Shelix Cutterhead comments

[Kyle Kraft]

Tell me all your stories, raves, gripes, etc. about the Shelix cutterhead. Planer and/or jointer comments are welcome. I'm thinking about getting one and would like to get a consensus on it. Shelix vs. conventional knife surface comparisons, noise, increased or decrease hp issues....anything and everything. Let'er rip!

[Michael McCoy]

There were a couple of threads fairly recently that a search should turn up. The biggest difference I saw on my jointer was the feed rate had to be a little slower but the surface is a whole lot smoother. On my Dewalt DW735, I found that I had to reduce the amount I was taking off at one time but the lack of tear out was worth it. In both cases, the machines are quiter. The planer is still loud as heck but the jointer (Yorkcraft 6") doesn't even drown out the radio.

[Joe Jensen]

I have 30 years of serious hobby experience. I had a PM60 jointer and a 12" PM100 planer with straight knives for 17 years. I am a fanatic for setting knives and tuning my tools. I was able to get the planer knives within a +/- .0005" meaning all three knives cut within a .001" window. That would take me about 4 hours with a dial indicator. Magnaset and other gadgets wouldn't even get close as the knife lock screws would move the area of the knife where they tighten by anwhere from .000" to .003" each time I tightened. With the planer knives fresh from a professional sharpening shop, and adjusted as I discussed above, I could get amazing resultes on straight grain for a few hundred board feet. I now have a Byrd head in the planer and the cut is not quite as good as the fresh knives, but 2 years later, the cut is better than after a few hundred feet on the fresh knives. Based on my experience with the $1000 planer head, I upgraded from a Tersa head in the PM60 jointer to a Byrd head. I've since sold the PM60 and I bought a 12" SCMI jointer. In the renovation of the SCMI, I put in another expensive Byrd head.

One of the concerns folks have with the Byrd heads is the scalloping of the surface. There is scalloping. But, if you take a board straight off a planer with well adjusted knives, you can't go straight to finish there either. At least with my planer, there were very small (maybe 1/32" spaced knife marks) from the straight knives. The Byrd leaves different marks, but no more difficult to handle than the knife marks from the old planer. I don't think there is a powered jointer or planer that you can go from machine to finish.

In my experience here are the benefits
1) No more tearout
2) longer life (I am getting maybe 10X the life, not sure as I don't have to rotate cutters yet or any time soon as far as I can see. Also, I get 4 sets of edges on the carbide inserts.
3) No more adjusting knives. Even though I'm an engineer and I enjoy working on my tools, I was DONE with setting knives.
4) Quiet

The only downside I see in real world use is the up front cost.

I am thrilled, but as they say, you have to pay to play.

One last observation. The scallops on the planer were less than the PM60 jointer. The new SCMI jointer has nearly invisible scallops. I wonder if the curved geometry is optimized for larger dia cutterheads. The PM60 cutterhead was about 2.5" in dia. The PM100 planer is around 3", and the SCMI is almost 4". I'd like to hear from some users of the new Byrd heads on the lunch box planers.

[Lee Schierer]

The most recent issue of Wood magazine raised some concerns about the shellix type cutter heads for planers and jointers. I believe their tests showed the surface to be not as flat as a conventional cutter.

[Clifford Mescher]

I have 30 years of serious hobby experience. I had a PM60 jointer and a 12" PM100 planer with straight knives for 17 years. I am a fanatic for setting knives and tuning my tools. I was able to get the planer knives within a +/- .0005" meaning all three knives cut within a .001" window. That would take me about 4 hours with a dial indicator. Magnaset and other gadgets wouldn't even get close as the knife lock screws would move the area of the knife where they tighten by anwhere from .000" to .003" each time I tightened. With the planer knives fresh from a professional sharpening shop, and adjusted as I discussed above, I could get amazing resultes on straight grain for a few hundred board feet. I now have a Byrd head in the planer and the cut is not quite as good as the fresh knives, but 2 years later, the cut is better than after a few hundred feet on the fresh knives. Based on my experience with the $1000 planer head, I upgraded from a Tersa head in the PM60 jointer to a Byrd head. I've since sold the PM60 and I bought a 12" SCMI jointer. In the renovation of the SCMI, I put in another expensive Byrd head.

