Grinders - does size matter?

[Bagmann]

Hi all, just a quick one. I currently have a 6" bench grinder for sharpening my turning tools and am thinking of upsizing to an 8", but am unsure if it is totally necessary. Can anyone out there shed some light on this for me please.

Thanks in advance

Simon

[robyn2839]

get the 8'' i bet you dont get one post to say it doesn,t make any difference, you will wish you had one years ago and wont be sorry......bob

[RETIRED]

I have an 8", 10" Tormek and 6". Had the 6" for 25 years before getting the others.

There is not a lot of difference except for 1 thing. The surface speed of the 8" is quite a lot higher than the 6" and therefore it is easier to blue the steel.

If you have a 6", save the money and buy a new tool.

There is not much difference in the concavity of the hollow grind.

At demos I have sometimes had to use what is there. The worst was a 4" hand grinder. It did not impress me much. :whistling2:

[RETIRED]

get the 8'' i bet you dont get one post to say it doesn,t make any difference, you will wish you had one years ago and wont be sorry......bob
Mines 1.:D

[Skew ChiDAMN!!]

:whs: (That's 2. :D)

I'll recommend an 8" to a first-time buyer or to someone replacing a "broken" 6"er.

But going from a working 6" to an 8"? Nar, the benefits gained aren't worth the dollars. (Not unless the 6"er only took 1/2" wide wheels in the first place. :wink:)

[badgaz]

There is not much difference in the concavity of the hollow grind.

I agree with . I have a 6" A&A and so far it seems to sharpen as per expectations. :;

I may be a relative newcomer to turning, but in my limited experience, the most important facet of the profile is the cutting edge. I'm sure a vast range of wheel diameters will produce an edge that will cut wood.

In the words of Dave Mustaine" It's not how big your pencil is; it's how you write your name.":p:)

Gazza

[Bagmann]

You guys are great!:2tsup:, I am leaning very heavily toward staying with what I have, should have said before that it takes 1" wide wheels, anyhow thanks a million for your advice.

Great work & thanks

Simon

p.s.
found an interesting system with plans on this guys website www.davidreedsmith.com (http://www.davidreedsmith.com) . He made it out of a modified drill press, looks pretty cool.

[jefferson]

Simon,

I can't agree with the experts on this one. At least not entirely. For turning chisels, the depth of the hollow grind comparing the 6 inch to the 8 inch wheels may not be critical. But if you want to sharpen non-turning chisels - particularly paring chisels where the bevel angles are much less that most turning tools, the depth of the hollow grind is important. IMHO you want as straight a bevel then as you can get without too much hollowing. Same for plane blades that are much thinner than most if not all turning chisels.

That's my TBW. :U

Grasshopper

[Calm]

There are plenty of must have " tools that i wouldnt buy a second grinder before i bought a lot of other things you need.

Keep the one you got and go to the next WWW show to spend the dollars on another "must have"

Cheers

[jefferson]

I forgot to say - and I'm sure that will cover this at the Sharpening weekend - that a decent sharpening jig (next to the right grade of stone) is probably more important than which size wheel.

OK, some can grind free-hand pretty well but for novices like me and many others, learning to turn can be difficult with blunt tools.

(Dare I say that even has "moved" his position somewhat on this score?:roll: Maybe he's spending too much time with the likes of me.) Woodturning is one set of skills, sharpening is another. But you must have both.

So I'd be voting for a decent jig, not for a bigger grinder. Unless you do more than turning, in which case you probably need:

- an 8 or 6 inch grinder with decent grade wheels
- a Tormek or equivalent with all the jigs for all kinds of chisels etc, not just turning ones if you want razor sharp
- a pro sharpener handy (they have a trade qualification that I can't remember) for saw and planer blades etc.

I'm not a fan of waterstones as they wear unevenly, but some of the sandpaper systems seem to work very well if the $ are in issue. I forget which magazine I read it it, but paper does work. Same problem though with the various grinding systems - you need jigs that work well.

