In this video Barry walks us through the process of grinding a left hand (LH) lathe tool. Since much of the process is the same as is covered in the previous video, this video is a bit shorter but still helpful to watch if you’re new to grinding HSS tools. However, if you haven’t seen part 1 yet, it would be best to start there (Part 1: Grinding a Right Hand (RH) Tool).
Other Videos in this series:
- Grinding HSS Lathe Tools by Hand: Part 1 – Grinding a RH Tool
- Grinding HSS Lathe Tools by Hand: Part 2 – Grinding a LH Tool
- Grinding HSS Lathe Tools by Hand: Part 3 – Grinding a Threading Tool
Hi, Barry Young here again with part 2 of the tool bit grinding video.
Now, I didn’t explain something in part one. This is a right hand tool bit. You can tell because if you look at the business end the cutting edge is on the right. This is left hand for exactly the same reason. If you’re looking at the end of it, the business end, the cutting edge is on the left.
I’m going to show you now how to do a left hand tool. We do it in exactly the same way. Side 1, side 2, and side 3. Just like we did last time. This one will go a little bit quicker because you already know so much about doing it. Again, I’m grinding this way faster than you would. Don’t forget that. We’re going to zoom through it. You can hear it boiling that water. Ok, that’s side 1.
Side 2 is going to be the side rake. Which is exactly like grinding the top rake on a right hand tool. But we do this first. I’m actually resting this tool on the tool rest and just tipping it up. And many people find that easier. I don’t do that unless I’m trying to really hurry myself. But you may find it easier. Some people do. Alright, that’s side 2. And it’s smoking a little bit still. That’s the side rake.
Now we are going to go on the other side of the wheel and cut the top rake in exactly the same manner. You can just slide it into the wheel and rotate the cutter to get the rake if you choose to. Not the way I normally do it, but that’s ok. Here’s how I normally hold the cutter. It seems to work well for me. You can do whatever works. Grinding this fast makes the tool very hot. And when we get close we’re going to just grind until we see sparks come off the top of the tool, and that means we’re there. Now I would continue grinding this a little bit. It’s not exactly sharp yet, but you get the idea.
This is what she looks like. That’s a left hand tool. And I’m going to throw a radius on there really quick, just as we did with the right hand tool. And there you have it.
If this were high speed steel and we continued grinding a little bit until the cutting edge was truely sharp we would have a wonderful tool to cut with. Ok, throw that in your toolbox and you’ll be able to use it for a number of years.