One of the concerns folks have with the Byrd heads is the scalloping of the surface. There is scalloping. But, if you take a board straight off a planer with well adjusted knives, you can't go straight to finish there either. At least with my planer, there were very small (maybe 1/32" spaced knife marks) from the straight knives. The Byrd leaves different marks, but no more difficult to handle than the knife marks from the old planer. I don't think there is a powered jointer or planer that you can go from machine to finish.

In my experience here are the benefits
1) No more tearout
2) longer life (I am getting maybe 10X the life, not sure as I don't have to rotate cutters yet or any time soon as far as I can see. Also, I get 4 sets of edges on the carbide inserts.
3) No more adjusting knives. Even though I'm an engineer and I enjoy working on my tools, I was DONE with setting knives.
4) Quiet

The only downside I see in real world use is the up front cost.

I am thrilled, but as they say, you have to pay to play.

One last observation. The scallops on the planer were less than the PM60 jointer. The new SCMI jointer has nearly invisible scallops. I wonder if the curved geometry is optimized for larger dia cutterheads. The PM60 cutterhead was about 2.5" in dia. The PM100 planer is around 3", and the SCMI is almost 4". I'd like to hear from some users of the new Byrd heads on the lunch box planers.
Good post. A keeper. Clifford.

[Joseph Hadley]

I just installed a byrd head in a 20" planer and am extremely happy with the results. I don't think I would characterize the finished cut surface as scalloped. I can't feel any differences in level with my fingertips, and I'm not a rock climber. It feels smooth. Even so, at a low angle in the right light I can see a series of very fine parallel lines, directly across the board perhaps 1/64" apart, that are probably very minor differences in level. Is that scalloping? I thought scalloping was something that would resemble cuts like a scallop shell would make...sort of cup shaped. Anyhow, sanding very lightly with 180 grit eliminates these fine lines.

The biggest benefits as far as I'm concerned are: no tearout on the figured walnut that I am currently working; the longevity of a sharp edge; a huge reduction in noise; easier dust collection; and time saved setting up new or newly sharpened blades.

The biggest drawback is the cost, closely followed by the amount of time it takes to remove and install the new head. Then again, tearout in a prized board can't be compared to the time it took to install the head.

IMO well worth saving up for.

[David Duke]

I just installed a Byrd head in my 15" Jet last night. I haven't ran the first board through yet so I can't tell you anything about the cut but can say that the planer is somewhat quieter than before and I don't have all the covers back in place so it should be even better when I do.

The installation went pretty well however no instructions came with it and the schematic on the planer left a lot to be desired. It took me about two hours last night to remove the old head and put in the shellix, I'm going check the adjustments on the infeed/outfeed rollers and cutting table then close everything up and see how it cuts tonight

[Joe Chritz]

Love it and if the cost wasn't killing me (and I have a drum sander) I would have one for my planer yesterday.

Joe

[Neal Clayton]

I have 30 years of serious hobby experience. I had a PM60 jointer and a 12" PM100 planer with straight knives for 17 years. I am a fanatic for setting knives and tuning my tools. I was able to get the planer knives within a +/- .0005" meaning all three knives cut within a .001" window. That would take me about 4 hours with a dial indicator. Magnaset and other gadgets wouldn't even get close as the knife lock screws would move the area of the knife where they tighten by anwhere from .000" to .003" each time I tightened. With the planer knives fresh from a professional sharpening shop, and adjusted as I discussed above, I could get amazing resultes on straight grain for a few hundred board feet. I now have a Byrd head in the planer and the cut is not quite as good as the fresh knives, but 2 years later, the cut is better than after a few hundred feet on the fresh knives. Based on my experience with the $1000 planer head, I upgraded from a Tersa head in the PM60 jointer to a Byrd head. I've since sold the PM60 and I bought a 12" SCMI jointer. In the renovation of the SCMI, I put in another expensive Byrd head.

