Helical cutterhead difficulties

[Jim Eisenstein]

I'm finding is near-impossible to properly seat the carbide cutter inserts on my
Grizzly G0856 8-inch jointer. It seems that no matter how careful I am to clean the
carbide inserts and the cutterhead body and apply the recommended torque to the installation screws, the
net result is a poorly jointed surface. In mild cases, the surface is slightly wavy (undulating a few thou
across the board), while in other cases there are clear ridges left behind by some of the inserts.

It seems obvious that the inserts are not seating properly. In fact, it appears that the angular orientation of the inserts is not repeatably registered. Slight variation of the applied torque to the screws can result in slight rotation of the insert. Even when I tighten to the same torque repeatedly, slightly different orientations of the inserts can result. The effect is small, but you can see it by eye and the jointed surface reflects this variability.

Is there some magic to the installation of the inserts? Have others seen similar problems? Is this
a Grizzly issue, or just an incompetent user?

[Bryan Hall]

Sorry to hear.

When I had an 8" grizzly helical jointer every pass seemed to leave a glass smooth finish. I upgraded to a 12" laguna and I get the ridges on every pass now. Sam from Minimax recommends the straight blades because of this. He calls the ridges "ghosting" and that's why he recommends straight knives over helical, no matter what brand. I don't have enough experience to tell you how to fix it, but I notice it as well.

[Kyle Stiefel]

I'm finding is near-impossible to properly seat the carbide cutter inserts on my
Grizzly G0856 8-inch jointer. It seems that no matter how careful I am to clean the
carbide inserts and the cutterhead body and apply the recommended torque to the installation screws, the
net result is a poorly jointed surface. In mild cases, the surface is slightly wavy (undulating a few thou
across the board), while in other cases there are clear ridges left behind by some of the inserts.

It seems obvious that the inserts are not seating properly. In fact, it appears that the angular orientation of the inserts is not repeatably registered. Slight variation of the applied torque to the screws can result in slight rotation of the insert. Even when I tighten to the same torque repeatedly, slightly different orientations of the inserts can result. The effect is small, but you can see it by eye and the jointed surface reflects this variability.

Is there some magic to the installation of the inserts? Have others seen similar problems? Is this
a Grizzly issue, or just an incompetent user?

I had a similar issue ages ago with an 8" Griz. Are you rotating or replacing? My situation may have been different as I was replacing, turns out they were slightly proud of the cutters that came on the original head.

[Jim Eisenstein]

I should have clarified that when the jointer was new (~1.5 years ago) it produced good surfaces. At some point one
insert started producing ridges. I tried rotating it, but that did not solve the problem so I replaced that one insert. The
remaining 35 are rotated versions of the original inserts. So the machine can work well, but my fiddling with the inserts
has upset it somehow.

[Phillip Mitchell]

I’ve experienced the exact same issues with a Byrd head in a Dewalt 735 planer in a shop I worked in at the time. Extremely sensitive to misalignment and really easy to get things wrong when rotating. I spent most of an entire work day once re-dialing the cutterhead back in after a rotation of some of the cutters. I found that cleaning the area where the cutter seats of pitch/dust build up with a soft but somewhat abrasive brush and degreaser helped matters at some point. I also recall a couple of areas that had some tiny broken bits of steel preventing the proper seat of the rotated cutter which took some time to realize and find. I still never got it cutting as it was from the factory but at least got rid of 95% of the ridges and non flatness.

Im sure some of the heads are better than others but I would take a Tersa or Terminus head over a Byrd head any day and twice on Sunday. I actually have one in my jointer and am always happy with it and love 5 minute knife changes.

[Jim Eisenstein]

Thanks, Phillip. Glad to hear that I'm not totally crazy. I was very careful about cleaning the inserts and cutterhead body, but from what you say I may need a microscope to find tiny shards of metal! I've also seen that it's easy to seat the insert slightly misaligned in angle. I'd have thought the machining tolerances would be tight enough to prevent this.
Definitely puts the lie to the sales pitch for how easy it is to rotate/replace the cutters. Also, thanks for the tip on Byrd; I'd been thinking about getting one!

