Models for grinding HSS Lathe Tools

[tmenyc]

Mike,
I reread 102 and 104. I think part of the problem has been the angle of the tool rest on my grinder. It's time to get a digital angle finder. Do you recommend one of the box ones where it just rests on the flat and reads off its angle from flat? Like this? Or is there a particular one you prefer?

 

[mikey]

Mike,
I reread 102 and 104. I think part of the problem has been the angle of the tool rest on my grinder. It's time to get a digital angle finder. Do you recommend one of the box ones where it just rests on the flat and reads off its angle from flat? Like this? Or is there a particular one you prefer?

The one you linked to will be fine. Mine is similar, from Beall Tools, but it does exactly the same thing.

The tool rests on bench grinders can give different angles, depending on how they are attached to the grinder. You might want to confirm that a 15 degree angle set by the digital protractor matches the face of the model. If it is off, you can remedy that by making a better stand alone tool rest. Jeff/@Z2V made a good one and he can give you some advice there.

You might also consider a small belt sander at some point. Mine takes up no more room than my bench grinder and it is vastly superior to the grinder for tool grinding.

 

[mikey]

Grinding good cutting tools been my current stumbling point of late. Had been trying to use some carbide inserts that I had inherted with varriying results and came to the conclusion that due to the size and power of my equipment HSS would do better and be cheaper.(?) I had expressed an interest in the model/examples some time ago but did not follow up on that... SO... not yet sure that'll need them now, Getting a larger 8" grinder tomorrow, only had a weak little 5" and my results were kind of hit and miss. Good to revist this thread and will be trying more again soon.

John, give it a go with the instructions on page 4. If it doesn't work out and you aren't sure how close you are, contact @Z2V and get some models in your hands to confirm. As Tim said, it can help. Show us some pics if you like and we'll give you an opinion.

 

[tmenyc]

Mike, looking at the Knife Tool presentation again, I'm still not sure all of what I did wrong, but it's a bunch. So I want to make sure I understand.
The first photo represents the tool at the first cut, the half inch noted in the previous paragraph; that's the first cut. Then the 65 deg line and cut are made as the second cut. In the second photo you can't see the first cut because it's underneath, correct? You can just see the edge in the third photo, on the left. The rake angles make sense, pretty sure.
I'm looking forward to re-seeing what I did when I get home tonight, think I got it upside down at a minimum.
Many thanks.
Tim

 

[mikey]

Mike, looking at the Knife Tool presentation again, I'm still not sure all of what I did wrong, but it's a bunch. So I want to make sure I understand.
The first photo represents the tool at the first cut, the half inch noted in the previous paragraph; that's the first cut. Then the 65 deg line and cut are made as the second cut. In the second photo you can't see the first cut because it's underneath, correct? You can just see the edge in the third photo, on the left. The rake angles make sense, pretty sure.
I'm looking forward to re-seeing what I did when I get home tonight, think I got it upside down at a minimum.
Many thanks.
Tim

Yup, you got it, Tim. You're going to be fine.

The knife tool is a really accurate tool for general and precision facing but it also works good for trepanning if the tip fits. I just used one to bore the bottom of a center height gauge for a friend and it cut stainless steel with a sweet hiss and the final cuts were like airborne pixie dust. Funny how I make tools for friends that are finished to fine standards but the tools for myself look like I used construction tools to make them. I need to treat myself better!

 

[mikey]

When you say "you are grinding" here about the knife tool, do you mean I SHOULD be or did but should NOT be?

Sorry, I missed this. I mean you should be. The side of the tool is oriented parallel to the face of the grinding wheel, so that as you feed the tool into the wheel it grinds the side of the tool blank. As you push the blank into the wheel, the grinding wheel will start to cut at the lower part of the blank. As your continue to grind, the ground part will climb up the side of the blank and approach the top surface of the tool. Stop grinding just as you reach the intersection of the side and top surfaces of the blank. Then move on to grind the end, and then the top rake angles.

Don't forget to put the tiniest nose radius you can stone on it. Try not to leave a sharp point because it will leave lines in your work and can crack off if you turn with it. A tiny nose radius works best.

 

[tmenyc]

thanks, Mike. That's what I thought, put the words as if spoken into my head, but wanted to make sure. It all makes sense.

Tim

 

[SonofHarold - Metal Carver]

John, give it a go with the instructions on page 4. If it doesn't work out and you aren't sure how close you are, contact @Z2V and get some models in your hands to confirm. As Tim said, it can help. Show us some pics if you like and we'll give you an opinion.

Well as of today I think I got over the hump. I have to hold touch and see things like this to learn it, and then the reading of details like are here seem to help more once I have done it on my own. I had such good results today following some instructions I just stumbled on a few days ago and now re-reading much of page 4, I don't think I'll need the models, as least not soon. Would it be inappropriate to post a link to the web site? Seems it made it more simple and being very basic, made it easier for me to duplicate the results. Plus... I was just fooling around to give it a practice run through this afternoon and am still quite happy with myself and the results. I'll try and get some pics up tomorrow but I have another mission in the What is it thread for this evening.

 

[machPete99]

Just for reference, at least one of the Tubalcain videos used some oversized wooden models to help show the angles, like this one:

 

[mikey]

Well as of today I think I got over the hump. I have to hold touch and see things like this to learn it, and then the reading of details like are here seem to help more once I have done it on my own. I had such good results today following some instructions I just stumbled on a few days ago and now re-reading much of page 4, I don't think I'll need the models, as least not soon. Would it be inappropriate to post a link to the web site? Seems it made it more simple and being very basic, made it easier for me to duplicate the results. Plus... I was just fooling around to give it a practice run through this afternoon and am still quite happy with myself and the results. I'll try and get some pics up tomorrow but I have another mission in the What is it thread for this evening.

Post away. Anything that helps understanding is a good thing.