One of the concerns folks have with the Byrd heads is the scalloping of the surface. There is scalloping. But, if you take a board straight off a planer with well adjusted knives, you can't go straight to finish there either. At least with my planer, there were very small (maybe 1/32" spaced knife marks) from the straight knives. The Byrd leaves different marks, but no more difficult to handle than the knife marks from the old planer. I don't think there is a powered jointer or planer that you can go from machine to finish.

In my experience here are the benefits
1) No more tearout
2) longer life (I am getting maybe 10X the life, not sure as I don't have to rotate cutters yet or any time soon as far as I can see. Also, I get 4 sets of edges on the carbide inserts.
3) No more adjusting knives. Even though I'm an engineer and I enjoy working on my tools, I was DONE with setting knives.
4) Quiet

The only downside I see in real world use is the up front cost.

I am thrilled, but as they say, you have to pay to play.

One last observation. The scallops on the planer were less than the PM60 jointer. The new SCMI jointer has nearly invisible scallops. I wonder if the curved geometry is optimized for larger dia cutterheads. The PM60 cutterhead was about 2.5" in dia. The PM100 planer is around 3", and the SCMI is almost 4". I'd like to hear from some users of the new Byrd heads on the lunch box planers.

now that you mention it, i have these heads on both my woodmaster planer (also about 4" in diameter) and grizzly 8" jointer (much less, maybe 2.5" in diameter about like the PM jointer), and i notice the same. the planed surfaces aren't ready for stain, but they need very little sanding. i can go straight to 220 on a random orbital and they're fine after that.

i think it's logical that the diameter of the head does in fact make a difference.

[J.R. Rutter]

I have had 3 different Byrd heads, and the larger heads did best.

To get an idea of the geometry involved in the inserts, get a pencil and a coffee mug. Hold the pencil straight up and down on the side of the mug. This is a straight knife. Now tilt the pencil over at an angle, keeping the middle touching the mug. If you measure out from the center of the mug to the pencil, you find that it is greater top and bottom, which is easily visible looking at it from above. That is why the inserts have a radius, to bring the top and bottom of the knife closer to the same distance from the centerline. This translates into a flat cut on the wood surface. Yes, the 4" radius on a Byrd insert is optimized for one diameter cutterhead. I haven't asked or done any calculations (I was an English major!) but I would guess that they are optimized for either 125 or 140 mm diameter heads, since these are the most common moulder planer head sizes.

[Tom Veatch]

...Yes, the 4" radius on a Byrd insert is optimized for one diameter cutterhead. I haven't asked or done any calculations (I was an English major!) but I would guess that they are optimized for either 125 or 140 mm diameter heads, since these are the most common moulder planer head sizes.

If my assumptions and math are correct, the radius of curvature (RC) along a helix wrapped around a cylinder is:

RC = RH/(2*sinA)

where
RC = Radius of curvature along the helix
RH = Radius of the cylinder (cutterhead)
A = helix angle. (0° is parallel to the axis of the cutterhead - a straight knife)

Just looking at pictures of a Shelix head, and estimating the helix angle at 15°, that means for an RC of 4", the optimum cutterhead radius would be about 2" or a cutterhead diameter of about 4".

Or saying it another way, a 4" radius of curvature on the insert would be just about optimum for a

1.4" diameter cutterhead with a 5° helix angle
2.8" / 10° helix
4.1" / 15° helix
5.5" / 20° helix
...
8" / 90° helix

FWIW.

[John Hedges]

OK I'm no rocket scientist so correct me if I am misinterpreting, but the radius cut (if that's what your referring to) is side to side on the insert and not the angle from the point it contacts the cutterhead to where it contacts the wood. The radius is just at the extreme outside of the point of the edge, if that makes sense.

[J.R. Rutter]

Thanks for that formula, Tom! So a cutterhead manufacturer could vary the helix angle on different diameter heads to make use of a single style of insert.

[Tom Veatch]

I've never seen one of those inserts up close and personal, so my assumptions may be all wet.