[Paul Haus]

First off, I do not have an insert cutterhead in my jointer or planer but I do have one for my shaper. One very important thing IMO to check is to insure that the cutters are machined exactly the same. If one is off ever so slightly it would have a tendency to cut deeper or shallower based on logic. If I was trying to diagnose this situation, I'd get out a dial indicator and magnetic base. set up a fence across the outfeed table to insure comparable setting while checking the cutters, then slowly rotate the cutterhead backwards and check the height of each insert.
I don't have an easy way to check the mounting point on the cutterhead to insure they're all machined the same.
Good luck

[Frank Pratt]

I've come to the conclusion that helical cutter heads can be more trouble than they're worth. The issues discussed in this thread are by no means uncommon. About the only thing that would drive me to switch is if I regularly worked with extremely hard/abrasive wood that destroys HSS knives.

[Mark Wooden]

Sorry to hear of your problem; I think the problem may be that you've got a slightly galled seat under the insert- and it can simply be the first thread is a little streached under the insert, holding it up just enough to produce that ridge. It's a problem I encountered with a shaper head, a hand countersink fixed it.
I have straight knife heads in my planers and jointers, never cared for the cut from a helical head. You can't joint the cutters on most of the helical insert heads, and even OEM inserts can vary in size. Most of the replacement heads are a sideways move at best, just to save setting knives. As for abrasive stuff, I have carbide tipped knives for that.

[Mark e Kessler]

I just rotated mine on a felder ad941, no issues and have never experienced ridges like you describe. I can’t imagine a better finish off a machine except for a widebelt

[Mark e Kessler]

I should have clarified that when the jointer was new (~1.5 years ago) it produced good surfaces. At some point one
insert started producing ridges. I tried rotating it, but that did not solve the problem so I replaced that one insert. The
remaining 35 are rotated versions of the original inserts. So the machine can work well, but my fiddling with the inserts
has upset it somehow.


when you replaced the one insert did the ridge in that spot go away? And when you rotated the 35 was it all good or were there ridges?

I have always wondered if on the inserts if the edges to the right or/left get worn some just by the chips that are being cut, I’d imagine they must somewhat but whether or not it cause issues I don’t know and some the heads like the non helical byrd head has those cutters essentially on a post with all 4 edges exposed.

[Mark e Kessler]

Sorry to hear.

When I had an 8" grizzly helical jointer every pass seemed to leave a glass smooth finish. I upgraded to a 12" laguna and I get the ridges on every pass now. Sam from Minimax recommends the straight blades because of this. He calls the ridges "ghosting" and that's why he recommends straight knives over helical, no matter what brand. I don't have enough experience to tell you how to fix it, but I notice it as well.


I am surprised Sam would say that about the scm helical, i can tell you that it does not happen on the Felder helical

[Jim Eisenstein]

Thanks, Paul. I am in the process of using a dial indicator to do something like what you say. As I mentioned in my first post, the angular orientation of some of the cutters is slightly dependent on
how you torque the screws. I'll try to be more quantitative in a later post.

[Michael Schuch]

I've come to the conclusion that helical cutter heads can be more trouble than they're worth. The issues discussed in this thread are by no means uncommon. About the only thing that would drive me to switch is if I regularly worked with extremely hard/abrasive wood that destroys HSS knives.

This thread has been an eye opener for me too. I have often contemplated changing the heads on my 15" planer and 8" jointer to a Byrd type head. The ease of rotating a single carbide cutter when there is a chip in the cutting surface was a big draw for me. Now... hmmm...

[Kevin Jenness]

This thread has been an eye opener for me too. I have often contemplated changing the heads on my 15" planer and 8" jointer to a Byrd type head. The ease of rotating a single carbide cutter when there is a chip in the cutting surface was a big draw for me. Now... hmmm...

Helical heads are said to deal with figured wood better, but the potential for misalignment is off-putting. I have noticed the wiggle factor on my shaper chiclet cutter, though haven't had a problem. Tersa is pretty much idiotproof. Maybe carbide Tersa knives coupled with a supersurfacer? :)

[Jim Eisenstein]

Wondering if there are Tersa heads to retrofit a Grizzly jointer?

[Phillip Mitchell]

Don’t know that you’d like the price, but you never know until you inquire. Tersa retrofits are pretty pricey from what I remember.

While you’re exploring, you might try to price a Hermance helical head. If I had to choose a helical carbide cutterhead that’s what I’d get, but again, I’m sure the price is likely more than the Byrd and other brands of more “available” heads for more hobbyist oriented machines.

