Models for grinding HSS Lathe Tools

[Profkanz]

In a recent thread by @Darkbluesky, http://www.hobby-machinist.com/thre...tools-ideas-of-what-to-buy.62043/#post-511618, @ttabbal joked about sending me blanks to be ground into lathe tools ... he was joking! But it got me to thinking ... yeah, I know it's not a good thing when Mikey gets to thinking ... but it got me thinking that reading about how a tool is ground and having a decent tool in your hands that you can see and touch are two different things.

So, what if I ground a set of tools from 3/8" mild steel keystock (just to discourage some bozo from actually trying to cut something with the models) so people could hold it in their hands to look at. You could use them to plop onto your tool rest to see what the rest angles should be and maybe how your hands have to align to grind the tool. You could also buy some keystock and duplicate them for a permanent reference, and then pass them on to the next guy who wants to have a look.

I'm thinking of making THREE sets of these model tools and mailing them out to guys who are interested. We would need to figure out a list if there are more than three guys interested in seeing them, and YOU GUYS need to sort out how to keep track of these things. I would guess one to two weeks of holding time per person would be reasonable and the guy who has them would pay to flat rate ship it to the next guy on the list. Naturally, the only guys who can get on the list would be members of the HM forum.

As to which tools to include in the set, I'll leave that to you guys. We can discuss it here and see if we can come to some consensus. I will probably write a set of notes with details on how each tool is ground and why the angles are what they are and how you can modify them to better suit your needs; these notes would be posted to this thread.

I don't know if this is of interest to anyone but on the off chance that it is, let's talk about this and see if we can make it real. I'll spring for the keystock, grind the models and send them out. After that, you guys need to sort out how to get them distributed. The last guy on the list can hang onto them until some other HM member contacts them or you can send it back to me so I can do the same.

Let me be very clear about one more thing. The models will be of tools as I grind them for use in my shop on my lathe(s). It is one way, not necessarily the right way or the only way. My hope is that it will help you to find your own way of grinding tools that work for you.

Thoughts?

Mikey

When I was still teaching, I made models from 2x2 lumber for students to use as examples. It did seem to help them.
At first I had examples ground from mild steel, but some fool would always try to cut with them. LOL

 

[mikey]

When I was still teaching, I made models from 2x2 lumber for students to use as examples. It did seem to help them.
At first I had examples ground from mild steel, but some fool would always try to cut with them. LOL

Several folks have brought up wooden models and I agree it is a good way to show and discuss these tools, especially when you're standing in front of a class. They are big enough to show the angles from a distance and you can color the different faces. The problem I faced was how to do that on the net. I also had to figure out a way to transmit the information while also sorting out how to help them set the proper tool angles on their own grinders, each of which is different. Trust me; I thought about wooden models many years ago but it just wouldn't work for this effort.

I do agree that I thought about someone trying to cut with the models, which is why I used keystock. They will cut but they won't last long!

The physical act of tool grinding is not difficult. What is difficult is to convey understanding of what the angles do and how to grind them properly over the net. A secondary goal was to encourage the idea that conventional tool angles could be modified to enhance tool performance to enable smaller lathes to cut more efficiently and with greater accuracy. It is my hope that we've at least made some inroads here.

 

[SonofHarold - Metal Carver]

I managed to cut a 5/16 HSS tool for some 6061 Aluminum, at first it was doing really bad, but finally figured out it was the tool hight, Thought I recalled to set it just above center, ending up lowering to be pretty close to or just below center and things starting working at least OK. I think also I was turning pretty slow.. figured I'd do less damage that way if something went wrong. Turning up the spindle seemed to help alot too. Just kind of experimenting with things today... but I think I could make use of the these example learning blanks. Can who ever has them get in touch with me please?
Thanks!

 

[mikey]

John, send a PM to @Z2V. He will know how to get a set in your hands.

I find getting the tool tip dead on center height works best. For aluminum, I tend to go as fast as my lathe will run. Works for me anyway.

 

[SonofHarold - Metal Carver]

John, send a PM to @Z2V. He will know how to get a set in your hands.

I find getting the tool tip dead on center height works best. For aluminum, I tend to go as fast as my lathe will run. Works for me anyway.

that would be like twice what I was running(?... 700-800 rpm) so like what RPM? even if turning something larger VS say something smaller that 0.500"?

