Models for grinding HSS Lathe Tools

[mikey]

Thanks for sharing that with us Mike. I'll give he's strong consideration for the 2x72 I'm making.

It cuts like crazy on my little 2x42. I can only imagine what it would be like using a 1-2hp motor and having 72" of ceramic belt running around. It would probably take you just a few minutes to crank out a lathe tool.

 

[Aukai]

Sounds impressive.....

 

[mikey]

Sounds impressive.....

The belts can handle mild steel, which isn't saying that much. We'll see how they do with a Rex 95 blank. If they eat that, too, then I'll really be impressed. I'm liking them so far, though.

 

[Randall Marx]

Sorry I've been away for a few days, but will start on solid models soon...possibly at lunch today. I think this is a GREAT idea for all that are involved and thank all who are helping!

 

[Metal]

Sorry I've been away for a few days, but will start on solid models soon...possibly at lunch today. I think this is a GREAT idea for all that are involved and thank all who are helping!

I ordered some filament for this on monday
All proceeds beyond costs will be donated to HM

 

[Randall Marx]

Update: I think I got the Square tool done, but will attempt to include a picture to make sure it conforms to Mike's design. I included no dimensions, but gave the classic 3-view drawing. All relief and rake angles are 15 degrees and both radii are 1/64". Mike, please let me know if this is right. If so, I'll get the other two done and models sent to Metal so he can try the 3-D printing.

 

[mikey]

Update: I think I got the Square tool done, but will attempt to include a picture to make sure it conforms to Mike's design. I included no dimensions, but gave the classic 3-view drawing. All relief and rake angles are 15 degrees and both radii are 1/64". Mike, please let me know if this is right. If so, I'll get the other two done and models sent to Metal so he can try the 3-D printing.View attachment 242086

Looks good to me, Randall. It might be an idea to wait until you get the model because for this project I made the side cutting edge angle a bit smaller to give more mass at the tip. The reason is that I don't know who will use it and how they'll use it. This small change of a few degrees will add a lot more strength to the tip.

I am done with the models ... almost. I was done but then I tried to make the square tools look pretty by honing off the grinding marks with a diamond stone. The material is so soft that this changed the geometry of the tool! I had to go to the hardware store for more keystock and should be able to get the square tools done today. I'll just deburr them and then I can get them in the mail. Sorry this is taking so long, guys.

 

[Randall Marx]

Hi Mike
Do you mean that the first grind is less than 60% or that the relief angle is less? If I have a good description, I can work from that unless you really think I need to wait. I put this one together from your article that you wrote on machinistblog (which I found to be quite informative and gave me a better idea of what the angles all do).
Thanks for the input and thank you VERY much for the great idea and effort.
Randall

 

[mikey]

Hi Mike
Do you mean that the first grind is less than 60% or that the relief angle is less? If I have a good description, I can work from that unless you really think I need to wait. I put this one together from your article that you wrote on machinistblog (which I found to be quite informative and gave me a better idea of what the angles all do).
Thanks for the input and thank you VERY much for the great idea and effort.
Randall

The side cutting edge angle is slightly less than I normally make it. The tool will look very much like the one in the How to grind a HSS tool article on HM. In fact, it will be almost identical to that one. My best advice? Wait for the tool or wait until you see the write up so you don't have to do it twice. I would hate to have you and Metal go through the trouble, only to have it not be the way the models are.

I think this project has to potential to help more people and if it does then its worth the effort. Grinding the tools is no effort. Writing them up is where the work is and I'm getting to that.

 

[mikey]

Well, I got the models done and they are ready to ship tomorrow. From left to right, a general purpose Square Tool, a general purpose Knife Tool and a 60 degree threading tool:







I am going to write these tools up but it is going to take me some time to do that. I ask for your patience as I do this. I will try to post my comments as I complete them in parts. You can follow along, correct me, ask questions and I'll do my best to keep up. By the time we're done, you should have what you need to reproduce these tools in HSS.

Each tool is proven to work as intended. None of them are ground to conventional angles. Instead, they are ground to cut with lower cutting forces and temperatures, which should allow them to cut deeper, size more accurately and finish finer on a smaller hobby class lathe. If you would prefer using conventional tool angles then just use the values found in the typical angle table. In fact, it would be a good idea at some point to grind a tool with conventional angles and compare it to a modified tool like those above and see what the differences are. Do the same with those tools and your carbide tools. You will quickly find which tool works best in the different materials you work with and will then know which tool is the best one for the job at hand. Personally, I don't believe that you should use only HSS or only carbide; I think you should use the right tool for the job and you cannot do that unless you can grind a good HSS tool. Then you have options, right?

Anyway, the tools will go out as soon as I can post them and then I'll get to writing.