[Rich Engelhardt]

Watch this video and see if it helps:

https://www.youtube.com/watch?v=XWkGXL2Jp88

[Jim Eisenstein]

Thanks, Rich. Good video. Been thinking about a luxcut replacement head.

[Mark e Kessler]

I've come to the conclusion that helical cutter heads can be more trouble than they're worth. The issues discussed in this thread are by no means uncommon. About the only thing that would drive me to switch is if I regularly worked with extremely hard/abrasive wood that destroys HSS knives.


Every time I hear about issues with helical heads there are always lower end machines that sport them or machines with byrd heads which btw are not true helicals.

I can tell you after being a straight knife guy for 25+ years I would never be able to go back, I almost never pay attention to grain direction and rarely get tear out and have never seen the ridges everyone is talking about. it’s quieter uses less power and the chips are smaller whats not to like!

if i had separates then my jointer would be a straight knife, i see no reason to have it on a jointer.

If you are going to replace a head do it with a Hermance not a byrd

[Robert London]

I just bought Grizzly’s 12” jointer planer with their new V helical head. Still in the process of getting it set up, but managed to get a few boards though the planer for test cuts. I took all the 48 inserts out, degreased the head with a brush, cleaned all the inserts, and blew out the holes to make sure everything was as clean as possible.

Was very happy with the results. No scallop marks and a clean cut. You’re ready for 180/220 sanding.

You shouldn’t have much work to clean up a helical head. You have something wrong with your inserts or the out-feed roller is making impressions. Marks could be coming from the metal out roller and most have switch to rubber.

What’s so impressive about the helical head is how quiet it is. Straight blades are incredible noisy, especially when you go up to 16-20 inches. I ran my planer without hearing protection. My dust collector is noisier than my planer jointer.

I could run my helical jointer at 11pm and my neighbors wouldn’t know. Would never go back to straight blades. I could see Tersa being a great option for those who still like straight knives. A compromise on both but still easier to work with than straight blades.

[Andrew Hughes]

I have a planer with a bryd head it’s on the second set of inserts. I used to have a jointer with a insert head. I sold it because I realized when I hand feed wood across the head sharp wins every time.
Heres a pic of port orford cedar from the planer and the other side off the jointer. Can you tell which one is which :)
Sometimes I clean up the bryd head furrows with the jointer.

[Mark e Kessler]

Is that 1st pic what it normally looks like from a byrd head or is it just yours?



I have a planer with a bryd head it’s on the second set of inserts. I used to have a jointer with a insert head. I sold it because I realized when I hand feed wood across the head sharp wins every time.
Heres a pic of port orford cedar from the planer and the other side off the jointer. Can you tell which one is which :)
Sometimes I clean up the bryd head furrows with the jointer.

[Jim Eisenstein]

Over the last several days I have cleaned and reset the inserts several times. I'm ridiculously careful to clean the inserts, the screws, and the cutter
head beyond reasonable expectations. This includes carefully removing any evidence of pitch on the inserts and cutterhead, blowing out the threaded
holes, etc etc, and inspecting everything with a 10x eye-loupe. I'm super-careful to make sure the inserts seat properly, as that is an obvious pitfall.

In spite of all this nonsense, the scallops are still there and ridges show up. The detailed locations of these defects vary from attempt to attempt,
but the basic result is unchanged. Seems like I am barking up the wrong tree!

Aside from edge jointing for glue-ups, I could live with the scalloping; my planer (DW735, straight HSS knives) leaves beautiful surfaces after the jointer.
But edge jointing is pretty essential...

The Luddite in me is considering replacing the helical cutterhead with a straight knife job. Based on the responses I've gotten, a Byrd or Lux-Cut may be throwing
good money after bad.

[Mark e Kessler]

The scallops are expected from a Helical, they are the signature mark so to speak of a Helical or Helical imposter, nothing wrong with this its no different than say what a straight knife leaves just in a different pattern.

Here is what my scallops look like and I would consider this severe. This is on White Oak, in jointer mode and probably about a 1/8” cut at a fast feed rate on a Felder with the silent power helical head. It would take no time to sand these out with 180 but the reality is that it’s usually better then this when it comes out of the planer with a controlled feed rate.

