Pros and Cons of Helical Heads for Jointers

A long discussion of spiral cutterhead performance. May 16, 2014

I have a 12" Oliver 166 jointer with a three knife cutterhead and I am planning on installing a shelix spiral cutterhead. Just wondering if anyone else has this setup, and if so do you like it? Is it worth the $1700+/- just for the head?

Forum Responses
(Solid Wood Machining Forum)
From contributor M:
I can't say enough about how great our Byrd Shelix has performed on our Delta DJ30 12" jointer. First - the sound is much quieter! Second - the cuts are much smoother and the wood more easily fed through. No splitting or chunking or tearout when using burled wood. We are in the middle of a 30 passage door construction job using rustic oak. The knots are horrific - but when jointing and facing the boards on the Byrd head you would think you're running clear pine!

I'd say go for it. You'll never have down time again resetting or sharpening straight blades - swiveling or replacing these carbide blades take seconds only. The cut is awesome, my ears just love the lack of high pitched noise, my wood thanks me for such smooth milling and on top of that the videos we made using this head go a long way to impress our clients.

From the original questioner:
Thanks for the info. I currently have an 8" spiral head (Grizzly) jointer and it works great. I would never want to use/set knives again! I think the Byrd is my only option if I want a spiral head for the Oliver. Itís just expensive and I'm a little concerned about the scalloping that people talk about online. Not sure about the Delta but the head for the Oliver is 5" in diameter, hence the extra money. I think it is $1571, but by the time it gets here.

From contributor M:
I have zero scalloping on my 12" Byrd head. I was also apprehensive - but my worries were for naught as the finish cut is flawless. Just checking I see the head needed for my 24" planer is only $2,295 - much less than I had been quoted since the model number I had given them (RC-63) is not my machine, but rather 22-503. I'm assuming a similar size issue as you have - 4" radius vs 5" radius. That extra inch adds a lot more cutters! I will be ordering the 24" head sometime in the next two weeks. I'll post results with the planer once I'm up and running with it.

From contributor G:
I put a Byrd on my 13" Griggio a few months ago. I purchased it through Holbren for a little more than $1000. It took a while to get it - three months or so. It was worth the wait though and I love it.

My head is about 5" in diameter and I had to remove it from the jointer and compare it to measured drawings they sent me. I then had to reinstall it while I waited for the new head. I checked their measurements with a caliper and made two changes and to my surprise it fit.

From contributor F:
You may want to search this topic in the Knowledge Base as well. I know it's come up here several times and there has been a good amount of feedback. IIRC the Tersa style heads have been more popular than the insert types for several reasons. I'm still running straight knives in my jointer as the head for my 16" is way up there in price! Jointers don't realize quite as much advantage in my opinion due to most material being surfaced by another machine after jointing. The noise issue is moot for me as I run a dust collector.

I am toying with the idea of installing a Byrd on my DJ20 though as they're priced well when on sale. It would be nice for that odd occasion when I need to do something with really stubborn grain.

From contributor M:
To contributor F: Can you tell us the reasons you quote the Tersa heads are more popular? I think they are no different than regular straight knives other than the ease of changing blades - no need to recalibrate. But you still have the noise factor which is crucial to long term hearing loss and you still have the potential for tearout with knots, curly grain and burled wood. With the Byrd there is no need to sight your board for grain direction as it cuts cleanly in both directions. You lose the advantage of less amperage draw such as the Byrd, which significantly saves on electric requirements. And also, very importantly, with the Tersa if you get a nick in the blade you need to replace the entire blade whereas with the Byrd you need only swivel the culprit blade to a new cutting surface (four on each blade).

That all being said I've had no personal hands on with Tersa, but have heard many defend them passionately! But the points I've made above are blown off with deaf ears to them, so I'm not quite sure what the attraction is with a Tersa head.

So, besides ease of changing blades (more expensive than Byrd cutters) exactly what are the advantages with the Tersa? I'm honestly and peacefully just trying to find out valid info since those I know personally swear by them with no answers to my questions. I've not done a cost comparison (which should also include long term blade replacement as well as the initial cost). My 12" Byrd Shelix did come with a box of 10 extra blades (40 cutting surfaces) and after three months use we have yet to replace one - spun a couple but that's it. Our jointer is in use every day - averaging probably two hours per day mostly hardwoods (oak, cherry, maple and poplar).

