Thread: My thoughts on grinders.Long Post.

My general thoughts on sharpening turning tools sparked (pun intended) by the Tormek thread.

First off remember that any tool or machine that rotates has the ability to seriously injure or maim you. All operations on tools require the utmost attention at the operating area.

When people started using cutting tools they used shards of rock that already had an edge on them of sorts.

They further enhanced the edge by chipping with a harder rock.

Some of these were extremely sharp but a bit brittle.

Next came the Bronze age where metal was starting to be used for tools. Their sharpening methods consisted of a whetstone only. They were deemed so valuable in some cases that they were carried around the neck like a necklace.

Then we came to the Iron Age. The cutting edges on tools was sometimes hammered in by the maker of the tools or weapons. Whetstones were also used in the field or factory to maintain an edge.

Grinders started by being a round sandstone wheel powered by slave or treadle. It was not until about the mid to late 1800's that manufactured wheels came into being. I would say they were probably expensive in their day and only factories had them.

The bench grinder as we know it became affordable for most people just after the second world war.

Ever since then arguments about the right speed, what sort of wheels to use and to be wet or dry have ensued.

There has been some brilliant turning work done where I am sure that the tool was probably sharpened by a flat rock that was found in some paddock.

Now on with the main part of this post.

I am not going into the different properties of all the wheels available. I am trying to give you the options available to sharpen your tools and approx prices as at 2012.

The first thing to do with most grinders is take the useless rest off and throw it away. They are flimsy, vibratory pieces of junk and shouldn't have the name "rest".

There are stages of sharpening or should I say cost of sharpening and which you choose is governed by a number of factors. Your budget, the type of work you do and the type of tools you use. How often you turn also comes into it.

I am talking about power sharpening here. If you have a set of Carbon steel chisels and you turn the odd thing every once in a while, a good oil stone will suffice.

There is a difference in shaping a tool and sharpening it. Shaping occurs when you buy the tool to get it the way you want. Sharpening would sometimes be better called maintenance.

Once shaped it does not take long to sharpen it.

Stage 1: Cheapest option.

When someone starts turning they generally have a 6"-8" grinder at their disposal generally costing between $60 for a good cheap one to $400 for a good high quality one.

I personally don't think it makes much difference in the size of the wheel but 5" is a bit small and 4" definitely so.

These are generally fitted with grey wheels when you buy them. These wheels will sharpen mild steel or high carbon steel as in bench chisels, early carbon steel turning chisels and normal plane blades. Some of the higher priced ones come with Aluminium Oxide wheels fitted.

They will sharpen High Speed Steel (HSS) but tend to overheat the steel because the bonding in the wheel is not friable enough and they clog with detritus.

The answer to this is Aluminium Oxide (Al Ox)wheels. These can be pink, white, blue and ruby. It does not matter what the colour it is, it is still an Al Ox wheel.

They come in various grits from 36#-120# with the preference for most turners being 80#. That grit will shape a tool rapidly and will also sharpen to a reasonable edge. The cost of these wheels goes from approx $25 for a 6" - $90 for the 8".

So if you can freehand sharpen the setup will cost approx $90 for a cheap 6" grinder to $400 for a top of the line setup. Add $20 for a diamond stone dresser. I prefer the "T" shaped ones as a straight point makes it very easy to put grooves in the wheel.

That was the set-up I used for 30 years, 6" grinder (good quality) and a 80# wheel. I still use it occasionally for some things. I sharpen my big 2" "U" shaped spindle roughing gouges on it.

Now you will notice that I said freehand sharpening. A tip if you do try freehanding: Put the grinder at the same Centre height as your lathe. This enables you to hold the tool as you would when using the tool to turn and should make it easier.

If you can't freehand sharpen (there are a lot) it is not the end of the world. Most sharpening can be accomplished with a simple platform and a steady hand.

There are numerous plans on the net for these that you can make yourself or you can buy one for about $30-$50.

Of course you do not need a grinder as such. I have seen some ingenious ideas that just use a motor. After all the wheel only has to spin but if you go this way make sure you do not exceed the rated speed of the wheel.

Now we get on to stage 2: Jigs.

The biggest problem for a beginner is that in most cases (there are exceptions) tools don't come sharpened, let alone with the correct angles.

