE grade.
Highest grit I've seen in that type, size, abrasive and hardness is the
46 grit. A much greater variety of grades are available in the 1/2"
thickness. This is the most common size used on surface grinders for
general work. I have seen the 38A80-H8VBE in O1 7 x 1/2 x 1-1/4.

For what it's worth, in my experience, the 32A runs a tad cooler than the
38A, and the 32AA is even cooler still. They are correspondingly more
expensive. These are a gray aluminum oxide, but definitely not to be
confused with the el-cheapo gray ones that come on el-cheapo grinders and
which can be found on the shelf at the local borg or hardware store.

Jim

(Thank you, Jim)


Doug

Black_Moons
10-25-2009, 04:42 PM
thanks evan on the advice of CBN on carbide. I allways wondered what would happen if I bought a CBN for general perpose use...

Wow at that collection.. looks like you need the quick change grinder wheel system iv been considering making :P