Jointer knife replacement

[rdewinter]

I just replaced my jointer knives with new ones purchased from SS. I am not real happy with the results. I get a lot of vibration with the new knives and sometimes a little tear out at the end of the board. Any tips on installing and aligning the jointer blades? I did a search in this SS forum and found reference to a jig called Jointer Pal, but I can't seem to find any info about it. Any help would be appreciated as I have a lot of white oak that needs to be squared up for a project.

[billmayo]

Please see the following post http://www.shopsmith.net/forums/showthr ... ner+knives
An excellant jig for quick and easy setting setting of the joiner knives was discussed. Stiil on my to do list.

[JPG]

I just replaced my jointer knives with new ones purchased from SS. I am not real happy with the results. I get a lot of vibration with the new knives and sometimes a little tear out at the end of the board. Any tips on installing and aligning the jointer blades? I did a search in this SS forum and found reference to a jig called Jointer Pal, but I can't seem to find any info about it. Any help would be appreciated as I have a lot of white oak that needs to be squared up for a project.

Are all three knives set to the same height at both ends?

[dusty]

I just replaced my jointer knives with new ones purchased from SS. I am not real happy with the results. I get a lot of vibration with the new knives and sometimes a little tear out at the end of the board. Any tips on installing and aligning the jointer blades? I did a search in this SS forum and found reference to a jig called Jointer Pal, but I can't seem to find any info about it. Any help would be appreciated as I have a lot of white oak that needs to be squared up for a project.

"A lot of vibration" and "a little tear out"

These are not symptoms of jointer knives that have simply been adjusted improperly.

I would start all over by removing the blades and all the screws from the cutter head and then performing a thorough cleaning. I assume that there was NO vibration before the blade change.

Put the blades back in setting them as deep as you can into the cutter head, secure them and test for vibration. You could also test for vibration before the blades are reinstalled.

Obviously, if there is no vibration, there is the task of realigning the blades which can be very time consuming but when done properly is very satisfying.

The tear out is another issue all together and is most likely not a function of blade alignment. Does it happen on all woods that are jointed?

[benush26]

"A lot of vibration" and "a little tear out"

These are not symptoms of jointer knives that have have simply been adjusted improperly.

I would start all over by removing the blades and all the screws from the cutter head and then performing a thorough cleaning. I assume that there was NO vibration before the blade change.

Put the blades back in setting them as deep as you can into the cutter head, secure them and test for vibration. You could also test for vibration before the blades are reinstalled.

Obviously, if there is no vibration, there is the task of realigning the blades which can be very time consuming but when done properly is very satisfying.

The tear out is another issue all together and is most likely not a function of blade alignment. Does it happen on all woods that are jointed?

The last new set I bought was a very long time ago, but out of the tube they had to honed. A quick exam with a magnifying glass showed a couple small "slivers" that had to be removed, so I just honed all three pieces.

[dusty]

The last new set I bought was a very long time ago, but out of the tube they had to honed. A quick exam with a magnifying glass showed a couple small "slivers" that had to be removed, so I just honed all three pieces.

I treat nearly all cutting edges as though they need some treatment, even when brand new. I can't afford those that come finally finished and ready for use.

[charlese]

I just replaced my jointer knives with new ones purchased from SS. I am not real happy with the results. I get a lot of vibration with the new knives and sometimes a little tear out at the end of the board. Any tips on installing and aligning the jointer blades? I did a search in this SS forum and found reference to a jig called Jointer Pal, but I can't seem to find any info about it. Any help would be appreciated as I have a lot of white oak that needs to be squared up for a project.

White Oak, if really dry will chip out around the ray cells especially. This issue can be fixed by wetting the surface to be machined. On flat sawn wood, you will find these cells on the edges.

[benush26]

I treat nearly all cutting edges as though they need some treatment, even when brand new. I can't afford those that come finally finished and ready for use.

So, is it possible, that his "new" knives were dull enough to cause the tearing?

Though I'm still wondering about the vibration. Could the new blades be dull enough to make them cause a vibration?

[dusty]

So, is it possible, that his "new" knives were dull enough to cause the tearing?

Though I'm still wondering about the vibration. Could the new blades be dull enough to make them cause a vibration?

Yes, it is certainly possible. Just not my first suspicion.

[WmZiggy]

You have some good advice from others, but what the hell I will jump in too.

You might want to look at PTWFE page 124 for trouble shooting the jointer. It doesn't address vibration, but as you know that is probably from the cutterhead being out of balance - most likely from sawdust or resin buildup or material that has gotten lodged in screw holes or small places. I would run the head without screws and blades cleaning it completely with turpentine and blowing it out with compressed air. Check the balance on your blades next. Perhaps you have one that weighs more than the others. If so you could return them to SS or remove metal on the heavy one until they balance. Honing is important and you can do that from time-to-time without removing the blades. I use a tongue-depressor size stick with leather attached to it that's impregnated with honing compound. "Sniping" at the end of the board is a result of having a blade set too high. These blades are a bitch to set without some measure of sniping. Jointer-pals are your best bet. I've used the ruler method, a micrometer, but jointer blade jigs are best because of the unseen movement you get when you tighten the screws. Finally, you can get tear out from working against the grain and of course some woods are worse than others, so you have to pay attention to grain direction when jointing wood.

Not sure I've added anything to the discussion here, but you do need to address the vibration first. Getting a good setting after that is solved is second and doable with less headache by investing in a jointer blade setting jig.