Another problem for a beginner is that if an angle is altered they can't adjust their turning to compensate for it. I will use a quote here from Oneway lathes:

* Professional turners have a lot more experience at the grinder, so are more qualified to sharpen tools.

* Professional turners have more experience at the lathe, so they are better equipped to handle tools which behave differently. If they don't get exactly the same shape on their

tool after they grind it, they can easily compensate, while the hobbyist may have more troubles from their tools if they don't behave in a predictable fashion.

This is what jigs enable you to do. To get a sharpened edge with consistent angles so that you don't have to re-learn how to use the tool every time you put it near a wheel.

As with all new toys there is a learning curve but reading the instructions, watching someone demonstrate it and practice make it easy.

Jigs readily available in Australia are the Tru-grind and Tormek. The Tru-Grinds cost is approx $179 and it does represent good value for money.

The Tormek BGM100 and the associated Woodturners Kit. You can buy the jigs separately but if you are contemplating getting a Tormek later, get the kit. The BGM 100's cost is approx $125. The woodturners kit is $375, The separate jigs range from $40 -$180. The jigs are expensive but they are very well made.

I don't agree with the angles that they suggest in the set up of these jigs but this is a personal thing. I hand shape and sharpen a new tool first and then set the jig to that, not the other way round i.e. set the jig and then shape the tool.

When setting up these grinders to use with jigs I find the best height is just below or at waist height. The reason for this is that you need to be able to hold the jig on the wheel as well as in its locating pin.

Do not hold the handle as instinct tells you to lift it and you dislodge the jig with sometimes disastrous results.

In summary for $110 (grinder, wheel and dresser)+ $180 (Tru-Grind)= $300, you have a good set up that will sharpen your tools with consistently good results.

Or you can go to this. A good 8" grinder ($250), fitted with an 80# and 180# CBN wheels ($500), a Tru Grind ($180) and a Bgm 100 ($125) with the Tormek accs ($375) Total $1055, and you can sharpen just about anything. This is one of my set ups.

This is my main grinding set up for production work and big poles. I do not need tools sharpened to th nth degree as they last a nano second longer than if they were honed to 4000#

I only hone my skews for a final cut in soft timbers.

Or any where in between.

Stage 3: Top of the wozzer or wet grinders. I have demonstrated the Tormek for Jim Carroll on quite a few occassions but have no financial interest in Tormek nor received any payments or concessions from them.

There are a few slow speed wet grinders on the market in Australia: Jet, Scheppach and Tormek.

The Jet retails for approx $630, the Scheppach for approx $180-$290. Be warned that there are 2 models. Do a search on the Forums for further information.

The Tormek has 2 models: the T3 and the T7. The T4 retails at about $670 and the T7 for about $995. The Tormek is expensive but in most cases is probably the only grinder you need for most sharpening jobs.

The differences in these models are as follows.

The T3 has a 40% duty rated motor, the case is plastic, the wheel is 8" in diameter and only 40mm wide. Most jigs in the Tormek range fit. It pays to ask the dealer.

The T7 has a 100% duty cycle rated motor, the case is steel, the wheel is 10" in diameter and 50mm wide. All jigs fit this machine.

Fortunately the Tormek jigs are interchangeable with the Scheppach.

I have not used the Jet and only used a Scheppach once so all comments will be confined to the Tormek.

What a Tormek will not do. Unless you are a masochist it WILL NOT shape tools quickly. It will not turn you into a great turner. Only practise does that.

What it does do. It probably puts the best edge on that can be got from a powered grinder. It does it consistently and once over the learning curve it does it easily and reasonably quickly. 45 seconds was my best effort.

It is safe with no sparks and as has been stated, if you slip it will give you a slight graze.

The jigs are the best made on the market except in a few cases and it can be used for more than just turning tools. I find the skew jig hard to get the tool centred so I shimmed mine.

I have found the best height for grinding on the Tormek is waist height and working about a quarter the way round. You tend to be in the way sharpening tools with long handles.

If you have the room make sure you can get at the back or at least be able to easily turn the machine around.

I have one and use it for when I do fine work. I don't always work on big stuff.

In summary. It all boils down to what you can afford. Most setups will give you a good edge. Some better than others.