Budget HSS lathe tool grinder

[clockworkcheval]

Diamond at high temperatures becomes brittle and just desintegrates in little particles. So the recipe is low speed, say 100 - 150 revs, low pressure and preferably cooling with water. At this low speed there is no watersplashing. The result with a fine diamond disc is a mirror-smooth finish.

 

[pete]

It's not that diamond wheels can't grind HSS tools at high rpm, they can. At least for awhile. But how diamond reacts to high heat and carbon are where the problems come up. From everything I've read, it's that high heat at the actual grinding location on the wheel surface combined with the carbon in ferrous metal that the diamond somehow absorbs under those conditions are what helps to quickly wear down and destroy the diamond plating or coating. Apparently grinding carbide at the same rpm doesn't have the same issues as long as you watch the build up of excess heat. But your then creating loads of fine carbide dust when it's ground dry at those high rpms. A simple Google search explains why that's not a healthy situation.

 

[RM-MN]

If you mix iron (steel?) and carbon(diamond) at high enough temperature, the carbon will dissolve into the iron, making it have a slightly higher carbon content. That's how carbon steels are made. You don't want to do that to your diamond wheel. Either run them at low speed and/or with coolant or don't use them on iron containing material.

 

[Lloyd-ss]

Hmm, I have a 7" wet tile saw with tilting table and diamond blade. This calls for some experimentation!It cuts thru all natural and fired materials like nothing.

And I have never had one of these super-handy-sounding belt sanders. I feel like I have been missing out, but it won't be the first time I have tried something new and wished I knew about it 10 years ago.

 

[ajoeiam]

Hmm, I have a 7" wet tile saw with tilting table and diamond blade. This calls for some experimentation!It cuts thru all natural and fired materials like nothing.

And I have never had one of these super-handy-sounding belt sanders. I feel like I have been missing out, but it won't be the first time I have tried something new and wished I knew about it 10 years ago.

Careful please if you're going to experiment with that tile saw!
The blades work very well for cutting but they really aren't designed for much of any side pressure - - - I've never had a blade disintegrate on me but have heard a lumpy face from exploding grinding wheels called a 'machinist's' face. I don't think I would like that (don't think you would either). A catastrophic failure on a cutting blade would not be pretty - - - there would likely be some of the crazy red stuff around - - - I really don't like cleaning that up!!!!!!!!!!!!!!!
(Oh yes I also push the margins on stuff - - - so far haven't been bit yet - - - so I'll try to keep the 'sperimenting' under fairly tight control - - - grin!)

 

[Lloyd-ss]

Careful please if you're going to experiment with that tile saw!
The blades work very well for cutting but they really aren't designed for much of any side pressure - - - I've never had a blade disintegrate on me but have heard a lumpy face from exploding grinding wheels called a 'machinist's' face. I don't think I would like that (don't think you would either). A catastrophic failure on a cutting blade would not be pretty - - - there would likely be some of the crazy red stuff around - - - I really don't like cleaning that up!!!!!!!!!!!!!!!
(Oh yes I also push the margins on stuff - - - so far haven't been bit yet - - - so I'll try to keep the 'sperimenting' under fairly tight control - - - grin!)

Thanks Joe, I will be cautious. But I also know that when something bad happens my butt is already puckered up which warning me of a 50-50 chance, at best.
The tile blade is a diamond impregnated steel one, so it is pretty tough. I have used the side of the blade to break the edges on pieces of tile, so some off-label usage already. I have a feeling it might be spinning too fast, and whether I place the tool in the "uphill" or "downhill" side will be critical. I am already starting to feel that 50-50 pucker.

 

[timo_gross]

Thanks Joe, I will be cautious. But I also know that when something bad happens my butt is already puckered up which warning me of a 50-50 chance, at best.
The tile blade is a diamond impregnated steel one, so it is pretty tough. I have used the side of the blade to break the edges on pieces of tile, so some off-label usage already. I have a feeling it might be spinning too fast, and whether I place the tool in the "uphill" or "downhill" side will be critical. I am already starting to feel that 50-50 pucker.

Caution is always a good thing when grinding. I tried to cut of some carbide rounds with one of those diamond tile blades for the 4" angle grinder.(electroplated diamond)
It did not work at all. I just ruined the blades (two brands). So be careful, there might be a 2nd risk that you damage the tile blade.

 

[ajoeiam]

Caution is always a good thing when grinding. I tried to cut of some carbide rounds with one of those diamond tile blades for the 4" angle grinder.(electroplated diamond)
It did not work at all. I just ruined the blades (two brands). So be careful, there might be a 2nd risk that you damage the tile blade.

Hm - - - wonder if the diamond coating on the blade was too coarse for the carbide?
I'd have to check as I rarely had opportunity to use a diamond wheel - - - even CBN was seldom - - - (damn) can't remember what the greenish grinding wheel is but that was the most common grinding wheel I got used to for grinding carbide!

 

[stanstocker]

One thing that effects the use of diamond grits in the home shop is that it's a HOME shop. Many things that are accepted practice or avoided in industrial production just don't matter in our little world. I really don't care if I trash a small $20 diamond disk or wheel every two or three years because I used it on HSS tooling as well as on carbide. Different story in a high speed high volume environment. I've often heard home shop guys pontificating about how it is done in industry (usually guys who never worked in industry or did 40 years ago) and telling others that their way would never be done in a manufacturing plant. OK. So what? I don't have a manufacturing plant, my lunches for the year cost more than my hobby "overhead and consumables" costs.