Jeff

[powderpost]

I prefer 8" grinders, but have a 6" wheel mounted on a shaft that fits the lathe when demonstrating out of the shed. Not to sure I would upgrade from a 6" wheel just for the sake of it. I love water stones... no oil to leave stains.
Jim

[jefferson]

I prefer 8" grinders, but have a 6" wheel mounted on a shaft that fits the lathe when demonstrating out of the shed. Not to sure I would upgrade from a 6" wheel just for the sake of it. I love water stones... no oil to leave stains.
Jim

Jim, I've not quite the knack of it with the water stones (or free-hand grinding for that matter).

I'd really like to know how to sharpen my plane blades on a stone with a slight concave so I can smooth plane without the dips from a flat but sharp blade off the Tormek. Keep me posted!

Jeff

[joe greiner]

8" grinders typically run at about half the speed of 6", so in terms of surface speed alone, it's more of a toss-up than it would seem.

None of the jigs and such fell from the sky in their final form. If you can learn free-hand grinding, your jig selections will be more enlightened.

Cheers,
Joe

[powderpost]

Jeff, I have two water stones, I rub them together periodically to keep them flat. When honing, I use a figure 8 motion as well as straight up and down, and use the full length of the stone. Oil stones will develop a hollow as well if not used carefully. I used to flatten my old oil stone in the concrete floor with plenty of water.
Jim

[INVENTOR]

Just to clarify something. In Australia, most grinders run at approx 2800 ( 6" or 8") which means they vibrate (even with trued wheels) and remove way too much material, in most cases. You are there to sharpen, not grind away your money.

So, Bagman if you were looking at improving your sharpening, seroiusly consider buying a slow speed 8' grinder ( Carba tec sell them). They work great. Not too slow, so you can still reshape your tools, but not too fast so you grind away too much and almost none of the annoying vibration ( you know what they are like when they slow down!).
I wish I had bought mine years ago. If only someone told me.

Also, if you happen to 'blue' your HSS tools, don't worry, while its not great, they are not 'damaged'. Also, get rid of any water basins near the grinder. they are not needed with HSS tools.

Hope this helps.

[Paul39]

I recently got a 1725 rpm, 203mm / 8 inch grinder and Oneway jigs along with a bunch of other lathe stuff. It does work well.

For several years I used a 25mm / 1 inch wide belt sander with 120 grit to sharpen everything freehand.

A wider belt sander and selection of belts is nice for skews, plane irons, lathe and non lathe chisels, bowl gouges, axes, shovels, hoes.

4, 6, 800 grit wet or dry sandpaper taped to a piece of scrap 6 mm / 1/4 inch plate glass and kept flooded with water will put a lovely edge on skews and plane irons.

Everything mentioned in the above posts will sharpen.

I think sometimes we get all caught up in the sharpening techniques and rituals rather than giving the tool a few swipes on something abrasive and gouging off bushels of shavings.

[Skew ChiDAMN!!]

I think sometimes we get all caught up in the sharpening techniques and rituals rather than giving the tool a few swipes on something abrasive and gouging off bushels of shavings.

:yes:

I also think that sometimes we get too involved in making a tool look "pretty."

For example, the most difficult turning tool to sharpen freehand is the bowl gouge, particularly fingernail grinds.

But almost everybody who can rub the bevel when turning can rub the bevel when grinding... except on the RH side, which is where they have the greatest difficulty. Why? because we don't normally use that side of the tool for cutting, so don't have the "muscle learning."

So... we don't use the RH edge... yet we persist in trying to get the bevel nice & symmetrical when in actual practice we could more or less grind everything past the 1 o'clock position (if the centre of the tip is 12 o'clock) away so that it doesn't catch, and leave it at that!

Admittedly there are rare occasions when the RH side is used... but not so often that we have to always sharpen every gouge symmetrically. :rolleyes:

[TTIT]

:yes:....................
So... we don't use the RH edge... yet we persist in trying to get the bevel nice & symmetrical when in actual practice we could more or less grind everything past the 1 o'clock position (if the centre of the tip is 12 o'clock) away so that it doesn't catch, and leave it at that!

Admittedly there are rare occasions when the RH side is used... but not so often that we have to always sharpen every gouge symmetrically. :rolleyes:That made a lot of sense until I thought about the way I use my gouge :B I use the right-hand side quite a bit - could be partly to do with being self-taught - none of those "this is the only way to do it" hang-ups, and partly because it's so easy to work both sides of a bowl on the Stubby without reversing the work. :shrug:

[Ozkaban]

This is a pretty interestiong conversation. I have a A&A 6" grinder with a 1" white wheel, and was wondering if I should upgrade to an 8". While thinking about that I bought a tru-grind jig, as my free hand grinding is ok, but not great, and I find it fantastic - it takes a few seconds, chisel is sharp and minimal material removed.