I would like to know how it compares to what others are seeing on non Felder,scm,Hermance helicals because it seems like helicals get a bad rap on this site and I can’t understand why because I am blown away by the results by my machine, i can only come to the conclusion that good engineering cost money and bad less.


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Over the last several days I have cleaned and reset the inserts several times. I'm ridiculously careful to clean the inserts, the screws, and the cutter
head beyond reasonable expectations. This includes carefully removing any evidence of pitch on the inserts and cutterhead, blowing out the threaded
holes, etc etc, and inspecting everything with a 10x eye-loupe. I'm super-careful to make sure the inserts seat properly, as that is an obvious pitfall.

In spite of all this nonsense, the scallops are still there and ridges show up. The detailed locations of these defects vary from attempt to attempt,
but the basic result is unchanged. Seems like I am barking up the wrong tree!

Aside from edge jointing for glue-ups, I could live with the scalloping; my planer (DW735, straight HSS knives) leaves beautiful surfaces after the jointer.
But edge jointing is pretty essential...

The Luddite in me is considering replacing the helical cutterhead with a straight knife job. Based on the responses I've gotten, a Byrd or Lux-Cut may be throwing
good money after bad.

[Mark Carlson]

I have two machines with Byrd heads, a Powermatic 54a jointer and a Hammer A3-31 jointer planer. Couldn't be happier with the performance. I get perfectly smooth results and the knives stay sharp for a long long time. Rotating the inserts is quick and painless. I wouldn't go back to straight knives.

[Alan Lightstone]

The scallops are expected from a Helical, they are the signature mark so to speak of a Helical or Helical imposter, nothing wrong with this its no different than say what a straight knife leaves just in a different pattern.

Here is what my scallops look like and I would consider this severe. This is on White Oak, in jointer mode and probably about a 1/8” cut at a fast feed rate on a Felder with the silent power helical head. It would take no time to sand these out with 180 but the reality is that it’s usually better then this when it comes out of the planer with a controlled feed rate.

I would like to know how it compares to what others are seeing on non Felder,scm,Hermance helicals because it seems like helicals get a bad rap on this site and I can’t understand why because I am blown away by the results by my machine, i can only come to the conclusion that good engineering cost money and bad less.


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My results on my Felder A941 jointer and D951 planer with the silent power helical head pretty well always look like this or better. No issues on my end. I agree that the power feeder with the controlled feed rate on the planer helps.

The wide belt can clean this up in one tiny pass.

[Erik Loza]

Tersa heads are awesome but having dealt with only spiral heads since coming back into the industry, I have come to the conclusion spirals give the ownership experience most weekend warrior ww’ers are actually looking for. Yes, there is no better finish than HSS Tersa but that is only on properly dried domestic softwoods and hardwoods. The moment you get into tropical species or some of the oddball domestics like mesquite, you’ll want carbide unless you plan to be scooching/flipping/discarding your knives regularly. Carbide Tersa knives are available but uber-$$$. Back in my Italian days, I sold a 20” Tersa planer to a commercial flooring shop that was running lots of teak. They called me pretty soon thereafter, complaining about knife longevity. I think I suggested carbide knives. They either sold the machine or went Byrd not long after. The cost of perpetually replacing 510mm carbide knives must have been astronomical. What they really needed was a spiral head.

Not shilling for my employer but I have sold LOTS of jointer/planers over the last few years (all spiral) and zero complaints. Not a single one. Folks love that cutterhead and I never have to have the “what alloy knife should I use for this or that species of wood?” conversation any more. If I were a one-man outfit, ONLY did kiln-dried poplar, cherry, oak, etc., and was dead-set against any finish work, I would go for Tersa. But I would also make sure to have a number of extra knives on hand, which is adds to the MRO cost. Nobody gets away with the same set of Tersa knives for long. If I were shopping for a machine where I just never wanted to have to worry about species of wood, the odd nail or piece of grit, or being lazy about rotating inserts, spiral hands-down. All this being said, there is probably a difference between the mass-produced Chinese heads and a Silent Power or Xylent cutterhead as far as tolerances and insert quality, which could explain some of the complaints about finish quality that was mentioned.

Erik

[Kevin Jenness]

I sold a 20” Tersa planer to a commercial flooring shop that was running lots of teak. They called me pretty soon thereafter, complaining about knife longevity. I think I suggested carbide knives. They either sold the machine or went Byrd not long after. The cost of perpetually replacing 510mm carbide knives must have been astronomical. What they really needed was a spiral head.


