I recently changed knives in my Grizzley 6″ Jointer and must of changed something else inadvertently. Now using same techniques Ive always used im getting big snipe on tail edge of the board. I mean Ive seen this on a few pcs before but now its every cut and the snipe gets bigger with every pass creating a bow in the “jointed ” edge.
The outfeed table is set to the apex of the knives in the cutterhead. Dont know where to go from here. Can hieght of blades in the cutterhead affect all this? Any Help would be appreciated. Thanks.
Replies
It sounds like you know what you are doing. Make sure that the leading edge of the knives are top dead center when you use a straight edge to align the outfeed table. Also, check that all the knives are set to the same height, though I doubt this is what is causing you grief.
Chris @ www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Tree,
". Now using same techniques Ive always used im getting big snipe on tail edge of the board. "
That shows that the outfeed is below the top of the cutters i.e below the top of the cutting circle described by the cutters/knives.
You need to either raise the out feed or re-set the knives. If you can prove that all knives are projecting equally from the block, and in the same plane as the tables then it is best to raise the out feed-if you have any adjustment left.
How did you determine the position of the knives in the block?
If you are really cutting a bow on your jointed edge you have a sagging issue with your jointer tables. They are not dead flat. That can be checked with a straight edge when the tables are brought up even with one another. There should be no gaps on the ends of the jointer tables. Check with a feeler gauge. The snipe is caused by the knives being higher then the outfeed table. This is very easy to check. Take a piece of flat stock with a square edge and sit it on edge across the cutterhead. When the knives touch the edge of the wood make a pencil mark on the board at the cutterhead edge of the table. Now spin the cutterhead until the knife goes below the infeed table. If the pencil mark moved more then 1/4" your knives are too high. Check all three knives. This is all done by hand with the machine unplugged.
If the knives are set to high in relation to the outfeed table they will cause snipe AND create a convex bowed edge or surface. If the bow is concave then there is likely a table sagging issue. Since the OP was not having problems before then it is most likely that the knives are too high. If they all are equal then the easy fix is to raise the outfeed table just untill the snipe disappears. Allways adjust the outfeed table final position by raising it to that spot rather than lowering. That takes out any freeplay or slack in the works.
RichThe Professional Termite
Rich,I always assume the knives are too high when the jointer is cutting a snipe. I like to check each knife at each end with the 12" block of wood to make sure they are set right end to end. One high knife will throw it all off as well. I always check for sag, but it is almost always the knives are set too high. If you are lucky they are all too high and you can use John Whites demo and raise the outfeed table. If the knives are all off, get out the wrenches.
wow thanks for all response/ think ill concentrate on knive height and eveneness as nothing else was changed during changeover of new blades.
Did you resolve this? How?
Ill get a chance next couple days.Interesting someone else had problem witjh Jet jointer setup. I know it was me tho probably since it only happened after i changed blades.
I'm sure you have checked this but just in case. I adjusted my PM to work just perfectly. The next time, just a little snipe. The next time more snipe...... I found out I'd neglected to lock the outfeed table. Guuuuuuuu.
Think i found the problem. One of the knives was canted in the holder so it was a bit higher on one side than other ... and outfeed table was set to TDC of the other lower ones. Plus the springs in knife holder were missing which i amazingly found under jointer (and keep that area pretty vacuumed. Works alot better now; thanks for everyones help!
John White knows everything. Here's a video on how to do it:
http://www.taunton.com/finewoodworking/subscription/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=31033
I have had the same problem on a Ridgid 6" jointer the first time I sharpened the knives. I used the knife setting jig that came with it and tried like heck to adjust the outfeed table. It simply didn't work, so I bought a magnetic knife setting jig for jointers. I removed the springs from behind the knives and set them using the magnetic jig. The results were perfect the first time. I have used it several times with perfect results every time. The magnetic jig is way quicker and easier too.
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