blade stiffeners and stuff

[reible]

Hi,

[After writing this post I have realized that I'm very out dated on this subject. I have items from 30+ years ago and findings based on observations over 10 years ago. I'd like to hear some fresh views... so if you've got them post them.]

The subject has come up several times so I thought I'd do a post on the subject. I know some of you have these, some of you use them, some of have them but no longer use them, some of you have no idea that these things look like.

First there stiffeners often have various names, sometimes called dampeners, or some mix of the names. So if you have another name that's fine call them what you will.

So what is the big deal about them? Here is a short list:
Makes the blade more rigid.
Holds the blade more "true".
Reduces blade noise.
Dampens out transmitted vibrations.
Reduces cut noise.

I don't know maybe someone can think of a few more for the list???

I first became aware of them back in the early/mid 70's when I joined a large woodworking club and they were the talk of the day. Keep in mind this was the still the day of steel blades. I'd say most of the group were pro stiffeners and the number grew as people purchased them. I was one that became a user and at that time they were a great help.

When I got a shopsmith they kicked me out of the club... just kidding. When I got a shopsmith I used them for a time. Even as the prices dropped on carbide blades they still were prone maybe even more so prone to the same issues of vibration, noise and lack of being true. However as things progressed the manufactures figured out how to make the blades better, things like expansion and vibrations damping, laser cutting, and well the list goes on.

What I found was the more modern and costly blades had solved most of the issues and made using the stiffeners optional... all the way to the point that mine have sat in a drawer for years now. [Lets say 10 years.]

As a rule of thumb stiffeners were sized in the range of 1/2 the blade dia. or on a 10" blade 5". This ment a large reduction in the depth you could cut with them on. For normal operations up to the stiffener would offer a 2-1/2 depth of cut. Some people felt it necessary to use even larger stiffeners, thus limiting the depth of cut even more and some like myself went to a smaller size to allow very nearly full depths of cut. I purchased the 3-1/2" size, which lets you cut to 3-1/4". So maybe mine is a little undersized??

I have no idea what I paid but these were more then likely mid priced ones, what ever that amounted to. If I had to guess... well maybe $15???? I have no paper work so I can't say how flat they claimed to be nor can I tell you the brand or where I got them.

Now for a few pictures. First is one next to a rule, as you can see it is about 3-1/2". On the other end of the ring is the shopsmith saw arbor coming in at 1-7/8". Then a shot to show the relative differences in size between the two.
[ATTACH]3109[/ATTACH]

[ATTACH]3110[/ATTACH]

[ATTACH]3111[/ATTACH]

Keep in mind the stiffener pictured is 3-1/2", not the 5" which might be the recommended size... and other options like 6" or even 7" are sometimes used.

What I haven't done is attemp to mount the stiffeners and a blade on my shopsmith since I've upgraded to the 520. I have no idea if the spacing can be adjusted for alignment so these may not even work anymore. I might give it a try once it warms up again... now that I have gotten them out.

I you choose to look into this more keep the spacing issue in mind. The ones shown are many years old and I have not been tracking the trends or developments of them... I'm sure they have made improvements and revised guide lines several time...

The fact that I no longer use them show how we tend to get to a point where we are happy with things the way they are and stop looking for possible improvements or updates to "our" way. I think age does this to us... well I'm going to blame it on age anyway. So as of now I will say I'm not using the old set I have but I'm open to change and look forward to hearing what other think on the subject.

Ed

[a1gutterman]

Thanks Ed! That was a very informative narrative and with your usuall appreciated pictures!

I seldom use non-carbide tip blades. I do knot use stiffeners and I do knot believe they are necessary. But that is just my opinion.

[reible]

Like I often do, I studied the situation a little more so here are a few more words describing what I've found.

First after rereading and think about my first post I need to a revised version of the depth of cut issue. Since is certain you have some saw insert mounted in the table then the actual depth of will happen as the blade contacts the insert.... So any numbers posted should be reduced by the thickness of the insert. If you happen to be a do-it-yourselfer and made the insert out of 3/8" material then subtract the 3/8".

