Jointer Knives

[djkwoodcrafts]

I'm somewhat new to the Tormek system, and I'm having a bit of a hard time sharpening some 8" jointer knives.
Nothing fancy about my knives: 8", 40-degree bevel. I just can't get a consistent edge. What I've found is that on my SVH-320 jig there is a little bit of play between the support and the blade holder at the sliding contact point. When sharpening, this play seems to cause the support to move up and away from it's adjustment screw. This tends to close the gap between support and the blade holder causing an incomplete grind. Does this mean I just need to continue sharpening until the support again contacts the adjustment screw? I've been working at this blade for 30 mins and it seems like I'm getting no where. I want to make sure the play between the support and blade holder is normal.

Thanks!
DJK

[Jeff Farris]

.... Does this mean I just need to continue sharpening until the support again contacts the adjustment screw? I've been working at this blade for 30 mins and it seems like I'm getting no where. I want to make sure the play between the support and blade holder is normal.

Thanks!
DJK

That is exactly it.  Everything should be in contact when you set your zero point.  Then, when you set your depth of cut the gap will appear either between the blade carrier and the support beam or between the support beam and the bevel angle adjustment screw.  It doesn't really matter where it shows up, and if you fiddle with it a little you'll see that you can make it appear either place just by adjusting the pressure points.

If the grind is taking a long time, reactivate the stone with stone grader.  Tip it on edge so that only the corner is engaged and use some pressure.  If the stone shows any staining, it is not cutting as efficiently as it can.

[djkwoodcrafts]

Well, I kept regrading the stone every 10-15 mins, and finally got a full grind...
But now the knives aren't straight. They're about 1/128" low off the ends.
Is there a trick to keeping the knives straight? After 4 hours of grinding these knives, my stone is now humped in the middle about 1/128" to the sides. Do I have to go through the whole process of re-truing and re-finding zero and then resharpening to get the knives straight?

[Jeff Farris]

The stone does have to be straight and concentric.  Also, if you're finished blades are overground on the ends your depth of cut is probably set too deep.  The depth of cut should bottom out so that it would be impossible to have anything other than a straight grind.

[djkwoodcrafts]

Thanks Jeff, that was it. A little too deep on the cut.