 

[mikey]

I suppose I should have qualified that statement. Cutting speed for aluminum when turned with HSS is 500-600 sfm. I use the formula, RPM = cutting speed in sfm X 3.82 / diameter of the work. Most of my stuff is below 1" so I tend to go faster. This formula will basically give you a starting point and you can vary speed up or down as needed. When I use carbide insert tooling, I don't even calculate speeds because the required rpm is almost always faster than either of my lathes will go unless I am turning something huge so I just start at max speed, which for my 11" is 2400 rpm.

 

[SonofHarold - Metal Carver]

I think I was running in the low 600RPM range when it seemed to being well, It made a great facing cut, OD looks only fair, but I was kind of fiddling with things during that cut also.. I got up to around 800 but just felt the slightly slower RPM was cutting better. Was using WD40 a cutting fluid and probably not keeping it covered as should. Playing more today as long as I don't get called out for work.

 

[Highsider]

In a recent thread by @Darkbluesky, http://www.hobby-machinist.com/thre...tools-ideas-of-what-to-buy.62043/#post-511618, @ttabbal joked about sending me blanks to be ground into lathe tools ... he was joking! But it got me to thinking ... yeah, I know it's not a good thing when Mikey gets to thinking ... but it got me thinking that reading about how a tool is ground and having a decent tool in your hands that you can see and touch are two different things.

So, what if I ground a set of tools from 3/8" mild steel keystock (just to discourage some bozo from actually trying to cut something with the models) so people could hold it in their hands to look at. You could use them to plop onto your tool rest to see what the rest angles should be and maybe how your hands have to align to grind the tool. You could also buy some keystock and duplicate them for a permanent reference, and then pass them on to the next guy who wants to have a look.

I'm thinking of making THREE sets of these model tools and mailing them out to guys who are interested. We would need to figure out a list if there are more than three guys interested in seeing them, and YOU GUYS need to sort out how to keep track of these things. I would guess one to two weeks of holding time per person would be reasonable and the guy who has them would pay to flat rate ship it to the next guy on the list. Naturally, the only guys who can get on the list would be members of the HM forum.

As to which tools to include in the set, I'll leave that to you guys. We can discuss it here and see if we can come to some consensus. I will probably write a set of notes with details on how each tool is ground and why the angles are what they are and how you can modify them to better suit your needs; these notes would be posted to this thread.

I don't know if this is of interest to anyone but on the off chance that it is, let's talk about this and see if we can make it real. I'll spring for the keystock, grind the models and send them out. After that, you guys need to sort out how to get them distributed. The last guy on the list can hang onto them until some other HM member contacts them or you can send it back to me so I can do the same.

Let me be very clear about one more thing. The models will be of tools as I grind them for use in my shop on my lathe(s). It is one way, not necessarily the right way or the only way. My hope is that it will help you to find your own way of grinding tools that work for you.

Thoughts?

Mikey

Reminds me of a practical joke back when industry was still using some tool steel cutting tools. Occasionally someone would grind up a fake tool from keystock and drop it into his buddies tool box. Didn't leave much of a mark on the 4140 or 4350 shafting we were machining, but you knew you'd been had.

 

[mikey]

I think I was running in the low 600RPM range when it seemed to being well, It made a great facing cut, OD looks only fair, but I was kind of fiddling with things during that cut also.. I got up to around 800 but just felt the slightly slower RPM was cutting better. Was using WD40 a cutting fluid and probably not keeping it covered as should. Playing more today as long as I don't get called out for work.

What is the OD of your work piece and how long is it? If it is greater than 1.5 - 2 x the OD then you need a live center. It might help us to help you if you show us your tool. It also helps to know what lathe you're using. Wanna' help but need more info.

 

[SonofHarold - Metal Carver]

What is the OD of your work piece and how long is it? If it is greater than 1.5 - 2 x the OD then you need a live center. It might help us to help you if you show us your tool. It also helps to know what lathe you're using. Wanna' help but need more info.

Been a busy week and so a little slow to get back to things. The OD was right at 1.125 and I was try to get down to about an even inch. This little project needs no pression so making use of it to learn and work some things out. I think mostly I need more practice grinding tools, a couple of times it I got it looking pretty good then I think the tool gummed up so tried to touch it up on the grinder and it was then way worse. Was working dry and using WD40 seems to help a lot too. right now I'll probably not get much shop time before next week, Granddaugher spending the weekend with us and some house upkeep chores I am going to be kept out of the shop untill at least mid next week.