There's two ways to interpret the 4" radius mentioned. Looking down at the top of the insert, IOW plan view, the cutting edge could be curved so that the insert looks like a square with bulging sides - the center of an edge is "farther forward" than the corners. That wasn't obvious in the pictures I saw, so I made the other assumption. Looking at a side view of the insert, I assumed the insert is curved so that the corners are "lower" than the center. With that assumption, when the insert is turned so that an edge lines up with the helix angle, the curve in the insert tends to "wrap around" the cylinder. If that was a wrong assumption, then my calculations are meaningless and should be ignored.

[Dave Verstraete]

Kyle
I have the Grizzly style carbide inserted heads. If you want to try a e few board feet, come on up to G.R. area and I'll let you try it

[John Hedges]

I hope this clarifies. If you are looking down on the top of the insert so you see a square, the edges of the square are relieved ever so slightly. When you combine this with the fact that the Byrd head inserts are angled in relation with the head so that the angle it hits the wood at is a shear and not a straight on (the grizzly inserts are at a right angle to the wood), it produces slight ridges (very slight), and virtually eliminates the chance of tearout. Because of this the angle of the insert is constant no matter what the diameter of the cutterhead is. I hope that makes sense.

[Kyle Kraft]

Thanks for the replies and to Dave for the offer. I haven't been on line for a few days or I would have replied sooner.

Sounds like an upgrade that's worth saving up for!!

[Daniel Berlin]

One last observation. The scallops on the planer were less than the PM60 jointer. The new SCMI jointer has nearly invisible scallops. I wonder if the curved geometry is optimized for larger dia cutterheads. The PM60 cutterhead was about 2.5" in dia. The PM100 planer is around 3", and the SCMI is almost 4". I'd like to hear from some users of the new Byrd heads on the lunch box planers.

The larger the circle, the more a given size contact area approximates being flat.
(http://books.google.com/books?id=VzxnxQGdvcsC&pg=RA1-PA82&lpg=PA83&ots=TTHOYOK_t1#PRA1-PA88,M1 has diagrams, but this is just geometry :P)
Given the direction of the scallops, it is probably related to the size of the radius of the carbide inserts, which i assume is larger on the larger cutters.

[Joe Jensen]

:D
The larger the circle, the more a given size contact area approximates being flat.
(http://books.google.com/books?id=VzxnxQGdvcsC&pg=RA1-PA82&lpg=PA83&ots=TTHOYOK_t1#PRA1-PA88,M1 has diagrams, but this is just geometry :P)
Given the direction of the scallops, it is probably related to the size of the radius of the carbide inserts, which i assume is larger on the larger cutters.

Byrd has only one radius they use on the cutters. The cutters are universal. If the cutters had a custom radius for each cutterhead diameter, there would be no scallops. My experience suggests the radius they chose for their carbide inserts is optimized for about a 4" diameter cutterhead. I may call them just out of curiosity

[Richard McComas]

You may find this thread of interest.

http://www.woodweb.com/cgi-bin/forums/swmf.pl?read=592578

[J.R. Rutter]

I've never seen one of those inserts up close and personal, so my assumptions may be all wet.

There's two ways to interpret the 4" radius mentioned. Looking down at the top of the insert, IOW plan view, the cutting edge could be curved so that the insert looks like a square with bulging sides - the center of an edge is "farther forward" than the corners. That wasn't obvious in the pictures I saw, so I made the other assumption. Looking at a side view of the insert, I assumed the insert is curved so that the corners are "lower" than the center. With that assumption, when the insert is turned so that an edge lines up with the helix angle, the curve in the insert tends to "wrap around" the cylinder. If that was a wrong assumption, then my calculations are meaningless and should be ignored.

The inserts are flat, with a 4" radius on each edge. I just retipped my RC-63 planer head with 160 new tips. Global Tooling has some that work for about $2 / ea. They are marked BT.

[Kyle Kraft]

So are these lines that appear after indexing the cutters similar to the ones left by my straight knives after they are nicked?