Models for grinding HSS Lathe Tools

[Brento]

Cut this this morning i have not done the radius bc i will use my diamond cards to bring it in. This is the generic square tool. The side angle towards the back isnt perfectly ground straight but the grinding wheel needs to be replaced and the bit is so tiny to hold. The cutting edge is straight just towards the back is like sloped

 

[Brento]

This is the aluminum version. I went to a 22 degree angle to lower the cutting force a little on the back rake.

 

[ttabbal]

Particularly considering they were ground with a dremmel, they look good. Hone them up and make some chips.

 

[Brento]

These were not from the dremel. From a grinder. Im going to try a dremel grinder on the steel and brass version later in the week.

 

[tmenyc]

Brento, that looks good!

Somehow I missed the instruction probably almost two years ago about getting a white AO wheel for tool grinding instead of the grey one. I posted about this choice some days ago (here...), after seeing a Blondihacks video where she ground a tool using a white wheel that got me thinking...before I knew enough to start asking why I didn't know about that...

So I bought one from Lee Valley, a Norton 3X 80 grit, acting on the advice of members I respect here, and WHAT A HUGE DIFFERENCE! Ground the first square tool today. It used to take me close to an hour, burnt fingers and a ton of dust to bludgeon a tool into submission. Today, this one took around 20 minutes start to finish, no faceting, just let the grinder do its thing. Much much cooler, much quicker and easier. Dressing still creates a bit of dust, but nothing like before. I've always liked the result of grinding my own HSS tools, but it was painful, and I hadn't realized why until now, and now it's fun! Next up, a cobalt square tool that I can make my main tool.

Note: this is fresh off the grinder, no cleanup, NR or honing yet. The color change is just color, not faceting. There are tiny bits of microcloth stuck on the lead edge, too. Promise.
Thanks again, Mikey!

For the all-purpose cobalt tool, should my NR be closer to 1/32" or closer to 1/64"?

Tim

 

[Brento]

Ill have to get one of the white stones. I used a worn out great wheel on a grinder but im going to try a dremel and cut off wheel bc these bits are so tiny that it may work a little better in a way. When i buy a grinder i plan to find a decent diamond wheel for carbide touching up, and the white wheel and then i will change them around and set up a buffing wheel on the other side. Id use a belt sander but i need a motor to go with the belt sander i picked up from my old job that they were going to scrap. It was my first time making a tool minus a threading tool. My bits are m42 so i believe it already has cobalt in it.

 

[mikey]

Brento, that looks good!

Somehow I missed the instruction probably almost two years ago about getting a white AO wheel for tool grinding instead of the grey one. I posted about this choice some days ago (here...), after seeing a Blondihacks video where she ground a tool using a white wheel that got me thinking...before I knew enough to start asking why I didn't know about that...

So I bought one from Lee Valley, a Norton 3X 80 grit, acting on the advice of members I respect here, and WHAT A HUGE DIFFERENCE! Ground the first square tool today. It used to take me close to an hour, burnt fingers and a ton of dust to bludgeon a tool into submission. Today, this one took around 20 minutes start to finish, no faceting, just let the grinder do its thing. Much much cooler, much quicker and easier. Dressing still creates a bit of dust, but nothing like before. I've always liked the result of grinding my own HSS tools, but it was painful, and I hadn't realized why until now, and now it's fun! Next up, a cobalt square tool that I can make my main tool.

Note: this is fresh off the grinder, no cleanup, NR or honing yet. The color change is just color, not faceting. There are tiny bits of microcloth stuck on the lead edge, too. Promise.
Thanks again, Mikey!

For the all-purpose cobalt tool, should my NR be closer to 1/32" or closer to 1/64"?

Tim

View attachment 355916View attachment 355919View attachment 355918

Really nice job, Tim. That's going to be a good tool.

 

[Brento]

Tonight i honed the tools i made earlier today. I think they came out good. The generic square tool has a 64th radius and the aluminum tool i got a little carried away and it ended up being a 32nd i also started with a coarse diamond card and then went to fine followed by extra fine. When you guys hone do you use a diamond stick or do you use a stone? I always thought for honing you use a diamond card or stick.

 

[tmenyc]

Looks good!

Mikey,
I know you told me way back, but I can't find it, about what angles to use for acetyl and ebonite (also known as vulcanite, it's compressed organic hard rubber, still used for smoking pipes and saxophone/clarinet mouthpieces and, for me, replacing vintage fountain pen parts with original materials). I know you said that anything I use for aluminum would work, but now that I'm able to grind much more easily, I could make a tool and dedicate it to the softer stuff. What do you recommend?

Many thanks,
Tim

 

[ttabbal]

Tonight i honed the tools i made earlier today. I think they came out good. The generic square tool has a 64th radius and the aluminum tool i got a little carried away and it ended up being a 32nd i also started with a coarse diamond card and then went to fine followed by extra fine. When you guys hone do you use a diamond stick or do you use a stone? I always thought for honing you use a diamond card or stick.

Looks good. The pics are a little grainy when zoomed, but that's difficult to deal with for most simple cameras. The radius should be fine. It increases cutting forces a little, but you need some. Without it you get a finish that looks like a vinyl record. A bit like if you used a threading tool for everything. The nose tends to be a bit weaker as well. I use diamond cards for honing and the radius. Stones and sticks can work as well. The catch I would have with stones is when they start wearing down they get a bow where they get used the most. The cards are cheap enough that tossing them when the grit wears down isn't a big deal. Good stones cost a lot more.