Erik

Seems like a fair comparison would be between carbide Tersa and carbide inserts. Four carbide knives from Tersaknives.com cost $548.80, or $274.40 per knife change. https://tersaknives.com/products/carbide?variant=14070872646 108 Byrd inserts for a 16" cutterhead replacement for a Powermatic 160 cost $4,482, $1,120.50 per changeout. https://byrdtoolexperts.com/checkout Are other brands of inserts less expensive? Do carbide inserts last any longer than carbide Tersa knives? A hobby user might never wear out their first inserts, but a commercial shop certainly would.

I think I recall that Joe Calhoon runs 2 carbide knives and 2 dummies in his Tersa jointer.

Here's Sam Blasco's opinion. https://www.elitemetaltools.com/article/tersa-vs-xylent-cutter-heads-expert-opinion

I have no horse in this race. I have a 16" jointer with carbide straight knives and a Powermatic 160 with an onboard grinder. I have a 10* face bevel on my planer knives for diminished tearout. I know from limited experience that the helical heads are far quieter, easier on dust collection due to smaller chips and better on highly figured woods than straight knives.

[Warren Lake]

Teak has sand in it. So you are saying that the carbide tersa didnt last and were replaced with the carbide spiral? Carbide spirals have Kryptonite?

[Bob Falk]

I put a helical head on my Woodmaster 18" planer and have planed hundreds of feet of hardwoods and softwoods. I have yet to rotate the cutters and it still cuts beautifully. Love the fact that it is lower noise.

[Erik Loza]

…Do carbide inserts last any longer than carbide Tersa knives? A hobby user might never wear out their first inserts, but a commercial shop certainly would…

No idea! I never actually talked to a hobby customer who ended up splurging for a head full of carbide Tersas. Once they heard the price from Simantech or whoever, that conversation was over!


…Here's Sam Blasco's opinion. https://www.elitemetaltools.com/article/tersa-vs-xylent-cutter-heads-expert-opinion…

Sam didn’t write that. I did. Probably around 2012, when I sold for SCM. It was from a page on my sales site….

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Sam might have inserted a little testimonial in the middle but rest is direct copy-and-paste from my site. That was when I was trying to sell Tersa against Felder Silent Power. I still stand by all those statemements: Tersa is awesome and has many advantages over spirals but having sold (and used) a good spiral head for several years now, I do think it is what most ww’ers are truly looking for in an ownership experience. There must be something to this, since both SCM and Martin now offer their own spiral heads in addition to Tersa. By the way, I can order any Felder machine with a Tersa head and gladly do that but it’s simply not a request we ever seem to get.


Carbide spirals have Kryptonite?

Warren even better: Dust, ground from the bones of angry old woodworkers.:D

Erik

[Andrew Hughes]

Teak has sand in it. So you are saying that the carbide tersa didnt last and were replaced with the carbide spiral? Carbide spirals have Kryptonite?

Sand and oils it’s a double whammy. I’d wager a box of Daniel Webster cigars most run the carbide insert past the point of sharpness. I would like to know what super tungsten knives are like. My machine has a badge says they were offered 60 years ago.
I had a set of hss street knives that had a black oxide coating on the face they were very long lasting. But they were not the proper thickness for my machine to stopped using them. Through them out so I wouldn’t be tempted .

[Warren Lake]

im old Erik but not angry, I am blunt and there is enough nonsense on enough posts. I never joined the rat race.

[Kevin Jenness]

im old Erik but not angry, I am blunt and there is enough nonsense on enough posts. I never joined the rat race.

Blunt, but never dull.

[John Lanciani]

Seems like a fair comparison would be between carbide Tersa and carbide inserts. Four carbide knives from Tersaknives.com cost $548.80, or $224.40 per knife change. https://tersaknives.com/products/carbide?variant=14070872646 108 Byrd inserts for a 16" cutterhead replacement for a Powermatic 160 cost $4,482, $1,120.50 per changeout. https://byrdtoolexperts.com/checkout Are other brands of inserts less expensive? Do carbide inserts last any longer than carbide Tersa knives? A hobby user might never wear out their first inserts, but a commercial shop

I think I recall that Joe Calhoon runs 2 carbide knives and 2 dummies in his Tersa jointer.

