Straight vs.Spiral cutterheads..

[Brent Harral]

I'll be getting the last jointer of my life soon and I've convinced myself to a 90 percent certainty that I will prefer a standard straight edge cutter vs. the spiral option. The spiral option being the carbide inserts with four cutting edges. It sure does sound slick, but I work primarily with straight grain hardwoods and really never had issues with excessive tear out or bad finish prior to final milling..so if it ain't broke, don't fix it (?). I am very comfortable setting jointer blades so the appeal of not having to set the knives is not a real big incentive for me...and could care less that they are more quite. Not sure of the cost of replacing those little carbide buggers, but I'm thinking in the long haul it's going to be more than just resharpening a straight blade. See..I'm talking myself out of them as I speak :D BUT, I wanted to hear anyone's thoughts who has used/seen these new spirals in action and it's a mind blowing experince and a gotta have kind of thing :eek:

Comments?? Many thanks..

[Paul B. Cresti]

All I can say is ....Tersa head..... once you use one nothing else can compare

[Alan Schaffter]

Forgot to mention earlier- one big benefit of the indexible cutter inserts like on the Shelix is that if you get a nick you only have to rotate a few inserts. With blades, you live with the nick until you run each piece through the drum sander, you slide the knife (knives) a fraction sideways to offset the knicks (may need to reset), or replace or resharpen all 3-4 blades. I assume you want the extra 4" to face plane wide boards, then go with the spiral head (Shelix not one piece solid spiral). Each insert has four carbide edges to boot, so you won't have to change them very often. Since your business is "doing well" :) and this is your "last jointer", go for the gold:) . If I was still working and not retired on a fixed income:( wait, :) , that's what I would do. Besides, the decision is reversible- if you don't like the Shelix, I'm sure someone on Ebay would take it off your hands for close to what you paid:) . Oh, also, the Shelix is supposedly much quieter than a straight blade cutter head- maybe ask for noise abatement donations from your neighbors. Like I said before, its only $800-$900 more:eek:

Now, how much more is the 16" than the 12", Hmmmmm????:D :D :D :D

[Alan Turner]

Andy,
I have 2 wide jointers, a 12" with Byrd, and a 20" with straight knives. The Byrd is far and away better. Less to zero tear out, quieter, and about 1/2 the feed pressure. But, the cost is substantial.
I have run my 12" Byrd for maybe 3 years, and have yet to need to rotate an insert.

[lou sansone]

for your applicaton the tersa seems like the right way to go
best wishes
lou

[Brent Harral]

Throwing that into the mix to confuse me more are you? :D I did do a search and found a good older SMC thread with some great info on the Bryd head. Alright you Byrd and Tersa fans, guess I'm going to research and give it a lot of thought. Still would like to hear from anyone who is using either for your thoughts....Thanks!

Dang, $1100 for a 12" Byrd head :eek:

[tod evans]

tersa hands down! .02 tod

[Jim Becker]

Aside from nice cuts that are possible with alternative knife formats, losing the need to "set/align" the knives with Tersa or the Byrd or similar cutter systems is wonderful. Tersa has a further advantage of very fast replacement/rotation which also makes it easy and practical to keep different formula knives on hand for different kinds of work. It takes me about three-five minutes to change my Tersa knives.

All of this comes at a cost, however, especially if this is a retrofit situation. My MM J/P came with the Tersa knives as standard. Some machines come with the helical systems or other spiral formats standard, or as an option.

[Jeffrey Makiel]

The Tersa head seems like regular straight knives. Is it the ability to be quickly change out blades that makes them so desirable? Or is there another secret to the Tersa system that I'm missing?
-Jeff :)

Edit: I think I just got my answer from Jim.

