Roughing tool,High speed steel

[mr herb]

Here is a tool that I found in a old issue of Model Engineer. Forget who wrote it up, but it may have been the former Tubal Cain.that I learned it from

Grind a High Speed tool like this--I hope I can remember all that was on the tutorial!
About 8 degrees on the cutting side, same on front edge--but about 45 degrees to lead the chip away from the cut. Also works great on a shaper. but there the chips tend to chase you around the room. Don't try to grind a chip breaker into the tool, it will put too much heat into it when it is in action. This grind cuts the metal, and the majority of the heat is created in the chip after it leaves the cut.

Attachment 32213

Attachment 32214

Notice that all the edges that are ground, can be continued farther on the bit--nothing is wasted if the angles are reground. If you look at the second photo you will see the cutting edge pointed to by the white pointer. Sometimes I stone a small flat on the top, which I have put on this tool.Probably not a good idea on a small lathe with limited HP, just leave that edge sharp. The amount of metal that you can remove is based to the torqque that you can put to your spindle. I have challenged lathe operators that are using Carbide inserts in South Bend lathes (and others) and I have been able remove more material than they can. Run this bit slow--it is torque that removes the metal.


Now, granted, you aren't going to rip a chip like this off if you have a bench top lathe, but this tool grind WILL allow you to remove the maximum amount that that your lathe is capable of.
Picture shows a Lodge and Shipply with a 5 HP DC motor cutting 4340 heat treated steel blank that was eventually a crank for a Stanley steam car of the teens.

mr herb.

[DIYSwede]

-Welcome aboard, mr herb!
I can't get the attachments to work: "Invalid Attachment specified."
I'm personally quite curious of what kind of grind will achieve this.

Cheers
Johan

[DIYer]

Thanks mr herb! We've added your Roughing Tool to our Machining category,
as well as to your builder page: mr herb's Homemade Tools. Your receipt:

Roughing Tool by mr herb

tags: machining

[mr herb]

Thanks for responding, Johan. Those two photos were there when I looked the post over before I posted. Don't know what happened, but here they are again
Both are jpeg files, don't know what's going on? any other questions I will be pleased to try to answer (except why do cornfuters do things they do!)

mr herb

[TrickieDickie]

Those are some pretty dark blue pig tales for HSS tooling but it looks like it works fine.