Here's Sam Blasco's opinion. https://www.elitemetaltools.com/article/tersa-vs-xylent-cutter-heads-expert-opinion

I have no horse in this race. I have a 16" jointer with carbide straight knives and a Powermatic 160 with an onboard grinder. I have a 10* face bevel on my planer knives for diminished tearout. I know from limited experience that the helical heads are far quieter, easier on dust collection due to smaller chips and better on highly figured woods than straight knives.

You added a zero to the price of the Byrd inserts; they are priced per 10, not $41.50 each. Big differrnce.

[Warren Lake]

I like teak. I let a friend use my shop over 40 years ago and he trashed my knives with Teak. Letting him use the shop was a good thing as he worked in a top shop and info was shared.

[Kevin Jenness]

"Do carbide inserts last any longer than carbide Tersa knives? "

Do
No idea! I never actually talked to a hobby customer who ended up splurging for a head full of carbide Tersas. Once they heard the price from Simantech or whoever, that conversation was over!


Erik

It seems like a question that I would want answered if I were contemplating Tersa vs helical.

Since you have sold numerous insert head machines, do you have an answer to the original poster's question?

[Warren Lake]

The machine I priced a tersa for think was about 7k canadian without the knives. Ive never not been able to do a job so far on old school stuff.

If you asked me to run 500 feet of teak then for sure im not set up for that and would have to figure it out if I wanted to take the work. Esta has the drop in knives but dont think they have carbide. Combo machine wont have a head replaced when a saw is on one side and a mortiser on the other end of the shaft.

[Kevin Jenness]

You added a zero to the price of the Byrd inserts; they are priced per 10, not $41.50 each. Big differrnce.

John, thanks for the correction. That would make the material cost of swapping out the inserts $112.05 vs. $274.40 for 4 knives in a Tersa head, a significant difference. If one ran two tersa knives in a jointer the difference would be halved. What would the relative labor cost be at let's say $75 per hour? Two minutes for tersa and an hour for inserts? Then there is the question of longevity of inserts vs Tersa, which I can't answer.

[Erik Loza]

…It seems like a question that I would want answered if I were contemplating Tersa vs helical.

Let’s put it like this: I see every every spare parts order that goes through my sales territory and rarely see orders for replacement inserts. Now, to be fair, probably 80% of the machines in my area are in hobbyists’ garages, so you might never actually need to buy replacement inserts under that level of usage (which actually I suppose is a selling point in and of itself, since we took orders for Tersa knives left and right during my Italian days…) but the larger message is that spirals definitely require less “involvement” from the ownership standpoint than Tersa.

I recently placed an order for a complete set of replacement inserts for a local pro shop on their 16” machine. 60-something inserts, it was several hundred dollars. He works only with domestic hardwoods and his machine was around five years old. Way more board-feet through that machine than a hobbyist would ever see. This was the first time he actually purchased any new inserts and just wanted to do it all at once. I’ve never actually run the numbers but just off the top of my head, it could easily be 4X-5X the costs over the life of the machine if carbide Tersas. If you hit a nail with a spiral head, it will fracture one insert but if you hit a nail with a carbide Tersa, that knife goes in the trash. Again, this is not sales schtick. There’s probably a pretty good reason why Martin (the most die-hard of die-hard Tersa flag bearers) came out with a spiral head.

Erik

[Kevin Jenness]

Let’s put it like this: I see every every spare parts order that goes through my sales territory and rarely see orders for replacement inserts. Now, to be fair, probably 80% of the machines in my area are in hobbyists’ garages, so you might never actually need to buy replacement inserts under that level of usage (which actually I suppose is a selling point in and of itself, since we took orders for Tersa knives left and right during my Italian days…) but the larger message is that spirals definitely require less “involvement” from the ownership standpoint than Tersa.

I recently placed an order for a complete set of replacement inserts for a local pro shop on their 16” machine. 60-something inserts, it was several hundred dollars. He works only with domestic hardwoods and his machine was around five years old. Way more board-feet through that machine than a hobbyist would ever see. This was the first time he actually purchased any new inserts and just wanted to do it all at once. I’ve never actually run the numbers but just off the top of my head, it could easily be 4X-5X the costs over the life of the machine if carbide Tersas. If you hit a nail with a spiral head, it will fracture one insert but if you hit a nail with a carbide Tersa, that knife goes in the trash. Again, this is not sales schtick. There’s probably a pretty good reason why Martin (the most die-hard of die-hard Tersa flag bearers) came out with a spiral head.

