Thread: What exactly is Feedback?

So, when I crank the sound system in the church, or put a mic in front of a monitor I get feedback. It's a sound loop that amplifies itself until you shut it off or break something.

When I teach a college course I conclude with a "Feedback Survey" and get feedback on the highs and lows of the course.

When I tune a carburetor the rpms, smell, and throttle response give me feedback allowing me to find that sweet spot where she runs smooth, efficient, and responsive.

When I hone I use tests like shave tests, magnification, "hair popping" etc. to get feedback on where the edge is on its journey toward shave-vana.

When I read honing threads or articles, or watch Lynn, Glen, or Sham hone I find this word "Feedback" popping up time and time again, but I've yet to find a clear answer on what is meant by this term. At one point it seems to be a feel, or a suction, at another point it seems to be a sound, then again at other points the term seems to be referring to the composite of information gleaned from various tests.

Right now I'm in the midst of a "no shave" experiment, but as I near the end of this experiment I'm honing up my razors and getting ready for all the glories of my daily straight routines. Refreshing myself after some time off I'm coming up against this term again.

Anybody have a clear definition on this term?

Thanks,
Jim

This is a good question.

I wondered for a long time.

Then I decided that it didn't really matter how other people used it, cause I don't talk to other people about honing feedback.

But for me, feedback is any sensation I receive from the razor on the stone, as a result of honing. This can be sound, feel, sight or touch. Good feedback, is feedback that I can interpret in a meaningful way. While poor feedback is a lack of any identifiable sensations I can interpret. This means I might get great feedback from my Norton stones, while the feedback from my coticule is poor. Why? Because I know what a properly set bevel feels and sounds like on a Norton stone. But on a coticule, each one is unique, and none of them like me. So..they don't talk to me.

JMHO, YMMV, and several other acronyms I'm sure.

The term can mean whatever you'd like and might have some basis in different hones. To me, in it's most simple terms, it's the drag caused by honing when the edge starts getting sharper. As the bevel becomes smoother it sucks and drags more. As the stone dries, or is re-wetted the feedback might change. It's all about the stone and what it does. Once you realize each stone does something when it's sharpening an edge that information becomes a critical aspect in honing.

For example the feedback while honing on Shapton is very good, feels like the razor is stuck to the stone once it reach its max potential on one stone, then move to a finer stone till that suction shows up again. Sound is a big part as well you get to know what sound comes for a particular stone, if it doesnt sound right something is out of wack, maybe more water or lapping or you moved from one stone to the other to fast, all part of feedback to acheive your goal.
Another good feedback is watching the water in front of the blade while honing, it will definately point out if there is dirt on your stone or grit.

There also feedback on ebay!

Hey There

So this is a good question, and one which is going to cause an angle to lose her wings

Ok ...

When I am honing I have an understanding of which hones are going to do what to the razor in my hand. We all know that we move from setting a bevel, to refining the bevel (some call this sharpening), next we move onto polishing the bevel. There are a number of interesting things going on throughout these processes.

Bevel setting -

When we are setting a bevel we are going to remove steel and have the two edges of the blade converge at a small point. When they converge at an acceptable angle, we can shave with the edge. We generally use stones around 1000 grit to bevel set. This stone is going to remove a moderate amount of steel, as such there are going to be certain things you can feel, hear, and see to use as feedback so that you know everything is going well.

First you are going to see steel being removed from the razor. You aren't going to see it happening but you are going to see evidence of it. You will see grey being deposited on your stone, and the lubricant you are using will become darker, and darker as it holds more and more steel. You will be able to see the lubricant moving in front of your razor, it will move more and more uniformly as the bevel becomes set and more uniform in nature. If your stone isn't flat, or the bevel isn't completely in contact with the stone the lubricant won't move in a smooth, wave form along your hone. If it isn't uniform then there is something wrong and you should fix it.

You will be able to hear a small amount of noise, the noise will get smaller and smaller as you go on with the honing, and the bevel becomes set. This is IMO because the surface of the bevel is reflecting the surface of the stone with it's scratch pattern and how "straight"/flat it is.

You will feel some vibration, these vibrations are minimal but important. The less vibration you feel, the closer to having a set bevel you are. Also as the bevel becomes set there will be less resistance along the line of the stone, but as you come to turn/roll the blade over the spine to come back in the opposite direction the set bevel with provide resistance, as it sucks to the stone.

Sharpening -

This is generally very similar to bevel setting with you using less pressure so the feedback becomes less, this is why as you hone more this feedback becomes easier to notice.

Polishing -

For me this feedback is more about the feel of the suction between the razor and the stone, and how the lubricant/slurry looks.
There should be more suction at this stage because the stone is harder (my stones are all natural), and the bevel is much smoother. You need to take care not to allow the edge push into the stone, as the suction could allow you to lift the razor from the stone. If this happens you will feel a horrible scratching in your fingers and you may see it.

My experience of the slurry is that a slurry forms more and more as I polish the blade. This is going to vary depending on who you ask BUT everybody's experiences with this are important (providing they end with an excellent shaver). My slurry get's whiter and whiter as I polish more. This is significant to me because I am done once I can't see the certain colors on my stone. For you, this could be different but you will gain your feedback with experience.

I HATE the following acronym but YMMV. I use it here because your fingers may be less/more sensitive than mine, your eyesight better/worse, and the same with your ears. You will have different hones, may use a different lubricant (as I make my own), and you may or may not have kids screaming at you as you hone lol.

I hope this helps

When you talk feedback in a sound system that is a specific thing and in fact is an engineering term and it can be defined and studied and seen on test instruments and acoustic engineers can quantify that. However with many other things it's just a term with no real definition except in the mind of the individual. With razors it's like that. it's all relative. Ten folks might hone the same razor on the same hone in the same condition and you might get ten descriptions of the feedback they perceive and some may feel nothing at all.

For me feedback is the feel of the razor on the stone.
Different stones can feel different on the same razor.Some stones feel similar on majority of razors, the ones that provide the most consistent feed back are the ones preferred by honers.

For me, feedback in relation to honing, is the result from the first shave of a just honed razor. It tells me all I need to know about the honing of that particular razor.

After a certain number of blades I developed an ability to sense feedback from the stones to help guide the progress.

Draw, grittiness feeling in the stroke, sound, and perhaps other less tangible perceptions I get through my fingers.

Predominantly, this is all relative and possibly unique to blade itself. Ideally all these perceived qualities diminish to a lesser state, but MOST importantly, they are consistent from heel to toe.

Often I find that the heel or toe need more attention than the interior of the blade. The feedback from the strokes on the stone are usually my first tip off

I suspect there is no definitive answer as we all key on different things, have different expectations of "sharp", and we all potentially have more/less acute senses. Some have great eyes, some have fantastic hearing, others have a sensitive touch....I have even heard some talk about taste as a sense that gets used (dull blades taste like steel, and sharp ones taste like blood )

To date, I have not talked to anyone that relies much in smell feed back at the honing/stropping level

Originally Posted by unit

To date, I have not talked to anyone that relies much in smell feed back at the honing/stropping level

Some naturals, after being slurried have a very distinct smell, for example the earthy smell of a coticule, the escher/thuri as well.