I use water stones for my other chisels and I'm really happy with them. Once again using a jig - the veritas MkII. No complaints and the stones stay reasonably flat if you use the whole surface and flattening them is easy enough.

Nice to hear other people saying not to worry about upgrading to an 8". When and if my grinder bites the dust I probably will, but will be happy with the smaller one in the mean time...

Cheers,
Dave

[jefferson]

That made a lot of sense until I thought about the way I use my gouge :B I use the right-hand side quite a bit - could be partly to do with being self-taught - none of those "this is the only way to do it" hang-ups, and partly because it's so easy to work both sides of a bowl on the Stubby without reversing the work. :shrug:


Skew, sorry to be a bother too, but I have the same issues at TTIT.

If I turn the outside of a bowl, I cut uphill towards the headstock with the gouge tilted at say 45 degrees using the left side of the tool. For insides, I do the opposite and use the right hand tip of the gouge.

Sorry, I may (probably am) stupid but you've sure confused me!

Jeff

[Texian]

Me too Jeff. I use both "sides", but probably the right side more than the left side. When the right side gets dull, I continue with the left side as much as feasible before sharpening.

[Skew ChiDAMN!!]

Skew, sorry to be a bother too, but I have the same issues at TTIT.

Hmmm... I guess I'm guilty of some "this how I do it, so everybody else does too" type thinking.

I usually turn the outside of a bowl first, with the foot towards the tailstock. So even if I use a bowl gouge on the outside - which I rarely do - it's still using the LH edge, cutting from the outside in to the centre. Then I reverse mount and hollow from the centre to the edge, again using the LH side.

Don't get me wrong, I'll still use the RH side of the tip, but very, very rarely do I go past the 1 o'clock position and use the RH "wing" of the gouge.

Like Vern, I'm self-taught. So I have my share of bad habits... :B

[derekcohen]

I think that HSS changes the rules.

With HSS, concerns about overheating the steel largely disappear. And so you can grind with just about anything.

For plane blades, largely O1 and A2 steel, which are vulnerable to overheating and losing temper, more care is required.

My own preferences are:

My turning is essentially restricted to spindle work as I only have a Jet mini (with long bed extension). I do all my grinding and honing on a disk sander (attached to my belt sander combo). The disk speed is 1400 rpm at the circumference (and very slow at the centre). I usually grind with 120 and hone with 240 grit sanding disks. The 240 will leave a mirrored surface. And if I need an even sharper edge, I slap on a leather strop disk with green rouge.

I do all this freehand, and it literally takes no more than a few seconds to rehone a skew or gouge.

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Honinglathechisel.jpg

When it comes to plane blades I either use a Tormek or a 8" half-speed Carbatec dry grinder (1400 rpm) with either a blue 46 grit Norton 3X wheel or a white 46 grit Norton wheel. The coarser the wheel on a dry grinder, the cooler it will run. The Norton 3X is the coolest wheel of all :;

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Sharpeningstation2.jpg

I have a 6" high speed dry grinder lurking in the background as well. This was replaced by the 8" as I wanted a shallower grind. A 6" high speed (2800 rpm) runs at the same speed as a 8" half speed (1400 rpm) at the circumference of the wheel.

Regards from Perth

Derek

[issatree]

Hi All,
I've have alway used 6in. Grinders, have never had to hone my chisels, in fact I like a little smidgon of steel on my wheels, as I seem to get a better egde. All bar 6 tools are P&N. Now that's me, & most likely not for everyone.
I like to clean my wheels often, as I use 60g. & a 120g. wheels & a section of an old Brickies Diamond encrusted wheel, to clean them with. Does a brilliant job, & next to no cost. I always use dry timber, as the green stuff give me a rash, & no way am I going to use Gloves.
Well That's my bit.
REGARDS,
ISSATREE.

[robyn2839]

well if there is no difference between 6'' and 8'' as most have stated who would like to swap my 3 month old 6''abbot and ashby for an 8'' grinder?????????????????????.bob