Models for grinding HSS Lathe Tools

I agree with you. I find myself jumping from page 27 to pages 4 and 5 constantly while grinding these tools. I think most people will read the first page hoping to find the information and not want to go through 27 pages to find the answers but then again there’s a lot more information in here then just on grinding the specific tools. Just so you know and everyone else knows, the majority of information you’re looking for is on page 4 and 5.
This thread is really great. The only problem is that it has become so large that it is unwieldy to use and hard to find stuff. One thing that I would find to be very usable is if there could be one place on the forum where the basic information in this thread could be presented. I am thinking of drawings, not pictures, of the different types of tool bits with the angles for the tool. My lathe came with a chart to be mounted on the wall for quick reference for the basic tool bits. It really helped me with grinding tool bits. I couldn't scan the entire chart do to it's size. A portion of the chart is attached.

I would be willing to do the drawings. I use google sketchup for drawing. Sketchup drawings are 3D that I would then convert into a jpg showing top, bottom, side and front views that could be uploaded to the forum.

No forum that I have been on allows sketchup drawings to be uploaded. If the actual sketchup drawing could be uploaded then the drawing could be viewed in sketchup where you could rotate and spin the drawing to whatever angle you wanted for viewing. Sketchup is a free program.

Just a suggestion.
 
Thanks Z2V. I dont want to jack the thread but I think I saw a CTS-V in one of your photos earlier on in this thread? I think it was around page 4 or 5 that I saw the photo. I have almost read every page of this thread. I think I’m up to page 22. I am trying to absorb every bit of information from everyone that has posted here !


Yeah, I sold a Z06 and purchased the CTS-V, Z2V was born. Great car.
Again, welcome to H-M
 
Nice! I had a V as well. It had more mods than factory parts. Never should have sold it. Thanks for the welcoming
Yeah, I sold a Z06 and purchased the CTS-V, Z2V was born. Great car.
Again, welcome to H-M
 
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OK here are the pictures of my LH and RH knife tools and the RH square tool.
I spent the most time on the RH Square tool because the first one I made I screwed up royally. I got distracted by someone talking to me and I wound up taking off to much material on the back and side rake. I couldn’t stand the fact that the tip was halfway down the 3/8” thickness of the Circle C tool so I made another one. I made sure that the angles on this one were dead on Especially the 16° Side rake and the 15° back rake. I particularly made sure that the angle was not just in the center of the rake but throughout the entire rake angle. I’m sure anyone who knows what it’s like grinding on a 6 inch grinding wheel, you get the radius of the wheel in the tool, especially when the wheel is worn down quite a bit. This tool is made from a piece of 1/2” Fagersta WKE 4 .002. This is some really really tough material and it’s very hard to get a sharp corner. I switched between five or six different stones and getting it flat and smooth and finally I finished with a white india stone and a fine diamond stone. I’m sure an extra fine diamond would get a better finish but I think this is going enough for now until I get one. There are no reflections of lights on any of the corners.
For the grinding tools I used a craftsman 6” Block grinder, a Harbor Freight 4x36 belt sander (80 grit belt I think) which also has a with a 6” disk which I had a 80 grit pad on. It’s really a piece of junk but it works. I am using a gator back Belt which has held up really well. The 6 inch pads are Harbor Freight sanding pads and they wear out really quick but the dull sandpaper gives a really good final finish. I also modified the belt portion so that I could grind the back rake and side rake. I basically cut a section out of the side so I could get the tool on the side of the belt. I believe someone on here posted the mod so I can’t take credit for it. I have on order the belts that Mikey recommended from Amazon and will have them shortly.
Anyway, back to the tools. The 3/8” knife tools are no where near as nice as some of the ones posted on here bit I am very very pleased with their performance. I think they work perfect for my expectations and I get a beautiful facing cut wiith them. They can take very small cuts and I’m very impressed with that. Maybe I should add more nose radius to these tools ? Anything else I should do to them? Don’t mind giving me your opinion even if it means telling me they look like crap, I can take it and would appreciate your honest opinion
From left to right: RH knife tool, RH square tool and LH knife tool
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Here are some more pictures of the RH square tool as I thought there were too many in the post

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As I stated previously the LH and RH knife tools are made from 3/8” Circle C. This seems to be really good HSS and was pretty easy to grind. Also it was relatively easy to get a very sharp edge. The RH square tool is made from 1/2” Fagersta WKE 4 .002. ( i’m not sure what the .002 stands for). Even though this was half-inch material it was very hard to grind. The grinding wheel kept loading up and I had to clean it a few times. I know I was not pushing it too hard into the wheel because I never let the tool get too hot, I took my time on this one. It is hard to get this material sharp as well. I have not tried it yet but I think it will hold an edge very very well. I will be going to the shop shortly and will make my first cut with it and post back here.
 
