How To Quickly Grind Lathe Bits

I would like to add that tool bits do not have to be pretty to work good. I would be ashamed to put a photo of some of mine on this site but they work fine. Don
 
"PA"; Once you find your wheels and practice; Instead of an hour, it will take you minutes to grind your cutters and less than a minute to resharpen one...
...here's a Google link to various pictures and charts (of angles) of lathe cutters.
...as some have said above: Practice, practice, practice (but also think, read and copy as yoose' practice, practice )
... add: The "flatter" all the angles on a lathe cutter when appropriate (except like maybe a chip breaker ground in), whatever those angles may be, and better the finish, the better the results...
(Remembering "rough" ("micro" sawtooth) on the finshed as ground angles that lead to and therefor on any cutting edge will last many times less.
"Rough" wears compared to smooth more, even when the work piece may be ledloy... rough finish cutters wear exponentially more as the tougher and harder up the scales the work piece is.
https://www.google.com/search?q=lat...X&ved=0ahUKEwjF5-HfianQAhVollQKHXQXCOgQsAQIGg
 
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Reeltor said:
Take a look at Oxtool and ABomb79's YouTube video series entitled Chip Control. Tom and Adam go at it trying to take the biggest cut using HSS hand ground bits, showing how they like to grind their tool bits. IIRC one of them uses a hand grinder with the bit clamped in a vise to rough in the bit then move to the pedestal grinder.
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Two thumb's up for the "Chip Control" video series. I was thoroughly confused on how to grind lathe tool bits until I watched the first video in the series.

One other thing I can perhaps add to the discussion: it really is very important to both true and dress the wheels on your bench grinder. Even the stock wheels on a Ryobi 6" grinder do a decent job grinding HSS *after* they are dressed (and of course the grinder shakes-and-bakes if the wheels aren't trued) *. I first bought a single point diamond truing tool off Amazon which did a good job (once I put a 3/8" drill stop on the handle to hold the point a fixed distance from the wheel), but the t-shaped tool with lots of little diamonds on it is far faster and easier to use for only a few dollars more. I bought it on a lark - along with a CGW "soft" 120 grit white wheel - from the local Woodcraft store. I use the usual star wheel type dressing tool (from HF), and it is flat out amazing how much faster the wheel will grind HSS after it is dressed (equally amazing - how quickly dressing reduces the diameter of the wheel and how much grit it throws into the air!).


* - I speak only of the efficacy of the grinder itself, not of my skill at grinding!
 
The grey wheels that come from an import machine are very good for honing your axe. Break it half or quarters for easier handling.
mike
 
kwoodhands said:
The grey wheels that come from an import machine are very good for honing your axe. Break it half or quarters for easier handling.
mike
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LOL... The wheels on the HF grinders I tried (both the 6" and 8" models) were, indeed, just that bad, but the stock wheels on the Ryobi (well, the fine wheel at least) do a passable job on HSS. That said, the CGW 120 grit wheel grinds HSS much faster and gives a finer finish than the stock ~60 grit Ryobi wheel, and it doesn't need to be dressed nearly so frequently, but it also cost $25 all by itself compared to $45 for the Ryobi grinder + 2 wheels.

I'm not ditching the other Ryobi wheel just yet, though; the slower metal removal rate is actually a plus as I learn how to grind lathe tool bits (and, simultaneously learn just how ugly a bit can look and still cut metal just fine... :eek:).
 
I was given an 8" bench grinder that came from HF. It vibrated and shook like the devil, and good luck trying to sharpen anything with it. It quickly became obvious why the previous owner wanted to be rid of it. Once I replaced the wheels with some good ones it was fine!
 
My HF 8" snag grinder I took back...the one on display seemed to spin fine by hand but mine looked like 2 potato chips spinning...
...upon turning on and then inspection at home, not only were the wheels molded like potato chips when I took them off but the spindle shafts (I think it's design had 2 separate and not one thru?) didn't run on center (As a matter of fact one side ran so far out it was more than the apx .030 travel one direction of my test indicator!)

No complaints though on the metal cutoff/band saw I bought from them (except the blades aren't the best)

PS: I checked out some of their drill presses last week but this time it was the sound and eyeballing the runout of some of the chucks by hand (maybe it was the spindles too) that scared me away...

It makes one think about the QC of some imported "stuff"...
 
I have a bench & a mini from HF. The mini once I throw away the handheld attachment was great out of the box. The bench grinder has some vibration but most went away with normal use. I finally dressed it & it runs smooth now.
 
Christian Poulsen said:
My HF 8" snag grinder I took back...the one on display seemed to spin fine by hand but mine looked like 2 potato chips spinning...
...upon turning on and then inspection at home, not only were the wheels molded like potato chips when I took them off but the spindle shafts (I think it's design had 2 separate and not one thru?) didn't run on center (As a matter of fact one side ran so far out it was more than the apx .030 travel one direction of my test indicator!)

No complaints though on the metal cutoff/band saw I bought from them (except the blades aren't the best)

PS: I checked out some of their drill presses last week but this time it was the sound and eyeballing the runout of some of the chucks by hand (maybe it was the spindles too) that scared me away...

It makes one think about the QC of some imported "stuff"...
Click to expand...
QC on most Asian stuff that comes to hobby-machinists is outsourced -- to the final purchaser! The machine tools come with an inspection card that appears photocopied multiple times. Those tools are going out the door, regardless.
 
Bob Korves said:
QC on most Asian stuff that comes to hobby-machinists is outsourced -- to the final purchaser! The machine tools come with an inspection card that appears photocopied multiple times. Those tools are going out the door, regardless.
Click to expand...
That is the best way I've ever heard it put. I actually usually buy this stuff planning to finish it when I get it.
 
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