Erik

Thanks, Erik. Have you ever fielded any complaints about insert seating like the one that started this thread? If I were buying new I would lean toward spiral/helical but for that worry. The typical minor "ghost lines" I have seen would not bother me.

The shop I used to work at first swapped out the inserts on their new SCMI planer after several hundred hours of use. Would you say that is a fair average for domestic woods?

[Jim Eisenstein]

Well, this thread has evolved well beyond my experience and expense level. It seems to me that a hobbyist machine
like my Grizzly 8" ought to be able to produce decent results without the user having to be a NASA engineer. I am
in fact a retired professor of physics with *lots* of experience with equipment far more complex than a jointer. And
yet there it is; I've not been able to get the thing back into decent shape. If and when I do, I'll repost. In the meantime here's a photo
of a typical recent result from my jointer on poplar. It ain't acceptable to me.

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[Frank Pratt]

Well, this thread has evolved well beyond my experience and expense level. It seems to me that a hobbyist machine
like my Grizzly 8" ought to be able to produce decent results without the user having to be a NASA engineer. I am
in fact a retired professor of physics with *lots* of experience with equipment far more complex than a jointer. And
yet there it is; I've not been able to get the thing back into decent shape. If and when I do, I'll repost. In the meantime here's a photo
of a typical recent result from my jointer on poplar. It ain't acceptable to me.

471251

I was about to post a reply about how people should not expect a finish ready surface right off the planer or jointer, but that board is pretty awful. It would take more than a couple of light passes with a sander to get that out.

[Brian Holcombe]

I would contact the manufacturer. I use a lot of insert carbide for machining and they are always easy to reinstall.

I prefer Tersa carbide for jointer/planer. I get about 1-1.5 years from a set of knives. I generally do not run exotics, there is a local shop near me that runs a lot of exotics and I’d be amazed if spiral knives actually do last longer since their knives always seem perpetually worn out. Teak and sandy woods just beat up cutters.

[Kevin Jenness]

I prefer Tersa carbide for jointer/planer. I get about 1-1.5 years from a set of knives.

Brian, why do you prefer Tersa for this application?

For comparison, I get about the same time between sharpening on my carbide jointer knives. Of course I have no idea of our relative volume. I would say I sharpen my hss planer knives 5 or 6 times more frequently.

[Brian Holcombe]

I prefer it for ease of swapping knives.

[Jim Eisenstein]

Thanks, Brian. I'm not really familiar with Tersa, but are these carbide straight knives retrofitted into a pre-existing machine?

[Joe Calhoon]

I ran about 500 feet of Teak for a contractor a while back with no noticeable wear on the carbide Tersa on my S4S machine. I would think carbide spiral would be the same. One Teak board will will wipe out HSS knives. With Tersa HSS will not last long in anything other than clear softwoods. M42 is a little better but will chip easy if any knots. Since I work a wide variety of material I use mostly coated HSS like the Kanafusa Tersa clones and carbide. I have not been totally happy with the Tersa brand of carbide. It does not seem to cut as well as Leitz carbide carbide clones I had in the S4S machine for a while. At the moment I am trying Rangate’s diamond coated Tersa in the planer. Too soon to see how they do. At first I did not think the coated Kanafusa Tersa were that good but after much use those hold up really well. I do run 2 knives in all my Tersa heads.
At least now with the Tersa patent expired there are several choices. I recently looked at a Martin spiral planer and jointer in a local shop and was pretty impressed with the finish off those and even though Tersa is pretty quiet these were really quiet.

I expect to get finished surfaces off my jointer and planer. Way back with straight HSS I always expected to have to sand most species after planing.

[Ronald Blue]

I installed a Grizzly insert head on my Jet 6" jointer a couple months ago. It had been returned and was in their scratch and dent room. It had a missing insert and a damaged one. I installed a new one and turned the damaged one. It leaves a glass smooth finish. I've not ran any exotics over it but can't imagine any different results. Post a photo or two showing your insert head. Something is wonky here.

[Jim Eisenstein]

Something is wonky for sure. Attached photo show 1 of 4 rows of inserts on the cutterhead. Other rows appear
the same. As bad as the scalloping looked in the previous photo (taken in oblique illumination), the scallops are
in reality only about 0.002" deep (via feeler gauge). Might be hard to detect this by eyeing the inserts.

