Milling the Primary Angle?

[MTBob]

In Don Robinson's book, Slipjoints My Way, he demonstrates cutting a blade's primary angle on his mill using a tilt table. I would show a photo, but don't want to violate his copyright.
Don actually mills two blades using this method, connected end to end on one piece of metal. It's a clever technique that I might use not only on slipjoints, but also fixed blades. It essentially allows establishment of an accurate and controllable primary angle and plunge line. All that's necessary after milling is cleaning up the cutter marks on the belt grinder.
How many of you use this method to cut a primary angle?

 

[J. Doyle]

It seems to me like it's a lot more time and effort and possibly tooling costs than just grinding the bevels.

But.....if you don't have any other alternative, I have no doubt that it can be done accurately and efficiently with proper tooling and set up.

 

[Mark Knapp]

I do it on my production knives, in the CNC mill. On my one-offs, it's all by hand. For a one-off, I can have the bevels ground on the 2 X 72 faster than it would take to set up the milling machine.

The nice thing about all this stuff is, you can find what works best for you and do that.

 

[Smallshop]

In Don Robinson's book, Slipjoints My Way, he demonstrates cutting a blade's primary angle on his mill using a tilt table. I would show a photo, but don't want to violate his copyright.
Don actually mills two blades using this method, connected end to end on one piece of metal. It's a clever technique that I might use not only on slipjoints, but also fixed blades. It essentially allows establishment of an accurate and controllable primary angle and plunge line. All that's necessary after milling is cleaning up the cutter marks on the belt grinder.
How many of you use this method to cut a primary angle?

I do it on my Bowies to remove extra material before grind....I leave a lug along the edge to protect it during heat treat. it will be some time before I recoup the time spent tooling and programming...Lol! but health issues dictate that I can no longer rough grind in a large blade before grind. I also profile 'em at the same time. Prolly cheaper to water-jet...but I have the machine and no funds for water jetting...milling a profile on 1/4" thick tool-steel is pretty slow...

 

[Kev]

I tried that method when I was starting out, and honestly it’s not worth the time or the money to do it that way. For the price of tooling you can buy gobbs of steel and belts to practice with. I got 90% of my tooling for free and it still wasn’t worth it.

 

[MTBob]

Ok, seems like the verdict is in - possible to do, but not all that worthwhile. Thanks for saving me from a long journey down a slippery slope!

 

[Smallshop]

Ok, seems like the verdict is in - possible to do, but not all that worthwhile. Thanks for saving me from a long journey down a slippery slope!

I believe some of the most recent technological advancements in manufacturing have been in abrasives. The variety of abrasives available to the knife maker currently is downright amazing. In some ways your belt grinder may be the most sophisticated piece of equipment in your shop. Historically metal removal by abrasive has always been the most efficient means and is still true today. It's just not applicable in every area...But blade making is simple....and a belt grinder is very hard to beat for efficiency...and always will be at most of our levels of production.

in manufacturing the word efficient ALWAYS means cheaper....when you look at the cost of a ceramic belt versus a micro grain carbide endmill...and the amount of work the two will do....you will hug your belt grinder.

 

[Smallshop]

I just realized that I may be echo-ing things John Wilson told me about 5 years ago....lol. Us guys coming from a manufacturing background think we're gonna stand the knife-making biz on end...then the schooling starts...lol!

 

[MTBob]

I believe some of the most recent technological advancements in manufacturing have been in abrasives. The variety of abrasives available to the knife maker currently is downright amazing. In some ways your belt grinder may be the most sophisticated piece of equipment in your shop. Historically metal removal by abrasive has always been the most efficient means and is still true today. It's just not applicable in every area...But blade making is simple....and a belt grinder is very hard to beat for efficiency...and always will be at most of our levels of production.

in manufacturing the word efficient ALWAYS means cheaper....when you look at the cost of a ceramic belt versus a micro grain carbide endmill...and the amount of work the two will do....you will hug your belt grinder.

Those are some profound thoughts that make a lot of sense. Thanks!
Actually my belt grinder and I have a very special and intimate relationship.

 

[Daniel Macina]

Actually my belt grinder and I have a very special and intimate relationship.

To much info. I mean we all had a hunch but you didn’t have to just come out and say it!

 

[Kev]

I just realized that I may be echo-ing things John Wilson told me about 5 years ago....lol. Us guys coming from a manufacturing background think we're gonna stand the knife-making biz on end...then the schooling starts...lol!

Yep. I spent 20 years in a machine shop, and it took me a while to realize that most of the mistakes in knife making had already been made, I just had to listen.

 

[Bruce McLeish]

Yep. I spent 20 years in a machine shop, and it took me a while to realize that most of the mistakes in knife making had already been made, I just had to listen.

wanna bet? I make new ones every day that I'm in the shop.

 

[Kev]

wanna bet? I make new ones every day that I'm in the shop.

I supposed I could have phrased that differently. Most mistakes in knife making have already been made by someone else.