Disappointed with (Byrd etc) cutterheads...

[Phil Winn]

FWW Dec2005 #180 --Jointer cutterheads
Page 70....The author Mr. William Duckworth was comparing:
"Chevron Pattern with Carbide Inserts;
Spiral Pattern with Carbide Inserts at Shear Angle (Byrd Head);
Spiral Pattern with Carbide at a Right Angle;
Spiral Pattern with 3 High-Speed Steel (HSS) Knives (Powermatic etc).

"The HSS knives produced very smooth cuts, but I was disappointed with the quality of the cuts made by the carbide inserts. All Three ran 5 db to 10 db quieter than the straight-knife heads."

"Are upgraded cutterheads worth the money?" ... "For a shop
where the jointer sees occasional use, I'd stay with the less costly straight knives."

(From what he wrote, I do not think he tested the "Spiral Pattern with Carbide at a Right Angle")

Your thoughts?
Phil

[lloyd morris]

Phil,I read the article was surprised by his conclusions and had the same questions. Thanks for bringing it up, I would really like to know as well.Lloyd Morris

[Dev Emch]

Once again, FWW is using their "Selective Research" department to conjure up articles with, I hate to say it, predefined outcomes.

The basis for comparison is a head using high speed steel knives. Now, there is a lot that can be done here. First, I replace all vintage HSS knives with new schmidt knives which are T1 HSS, an alloy not available 20 or more years ago. Second, to optimize standard knives, you really need to joint the knives in place. Knife grinders like those found on industrial machines do this. It produces a fluffy, goosoemer like shaving like no other you have seen. And the surface finish is excellent.

But HSS, even T1, does not last long. Granted, HSS will hold a much keener edge than carbide ever will, the fact is, carbide will last longer and take more abusive cuts such as those found cutting excotics with high silica content. Nonetheless, HSS does offer a very reasonable performance life.

So why go to insert technology? Well, it is true that insert heads tend to run a bit quieter than straight knife heads. This gives OSHA a nice warm and fuzzy. But in shops full of jointers, multi head planers, moulding machines and shapers, you will find yourself yelling no matter what head is being used. The old timers have a trick for dealing with this noise.... ITS CALLED HEARING PROTECTION!!!!!!

But certain insert heads have proven themselves in one other way that is never really offered as a driving rational for getting them. And this is a mystery for me as it should be the number one reason above all others.

PAGAN GRAIN LUMBER! Yup, high figure lumber such as curly maple, ribbon bubinga, flame birch, etc. have always had issues with blowout. These insert heads tend to do an excellent job on these types of wood. In particular, the oliver ITCH head has shown itself viable since the mid 1960s or so when this head was made available.

Now, the ITCH head is totally different from anything you guys have seen. The insert is actually set into a pocket such that its perpendicular to the tangent of the cutter cylinder. Only one edge of the four avilable for each insert is actually visable to the naked eye. This is not true with helical insert heads or byrd shelix heads which is a take off of the helical insert head. In these two heads, the insert is actually sitting flat in a pocket on the surface of the head. Both are machined into place using a helical lead pitch angle; however, the angle of attack for the standard insert head uses a 0 degree shear angle whearas the byrd head uses a positve degree shear angle.

Once the inserts for the ITCH head are installed, then the user will traditionally use an ITCH head grinder to grind and hone the edge of the insert. First of all, the grinding stone is a diamond stone or a borazene (sp?) stone which can grind the super hard carbide. It rides a frame similar to that used to grind traditional knives. But instead of using a pin anchor lock on the head to fix the knife position during grinding and honing, this process is a bit different. The user will dial in the grinding height of the grinder head to endure the same height for all grinding. Then, staring with one row of inserts, you use one hand to operate the grinder head and the other hand to position the cutter head such that each insert is facing straight up. The grinder moves back and forth about an inch and faces off each insert. Then you move the grinder to the next position. Then rotate the head a few degrees to bring the next successive insert into position and repeat. You continue this process for each insert in the row and then repeat the process for each row of inserts you have. A head for a 20 in planer or jointer will take about an hour or so.

The advantage is that each insert is at the indentical height with the identical facing cut. Thus, the cutting circle is extremely precise with each insert cutting.

How accurate are the standard helical heads and the byrd shelix head? They are pretty accurate but I dont know if they can outperform the ITCH head. The ITCH head has been in heavy industrial use since the the mid sixties and has quite a track record. Only time will see if the other two forms can compete here.

