Lining up a Slitting saw for a "precision" cut..?

[EmilioG]

I making a 7/8" thk. finger plate from O1 tool steel and I need to make a fairly precise cut across the plate
at 3/8" in from one side of the plate. How do I line up a .046" thick x 3" saw blade to hit the mark?

It will be cut on a BP mill horizontally. Do I touch the blade to the top then dial in .3750" on the dial?

 

[microshop dinker]

How deep is the cut? Coolant? RPM on the saw blade?

 

[David S]

Do you want the kerf to be centred on the .375 line or to one side?

David

 

[EmilioG]

I need to cut a straight line right at .375" in from one end. .046" wide, .500" deep.
Right on the line., centered.
I spoke with a tech at Martindale Electric and they suggested a certain saw for the O1 tool steel.
Now I have to learn how to line up the saws teeth to cut right on the line that I have layed out.
If I can use a DRO, it will be cake.

 

[Billh50]

When you move the .375 also add .023 for half the cutter width. So after touching off you would need to dial in .398 to put the saw on a .375 centerline.

 

[EmilioG]

Thanks Bill, Right. forgot about calculating the saw width.
I just changed the width of the slot to .075", but the idea is the same. Add half the saw blades width.
So now it is .4125" after touching off. A DRO will make this so much better.
Martindale Electric, the makers of excellent USA saws, will custom grind an order for only $10 for all of the saws!
They also have a coating service, TIN, TiCN,... I'll probably order the blades in that width. About $100 for 8 , 3" saw blades., shipped.

 

[Bob Korves]

If possible, set up a sacrificial piece alongside and touching your work, make a cut into it to determine position, depth, width, and confirm you are getting a good cut, and then measure the cut location from the edge, and step it over by the required distance.

 

[ch2co]

You beat me to it Bob.
Yeah do like Bob said and I would have said if I beat him to the punch.
Better to cut a sacrificial piece wrong than the real thing

 

[EmilioG]

If possible, set up a sacrificial piece alongside and touching your work, make a cut into it to determine position, depth, width, and confirm you are getting a good cut, and then measure the cut location from the edge, and step it over by the required distance.

Awesome. Thanks Bill. That is great advice. I'll have to find a piece of steel at least the same size or larger. O1 flat stock is expensive, so I'll use 1018.