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Problem with jointer knife sharpening guide
Posted: Mon Oct 26, 2009 12:57 pm
by mindpilot
Just purchased the 555471 Planer/Jointer Knife Sharpener. I had a heck of a time getting the blades to set in the jig straight. After the realization that I was grinding one of my knives nice and crooked at about the same instant the knife exited the jig and shot across the shop, I took the jig apart.
The spring washers that raise the clamping bar are way too big and can slide under the back edge of the knife.
The washers don't seem to add that much functionality; at least not enough to warrant spending any time in the same room with flying knives. I remanded them to the random hardware I may need someday bin, and I now have square and sharp, although slightly narrower, jointer knives.
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Posted: Mon Oct 26, 2009 1:15 pm
by doug45601
This is an old issue... Been discussed several times yielding the fact that the spring washers are much to large. Shopsmith is aware of our concerns but has not made any changes to what they are selling. Do a search on this site and you'll find lots of discussion.
Posted: Mon Oct 26, 2009 1:15 pm
by dusty
mindpilot wrote:Just purchased the 555471 Planer/Jointer Knife Sharpener. I had a heck of a time getting the blades to set in the jig straight. After the realization that I was grinding one of my knives nice and crooked at about the same instant the knife exited the jig and shot across the shop, I took the jig apart.
The spring washers that raise the clamping bar are way too big and can slide under the back edge of the knife.
The washers don't seem to add that much functionality]6313[/ATTACH]
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I've got to take some pictures and then I'll post the balance of this. Until then, let it be said that the washers are the size that is called for (they are not too big). I'll also search for a much earlier thread on this same subject. This is a repeated problem that really should be addressed in the literature that comes with the guide.
Well, darn!
Posted: Mon Oct 26, 2009 1:39 pm
by mindpilot
I thought I had made some great original discovery.
Posted: Mon Oct 26, 2009 2:04 pm
by beeg
Thanks for that!
Posted: Mon Oct 26, 2009 2:30 pm
by mindpilot
I got good results leaving the washers out; but I will see if I can get a couple of 7mm washers next time I'm at the hardware store. I also noticed the tendency for the guide buttons to catch on the fence. I think the next time I have to use it I will attach something to the fence to give the guide a better surface.
And yes, grinding three blades at once without knowing the washers were there did result in three different blades!
Thanks for bringing this back up
Posted: Mon Oct 26, 2009 8:07 pm
by kd6vpe
I have had this sharpener for awhile now and have not used it. I have spare set of knives and need to work on sharpening my old set. I would have probably never noticed this until it was too late also. I was planning on doing all threee knives at the same time. Now I will go and check to see what I have. Thank you again you guys for the continued updates this forum is such a blessing.

Posted: Mon Oct 26, 2009 9:04 pm
by charlese
Thanks Bob (beeg) for finding that thread! Wow! way back on thread #284! I had given up looking in the archives and was going to try to use memory! Always dangerous!
I bought a package of several 7mm spring washers at Lowe's.
Posted: Tue Oct 27, 2009 7:13 am
by dusty
mindpilot wrote:I thought I had made some great original discovery.
It is always good to raise these issues again. There is a wealth of information that lays buried in the previous postings. It is good that you asked.
I can add nothing to what has already been posted by others except to say that even with the seemingly oversized washers, the jig works very well for sharpening jointer and planer blades. Just make certain that the washer is pushed back out of the way when you assemble the jig with knives installed.
As you have learned, if the washers interfere, the blades are not held secure and will not be sharpened correctly.
Posted: Tue Oct 27, 2009 10:09 am
by JPG
Observation and 'opinion' of a bystander(I do not own one of these[yet].
It appears to me that the purpose of the spring washers is to help release the blade(s) from the clamp by pressing up on the clamp so it moves away from the blade(s) when the wing nuts are loosened. To be effective, the height of the spring washers and the spring constant must be sufficient to move the clamp far enough to enable removing the blade(s). Thus the size used was determined by the requirements just mentioned.
Unfortunately the location of the wingnut studs and the possible shifting of the spring washers was/has apparently been overlooked.
I think it would function properly with the spring washers removed, but you would be giving up the release assist they provide.
An alternative to removal would be to try spot gluing one end of the washer to the bed in a position clear of the clamp lip but that would allow the other side of the spring washer to 'float'. A rubbery adhesive should work(it needs to tolerate the spring motion as it is depressed).