Very soon, like in a few minutes I am going to do a review on my little 150x200 planer thicknesser, this tool does the job, I get no snipe becouse I don't give the cut "too much wellie" if I do inadvertantly then snipe occurs, so keep it down a bit!!!

Derek. 

In a previous life i was in engineering and in that time i took on a lot of tool & cutter grinding.

The reason a "helix is put on the cutting edge of tools such as slot drills router cutters & planer blades is to reduce the amount of cutter in contact with the work piece thus reducing chatter and horsepower required to drive the cutter.

Hi Baz, I was looking through that book last night (Popular Mechanics: Jointer & Planer Fundamentals) but it doesn't have as much information as I was hoping for. It briefly mentions that these "spiral" cutter blocks (assuming I am thinking of the same thing...) are available (in America) as a replacement for standard blocks.

I did pick up a couple of goods tips though...

One common problem people sometimes encounter involves the knives shifting as you tighten the bolts in the cutter block. The author of this book suggests you file the heads of the clamping bolts and the bar faces to remove any burr.

If you're having trouble with tearout while edge-jointing and, you don't have a spiral cutter block, they recommend you fix a tapered piece of timber to your fence so that you're feeding at a skew-angle across the knives. I'm sure most of you have tried feeding the timber through a thicknesser on the skew at some point.

They also go in to detail on how to create raised panels with a surface planer - but, I won't even go there!!