Blanchard grinding

[Marc Coogan]

I picked up a Newman 12" jointer that has some weld repairs on the infeed side. I called a few machine shops with no luck about Blanchard grinding. Does anyone here know a shop for this in NJ area?

[Steve Menendez]

Does it have to be Blanchard (segmented wheels, rotary head), or will other surface grinding methods work for the application?

Steve.

[Sam Puhalovich]

Marc, I had my 12" jointer tables re-surfaced by a engine re-building shop using their head surfacing machine.
Cost was $50 per table, results were perfect.

[Peter Kelly]

Does it have to be Blanchard (segmented wheels, rotary head), or will other surface grinding methods work for the application?

Steve.

I'm not sure I understand the obsession with Blanchard grinding here either. Regular linear surface grinders are more common and work just as well.

[Steve Menendez]

In some ways, I think that the term "Blanchard" grinding has taken on a life of it's own, kind of like Kleenex, or Xerox, or Coke.

Steve.

[Peter Quinn]

What do you call those tables ground with the regular series of swirl marks? I was told blanchard ground, is that not correct? My obsession with them is they rock. Particularly on hand fed machines like jointers, table saw, BS, shaper etc. Far less feed resistance than a flat shiny table IME. Seems popular among Italian machines, I for one prefer them on wood working machines.

[Peter Kelly]

As Steve mentioned above, "Blanchard" refers to a machine with segmented wheels and rotary head which will leave the swirled pattern. An example of this would be the surface of an older PM 66 saw.

The Italian-made machines I own and have owned in the past have surfaces that look more like they were done with really large fly cutter rather than a Blanchard-type grinder.

[Erik Loza]

I'm not sure I understand the obsession with Blanchard grinding here either. Regular linear surface grinders are more common and work just as well.

In some ways, I think that the term "Blanchard" grinding has taken on a life of it's own, kind of like Kleenex, or Xerox, or Coke.

Steve.

This ^^^^

There many ways to get a surface flat. And, run wood over it for six months no matter how it was ground to begin with, it will all look the same in the end.

Erik Loza
Minimax USA

[Bruce Page]

In some ways, I think that the term "Blanchard" grinding has taken on a life of it's own, kind of like Kleenex, or Xerox, or Coke.

Steve.

So true. I worked in a shop that had a large Mattison rotary grinder and never heard of “Blanchard” grinding until I worked at a shop with a Blanchard grinder.

[Peter Kelly]

I think the only real reason so many woodworking machines have rotary-ground surfaces is speed of manufacturing and cost rather than precision. I've never seen Blanchard-type finishes on the reference surfaces of precision metalworking machinery. The tables of the Bridgeport J-Head Mill I learned on were hand scraped.

[David Kumm]

Machines used to have planed surfaces more often. More expensive but the straight line ridges are very effective at reducing friction when feeding stock. As an old machine guy i prefer them as it is easier to see the wear pattern on the table. I have machines from the 1930s and newer where you can still see the lines all the way across the table. SCMI used to do it until the 1990s and a few still do on selective machines but it is disappearing. Dave

[Steve Menendez]

I think the only real reason so many woodworking machines have rotary-ground surfaces is speed of manufacturing and cost rather than precision. I've never seen Blanchard-type finishes on the reference surfaces of precision metalworking machinery. The tables of the Bridgeport J-Head Mill I learned on were hand scraped.

"Bridgeport" is another example of a name brand that has become almost synonymous with a whole family of vertical milling machines. You can't buy that kind of publicity.

Steve

[Marc Coogan]

I talked to a local machine shop and emailed some pictures hopefully they can help. I purchased the jointer thru I.R.S. auctions and the seller forgot to mention the repaired table. I.R.S.thought it was shady that the seller did that, but couldn't do anything about it.

[Marc Coogan]

I'm open to whatever process can true up the tables.

[Peter Quinn]

This ^^^^

There many ways to get a surface flat. And, run wood over it for six months no matter how it was ground to begin with, it will all look the same in the end.

Erik Loza
Minimax USA

So what process does SCMI/minimax use? The tables on my little t-40 at home and the T-130 I'm using at work, as well as every SCMI jointer I've used have that swirled clearly rotary "flat over the distance but not quite flat in a given area" finish with a dull grey luster. A little wax and stuff just flies over these tables in a way the shiny polished tables never does. Google search indicates blanchard or rotary grind is not ultimately the most accurate way to grind but has an efficient balance of speed and precision appropriate for wood working machinery, another source indicates it can be highly accurate if required, well beyond requirements for wood working machine tops.