I'll make some comments but let me preface them by making something clear to you and everyone else. Your work piece doesn't know or care what your tools look like, and your lathe only cares about what your tool angles are. Many of us are grinding on small bench grinders or belt sanders; not everyone has a cool 2 X 72 and this will impact on the quality of the tool - can't be helped. Add to that the fact that for many of you, this is a new endeavor and your brain is still learning how to move your hands to produce a working tool. Please do not compare your tools to anyone else's efforts, including mine, because it doesn't matter.

Okay, your square tool came out really, really nice. All the angles are there and you stopped the rake angle grind at exactly the right place so that the tip is at the same height as the shank - good job. Your nose radius is on the large side but not overly so. This tool will cut well, for you, Sir, and I think you did great! I honestly don't think I could have done that tool much better.

Your knife tools are a bit rough but again, the angles are there and those tools will work for you. I know they will because my early knife tools looked very much like them and they could shave off a few tenths on tool steel. I cannot see a nose radius on them but I can barely see one on mine; as long as it is there then it will work for you. In time, they will look nicer but I'm not sure they will work better.

This stuff takes practice. It took me a very long time to make tools that actually look like lathe tools. Not everyone has the talent to grind tools right off the bat like Jeff, Travis, DaveH, Brino, HBilly or Barry. If you ask me, those guys are mutants. For us regular guys, Brandon, I think you did great. More than that, I bet your tools will work just fine and your grinding efforts will only get better with time.

My suggestion is to work at understanding how the tool angles work and how you can adjust them to do what you want them to do. The shape of a tool only determines function; how well it works depends on the tool angles. The other thing to consider is making/buying a good belt sander if tool grinding is something you intend to stick with. If you go that route, consider a 2 X 72. It will be good for tool grinding but it will be even more useful for general shop use and fabrication.
 
I suppose there are worse things to be a mutant over.. :) I do think I should be able fly or something though. Bit disappointing. :)

Build a 2x72 and blame @mikey for it. I did my first model copies in keystock on a HF belt/disc sander. Even with 36 grit ceramic belts I wasn't a fan. The same type of belts in a 2x72 chew up HSS faster than the HF can work keystock. And with less heat. I was shocked the first time I ground a bit on it. I thought I had been had by the seller of the bits and they sent me aluminum or something.

I don't claim any great talent for grinding. I blame @mikey for great instructions and having models in hand to look at.
 
Mikey and I exchanged a few emails regarding me doing some drawings of the common tool bits. He thought that I should post my drawings. I did the drawings in Google Sketchup. Then converted the drawings to a jpg image. I can't upload the sketchup files. If anybody would like a copy send me a pm. All of the angles are what Mikey set forth on page 4 of this thread. I did the drawings using 3/8 x 3/8 x 3." While the actual drawings are to scale I doubt that the jpg images are to any particular scale. I did not attempt to round the point. Sketchup won't do a 1/64 radius. Hope these are helpful.

Based on comments I have edited my drawings to include the angles used and removed Mikeys angle table. The area ground for side clearance is shown in red. The area I am calling "end clearance" is shown in yellow. I did some searching looking for what people called this and nobody seemed to have a name for this except for one video that referred to it as the "end." I thought that was a good description. Referring to the side rake and back rake as "top side rack" and "top back rake" is more descriptive to me. This portion of the drawings is shown in blue.

LH Tool 001.jpg

RH Tool 001.jpg


RH Knife Tool 001.jpg


Threading tool 001.jpg
 
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I just got done turning the OD of the 1018 CRS from .875” to .815”. This portion that I turned down is the head of the slitting saw arbor. I am still unable to get a decent surface finish although I will admit that the square tool gave me a better finish than I was able to get with any other tool. I tried varying depths of cuts, feeds and speeds, I turned the tool in all sorts of directions and I even played with the height a little bit. I don’t know what’s going on here. Did I put too much of a nose radius on the tool? What’s got me even more perplexed s that the surface finish will change during a cut. I get this weird finish almost like the way some CRS has that factory pitted appearance. Sometimes it seems like I hit a hard spot as well. When I hit the hard spot sometimes I actually get a brighter finish but only for an 1/8” or less. I am thinking that I need to modify the angles on this tool but I don’t know where to go with it. Or it could be that this material is of cheap quality and there’s no getting it better unless I finish it with some sandpaper.
Anybody have any thoughts.?
Here is a photo showing the best finish I was able to achieve. 1” from the left side towards the center you can see a dull ring where there appears to be a hard spot in the material. Sometimes I see it after a pass and sometimes I don’t.
Sorry if I should be posting this somewhere else. I feel like I’m beating a dead horse on this subject.
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Here is a photo showing 3 spots that I think are hard spots. The tool I was using is an AR Warner T15 HSS insert. I tried this for a few passes at different angles, speeds, feeds, etc. I also have a smaller nose radius T15 insert as well as carbide inserts but that’s not intended to discuss here.
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