Replies

1. 
   user-148830 | Jan 23, 2007 07:42pm | #1

   George,
   There are articles I’m sure in the FWW archives about setting jointer knives. Ask Matt Berger if he can direct you to one.

   Here’s the quick version of setting knives. I set my knives in the cutterhead using the magnetic setter and a dial indicator to get my knives within .001" of each other. That is they are set about 1/8" above the cutterhead surface and all heights almost exactly equal. My magnetic setter rests on the two tables aligned evenly with one another. It gets the knives close but not perfect relative to one another. That’s why I use the dial indicator to line them up almost perfect. Then lock them down tightly.

   Next, and this is the important part, you adjust the outfeed table to line up perfectly with the knives at Top Dead Center. This will prevent tapered cuts or snipe. Just remember that these are two separate jobs. Set the knives first and then align the outfeed table to them. Good luck. Gary

1. 
   GFree | Jan 23, 2007 10:02pm | #2

   Gary;

   Thank you for your quick reply. The difference between your magnetic setter and mine is that yours is based off the in-feed and out-feed tables whereas mine is based off the cutter head. My question deals specifically with the setter being based on the cutter head.  The setting magnets actually rest on the cutter head on each side of the blade with a bar and magnets in-between to set the blade to.  Does it seem to you to be an acceptable base (the cutter head) to set the knives to as opposed to setting them based on the in/out feed tables?

   I have looked in the archives and have not seen a discussion on this type of magnetic setter. The discussions I see discuss your type of magnetic setter.

1. 
   user-148830 | Jan 23, 2007 10:59pm | #3

   George,
   Your method will work fine. It’s probably more accurate. I have a cutterhead gauge for my planer knives that works very similarly. My jointer table method does not really set the knives to the tables. It sets the knives so that they are consistent just like your method. I just happen to use the tables as a reference no matter how high or low they are. But after I’m done setting the knives, I have to readjust my outfeed table to the cutterhead at top dead center. I hope that’s not confusing. In any event, I think your gauge will work fine, just reset your cutterhead to your outfeed table after the knives are set. Good luck. Gary

2. 
   JohnWW | Jan 23, 2007 11:14pm | #4

   Let me see if I can help out here.

   The answer is no, you cannot set the knives on a jointer with a jig that references to the head, you need to set the knives to be parallel to the outfeed table.  The jig you have is for setting the knives on a thickness planer.

   The head on a jointer may, by sheer luck, be perfectly parallel to the outfeed table, but manufacturers know that this isn't a necessity and so they don't try to get the machining perfect and most makers don't include anything in the machine's design to allow adjusting the head to be parallel after the machine is assembled.

   In all this I'm discussing the most common type of jointer, ones with sloped dovetailed ways and conventional knives.  Jointers with a parallelogram system under the tables can be adjusted to bring the tables in line with the head, which is a necessity on machines with disposable knife heads where the height of the knives is preset and can't be adjusted.

   John White, Shop Manager, Fine Woodworking Magazine 

2. 
   MBerger | Jan 24, 2007 12:27am | #5

   I'll add another voice to this chorus.

   Here is a video demonstrating a really great jig that John White came up with for setting jointer blades. It is should go along well with John's answer above.

   Matt Berger
   Fine Woodworking