OK now on to the blade mounting options for shopsmith users. After thinking more about this it is clear that the set I have would not ever work if you wanted to use the shopsmith top guard. If you take the guard out of the equation because you have an alternative then maybe. I also looked but not tried or measured and it looks like you might be able to mount a washer, then blade then stiffener then washer then notched washer then nut on the 5/8" univeral arbor. There is some missalignment but it looks like it might be with in range of the adjustments on the shopsmith.

If you read the above you will note that I have only one stablizer mounted. Well that was another suprize for me. As it turns out Forrest sells one that is designed to work that way. So yes things have changed since I last looked at these.

I also found out that the newer ones are in the 3/32" thick range for ones like mine. That is .093" verses the .270" that mine are!

I also noticed that several blade manufacuters recomend the use of stalizers. Of course the corus of they are just trying to make more money off of you starts to rise in background... perhaps you are right but if you purchased anything that Nick promoted you just did the same thing so if your happy with all of those things maybe some other companies might also be trying to make you a happy camper... I mean a happy woodworker.

Several of the high profile blade makers sell them, Forrest, Freud, CMT, and Amana...

If you happen to have access to Jim Tolpin's book "Table Saw Magic" take a look at the top of page 67. I didn't see the claim but he mensions a major noise reduction is being advertised, so if you get a 9 dB drop that is a major drop keeping in mind every 3 dB will be something you can actually hear so that will be a very noticable indeed.

I also read some reviews and postings on several sites. A lot of people seem to feel that they are not needed... something I have often said but very few ever mention if they have actually tried them... easy to have an opinion when you don't even own one to know something about them.... but that is the prevailing wind. I actually found a site that had some interesting reading from boat builders... but that's another story.

Let me say this one more time, I am not yet pro stablizer but then I'm also not going to say "don't get one" any more either... I'm going to stay open minded at this point.

Ed

[charlese]

Well, I believe stiffeners are no longer needed. At least not needed on the "new" (that's for us old guys) carbide tipped blades.

The older stile steel blades had their teeth set (bent) in order to make a kerf wide enough so the body of the blade wouldn't bind in the cut. The carbide blades kerf is always wider than the blade body, giving a friction free run for the blade body.

In addition to the teeth being set on the old steel tipped blades, the set was hardly ever exactly even. The result of an un-even set is to cause the blade to drift from side to side while turning. (This is the same thing that causes band saw blades to drift.) This drift,or wobble could be offset somewhat by stiffening the blade. With the improved carbide blades the carbide is sharpened to a uniform width making the stiffeners no longer necessary.

There are several different grinds available on the tip of the carbide teeth that may help with a smoother cut, depending on what the blade is cutting.

That's my take!

[Ed in Tampa]

I guess I bought into SS's story that their larger arbor hole and arbor assembly removed the need for stiffeners. I have never used them.

Now that I'm messing around with guide saw systems (Festool Ezguide, Dewalt) I'm finding that even fairly cheap carbide blades in a circular saw can produce Forrest WW2 type cuts if the saw is properly aligned and there is chip suppression guards in place.

I think all the credit must go to two places, saw technology and zero clearance inserts. These two advances in the craft along with proper initial alignment of the saw makes all the difference between a rough cut and an acceptable cut and a superior cut.

[reible]

Ed you are being seduced by the dark side... those Festools....

Sorry, I know they have a place in many peoples workshops it just is this feeling I get every time I see or hear about them... I can't explain it but I get it every time. BTW I have heard from at least a dozen places in the last few weeks that I should be getting them soon as they are yet again raising prices... and I keep thinking I can't even afford any of them already so why are you filling my email with this???? I'll have to work on getting over this I guess... couple of deep breaths....

I also wanted to point our the zci have been around for a long time... we just didn't know to call them zci. I bet if you found an old shopsmith book from the late 40's they would have had instructions on how to make them... So the term is newer but the technology is old. If you are talking circular saws then yes I would say that it something a lot more current... maybe because they were more for construction then fine woodworking.

