CBN inserts

[BILL-C]

I'm wondering which brand cbn inserts other shops have found to work the best on decking aluminum blocks with Darton sleeves. The .500 dia, .125 thick ones i am using now don't last good enough. Cutter has to be rotated every pass.

[PackardV8]

Same problem with some exhaust manifolds and all diesel heads with pre-cups. They just eat inserts. Only solution is to charge accordingly for time and materials.

[pdq67]

Are industrial diamond inserts available and if so, can you afford to use them?

I think I have read where diamond stuff lasts like at least 10 times longer than the next hardest material?

pdq67

[KnightEngines]

I surface grind alloy blocks with sleeves & diesel heads with pre-combs.

Plenty of lube & alloy grinds just fine with a segmented wheel.

[BillK]

Bill,
I have been using the ones that Joe Baker sells. They are gold colored. I haven't done a block with Darton sleeves but a few aluminum LS blocks and have not noticed any problems. How much are you taking off per pass ?

[BILL-C]

Stock blocks with stock iron sleeves cut like butter, it's the Darton sleeves that are tough to cut. There is almost the same insert life no matter what feeds and feeds we use. I suspect the insert just isn't up to this task. We ordered a special heavy duty insert from quality cutters today designed for diesel heads with precups and also exhaust manifolds. We'll see what happens Lol.

[pdq67]

AP Green Refractories diamond ground their 100 percent zero porosity 99.7 percent pure AL203 ARC Hard-D.

The stuff was 20,000 PSI iso-statically pressed to zero porosity and then it took a week up and down to fire it from room temp to 3200 and back down.

Green's took the fired raw tile/block and cut and ground it into whatever they needed it to be to sell it.

pdq67

[racear2865]

pre-cup heads require a cutter with a slight chamfer on it. Every thing else uses a sharp edge. Also, Ive had better luck using a 14 inch cutter made of cast iron using a 3/16 x .500 cutter.
reed

[ProPower engines]

I'm wondering which brand cbn inserts other shops have found to work the best on decking aluminum blocks with Darton sleeves. The .500 dia, .125 thick ones i am using now don't last good enough. Cutter has to be rotated every pass.

How much relief angle are you running on the cutter or tool bit holder??
Also have you tried PCD instead of carbide inserts?? The PCD inserts seem to cut better on harder surfaces then carbide.
Also the cutter speed has a lot to do with longevity of the insert. I have used the smaller 3/8" inserts with no issues but have wondered about the .500 inserts as I see them advertised less then the 3/8" inserts and also depends on where they are made as well. There is a lot of off shore inserts on the market at this time and while I thing the India made inserts are currently running up front it won't be long till the Asian inserts catch up.

Most times insert quality and coatings play a big part in how well they preform as well as how long they last on certain materials. Some are double sided and some are single with a back up shim attached but it still comes down to relief angle for a quality finish. Just think of it as an odd shaped single angle seat cutter insert. some cut fine at a certain speed and others not so much as not all tool holders are the same.

I would try a top quality insert specific to your holder and if that does the job your golden if not more R+D is needed.