With that said, I wouldn't rough grind an HSS tool to shape on a diamond wheel, that would both likely eat the diamond wheel and waste a LOT of time compared to a belt grinder or 46 grit wheel. I do hone and sharpen HSS now and then on diamond plates or wheels without regret or feeling inept for doing so.

 

[ajoeiam]

One thing that effects the use of diamond grits in the home shop is that it's a HOME shop. Many things that are accepted practice or avoided in industrial production just don't matter in our little world. I really don't care if I trash a small $20 diamond disk or wheel every two or three years because I used it on HSS tooling as well as on carbide. Different story in a high speed high volume environment. I've often heard home shop guys pontificating about how it is done in industry (usually guys who never worked in industry or did 40 years ago) and telling others that their way would never be done in a manufacturing plant. OK. So what? I don't have a manufacturing plant, my lunches for the year cost more than my hobby "overhead and consumables" costs.

With that said, I wouldn't rough grind an HSS tool to shape on a diamond wheel, that would both likely eat the diamond wheel and waste a LOT of time compared to a belt grinder or 46 grit wheel. I do hone and sharpen HSS now and then on diamond plates or wheels without regret or feeling inept for doing so.

You just 'fly at 'er' if you consider grinding carbide tooling on coarse diamond blades as a normal function.
I think that using a finer gritted blade just might make sense (and would save the coarse blade for my next tiling project!) and really not cost that much!
(The last diamond blade for cutting concrete that I bought cost me a LOT more than $20 - - - - far closer to 10x that in fact.)

 

[Lloyd-ss]

One thing that effects the use of diamond grits in the home shop is that it's a HOME shop. Many things that are accepted practice or avoided in industrial production just don't matter in our little world. I really don't care if I trash a small $20 diamond disk or wheel every two or three years because I used it on HSS tooling as well as on carbide. Different story in a high speed high volume environment. I've often heard home shop guys pontificating about how it is done in industry (usually guys who never worked in industry or did 40 years ago) and telling others that their way would never be done in a manufacturing plant. OK. So what? I don't have a manufacturing plant, my lunches for the year cost more than my hobby "overhead and consumables" costs.

With that said, I wouldn't rough grind an HSS tool to shape on a diamond wheel, that would both likely eat the diamond wheel and waste a LOT of time compared to a belt grinder or 46 grit wheel. I do hone and sharpen HSS now and then on diamond plates or wheels without regret or feeling inept for doing so.

At the risk of getting too far off topic, I have to say that in my home shop, "making do," with what I have on hand is the norm. I have neither the money nor time to get exactly the right tool for each and every application. However, I am very careful NOT to ruin tools while improvising. That said,I must admit that the grandkids once tried hand-lapping some rocks on one of my diamond lapping stones. Luckily it was a cheap one from harbor freight, but it will still do 80% of the work that an expensive stone will. That extra 20% of capability would cost me another 80% of $$, and I cannot justify that. By our very nature, home machinists know how to improvise. We HAVE to.

 

[timo_gross]

Hm - - - wonder if the diamond coating on the blade was too coarse for the carbide?
I'd have to check as I rarely had opportunity to use a diamond wheel - - - even CBN was seldom - - - (damn) can't remember what the greenish grinding wheel is but that was the most common grinding wheel I got used to for grinding carbide!

Possibly too coarse, plus the electroplated wheel will loose diamonds if it gets too hot. So there are not enough diamonds in the first place and they get lost. Was an experiment and I gave it a try it did not work and the seller did not claim it would.
I am not too disappointed and the loss was calculated.

 

[pete]

Carbide or even HSS can be shortened much like cutting glass. It doesn't need to be cut right through. Put a nick or groove around it, hold one end in a bench vise, cover with a rag, and a light tap with a hammer will usually break it to the length you want. Very hard equals brittle, that weakened area creates a break line for the material to separate at.

And it's not about what may or may not be done industrially, it's pointing out it can and will do wheel damage and why a possibly expensive diamond wheel might be ruined much sooner than it should. Yes there's lots of cheap diamond wheels available, there's also $300+ as well. If you already understand what the effect is but still chose do it anyway, then that's obviously up to you. But not everyone may know that information yet. Long before the WWW was invented I made quite a few costly mistakes with my shop equipment simply because I didn't know any better.

 

[E. Davis]

One thing that effects the use of diamond grits in the home shop is that it's a HOME shop. Many things that are accepted practice or avoided in industrial production just don't matter in our little world. I really don't care if I trash a small $20 diamond disk or wheel every two or three years because I used it on HSS tooling as well as on carbide. Different story in a high speed high volume environment. I've often heard home shop guys pontificating about how it is done in industry (usually guys who never worked in industry or did 40 years ago) and telling others that their way would never be done in a manufacturing plant. OK. So what? I don't have a manufacturing plant, my lunches for the year cost more than my hobby "overhead and consumables" costs.

With that said, I wouldn't rough grind an HSS tool to shape on a diamond wheel, that would both likely eat the diamond wheel and waste a LOT of time compared to a belt grinder or 46 grit wheel. I do hone and sharpen HSS now and then on diamond plates or wheels without regret or feeling inept for doing so.

Stanstocker

I agree with you about the home shop thing.
Not everyone has a team of engineers and metallurgist available at home.
We work with what we have and we learn by trial and error.
If some dude a 1,000 years ago can sand cast weapons and tools in his bare feet by a river then I can surely sand cast a bronze short sword in my back yard.