This is my DW735 planer from Dewalt.
This is it’s 3 knife cutter head that it comes with.
And this is the Shelix cutter head upgrade made by Byrd Tools. As you can see the shelix head has a series of smaller carbide inserts. Each insert has four cutting faces so if they get dinged up or just lose their sharp cutting edge they can be rotated 90 degrees to show a new cutting edge.
I’ve got a bunch of hickory cutting board blanks that I glued together some time ago and never planed them because hickory seems to dull the straight knives really quick. These will be good sacrificial material to run through the planer before and after the upgrade to not only see how the cut surface compares but also to measure the noise output of the planer.
Each of these cutting boards is about 10” wide and for consistency sake I marked the face and direction for the straight knife cut and the shelix cut.
This is my setup to measure the noise output. I downloaded a sound meter app on my phone and used a clamp in my leg vise to hold the phone in a constant position about 5 feet from the planer. I’m not sure if this is the correct distance to measure and I’m not sure how accurate the sound meter app is but in this case I really don’t care because I’m trying to get a relative reading and not an absolute reading.
It’s also important to note that one revolution of the depth wheel on this planer will remove 1/16” of the material thickness.
To document the noise levels I have the camera positioned so that the planer depth wheel, sound meter, and whatever cutting head that is not installed can be seen.
With just the air conditioner running in the shop I’m getting a reading of 19db.
With the air conditioner and the air cleaner car running I’m getting a reading of 54db.
There will be a lot of redundancy if I continue showing pictures to show the results so instead I’ll show a results graph in just a minute. Check out the video if you want to see the live readings as material goes through.
After taking readings of the factory cutter head a friend and I started disassembly. I’m not going to cover the entire process for installing the new head as it’s incredibly easy and already well documented online.
There are two different diameter shelix cutter heads for this machine. The larger diameter is the same size as the factory head and requires each carbide insert to be removed prior to installation and the smaller diameter is 1/16” less than the factory head and it can be installed with the carbide inserts already installed. That means the factory depth indicators, that I never used, are off by 1/32″. This one is the smaller diameter. Once the new head is in everything is repeated in reverse.
My first impressions with the machine were that it sounded like the motor wasn’t struggling as much with the hickory. There was a noise reduction as you can see from the chart.
It’s really hard to show surface cut quality on camera. The knives on the factory cutter head were relatively new so I was expecting a decent cut quality from them but I know just how quick those blades get dull. On this hickory the straight knife cut and the shelix cut looked identical but the shelix cut felt slightly smoother to the touch. The hickory ended up not being as good of a test as I had hoped for.
So to test something different I ran a piece of curly maple through the planer after the shelix was installed. I know from experience that the original three knife setup leaves a surface full of tearout on curly and figured wood.
The results definitely made me smile. I could not find a single area of tearout on the board even after running a few different passes changing the depth of cut.
There’s three main upgrades when installing this shelix cutter head in the DW735.
- Better cut quality on difficult to plane woods.
- It’s not as obnoxiously loud when cutting. This helps but isn’t a huge concern for me as my dust collector is louder anyway.
- Longer blade life. This is the biggest thing I’m looking forward to. I’ve owned this planer for about 5 years now and I don’t want to even calculate the amount of money I’ve invested in replacement blades. The blade life has been my #1 complaint since day one with this planer.