July 1, 2022

Helical Jointer vs Straight

As much as the helical and straight jointer are more identical than different in design and functionality, one should pay more attention to their differences before choosing one. The differences are in blade types, dust collection systems, noise levels, and prices. Take a quick look at the reviews below, matching each tool’s feature with your needs before making a final decision.

Helical jointer

The helical jointer is a jointer with machined screw holes that wrap around the head. The jointer comes with multiple knives that run in a spiral pattern and are much quieter than a straight knife planer. Sharpen the inserts on either 2 or 4 sides. 

You can turn them rather than sharpen them. Flip one or two if you get a kick rather than replacing the knife. The jointer cuts through any wood. Chances of an excessive tear-out are low, unlike when using a standard planer and IMO. 

It makes little wood chips that do not clog up your dust collection system like the large spiral shavings a regular planer makes. When you change the inserts, they are all indexed to a specific place. There is no adjusting or special tools required to set it up. 

Use the screw as you put in a new insert and put the screw back. Using a spiral head cutter does not come with a chopping effect, unlike straight cutter heads that come with small ripples on the surface of your workpiece as it comes out with the spiral head.

It comes with a powerful motor and features high-speed steel insert knives. Its models range from rigid, all-metal construction, machined aluminum tables, a quick depth setting mechanism with scale, and an adjustable fence that tilts from 90 degrees to 45 degrees. It has a spring-loaded safety guard and a front on/off switch.

Pros

  • Smooth cuts
  • Carbide inserts stay sharper long
  • Inserts are easy to replace
  • Less dust collection

Cons

  • Not affordable to upgrade 
  • A bit complex

Straight jointer

A straight knife jointer has 2 or 3 knives that run the length of the cutter head, unlike a helical head, which has multiple knives that run in a spiral pattern. The jointer knives cut the wood fibers and take off the material. Its popularity is based on the fact that it has been around for a while and is affordable.

Straight knife blades are the traditional cutterheads that make straight jointers. However, it comes with its drawbacks. It is quick to tear out, the knives are harder to adjust, and it requires more sharpening due to the knife that can chip and cause a ridge on the wood. 

One of their advantages is that they are more affordable than spiral cutter heads. However, straight knife cutterheads cost more over time because they require more maintenance and replacement than carbide inserts. The process of sharpening straight knives and replacing them is time-consuming and difficult. 

Spiral cutterheads are easy to maintain and have a longer use life since all you need to do is rotate the bit to a new edge once the older edge has dulled. A straight jointer uses straight knife heads. They take less power and still remove more stock with the same motor. That is when the knives are sharp. It takes me about an hour to change jointer knives in a straight jointer. That is, if there are no other adjustments required. 

Changing straight jointer knives is a challenging process that requires skill. You need to set your gauge to the height of the existing knives, then put the new knives to that same dimension. The process requires two sets of jointer knives. You need someone around to show you the process.

Pros

  • Affordable 
  • Smooth cuts
  • Easy to maintain 
  • It requires less power

Cons

  • Loses sharpness faster 
  • Large shavings result in more dust

Favorite Features

Knives

Helical cutters make smooth cuts, make less noise, and keep carbide edges sharp for a long time. A straight knife jointer has 2 or 3 knives that run the length of the cutter head, whereas a helical head has multiple jointer knives that run in a spiral pattern. These are quieter than a straight knife planer. 

Straight knives require less power. The helical cutters have a small surface in contact with the wood. The jointer knives are not in constant contact with the wood, but it is along a long surface when it is in contact.

Cutterheads

Helical jointer

Spiral cutter heads are the new and improved blades for jointers (Wahudatools.com). Helical cutter heads operate quietly, unlike the conventional straight knife cutter that takes one big bite of wood three or four times per rotation when the knife contacts the wood. Helical heads have inserts around the circumference of the head. In the end, only one or two inserts are in contact with the material at any time. The result is dramatic. By installing a helical cutter head, machine noise is reduced by almost 50 percent.

Spiral cutter heads are an improved blade for jointers. This innovative technology inserts tooling to make smooth cuts and maintenance. The design comprises a row of carbide cutter head inserts wrapping around a steelhead. That is where the name spiral came from. 

Another version known as helix design uses fewer inserts per row and wraps around the steelhead with less of a curve. Newer jointer models may be outfitted with spiral cutter heads, but you can upgrade your older jointer by replacing the cutter head.

Safety guard

Both jointer machines have a spring-loaded safety guard and a front on/off switch. Using the correct blade for your jointer machines also keeps you safe, even if there is a safety guard. Safety guards are physical barriers that enclose dangerous machine parts such as blades and prevent user contact with them (Rit.edu). Adjust all the parts upon the arrival of the jointer since it is prone to move during shipping. 

What could be better

Helical jointer

It could have more affordable models.

Straight jointer

The shavings could have been smaller for an effective dust collection system.

Similar Features

  • They both use cutterheads.
  • Less vibration is what you get. 
  • Both have an infeed and an outfeed table.
  • They use an adjustable fence.
  • They both have a function that raises and lower the infeed table to set the depth of cut.
  • The knives are fixed in a rotating cutter head that sits between the infeed and outfeed tables.

Key Differences

  • A straight knife jointer has 2 or 3 knives that run the length of the cutter head, whereas a helical head has multiple jointer knives that typically run in a spiral pattern.
  • The straight jointer is more affordable than a helical jointer.

The verdict

When it comes to jointers, helical and straight jointers have more similarities than differences. They use different knives and cutter heads. They flatten out cupped boards, remove twists, and prepare board edges so they can be glued together. For a smooth operation with minimal to zero vibration, go for a helical jointer. It also produces minimal dust. If you are working on a slim budget, consider the straight jointer.

David D. Hughes
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