Andy Sowers
10-27-2008, 12:25 AM
I've had the Rigid 6 1/8" jointer for about a year now, and a few months ago I noticed that there were ridges produced, esp when face jointing. So, I figured that at some point the knives had gotten nicked and it was time to get the knives sharpened. While I figured out where to get the knives sharpened locally I decided to buy a set of spare knives from Global Tool Supply since they were pretty cheap...
Well the knives arrived a few weeks ago, and I figured this weekend was the time to replace them. I've never had the "pleasure" of aligning the knives, and I've been agonizing over how painful this was going to be.
My first attempt met with dismal failure. I tried using my Lee Valley precision straightedge to align the tops of the knives with the outfeed table by rotating the knives and adjusting until they just "kissed" the straight edge. But after cinching everything up, the resulting "quality of cut" was horrible. There was a more "chatter" while running a sample board through, and when I was done, there were several grooves running lengthwise along the board... worse than it was before I had even started. This brings me to question #1...
1) Do these replacement knives need to be sharpened first before use? I didn't think these were like hand plane or chisel edges which need to be sharpened before use... was I wrong?
Figuring that I must have done something wrong I went back to check the height of each of the knives again. Gasp... a least one of them was much higher than the other two... I know I must have checked each a hundred times before tightening the locking screws down. After loosening everything up, I confirmed that yes, each of the knives was set properly, but that the act of tightening up the four locking screws was causing the knives to go out slightly as I tightened them up. This brings me to question #2...
2) Just how does one go about tightening the locking screws without throwing the knives out of alignment. I tried tightening them slowly alternating between the four, but that met with only partial success... it took several tries to get it tightened up... I may be tightening these too tight?
My final pass after reworking the height of the knives was much better. The "chatter" was gone and things seemed to be much as they were before. However, I can still see a tell-tale set of grooves in the face of the board... you can't really feel them if you run your fingernail across the width of the board, but you can see them... I checked the new knives (after installation) to see whether I could see any nicks in them but they still look good to me. (but as an aside, the old knives I took out also didn't show any signs of nicks, just overall wear). This brings to me my final question...
3) Any ideas why grooves are still present?
Thanks
Andy
Well the knives arrived a few weeks ago, and I figured this weekend was the time to replace them. I've never had the "pleasure" of aligning the knives, and I've been agonizing over how painful this was going to be.
My first attempt met with dismal failure. I tried using my Lee Valley precision straightedge to align the tops of the knives with the outfeed table by rotating the knives and adjusting until they just "kissed" the straight edge. But after cinching everything up, the resulting "quality of cut" was horrible. There was a more "chatter" while running a sample board through, and when I was done, there were several grooves running lengthwise along the board... worse than it was before I had even started. This brings me to question #1...
1) Do these replacement knives need to be sharpened first before use? I didn't think these were like hand plane or chisel edges which need to be sharpened before use... was I wrong?
Figuring that I must have done something wrong I went back to check the height of each of the knives again. Gasp... a least one of them was much higher than the other two... I know I must have checked each a hundred times before tightening the locking screws down. After loosening everything up, I confirmed that yes, each of the knives was set properly, but that the act of tightening up the four locking screws was causing the knives to go out slightly as I tightened them up. This brings me to question #2...
2) Just how does one go about tightening the locking screws without throwing the knives out of alignment. I tried tightening them slowly alternating between the four, but that met with only partial success... it took several tries to get it tightened up... I may be tightening these too tight?
My final pass after reworking the height of the knives was much better. The "chatter" was gone and things seemed to be much as they were before. However, I can still see a tell-tale set of grooves in the face of the board... you can't really feel them if you run your fingernail across the width of the board, but you can see them... I checked the new knives (after installation) to see whether I could see any nicks in them but they still look good to me. (but as an aside, the old knives I took out also didn't show any signs of nicks, just overall wear). This brings to me my final question...
3) Any ideas why grooves are still present?
Thanks
Andy