BTW I think I saw the forrest or was it freud blade for the Festool on sale for $125 somewhere the other day... wonder how that cuts???

Ed

I guess I bought into SS's story that their larger arbor hole and arbor assembly removed the need for stiffeners. I have never used them.

Now that I'm messing around with guide saw systems (Festool Ezguide, Dewalt) I'm finding that even fairly cheap carbide blades in a circular saw can produce Forrest WW2 type cuts if the saw is properly aligned and there is chip suppression guards in place.

I think all the credit must go to two places, saw technology and zero clearance inserts. These two advances in the craft along with proper initial alignment of the saw makes all the difference between a rough cut and an acceptable cut and a superior cut.

[foxtrapper]

Over 15 years ago I worked for Black and Decker in their power tool accessories test lab. A big part of the continuing work there was studying circular saw blades in pursuit of a sharper better cutting blade. God only knows how many miles of wood we cut. High speed photography, high resolution images of individual teeth, load records, etc. The data that's there is huge.

Here's some of the things I remember from the work:

All blades would rub their sides, regardless of tooth offset and such. As the blades dulled they'd heat up more and oilcan more and rub more.

All blades wobbled and wiggled in use. Theyh are not perfectly stable. This also contributed to side friction.

Thicker blades were more stable and cut better...on the test rigs. They didn't work so well in hand held saw testing as I recall. There the thin kerf blades worked better. Wider cuts took more electrical power.

Stiffeners worked. They held the blades more stable and prevented as much side friction.

Coatings worked. Friction reduction again.

A weird sort of rolling practice also worked. This is where certain sawblades were sent to some good old boys who'd roll the blades with tension rollers. Sorta like a cross between an english wheel and a record player. I have no idea what their methodology was for pressure and location of where they'd roll. But almost without exception, the blades worked better after they'd do this to them. This process had a name, but I can't recall it.

[charlese]

Hi foxtrapper! A couple of questions:

1) Do you remember if the blades you were testing had carbide blade tips?

2) How much was the wobble? Probably expressed in thousanths of inches.

[reible]

Ed in Tampa,

If I recall are you not that far from Infinity? And have you talked with the guy there on at least on occasion?

Where is this going? Well it just so happens they too sell saw blade stabilizers, item STA-300 and STA-500. If you feel he would give you (us) a straight answer jot that down for your next visit.

Ed

[reible]

That sounds like a heck of a job... did you ever get to do some long term testing at home?? How about high speed video? We did earth quake testing of our equipment and used high speed video about that far back, (they were just getting away from film for that sort of testing). Maybe your stuff was still to fast???

Anyway sounds like a fun job, well for a while anyway.

Ed

Over 15 years ago I worked for Black and Decker in their power tool accessories test lab. A big part of the continuing work there was studying circular saw blades in pursuit of a sharper better cutting blade. God only knows how many miles of wood we cut. High speed photography, high resolution images of individual teeth, load records, etc. The data that's there is huge.

Here's some of the things I remember from the work:

All blades would rub their sides, regardless of tooth offset and such. As the blades dulled they'd heat up more and oilcan more and rub more.

All blades wobbled and wiggled in use. Theyh are not perfectly stable. This also contributed to side friction.

Thicker blades were more stable and cut better...on the test rigs. They didn't work so well in hand held saw testing as I recall. There the thin kerf blades worked better. Wider cuts took more electrical power.

Stiffeners worked. They held the blades more stable and prevented as much side friction.

Coatings worked. Friction reduction again.

A weird sort of rolling practice also worked. This is where certain sawblades were sent to some good old boys who'd roll the blades with tension rollers. Sorta like a cross between an english wheel and a record player. I have no idea what their methodology was for pressure and location of where they'd roll. But almost without exception, the blades worked better after they'd do this to them. This process had a name, but I can't recall it.