I received a fax advertisement from Sunhill a few days ago which may be
what you saw. I called to talk to them about the spiral and helical
cutterheads and the guy I spoke with wasn't particularly knowledgeable.
The spiral ones they sell are HSS blades arranged spirally. The helical
ones are made by Byrd and I then called them to ask a few questions. I
ended up speaking with the VP. They call their design the Shelix and it
is similar to other spiral cutterheads, such as Grizzly's, except for
one thing. While both have individually replaceable square carbide
knives, the Shelix knives are arranged in spiral fashion such that the
knife edges are parallel to the helix on the cylindrical cutterhead
(so-called helical, like DNA), whereas the Grizzly one has knife edges
parallel to the long axis of the cylinder (so-called spiral). The
helical one is supposed to shear the wood and significantly reduce
tear-out, particularly noticeable on figured woods.

I learned that they design and manufacture/machine the cutterheads
themselves in Kentucky on a CNC unit and make several versions for
various machines. They made a DJ20 version a couple of years ago at the
request of a woodworker in Ohio, who sent them his factory cutterhead
as a template. I spoke with him and he swears by his new helical
cutterhead. Byrd is selling them for a hefty $445, so I doubt I'll be
buying one anytime soon.

Having just pulled my DJ20 cutterhead to replace a damaged table lip,
the installation process seems like it would take only 20-30 minutes or
so.

Hope this is helpful.

Stu

In article , max
wrote:

The cheaper spiral one is from Taiwan and the Helical one is made by Byrd. I
checked on ordering one for my 50's Rockwell Crescent 4 knife jointer. The
Taiwanese ones fir the standard models currently available. The Helical one
comes in two models, the standard one and then they make one for the older
Rockwell and Delta machines. Byrd is very nice to deal with. Sunhill on the
other hand tried to be helpful but didn't really listen to what I was asking
and I lost a lot of time.
max


"Winthrop Chan" winthrop_chan at hot mail dot com wrote in message
...
I was browsing the Sunhill Machinery website the other day and I noticed
this:

http://www.sunhillmachinery.com/Spir...Conversion.htm

It seems to be a conversion kit to convert my Jet (and other brands) of 6"
and 8" jointers from standard blades to either a spiral or helical
cutterhead. What I want to know is has anyone tried one of these and what
do they think about it? The helical looks more like what Grizzly sells on
their higher end models, but the 6" spiral jointer cutterhead is only $150
upgrade (which is easier to sell to the SWMBO than the $320 helical
cutterhead conversion kit).

Thoughts?
-Winthrop


IIRC Steve Knight of Knight Tool Works just installed a helical on his
jointer. Do a google search on his name and it should come up. This was a
recent thread within the last month. I think he went with a different
vendor.

David