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Models for grinding HSS Lathe Tools
- Thread starter mikey
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- Jul 2, 2014
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These hones also work well:
https://www.amazon.com/gp/offer-lis...ywords=ez+lap+diamond+sharpener&condition=new
The file shape is easy to hold and work around the tip of a tool. They are definitely expendable, so do not last forever. It helps if you do not push hard with them, a lighter touch works just as well, let the diamonds do the work.
https://www.amazon.com/gp/offer-lis...ywords=ez+lap+diamond+sharpener&condition=new
The file shape is easy to hold and work around the tip of a tool. They are definitely expendable, so do not last forever. It helps if you do not push hard with them, a lighter touch works just as well, let the diamonds do the work.
Ok, emboldened with how easy this basic square tool was for me, now I need a boring tool. Is there somewhere good to explain that shape? I have 2 cases:
1. I gather one can do it with a normal piece of square stock like I have (3/8") but the bore would be limited by the tip size obviously.
2. I've got a boring bar that has a holder/clamp for a teeny piece of tool material. I have no idea how to point that piece.
Be great if there were some instructions as good as post#104. Or similar.
1. I gather one can do it with a normal piece of square stock like I have (3/8") but the bore would be limited by the tip size obviously.
2. I've got a boring bar that has a holder/clamp for a teeny piece of tool material. I have no idea how to point that piece.
Be great if there were some instructions as good as post#104. Or similar.
- Joined
- Dec 20, 2012
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- 9,408
Boring bars can be ground but it involves taking a lot of material off. To be honest, it is simpler to buy one. Note, too, that a steel bar can only go to a depth that is about 4 times the OD of the smallest diameter of the shank. For example, if you had a 3/8" square bit and necked it down to fit into a 1/4" hole, the tapered part of the bar would be about 3/16" OD, so the depth of the bore would be limited to about 3/4" deep. A similar carbide bar from Micro 100 could go almost 2" deep. I no longer grind boring bars. Instead, I use solid carbide bars from Micro 100 for smaller bores and inserted carbide bars for deeper bores.
This might help: http://homews.co.uk/page140.html
Thanks. For some bigger bores I bought a insert bar that holds some inserts I got that I understood were for alu. It tends to make a chip ball/nest when boring something I do that's pretty big ID (6").
As for carbide tooling... almost everything I do is aluminum and my understanding was that carbide required much higher speeds to work well, and my little Southbend 9 won't go very fast.
For smaller stuff that I can' tdo with the large insert bar, I have this holder I mentioned (picture). Size wise it's been suitable for some bores I wanted to do, but I don't know how to grind it's point. From the education I've gotten here on the square tool I could probably make a stab at it. Being a noob though I dont' know which direction to cut when boring. I've been cutting toward the head.
Given the photo, any suggestions on the tip geometry for that piece of HSS?
As for carbide tooling... almost everything I do is aluminum and my understanding was that carbide required much higher speeds to work well, and my little Southbend 9 won't go very fast.
For smaller stuff that I can' tdo with the large insert bar, I have this holder I mentioned (picture). Size wise it's been suitable for some bores I wanted to do, but I don't know how to grind it's point. From the education I've gotten here on the square tool I could probably make a stab at it. Being a noob though I dont' know which direction to cut when boring. I've been cutting toward the head.
Given the photo, any suggestions on the tip geometry for that piece of HSS?
- Joined
- Dec 20, 2012
- Messages
- 9,408
Sorry but I don't know much about that type of bar. Looks like an Everede bar. They are still in business and it might be worth a shot to send them an email. I know they make bars with different tip angles and the bits are ground to that geometry.
You can also start a thread on the forum about this type of bar. I know some guys use them.
Boring is a huge discussion. Carbide inserts can be used quite effectively for boring but the geometry of the bar and insert is well beyond this thread.
You can also start a thread on the forum about this type of bar. I know some guys use them.
Boring is a huge discussion. Carbide inserts can be used quite effectively for boring but the geometry of the bar and insert is well beyond this thread.
- Joined
- Dec 20, 2012
- Messages
- 9,408
The rake angles look much better evan. As you practice, focus on keeping the tool shank aligned with the inked line on the tool rest and the back of the tool flat on the tool rest.
For example, in the third picture, the short tool second from the bottom: you lost your alignment with that inked line and also ground too much of the tip down. This resulted in the loss of most of the back rake and the tip of the tool no longer aligns with the level of the shank. Contrast that to the first tool; the height of the tip is even with the shank (good) and the back rake is retained.
The shape of your tools is fine.
Grinding the rake angles takes practice but you're getting it quickly. Good job!
For example, in the third picture, the short tool second from the bottom: you lost your alignment with that inked line and also ground too much of the tip down. This resulted in the loss of most of the back rake and the tip of the tool no longer aligns with the level of the shank. Contrast that to the first tool; the height of the tip is even with the shank (good) and the back rake is retained.
The shape of your tools is fine.
Grinding the rake angles takes practice but you're getting it quickly. Good job!
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- Feb 2, 2017
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- 1,237
Mike,
Thanks. I got the belt tracking better now, but I need to mill down the platen on my belt grinder--it's about 0.1" wider than the belt. Once I can use the edge of the belt I can do much better on the back rake. My bench grinder has issues as well--I can't find my diamond dresser and the wheel needs to be trued up.
Anyway, having the physical models helped tremendously. Great idea!
Evan
Thanks. I got the belt tracking better now, but I need to mill down the platen on my belt grinder--it's about 0.1" wider than the belt. Once I can use the edge of the belt I can do much better on the back rake. My bench grinder has issues as well--I can't find my diamond dresser and the wheel needs to be trued up.
Anyway, having the physical models helped tremendously. Great idea!
Evan
- Joined
- Dec 20, 2012
- Messages
- 9,408
The platen is critical in my view. It has to be flat and solid and you have to be able to track the belt beyond the right edge of it by about 1/16" when grinding the rake angles on a RH tool. I would strongly recommend you brace the platen in the back so it cannot flex at all and put a Pyroceram liner on it; this will allow you to grind accurately and it will last for many years.
Much of tool grinding is in the machine. While the person is important, the tool rest and platen have a significant impact on how well your tools turn out. I have a feeling that if these two things are addressed on your grinder, the results will amaze you. Please keep us posted, Evan, because I'm truly interested in seeing you do well.
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