Some folks believe that its just easier to use an insert head versus a traditional gib/knife head. Granted, for those new to jointers, the traditional head can be a real pain leading to high levels of frustration. But so can an insert head that is not set up correctly. And to trouble shoot any head with mimimal experience can be frustrating.

The advent of cheap helical heads by many of the import makers should be viewed with a tad of sckepticism. For many of these companies, its import em over hear and load off the boat. The less contact they have with the consumer, the better. And they clearly dont want customer service departments repleate with application engineers telling Joe Newto Woodworking how he needs to setup and use traditional jointer heads. This cuts into an already slim profit margin and many of these guys who sell these machines are not woodworkers.

Yup, when I talked to a guy from the BLUE oliver, he actually admitted to me that he knows nothing about woodworking. DUDE! Your selling high end woodworking machines! How can you not know about woodworking? Well, he admitted he knows more about marketing and metalworking. I guess its a job. So insert heads can produce a machine that requires less skill and knowledge and consumer handholding than one with a traditional head. So once again, the buyer beware. Insert heads do have a role in woodworking but the consumer needs to understand when its really necessary to use these. They are not a gimmick but an expensive solution to a number of industrial problems that most hobbist woodworkers may not need to worry about.

[JayStPeter]

I love my Byrd cutterhead.

I have to admit. On very clear easy to joint wood like Cherry, the glass smooth finish from a sharp set of HSS knives is not beaten by the Byrd. But, if there is a knot or other defect, tearout with the Byrd is minimal. When dealing with less clear wood with varying grain patterns, the Byrd is far better. The Byrd also eliminates having to determine grain direction before feeding. It works either way.
Don't get me wrong, the resulting cut from the Byrd doesn't require more sanding than the HSS knives. It just doesn't feel and look quite as smooth. I'm sold and will eventually get a Byrd equipped planer.

Jay

[Jeff Sudmeier]

Jay, having used a jointer with a Byrd head, I do have to admit, I would like to get one. However, I don't know if I want to spend 40% of the cost of the jointer ont he byrd head :) It will be awhile, but I will probably do it. As you said, the surface isn't glass smooth, but even with the best jointer cut, I will still be sanding, the slight difference in sanding time isn't worth measuring.

[JayStPeter]

Jay, having used a jointer with a Byrd head, I do have to admit, I would like to get one. However, I don't know if I want to spend 40% of the cost of the jointer ont he byrd head :) ...

I doubled the cost of my jointer by adding it :D . Definitely worth it.

Jay

[John Miliunas]

Well, I didn't double the cost of my jointer, but it was still a healthy investment. BUT, one which I wouldn't even think twice about if I had to do it again!:) It does sound like the ITCH head Dev refers to is probably the cat's meow, but for just Joe 6-Pack, like yours truly, the Byrd is truly a Cadillac! As indicated, you still need to plane or sand the surface after running it through a Byrd. At least for this mere mortal, I don't know of any cutter-type shop machine where you can get away without doing that. The degree to which it needs to be done, though, is indeed minimal, at best. In my limited experience, I feel it's substantially quieter, easier to feed material through, does a fabulous job with figured woods and grain direction is a non-issue. Sorry, I can't tell you about ease of cutter replacement, as I have yet to replace or turn any of them!:) I almost exclusively process hardwoods and, although I noted some degradation in the cut early on, it just hasn't seemed to get any worse. Will a fresh set of conventional HSS knives give you a smoother finish (on straight grained wood)? Probably. BUT, not for very long, IMHO. Been there, done that, didn't even get a T-shirt! All in all, very impressed with the head and, whenever I can scrape up enough $cratch, the 15" planer is getting outfitted with one, as well!:)

BTW, Dev, thanks so much for the crash course on the different style cutters! You are just a regular vault of WW machinery information! I wish I knew 1/10th of what you may have forgotten over the years!:) :cool:

[Alan Schaffter]

Are the cutting edges of the Shelix cutter inserts curved?

Geometry says if they are not (and I don't think they are) then a rectangular shaped cutter, with the cutting edge anything but perpendicular to the cutting direction, will make (slightly) grooved cuts. They may be smoother cuts but grooved none the less. This is because the edges near the leading and trailing corners of each cutter will be farther away from the center of rotation of the round cutter head and hence cut deeper into the wood. To visualize this, just lay a rectangular or square piece of wood on the cutter or any cylinder and see an exagerated view of what I mean.