[Jim Becker]

Yes, Jeff, they are straight kinves, double sided and indexed to the head so they are always "set". Believe it or not, the gibs that hold them in lock through centrifical force as soon as you hit the switch after changing/rearranging them and the head spins up. Here's a graphic that shows what the cross section looks like:

http://www.woodtechtooling.com/TERSA/Lardon_anim.gif

Now, being straight isn't quite as good for highly figured stock, but combining the ability to have very sharp cutters available with the fact that most Tersa-equipped jointers are wide, means you can get great cuts on figured stock by skewing the workpiece as it passes over the head. I did that recently with the figured maple for my candle stand project and got zero tear-out and a very nice machined surface.

[John Miliunas]

As I understand it, the Tersa head is great for quick blade changes BUT, having said that, it's still nothing more than a straight blade. For whatever reason, it really doesn't appeal to me to have the ability to change blades quickly in order to get chip and tearout! I'd much rather take a bit more time and rotate Shelix cutters for a near-perfect cut! :) Oh, and as for just doing straight grain, I still find the Shelix a time-saver, as you no longer have to pay any attention to grain direction for feeding; Either way works just fine!!! :D And, as Alan Turner eluded to, the cutters last a long, long time!!! :) Just my $00.01 (Hey, I'm cheap!:D ) :cool:

[Brent Harral]

There is another option of getting an import (non-shelix) head for about half the cost of the Bryd. Straight row of cutters but staggered of course. The tech guy at Wilke, who really sounded like he knew his stuff, said these really do an equally good job as the Byrd, but seems you sacrifice 20 percent depth (shorter tips, less chip clearence). Seems to be a non-issue for a jointer though...Don't know, I don't use my jointer as a "finished" surfaced machine anyway, so I may be splitting hairs between a "great" surface using sharp straight blades and an "excellent" surface with the other two. I don't run birdseye maple all day so I think I'm starting to answer my own question :D

Great info guys, thanks..

[Richard Riddle]

After a month or so of lurking around this forum, I'm gonna throw in 2cents worth on this one.
I dealt with Jerry at woodtech tooling in Hickory NC who cleared up a lot of marketing hype on the Byrd head. I use one in my planer because I run a lot of very thin material and for that it works very well for me. I have planed white oak to 3/32 inch without tearout.
The myth is that you can simply rotate the insert if you nick it. The carbide is very brittle, if you hit anything that will "nick" the cutting edge you will most likely break the insert and have to replace it altogether. Hit a nail and you will lose six inserts, three if you are lucky.
Like I said, It works for what I do; However, putting one on my jointer would be a waste of money.

[Bob Marino]

Ok, question. I have a 6" Delta jointer with the standard blades. Can either of the other type blades work on this jointer?

Bob

[Jeff Singleton]

Go with the Tersa or Terminus head. They both work on the same concept, index straight knife technology. The Tersa knives slide in from the end and the Terminus slide in from the top. The Terminus with fit any jointer or planer but the Tersa head has to have the side clearence so you can slide the knife out. I have a Terminus in my PM 180 and it is very quiet and cuts great, no tearout in oak, poplar, walnut, or cherry and just a little with maple. I don't know about the Tersa but with the Terminus can can put 3 or four knives end to end in the same slot. Terminus told me to get 3 different lenght knives to make up the 18" length and stagger them in the slots, short. med. and long in one row and then med. long and short in the next and so on. Terminus has a deal going on until the end of March I think. If you buy one arbor head you get another one for free or something along that line. Worth checking out.

Jeff Singleton

[Jim Becker]

Ok, question. I have a 6" Delta jointer with the standard blades. Can either of the other type blades work on this jointer?

Yes in theory...you have to change the whole cutter head to fit the new format knives. I'm not sure how cost effective that would be for a 6" jointer, however.

[David Eisenhauer]

John: There is a thread on WOODWEB (wood shaping forum?) with the pros-cons of Tersa vs Terminus.

[JayStPeter]

Brent,

In your first post, you said that none of the advantages I see with the Byrd head in my jointer were important to you (less tearout, easier "knife" changes, and quiet). There are a couple disadvantages of the things too, so there's probably no need for you to spend extra money.
I will, however, continue to think it's great :D .

Jay