Replies

1. 
   philip | Nov 27, 2009 12:41pm | #1

   it is not critical, as long as there is sufficient clearance angle so you can grind an angle of between 30 and 40 degrees as you like. The higher angle gives a stronger edge.

   Philip Marcou
2. 
   KeithNewton | Nov 27, 2009 05:13pm | #2

   I agree with Philip mostly. The angle which the knife is set in the head should be considered, and weighed against the kind of wood that you use most of the time.

   There is an ideal cutting angle for most species of wood, which can be found here. http://www.woodweb.com/knowledge_base/Knife_Grinding_and_Woodworking_Manual_5.html

   Since the knives in my 12" jointer are set at 30º, which would be best for softwoods, but I use hardwoods mostly, so I grind a 20º face bevel, to get the cutting angle down to 10º. This lower cutting angle eliminates the tear-out on highly figured wood, like fiddle-back.

1. 
   alanplanesaw | Nov 27, 2009 06:44pm | #3

   Phillip and Keith,

   Thanks for the info.  I should have included some additional info, in case that makes a difference.  When I bought the jointer, I bought an extra set of blades.  Actually, my intent last night was to put on the extra set as the originals are dull.  Looking them over, I realized the angle (on the blade itself) was steeper than my chisels (not that that should have any particular meaning, but it was an observation that got me to realize I should check and see what the angle on the jointer blade had been ground). 

   So, I measured the angle and found it was ground at 40 degrees, with what appears to be a microbevel. 

   I have learned to sharpen/hone most things in my shop. (Even learned that if I hone my Stanley utility knife periodically I have a much much sharper knife and I don't have to change blades very frequently.)  My intent is to try to sharpen and hone the now dull set of jointer blades, using either the Veritas jig or a Tormek.  

   So, if I am understanding what you are saying, the angle could vary from one machine to another, depending on the angle it approaches the wood.  Is that correct?

   Thanks,

   Alan - planesaw

   PS -- As Keith may remember from my visit to his shop, I am certainly not a pro like the two of you.  My work/career is with people, but woodworking is my "therapy" and I am lucky to be half-way decent at it.  I just don't get enough therapy.

    

    

    

   Edited 11/27/2009 11:20 am ET by Planesaw

1. 
   philip | Nov 28, 2009 11:33am | #4

   Plane,
   "So, if I am understanding what you are saying, the angle could vary from one machine to another, depending on the angle it approaches the wood. Is that correct?"
   That is so- it depends on the maunfacturer and the intended use for the machine, so the angle at which the knives are slotted into the cutter head can vary. There is a broad distinction between a cutter head designed for use on soft woods as compared to one for use on hard woods.
   This is or was the situation regarding industrial machines, but I don't know what the Grizzily generation does or if it applies to "home use" machines of today.
   If in doubt look at your cutter head , gauge the slot angle, measure the angle at which the knives are ground at, draw a circle of same diameter as the cutting circle of the knives , draw in a knife at the slot angle and see for yourself.
   Honing knives on the head between grinds is a good idea and keeps them sharp longer-one of those diamond plates attached to a handle does the job nicely, especially if you are able to stop the head at the right angle every time.Philip Marcou

1. 
   alanplanesaw | Nov 28, 2009 04:23pm | #5

   Philip,

   Mine is an 8 inch Bridgewood with 4 knives.  Bridgewood was the higher quality line of Wilke Machinery (now out of business) and Yorkcraft was their lesser quality line.  Yorkcraft was identical to Delta equipment except painted a different color.    

   I live in Pennsylvania in what is called Amish country.  Lots of small to medium to large woodworking shops, making furniture, cabinets, etc.  One will see Bridgewood machines in a lot of them.   All the way up to $80,000 pieces of equipment.

   But, I don't know that they are a lot better than Grizzly or other imports.  At one time I would have said yes, they were.  But, Grizzly appears to have improved considerably over the past 5 or so years.  Wilke Machinery used to be about 30 minutes from me and Grizzly is about 2 hours.  Spent too many hours in both.

   However, please tell me more about honing the knives while they are on the machine.  I did buy a little device about 4 inches long for that purpose, but I have never been sure how good it is.  Would appreciate any instruction you could give on both how to do it and using specifically what sort of device to do it.

   Thank you,

   Alan - planesaw 

   (When I started on Knots there was another Alan so I added planesaw to distinguish between the two of us.  Don't know that the other Alan is still around or not.)

    

1. 
   philip | Nov 29, 2009 07:07am | #6

   Alan,
   I don't do anything fancy at all. I merely have a diamond plate with a plastic moulded handle anout 6 inches long which I use to touch up the bevel. None of my machines have the means to fix the head at a suitable angle so I just wedge the head with a piece of wood .The shape of the handle protects my fingers.Philip Marcou