Inquiring minds want to know.

[Paul B. Cresti]

I got a J/P with a Tersa Head because of the ease of knife change. I can use any type of knife I want (chrome, HSS, M2) and I can attest first had just how sharp these knives are! Changing them is so fast it is scary. I have yet to hear of any one changing or spinning all those cutters yet but I can not imagine it would be very fast. I have a Byrd head for my shaper, definately not the highest quality I have seen. No thanks I will stick to lowly Tersa Head.

[John Miliunas]

Are the cutting edges of the Shelix cutter inserts curved?

Geometry says if they are not (and I don't think they are) then a rectangular shaped cutter, with the cutting edge anything but perpendicular to the cutting direction, will make (slightly) grooved cuts. They may be smoother cuts but grooved none the less. This is because the edges near the leading and trailing corners of each cutter will be farther away from the center of rotation of the round cutter head and hence cut deeper into the wood. To visualize this, just lay a rectangular or square piece of wood on the cutter or any cylinder and see an exagerated view of what I mean.

Inquiring minds want to know.

Alan, as a matter of fact, yes, the cutters do indeed have a curve to them.:)

Paul, I don't think I ever indicated that the Shelix is the answer to all answers, in terms of cutterheards. And, although I've not had to do it yet, I totally agree that changing cutters will be a much more time intense process than that of a Tersa setup. That said, it appears the top dog in cutters is the ITCH system and that seems to be the most time intense. :) As it stands, both the ITCH and the Tersa heads are more geared toward production shops and the machines these are attached to have price tags to match that technology! Many and, more probably, most of us out here can't afford such machines. I consider myself extremely fortunate that I was able to swing that Shelix when I was! :) Today, I couldn't do it! :( That said, most folks out here have a 6 or 8" jointer because, of room and/or financial considerations. The Shelix is a viable option for some of those folks, whereas the ITCH or Tersa equipped machines, may very probably be out of our reach.:(

IMHO, the Shelix is still head and shoulders above most all of our "typical" cutter assemblies. The advantages are many, and again, IMHO, worth it. Yes, I would most definitely do it all over again!:)

Signed,
Happy with my Shelix in Wisconsin!:D :cool:

[lou sansone]

hey dev and others

what about the "newman quiet cut" head? any thoughts on it? I have seen them and they look impressive. maybe the best of both worlds, except for trying to sharpen them


lou

[John Miliunas]

hey dev and others

what about the "newman quiet cut" head? any thoughts on it? I have seen them and they look impressive. maybe the best of both worlds, except for trying to sharpen them


lou

Well, fer cryin' out loud! I knew the guy was into movies and car racing and even salad dressing, but never dreamt he got into WW machines, too!!! :eek: What a guy that Paul is!!!!:D (BTW, never even heard of the Newman Quiet Cut, much less know about it!:o ):) :cool:

[Andy London]

Phil, I haven't seen the review and probably won't bother picking it up, I tend to rely more and more on the experiences of woodworkers here in the forums to base, probably, 95% of my purchases.

Based on my own experience, most (95%+) of my work is with domestic figured or exotic woods. I upgraded to a spiral some time ago due to tear out and read posts from people who were amazed at the switch. While the ease to change cutters and a quiter machine are important, they didn't even come into play on my decision. I wanted a perfect cut and that is what I get.

So based on my experience, in figured woods, especially Curly Birch which is the worst for tear out I have come across, a 3 cutter straight head does not hold a candle to a spiral head. Now a four head cutter might be better, in my case I felt based on what I read the spiral is what I needed.

The other advantage I noted is they last longer (stay sharper), I use the jointer every day and run a lot of material through it, even at 9 months I am getting excellent cuts.

Andy

[JayStPeter]

Since I can't leave well enough alone, one of the first things I did was rotate a row of blades. I didn't get the torque wrench with the cutterhead, but I may do so. I did the first few just fine, but then cracked one. So, I spent much time fretting over tight enough vs. too tight. Even with the crack and need to go into the box of spares, the row took me 8 minutes. With a proper torque wrench, I'll probably be able to do it in less than 5 minutes. That would mean < 15 minutes for the full blade rotate. A blade change would probably take a little longer since it does take some effort to fish the blades out of the little holder. Definitely not in the Tersa range by any means. But, it usually takes me in the range of 45 minutes to change my knives. I've only done it a couple times and admittedly am not good at it.

