Models for grinding HSS Lathe Tools

I think i will make a general purpose tool but out of the knife tool. I think that will be the most useful.
 
Another question is what should i cut for plastics like nylon and delrin?
 
For now, just use the aluminum tool. If very sharp, it will work well. Honing the tool makes a very big difference. We are talking slice your finger by just looking at it sharp. Ragged edges won't leave a nice finish.

The square tool is the most practical tool to grind first. It has lots of uses and is versatile.
 
Brento said:
@mikey @ttabbal i want to get a bench grinder but funds are maxed right now after buying this lathe i have a belt sander base but i need a motor to get that going. For making a tool with lower cutting forces should i just make the 15 degree tool? Is the 15 degrees on all sides?
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There are some bench grinders on CL in your area. Not sure where Vernon is but here is a brand new Porter Cable for $35.00.

Of all the tools we have discussed in this thread, the square tool is the most versatile. Yes, tools with a geometry optimized for a specific material class will work better but you will have a hard time finding a tool that will cut almost anything as well as a square tool. That includes aluminum, delrin and other plastics, brass, stainless, mild and medium carbon steels. What's more, it was actually optimized for a little Sherline lathe so it will work on your lathe, too.

If I were you, I would go find a bench grinder. Then go to this thread; it tells you exactly how to grind a square tool.

Another option is to have @Z2V or @ttabbal grind a 3/16" tool for you to get you started. I have seen their work and it is as good as I can do.
 
Brento said:
This is another tool i found with the lathe.

top viewView attachment 355775
Left sideView attachment 355776
Right sideView attachment 355777
From the front viewView attachment 355778

@Gaffer i have that download and i have the cheat sheet for the angles but the 35 just doesnt look right when im trying to mark it out
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I am now convinced that the guy who ground those tools had a different understanding of tool geometry than I do. Doesn't mean he is wrong but negative rake tooling on a very small lathe doesn't work well. Negative rake tools create nice finishes but also create huge cutting forces that require a lot of rigidity and power to utilize.

If I owned a little watchmaker's lathe, I would be using positive rake tooling and gravers.

If you do not have a solid understanding of the different tool angles, go here and read this stuff first:
 
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Im going to work on grinding one up tonight ill start with a square tool i guess. So when is a knife tool best used.
 
When the square one doesn't do the job! :D Believe me, the square tool is pretty versatile.
 
I don't use the knife much. It works, but I haven't found the right way to really get it to work as well as I think it should. I use various versions of the square tool for almost everything. The 15 degree is so versatile I can get a good finish on almost everything. I grind up special versions for a few things. Most steels work well, other than 1018, that stuff hates me. :)

I think the only small bits I have (<3/8) are harbor freight M2. I'll make you one if you need it. I have a set of model tools I can send as well.
 
I think i will be good @ttabbal i know the concept. Back to my original question i just wasnt sure how the 35 degrees was suppose to look or if i was measuring the angle right but now that i have seen the tool i know im measuring it right. I will make the square tool but i am making specialty tools as well bc im just that type of person. I like to challenge myself.
 
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