Lapping plates-3 Plate method

[Janderso]

Oxtool did a segment on this.
I thought I would have a go. I really enjoy working with cast iron! The one drawback is the graphite!
I'm going to cut the grooves with my 14" Delta band saw. 90 degree grid should be easy this way.

I have some lapping powder on the way. 600 and 1,200 grit.
The diamond paste will embed in the plate so I'm using garnet and silicon carbide

 

[benmychree]

Milling machine would be lots better for grooves.

 

[Janderso]

Milling machine would be lots better for grooves.

Well, I thought about it, the bandsaw took about 45 minutes total.
I have clean edges-sharp.
John, what are the benefits of using the mill?
I pondered a slitting saw on the mill too.

 

[rabler]

Milling machine would be lots better for grooves.

I'd be curious why it would make that much difference? Sure, a slitting saw on a mill would allow uniform depth and spacing, but how much difference would that make in using it to lap?

 

[extropic]

Interesting project. Please provide details of the CI you've got (dimensions?, grade?, source?).

Watching.

 

[benmychree]

Well, I thought about it, the bandsaw took about 45 minutes total.
I have clean edges-sharp.
John, what are the benefits of using the mill?
I pondered a slitting saw on the mill too.

Benefits? For one, being able to sit down while the machine does the work. Also, one could gang several slitting saws to hasten the work.

 

[Ulma Doctor]

interesting project!!!
i'll be watching!!!

 

[SLK001]

Milling machine would be lots better for grooves.

On a horizontal mill, yes, but a vertical mill will require setting up the disks on a 90º surface. Plus, there's the headroom required for the lower cuts. As for sitting down and watching the cut, once you get the angle right on the bandsaw, it seems like it would be the easiest method. After all, these aren't precision cuts.

 

[C-Bag]

If I remember right Tom used a circular saw to do his cuts. I don’t think he has a horizontal mill either.

 

[Janderso]

Benefits? For one, being able to sit down while the machine does the work. Also, one could gang several slitting saws to hasten the work.

"Gang several slitting saw".
John, with all due respect, I own "a" slitting saw, and to set up a gang of them would take me longer to set up than to just cut the darn grooves.
In the end, we are allowing a place for the slurry to go during the lapping process. To prevent a "bow wave" as Tom Lipton described it.
I appreciate the ideas of a lifetime machinist but some things are beyond my scope. In fact, most things are beyond my scope.