Jay

[Rick Schubert]

Andy,

Do you have the Byrd shelix or another spiral brand? And on what brand jointer if I may ask. I'm interested in the specifics because I'm thinking of buying one and have considered the Sunhill on sale at Amazon for $199.

Thanks a lot, Rick

[Mike Palmer]

I have had both types. I can say without exception that the spiral is much quieter and provides a better finished cut. I have a Casadei J/P with a cutter head that has two spriral knives that shear the wood. It is a different design from the segmented type but the concept is the same.

[Andy London]

Andy,

Do you have the Byrd shelix or another spiral brand? And on what brand jointer if I may ask. I'm interested in the specifics because I'm thinking of buying one and have considered the Sunhill on sale at Amazon for $199.

Thanks a lot, Rick

It is the Byrd on a very old Delta.

[Jack Easton]

There was also a review in the August 05 issue of Woodshop News, "The Cutting edge" or something like that, where the reviewer compared the spirals to tersa to standard. When I get home, I'll see if I can find it. He tested three catagories, and the tersa won all three. I have worked with both in a production environment (we had the spiral - pretty sure it was a Byrd - in the SCMI planer, and tersa in the Martin planer) Both planers worked equally well, but the tersa head offered more options, like being able to change knife types (from HSS to Carbide - or we generally kept 12" of the head HSS and the other 12" carbide and would use the side of the planer that was more appropriate), and knife changes, in general were easier. The spiral was a little quieter, but in a big shop you couldn't really notice. I had been talking about this for years, but the spirals seem to have caught on as a silver bullet in the last couple of years, so I kept my mouth shut. Don't get me wrong, the byrd head worked fine (just hope one of the screws don't freeze), but when I started my own shop, I sought out and got a planer with tersa head. Take that for what it is worth. For the average guy, coming from standard cutter heads, either system would be a joy to move to.

[Dev Emch]

Bear a few facts in mind.

1). A true helical cutter head has a continous spiral or helix shaped cutting edge. Northfield and others have made these knives and they are a royal pain! A second version has shown up via schmidt in NJ that uses a series of one sided inserts to achieve the same affect.

2). A standard helical insert head uses industry standard four sided inserts. Pockets are machined along a helical sprial or lead angle. One side of the insert is facing the wood directly as the planing process occurs. In other words, the centerline of the insert retaining bolts are along a helical arc but the cutting edge of each individual insert is parallel to the axis of the main cutter cylinder.

4). SHELIX heads are identical to standard helical heads with but one exception. The pocket for the insert is cut at a positve angle between the cutting edge of the insert and the axis of the cutter cylinder. This produces the same affect of skew cutting a board on your wide jointer. It is a shearing cut which is better suited to heavy figure. You also see hand tool guys planing wood with a smoother at a slight angle and not straight on. Same thing. Its a shearing cut.

5). ITCH heads are only available or were only available for oliver machines. It is an alternate approach but not necessarily the best approach.

6). TERSA heads are straight knife heads. Clearly they can complete with most straight knife applications in which new knives are installed and dialed in. But there is no way they can complete head on with a heavy duty machine using a full bore, in place, knife grinder. The reason is simple. During the final grinding stage, a stone is run across the head with the cylinder running. This stone is held on the traverse ways of the grinder and this joints the top of the knives to be identical. In this case, all knives are cutting.

No one else is jointing cutter head knives with but one exception. In extreme high speed moulder operations, the moulders are running at such an insane speed that it is required to joint each cutter head. Here, you will find jointing stones shaped to the exact profile of the cutter head. This sets the cutting circle to the exact height and allows wood to fly through these machines. Needless to say, these stones cost some coin and profiles subject to this treatment will be run for extremely long runs to justify the tooling costs.

7). I do not know much about the Newman head. But, many of these companies did borrow ideas (and employees) from each other all the time. So surfice it to say that if the newman head is insert based, it will most likely resemble the ITCH head. Newman and later Newman Whitney were known for some of the huge lumber yard planers where ITCH type heads were heavily used.

8). ITCH stands for Individual Toothed Carbide Head. So playing it really loose, I guess we can call all these heads including the shelix head ITCH heads.