Best microscope for analyzing sharpness?

[Dan Barr]

Hi all,I am looking for advice on which microscope is the best for analyzing sharpness. Intent: observe plane blades and chisels after individual/successive sharpenings on various media. I.e. Oil stones, waterstones, Arkansas, ceramic, strop, etc.I don't think I can afford an electron microscope. Who knows, maybe the prices have come down over the years. Maybe there's an electron microscope app for my iPad...... Any advice on an affordable microscope that will allow me to make meaningful observations would be appreciated.Thanks,Dan

[Prashun Patel]

Are you trying to make comparisons, or just trying to observe to make sure you're adequately sharpened?

[bill tindall]

Email Steve Elliot, sgelliott@cablespeed.com, and/ or check out his web site. Steve takes the best pictures I have seen with inexpensive equipment. That said, his images are not close to the detail one can capture with a microscope set up for imaging metal surface(and costing thousands of dollars). You can find images I have posted on WoodCentral taken with a Nikon set up for metal imaging. That said, the best by far imaging will be with a scanning electron microscope. In fact Lee Valley has recently bought such equipment to support their sharpening and metal selection studies.

As far as magnification to just support sharpening, a 10X quality hand lens works fine. Unless you are doing sharpening research the hand lens is all you need, so long as it is a quality lens.

[David Weaver]

A cheap dissection microscope will be fine. if you can find a setup that takes pictures like steve elliot's, even better. His pictures are fantastic, like bill says. I haven't seen anything as good just looking through my own stuff, let alone in pictures. Alex gilmore used to have excellent pictures, too, but he's removed a lot of that type of picture over time, I don't know why.

Just looking at edges will confound you in terms of trying to determine sharpness or usefulness in woodworking.

If you are really looking just for absolute sharpness, anything in the 15k shapton range will begin to leave a polish so consistent that it will be difficult to see the differences between stones for purposes of sharpness, they will all just look a little different. Natural stones or stones that allow swarf to roll around will create a duller looking edge, and deciding how sharp they actually are will be next to impossible unless they are hard enough to hold their particles in place and dig a groove in whatever you're sharpening.

Coarser stones will leave scratches you can see much more easily, and there will be some stones that leave mostly small scratches and a few big ones, that will make a yes-or-no type of comparison difficult to tell.

I think if you are comparing finishing stones, you will almost have to hollow grind or microbevel a chisel edge (polished on both sides of the bevel of course, with the stone in question) at about 20 degrees (any more blunt than that, and the HHT will seem to find an upper limit around 2/3), do a light palm strop of the chisel edge to make sure all semblance of the wire edge is absolutely gone and then do the hanging hair test.

You can do this with a plane iron, too, but you'll have more polish work to do unless you back bevel the iron.

I hate to say it, but when you get around a micron or below, it gets to be almost impossible to tell what's sharper. Technique becomes very important and a battery of hanging hair tests will sort of describe what edge is what.

It's really not particularly practical work for woodworking, but it is instructive and interesting to do, and the HHT will really help you gauge where the quality of your honing is.

http://www.coticule.be/hanging-hair-test.html

All of that said, like Bill says, above and beyond the loupe, this is really getting into space cadet kind of stuff (well, that's not exactly what he said, but I saw the word loupe ), but a lot of us have fooled around with it out of curiosity. I did it to try to find out how fine my natural stones were, many of which people described as being much finer than any synthetic hone, when in the end out of 10, 8 were different and less sharp, and two are sharper. They are both stones designated as razor stones from mines and would be difficult to use effectively woodworking.

I could not tell that from the microscope, though, only the HHT confirmed that.

[robin wood]

If you are not looking for photos then a good binocular microscope with magnification in the 20x-80x is what you want. Something like this 42632255.jpg

This is the one I use I picked it up new from ebay for £65 there are good old ones for similar money. This allows you to see critically the difference between the grooves left by a shapton 15,000 and a natural waterstone say. It helped me a lot to asses all my different stones (I have a lot) in a more objective manner, this in turn speeded sharpening. The other thing it does is I use it when sharpening to have a quick glance along the edge and check that I have reached the edge all the way along with each successive grit before progressing to the next. All this can be done with a £10 plastic microscope like this search ebay for "microscope loupe" but these are not so easy to use having a short depth of field and reversing the image, most Japanese woodworkers use them though. 30x is best for these.

[Dan Barr]

I would like to do both.Make comparisons and check for sharp.So far there are some really useful replies here. Thanks all for the input.Thanks,Dan

[Dale Sautter]

Dittos what Bill said above about simply using a hand lens to quickly check and move on... but for fun, a couple of my first pics taken using the following... 1,2,3:

Make a USB microscope article:
http://pcformat.techradar.com/articl...scope-11-06-10

Logitech 1080p Webcam Pro C910
http://www.amazon.com/Logitech-1080p...0&sr=1-1-spell

Celestron 44102 400x Power Laboratory Biological Microscope
http://www.amazon.com/Celestron-4410...8258228&sr=8-4

o88i13.jpg

262nxgx.jpg

[Randy Klein]

I use this loupe from LV while sharpening. It works great, especially when hold the light so that it rakes perpendicular to your scratches.

http://www.leevalley.com/US/wood/pag...56,43351,51092

99k1041s1b.jpg

[Prashun Patel]

If you ust want to check for sharpness, a cheap jeweler's loupe will allow you to see scratches and nicks even in the 8000gt range.

