Question
I'm looking into putting a helical head into our jointer, but am worried about the smaller blades leaving small lines due to even a minimal difference in height when putting in replacement cutters. We do a lot of face to face gluing of solid wood and even a small line above the surface could create a bad joint.
We have a Terminus head now and are not too happy with it. Blades dull too fast and angle of head doesn't seem to be same as compared with the other cutter head. Any insight into the helical heads would be appreciated.
Forum Responses
(Solid Wood Machining Forum)
From contributor J:
We played this game before. Right out of the box, you can't beat them. If you replace the inserts yourself, you are most likely to get those lines you are talking about no matter how careful you are inserting the new ones. If they can be resharpened on the head, then you are in good shape again, but most companies will only sharpen those once or twice depending on the condition. Plus it is quite costly.
However, before you give up on the idea, see for yourself. Even with the lines you should get a decent glue joint. The lines are visible, but face gluing, I don't think it would be a problem. Especially if you replace them all at the same time.
I have a Byrd head on my planer, and just ordered a custom Byrd head for my facing jointer. I got better results - less noticeable line pattern - after I rotated the inserts myself. Getting the remnants of machining dirt off of the seats made the difference.
My edge jointer still has straight knives, but even there, you get some very light scalloping due to the cutting circle, especially if you feed at a decent clip. This doesn't seem to affect the edge gluing.
On the other hand, contributor M testifies to the plus side of helical heads. Reduced noise is another distinct advantage!
One thing I have run into over the past few years having a bigger impact on these type of heads leaving lines or raised areas: using cheap import grade inserts. I have found that spending a little extra on Western European manufactured inserts makes a big difference in the end resulting cut. The European inserts have higher tolerances in thickness, hole location and carbide material itself. It would be like buying a brand new Mercedes, then turning around and putting the cheapest tires you could find on it, then wondering why you're not getting the handling performance you'd expect.
Comment from contributor A:
We use 3 Terminus heads in our molder as well as the insert small knife heads. We use rounded edge inserts and check on a comparator to see if there is a high knife then adjust. These are wonderful heads and do the job.