In the last two week period it has been used eight hours per day for four days. That's the most abuse we've given it is this recent project of 30 oak passage doors (1-3/8" x 80", widths varying from 24"-36"). This oak is the rustic which is loaded with squirrely grain, huge knots, twisted grain and just overall a real "jointer killer"! Two nicked blades and four dulled edges - mostly because the guy jointing all the panel edges did not vary the fence across the table - he ran roughly 2000' of 7/8" thick edges and never slid the fence to a different section of the cutter head. Still, the carbide held up great. These are by the way Byrd cutters which are made in Germany. Are the Tersa blades carbide? Or do you have a choice of HSS or carbide? I'm assuming that makes a difference as well.

From contributor F:
I could tell you the reasons, but then I'd have to go into the Knowledge Base myself and do a search, cut and paste, and generally spend an awful lot of time to defend something I have no real vested interest in anyway!

My point was only that this subject has been brought up before and that's the way a lot of guys seem to go. I don't have any of these heads so I'm not going to be yet another armchair warrior in this battle. If I were looking for myself I'd want as much input as possible though.

I do know the Tersa knives are available in different grades of steel as well as carbide. And although I have still not seen any hard evidence provided, many posts I've read seem to indicate the insert heads use a bit more power, not less? This is something I think the manufacturers should address since they must be able to provide some meaningful input! My only experience is with an insert head on a planer and I agree on some things. The finish is very good, not as good as sharp HSS knives, but it holds its sharpness much longer than HSS. Plus as mentioned it works better on gnarly grain and highly figured woods. It is also quieter, but again, I wear hearing protection anyway since my dust collector is running. My only other opinion is the planer would be the first for an upgrade head, jointer second - just based on my own personal use.

From contributor K:
We have a Tersa head on a 16" jointer. It's very convenient, and takes less than five minutes for a changeover. The results with fresh knives are excellent, but you can't ignore grain direction or expect absolute perfection with burly, gnarly wood. It gives at least equal results regarding tearout to our SCMI 20" thickness planer with freshly ground straight knives. New M42 knives cost us about $18 each, so each knife change (two sided knives) in a four knife head costs about $36 plus labor. From what I understand, segmented carbide knives perform better and last longer, but require more labor to do a complete change as the knife seats need to be carefully cleaned for proper registration. The larger the diameter, the more knives and consequent labor cost. As with conventional knives, a nick in the Tersa system can be mitigated by sliding the knife or knives sideways.

From contributor K:
The Tersa knives are available in carbide at a significant upcharge. Judging by my experience with a Makita , the carbide cannot take as keen an edge and produce quite such a clean surface, but gives an adequate surface for a far longer time. We tend to run a variety of material including barnboard with the potential for nails, so we stick with the less expensive HSS knives. If we have a job with a lot of abrasive material like teak, we'll invest in carbide and make sure those knives don't see any exposure to the nick producing material. Carbide is more brittle, so anything that might tend to cause nicks would probably wreak havoc with a segmented carbide head.

From the original questioner:
Thanks guys. I have searched the Knowledge Base and that is one place where I read about the scalloping and other mixed reviews. Most face jointed parts will go through the wide belt after, but it is good the hear that Contributor M has zero scalloping.

From contributor M:
As posted - we've just run literally thousands of feet of rustic oak (spelled large and frequent knots - one per foot or more) and so far we've had only one nicked blade - about 15 seconds to loosen the holding screw, rotate to a new edge and tighten the screw.

I admit it would probably take quite a while to change out all the blades, but after three months and dozens of thousands of feet of cut we've only had to rotate five blades. Those five still have three usable and extremely sharp edges left. I canít imagine a situation where weíd have to swap out all the blades on this head at one time. Yikes!

Not sure about the fuss with cleaning. Neither our shop nor an adjacent shop to ours (they own a DJ-20 8" jointer) have had any issues spending any time at all cleaning. Seeing their use of the Byrd head was the precipitating factor in upgrading our jointer. Loosen the one holding screw just enough to rotate the cutter and retighten. Perhaps if you have a run with a board species containing a lot of sap that could cause an issue but I can't vouch for that. We have run about 1,500 feet of clear pine, the rest has been a mix of hardwoods.

In the past (prior to investing in the Byrd Shelix) we did often have to slide one or more of our three single blades side to side when encountering a nick, but they still would leave a line. The time now to rotate a single or two cutters is only about 15 seconds per cutter - far less than sliding our single blades. No line left in the finished material.

If we had not been cutting so much of this rustic oak I doubt we would have had any nicked blades, nor would the other three have dulled as they did. But like I said a few seconds every thousand feet is certainly not what I'd consider a deterrent to purchasing a Byrd head. I can't speak for other brands, of course. But knowing the amount of use our jointer receives I felt best not trying to save a couple hundred dollars experimenting with a lower cost head.