[Andrae Covington]

I use this loupe from LV while sharpening. It works great, especially when hold the light so that it rakes perpendicular to your scratches.

http://www.leevalley.com/US/wood/pag...56,43351,51092

99k1041s1b.jpg

The microscopes are out of my league, I also use the LV loupe and find it handy. It was especially useful when I was first learning to sharpen, wondering "how long do I have to work on this stone to remove the scratches of the previous stone?" At the course grits, that's obvious to the naked eye, but further up it became difficult to see at times. I just read the product description again and noticed they say it can be used to help remove slivers. Since I usually get them in one hand or the other, and I need the unwounded hand to hold the tweezers, I'd need a third hand to hold the loupe.

[Stuart Tierney]

One this like.

Anything more is overkill, anything less might not be sufficient.


IMGP4557 (Large).JPG

This was taken with a 'proper' microscope, that still wasn't set up and had poor glass in it. It's at 400x and no, you don't need to go that far. The higher the magnification, the more troublesome things become but the more detail you get too.

Hope that helps, and I'd try and avoid a 'loupe', they can be useful for coarser sharpening, but a proper combination of lenses will show a lot more detail at a higher magnification and be a lot clearer as well.

Stu.

(Who's got a drawer full of glass and a shelf full of microscope with a K-mount sitting atop the mess...)

[Chris Fournier]

I have played around with this a few times over the years to say the least. Honestly, if you insist on relying on your eyes only you simply don't need any magnification to tell if an edge is sharp or not. The keenest edge reflects no light, in fact it kinda looks black. Right off the grinder and 800 grit stone I can tell if I've got sharp, no loup, no microscope, no guessing.

It is fun to look at cutting edges under magnification but it is really not a useful enterprise if your desire is to actually work wood rather than design his and hers multi-bladed personal razors.

And to cap it all off, your sight is only one sense that you can use to determine the sharpness of an edge. Pull a sharpened edge vertically along your thumbnail and you can tell just how sharp it is. Sure it may take a while to get the feel but I'm telling you that with your eyes closed you can tell sharp from sharpest.

Honestly, don't get bogged down with this microscopic inspection of your cutting tools, it is a waste of time and money to say the least. Employ good sharpening practices and equipment and use your everyday senses to tell you what is truly sharp, this is the path of a woodworker, though perhaps not the path of a writer. And many good writers have written about this subject and I am most certain that you will not move the subject matter forward one fine edge from where they have taken us to this day.

Spend your time and money on processes and tools that work wood - you'll become an expert sharpener with no need for coke bottle glasses.

[Russell Sansom]

A few years ago when I retired and started buying state of the art chisels and plane irons, I decided it was time to get even more serious about sharpening. I started looking for microscopes and landed very quickly on this kind:

Bausch and Lomb StereoZoom 4
An ebay search will show you what they look like.


The ones I know about were used for electronics assembly here in Silicon Valley. They offer two-eyed viewing and the power of the optics can go from 10X to about 65X. It took me a little practice, but I now I can clearly see where an edge stands. I can gauge pretty accurately how much grinding will be required to remove a nick. And I can quickly watch an edge degrade over time.

I have enjoyed this tool tremendously. I got a completely new understanding of my steel. And it's amazing for removing splinters.

[Jamie Buxton]

This guy has a very interesting site about sharpening, using a "toy" computer microscope for imaging. http://www3.telus.net/BrentBeach/

[Jim Koepke]

I have played around with this a few times over the years to say the least. Honestly, if you insist on relying on your eyes only you simply don't need any magnification to tell if an edge is sharp or not. The keenest edge reflects no light, in fact it kinda looks black.

I am with Chris on this. I used to use a hand lens. The parts of an edge that are not fully sharpened will look like little lights along the edge. If a section is not keen, it may look like light hitting a strand of a spider web.

The lens I use now in relation to sharpening is my magnifier lamp. I use it to watch while shaving arm hair to allow less shaving to see it working. After a lot of blade sharpening, there aren't a lot of hairs left to test the blades.

I like the HHT. The levels of sharpness corollate somewhat with shaving arm hair.

I just read the product description again and noticed they say it can be used to help remove slivers. Since I usually get them in one hand or the other, and I need the unwounded hand to hold the tweezers, I'd need a third hand to hold the loupe.

I have a couple of swing out hand lenses. I can curl a finger through the body of the open lens and use a couple of fingers from the same hand to hold the tweezers. A little awkward, but it works.

jtk