Cut Quality, Noise, and Downtime: How Surfacing Head Design Impacts Your Shop

With all the options out there, which surfacing head is best? Sounds like a trick question.  And it basically is.   

There is no right or wrong answer to this question if you understand the pros and cons of each option.  We will dive into the difference between a straight knife surfacing head (Terminus) and a multi knife sheared surfacing head (Helixhead) and find out which one is right for you and your application. 

Terminus Cutterheads 

Terminus has been a force in the market since it originally came out.  With patented gibbs containing springs for quick change of knives to the 2-sided unique design of the knives in either HSS (High Speed Steel) or Carbide, this has been a favorite of S4S and moulder applications.  Whether on journals or with a through bore, Terminus cutterheads fit into several applications for straight cuts. 

Because the insert is straight and held to a tight OD tolerance within the cutterhead and the tolerance radially, your cut will always be straight.  No little knife marks or shadow marks because the cut is not broken up.  Just a flat cut from one side of the board to the other.  The drawback to a cut like this is that the material can experience some blowout when the cutterhead disengages the material.  This depends on many factors including how much material is being removed and what type of material is being cut.  Since the cut is also straight, the chips produced will be larger (not small fine dust).   

Using the spring/gibb system in all the Terminus cutterheads, changing knives is fast.  The slogan isn’t “Quick Change” as a gimmick.  A push down with a little force and a slide into the crevice of the cutter, allows for the knife to easily come out to be rotated to the second side or replaced with a new knife.  Gibb then slides back into place, capturing and centering the knife back to that tight radial tolerance (in line with all the other knives).  

Another unique ability of the Terminus system is that the knives are produced with HSS or carbide. This allows users to be able to easily switch between the two based on their product needs. Running a job with some reclaimed lumber? Drop in some HSS knives to be able to take a better impact from the nails in the wood. Got a few pallets of knotty pine to run? Keep those HSS knives in to withstand the knots. Need to plane piles of clean white oak for a project or two? Switch over to carbide knives to last significantly longer.

Helixheads

Spiral designed cutters have been in the industry for a long time. Using industry standard 4-sided inserts (ICKs as many refer to them as) these cutters create a spiral effect across the cut length, breaking up the cut into smaller particles and guiding those chips to the direction of your dust hood. Helixhead takes this idea to the next level. Using a true shear design, the inserts don’t come directly at the material like spiral cutters of the past; instead, they slice the material at a shear angle. This superior geometry comes with many benefits.

Breaking up the cut by using multiple knives with overlap already creates smaller, manageable chips. With the Helixhead shear engaged, those chips become even smaller, into almost wood dust. Those smaller chips become easier to manipulate to a dust hood and easily drawn in to any extraction system. Using a V design with the shear, allows Helixhead to manipulate the dust to the center of the tool where many of the planer and jointer extraction systems are placed. This keeps the board cleaner as the cutterhead planes off the material, extending the life of the knives.

Another boon that is generated from the shear and overlapping inserts is the vast reduction of sound. Every customer who has switched from a straight wing planer to a Helixhead planer has noticed the sound level drop off in their shop. Truly a night and day difference in decibel levels.

Helixhead design uses the woodworking industry standard 4-sided ICKs in all the heads. This standardization ensures that customers will always have the ability to acquire these knives quickly and cheaply from H3D Tool Corp or any other tooling distributor. Proprietary inserts stunt growth and progress in our industry. Not only are these inserts readily available, but they hold a tight tolerance and are made from high grades of carbide. With these and the breakup design with shear, ensures that that these knives will outlast a straight knife in comparison applications.

OEM Straight Surfacing Heads

Various styles exist for OEM surfacing heads from straight wing knife designs to proprietary segmented carbide tipped cartridges.  Too many to go into full detail on so we will examine a few of these that are more common. 

Straight knife heads come in many forms and shapes.  Some are just straight knives that have no holes in them.  These drop into the heads and must be tightened down with gibbs pressed against the knives.  Pockets need to be cleaned out and the knives setup to be flat and level or a bevel will develop during the cut.  These knives can be sharpened but then would need adjusted in the pocket during the next run.  And all knives must be sharpened at the same rate or setup will require tweaking each pocket and knife individually of each other before running or checking.  If not, one wing could be doing all the work during the cut.  This type of engagement wears out a knife faster, creates several decibels of sound bad for one’s hearing and creates an inferior cut quality in the product.   

Other straight heads have cut outs or various holes for alignment for the gibb systems in the cutterheads.  These holes help line up the knives for straightness and ensure safe operation in the heads.  They are often thinner than other style knives and only come in steel.  So, the run time during strenuous jobs has an operator changing out knives more often.  Knives like this are also either proprietary themselves or harder to acquire as they are only produced by a limited number of manufacturers.   

Segmented heads seem like they are a good solution to moving away from steel knives and being able to have a twist in the cut to increase quality and reduce noise.  The biggest drawback on these heads is that an operator must sharpen these knives themselves with a system setup within the planer.  This is a task that could take hours or days to accomplish.  If a knot, nail, screw or anything chips or damages one of the segments on the cutter, the whole head needs to be ground down to the lowest point to ensure that the cut is straight and flat.  The other only option would be to replace the segment and then grind it down to match the other segments, which is not a quick or easy task to accomplish and get correct.  When all the segments get too low, they either need replaced or retipped and then ground back down again so they continue to match.  This is very time consuming and hard to get accurate.  The downtime to a company who wants to run product can be detrimental.   

In Summary – Which head is best?  

There is no straight solution to the question.  There are, however, two options that rise above in the industry depending on what is important to the operator and product.  Both Terminus and Helixhead bring the best design and technology to our ever-changing industry.  Terminus has the appeal with the ability to run carbide or High-Speed Steel (HSS) knives, with downtime being next to nothing due to the quick-change system.  And the quiet cut of the Helixhead with the fine dust chips flowing nicely into the dust extraction system, with the multi-knife shear cut design.  Both use readily available and industry standard knives so that a customer is never down or waiting on knives for their next job. Instead, they can stay focused on what matters most running their next job efficiently and productively.  

If you’re evaluating surfacing head options or planning your next tooling upgrade, the team at H3D Tool Corp. is available to discuss your application and help you select the right solution.