Models for grinding HSS Lathe Tools

[mikey]

Pics of your set up and your tool always helps us to help you.

Aluminum is so easy to turn that you should have mirror finishes on facing and turning cuts with very little trouble. If this is not so then let's find out why.

 

[mikey]

I just found out that all three sets of the model tools have been lost. We do not know who has them. As a consequence, Jeff aka @Z2V, has been making more models and sending them out to folks who need them, and he is doing it on his dime. He has taken the time and expense on himself to send tool sets to a guy in South Africa and another in Canada, so I know there is still a demand for them.

If any of you have these models, please contact Jeff via PM to arrange to return them.

A BIG THANK YOU to Jeff for all his hard work and generosity.

 

[Z2V]

Thanks Mike, I’m glad to be a part of this.

 

[ttabbal]

Nice Jeff! That's great of you to do. If you need another couple sets, let me know. I'll grind some models and send them out.

I finally made my first Cobalt tool. Really enjoying working with it. Took a 0.001" cut exactly and I nailed the diameter I was aiming for, measured with a tenths mic. I suspect it was half luck, but I'll take it!

 

[Z2V]

Hey, I’ll take luck any day. Luck builds confidence which leads to repeatability.
Good job

 

[mikey]

Hey, you have a good tool and you know how to use it. Where does luck enter the picture?

I have seen your tools in person, Sir, and I'm not surprised one of them can take a half-thou cut, not at all.

 

[mickri]

I am starting to plan what I need to make an ER32 chuck for my lathe now that I have the raw material to make the chuck. I will be cutting an internal 1 1/2 x 8 tpi thread. Videos on cutting internal threads suggest cutting a groove to the depth of the thread where the thread ends. I have boring bars that use 1/4" and 1/8" tool steel. I have both HSS and cobalt in these sizes. I am thinking of using 15 degree front and side clearances with an 8 or 9 degree back rake and no side rake to make a tool to cut the groove. Something like this.



Will this work?

 

[Z2V]

I just looked at the first page of this thread and all I can say is WOW . The participation has been outstanding.
14 months, 29 full pages, 865 replies, and over 55,000 views. I have lost count of how many members that have handled the models but I’m certain it’s well over 30. We have models in Canada, Australia, South Africa and 3 sets still floating around here. Thanks to everyone that’s joined in.
I knew nothing about grinding tool bits when I first saw this thread and now I can grind a tool that I can make repeat cuts with.
Mikey, you hit it out of the park with this topic.
Thank You

 

[mikey]

I am starting to plan what I need to make an ER32 chuck for my lathe now that I have the raw material to make the chuck. I will be cutting an internal 1 1/2 x 8 tpi thread. Videos on cutting internal threads suggest cutting a groove to the depth of the thread where the thread ends. I have boring bars that use 1/4" and 1/8" tool steel. I have both HSS and cobalt in these sizes. I am thinking of using 15 degree front and side clearances with an 8 or 9 degree back rake and no side rake to make a tool to cut the groove. Something like this.

View attachment 279441

Will this work?

Yes, it will work. The feature you are cutting is called a thread relief and the depth of that groove should be about 0.003-0.005" deeper than the anticipated minor diameter and about 2-3 thread widths wide.

The cutter is basically shaped like a parting tool. Unlike a parting tool, thread relief tools need more end relief because the ID is round; 15 degrees of end relief as you planned is fine. I think 5-8 degrees of relief on both sides will be sufficient. You can use zero rake on top and it will cut fine, although 8-9 degrees of back rake will help it cut with lower forces; if you're using a steel bar then this will be useful.

Good for you, Mickri! You designed a tool and nailed it and you should feel very good about that!

 

[mikey]

I just looked at the first page of this thread and all I can say is WOW . The participation has been outstanding.
14 months, 29 full pages, 865 replies, and over 55,000 views. I have lost count of how many members that have handled the models but I’m certain it’s well over 30. We have models in Canada, Australia, South Africa and 3 sets still floating around here. Thanks to everyone that’s joined in.
I knew nothing about grinding tool bits when I first saw this thread and now I can grind a tool that I can make repeat cuts with.
Mikey, you hit it out of the park with this topic.
Thank You

Thanks, Jeff, for all your help. You've been indispensable!

My thanks to all the readers and participants, too. You guys made this thread what it is. You opened your minds to a different way to grind tools and many of you showed those tools, even though that opened you up for criticism; that takes courage. I have seen guys go from tyro to tool grinders seemingly from the get go and that has truly been amazing. And from the comments I've seen here and elsewhere on HM, there is a better grasp of tool geometry than ever before.

So, my congratulations to you all!!

By the way, we are not done here. I still have to grind that shear tool - I haven't forgotten. Life is particularly challenging of late, that's all. I will get to it, I promise.