471263

[Ronald Blue]

So if you hit the board with a sander does it "smooth" up quickly? Usually when you can see the irregularity it's bad enough to be an issue. Doesn't make sense especially since it was good in the beginning.

[Jim Eisenstein]

don't know, haven't tried. in general I would be heading to the planer for thicknessing after face jointing. the planer produces an excellent surface.

[Erik Loza]

Thanks, Erik. Have you ever fielded any complaints about insert seating like the one that started this thread? If I were buying new I would lean toward spiral/helical but for that worry. The typical minor "ghost lines" I have seen would not bother me.

The shop I used to work at first swapped out the inserts on their new SCMI planer after several hundred hours of use. Would you say that is a fair average for domestic woods?

”No” to seating issues and “Yeah, probably” to the SCMI planer comment. In my experience, shops don’t really keep track of board-feet. They address it when boards start getting so streaky that guys are spending a lot of time sanding (assuming they don’t have a widebelt, which some don’t).

I have really never had major complaints with spiral heads. Once in a while you will get boards with tricky grain that cause problems. One of my local shops showed me a few walnut boards where the spiral cutterhead had lightly chunked out areas behind the eyes in the grain but I don’t think straight-knife would have done any better. I’ve seen Tersa do the same in white oak with similar character. The conclusion we came to was try feeding from the other end or angling the board if possible. Some boards are just tricky no matter what type of head you have.

Erik

[Mark e Kessler]

”No” to seating issues and “Yeah, probably” to the SCMI planer comment. In my experience, shops don’t really keep track of board-feet. They address it when boards start getting so streaky that guys are spending a lot of time sanding (assuming they don’t have a widebelt, which some don’t).

I have really never had major complaints with spiral heads. Once in a while you will get boards with tricky grain that cause problems. One of my local shops showed me a few walnut boards where the spiral cutterhead had lightly chunked out areas behind the eyes in the grain but I don’t think straight-knife would have done any better. I’ve seen Tersa do the same in white oak with similar character. The conclusion we came to was try feeding from the other end or angling the board if possible. Some boards are just tricky no matter what type of head you have.

Erik
Btw, i occasionally have a small area of tear out around Walnut knots, twisty turny interlocked areas and i just wet the trouble spots and no more tear out - most WW’rs probably know this bit thought i would mention it.

Also am amazed that i can take a .2mm pass on the ad941 with perfect results, no infeed/outfeed marks on hardwood being able to take that slim of a pass with constant results handles the tricky spots pretty good. If I am running a lot of pine for example i just take a little pressure off the infeed and outfeed rollers so it leaves no marks on a light pass

[Erik Loza]

Btw, i occasionally have a small area of tear out around Walnut knots, twisty turny interlocked areas and i just wet the trouble spots and no more tear out - most WW’rs probably know this bit thought i would mention it….

Ditto here. I think part of this Felder’s fault: Marketing Silent Power as some magical silver bullet for every board, every woodworker when the reality is that there are varying levels of experience on part of the operator, part of the board selection, and part of the expectation of results. All this being said, I still feel the spiral gives the ownership experience most folks are looking for more than any straight-knife system. Tersas are wonderful but I think we will see a day where your only option is a spiral head, from any manufacturer. We sell a mountain of jointer/planers and I can’t recall seeing any order that wasn’t spiral.

Erik

[Mitch schiffer]

I get a better finish with my powermatic jointer with their helical head which has about 1 inch long 2 sided carbide inserts then I did with my previous grizzly helical jointer. I was told by my dealer when I bought the grizzly jointer several years back to get the helical head (model g0858 i believe) then the spiral head (model g0490x). My understanding is the spiral versions that grizzly offers are much lower quality then the helical version.

[Alex Zeller]

If I had to guess I would say it's the inserts, not the head since the results change as you move/ turn the inserts. The inserts are mass produced at a very low price. I think I might try 10 of another brand and change then on just one side so when you run a board through the jointer you can see if that part of the board looks better than the rest. I remember that some of the replacement inserts through Grizzly were stupidly expensive. I think I would either try Carbide processors or Hermance (who I planned on checking with when the inserts on my 1033x need replacing). Both sell inserts made in Germany.