Of course all this is one shops experience. Every shop has different demands and different situations. But after 40 plus years of working in my shop (averaging six employees per year, some years as many as 13) I wish I had this Byrd head many decades ago! The adjacent shop owner and his two sons (25 years in the business) were as profound as I in purchasing and using this Byrd head. Were it not for them I probably would not have changed our system, thinking what I read online was just so much hype. Not so. Seeing is believing, and seeing theirs in use and hearing how they wished they had made the move years earlier I followed suit and have not looked back with any regrets! Other than having the head delivered and sitting in my shop for three months before I got around to installing it! Hey, you all know how it goes when you're busy!

I'll also add here that for our shapers we are making the move to all insert tooling, which has all the benefits I've outlined above for the jointer, as well as the accurate and constant size issue that is paramount with shaper and moulder heads. Without the need for sharpening no adjustments are needed after replacing a cutterhead (or in these cases replacing cutter blades). Itís a bit more expensive initially but the benefits way outnumber that higher initial cost. And again itís quieter, less effort is required and no thereís no down time while waiting for a cutterhead to be returned from sharpening.

I think I'd have to say after our usage to date the most remarkable assets of this head to me are two twofold. The unbelievable lack of loud sound just amazes me. Even without a load the cutter head noise is significantly lower. And for facing a board - forget it! I have a 4,000 square foot shop with three residences behind our shop. For the most part - noise is not an issue as we are zoned industrial and are allowed to make higher than normal noise during the hours 7:00am-8:00pm. But there have been many nights in the past where I would come in during the night for whatever reasons to work. Forget about trying to face any wood on the jointer - the loud, screaming sound had the neighbors scampering to their phone to call the police about sound issues. So I always had to make sure that any facing would be done during the day. It's one of the quietest milling machines in my shop! No need for hearing protection, just a low hum.

The second most impressive note is how little physical effort it is to push a board across the table surface. You would not think that the machine is even cutting it's just so smooth and effortless. Were it not for the small chips exiting the bottom chute I would have thought the table was set too high! I would urge any who are in proximity to a shop that has a Byrd head to do a favor and make a visit. Itís well worth the trip if you are in the market to upgrade your machine!

By the way we don't often use our dust collector on our jointer. I feel it's easier to just shovel the pile of sawdust into bags, especially since most times we are just running over to shoot one or two edges - the dust collector is not even up to speed before we are done running a couple edges. Plus most of these small chips are destined for a horse ranch that comes in to pick up the bags each month. They don't want any sawdust mixed with the chips so that also pre-empts the use of our dust collector. Not to say we don't connect it for jobs that require two hours or more of facing boards. Here the collector is an advantage to minimize our cleaning efforts.

I will finish this post by stating that a recent conversation with one of the sons working in the adjacent shop brought up an interesting note about other manufacturers. He had just last year been hired as a wood shop teacher in a local vocational school. They gave him a large budget to purchase all new equipment as he saw fit. So, after submitting a list to several suppliers he settled on all Powermatic machinery - including a 12" jointer and 15" planer - both equipped with their own spiral segmented heads.

After one semester of use his experience is that he sees very little difference between the Powermatic head and the Byrd that his Dad installed on their DJ20. He himself had 1-1/2 years use of the Byrd before taking on the teaching job (kudos to the school for their efforts to help train young potentials in our field) and so I feel is qualified to relate a valid take on the different manufacturers. So that tells you that Byrd does not hold an exclusive on the merits of using this type of head over others. I believe the Powermaticís are now being manufactured in China, correct me here if I'm wrong.

From contributor M:
On the scalloping issue - my neighbor does show very light scalloping on his 8" head (purchased three years ago). Though it does show when a light is shined across the grain it appears to have no impact at all on jointing or facing prior to glue-ups. And, for those times that sanding does follow a quick RO sander takes those lines out in seconds. The scallops appear deeper than they really are.

I was a little apprehensive when I ordered mine. I was very pleased when we found there were virtually no scallops at all on our finished cuts. Iím not sure, perhaps Byrd has changed something but there is a definite difference in our 12" head and Roger's 8" head with the output relative to scalloping. However, again no real issue, mostly more so in thought than practice.

From contributor U:
Having owned and used both Tersa and Byrd head jointers, I will opine that the Byrd was better for production work in difficult woods, and the Tersa is better for fine finish work where the surface will not be sanded. I love the Byrd head in my Delta 24" planer.