More sharpening advice

[barbender]

 I'm with ST, I think you have it adjusted wrong and the stone is coming right down on top of the tooth. You don't want to way over tension the holder either, you'll fry your gearmotor

[barbender]

In the top notch drawing above, the tooth to the left is where the wheel should come down. The one in the center is how I think your wheel is coming down on top of the tooth.

[SawyerTed]

@barbender has captured it with his "top notch" illustration!  It's actually worth 1,000 words.

Here is the link to the BMS25 sharpener manual.  

https://apps.woodmizer.com/Manuals/EngDoc.aspx?man=sharpener%2fpdf%2f2448.pdf#page19

Section 4.4 describes the adjustment for face grind of the tooth.  

[AaronS]

Brad, that's considered a large radius? And I thought I was keeping it fairly small...

If that's true then, I guess I should be keeping the radius almost 90 degrees?

[AaronS]

Barbender and ST, I could be wrong, but I've been trying very hard to take just the tiniest amount off the face, knowing that too much would cause a negative hook angle. There is an adjustment for the push rod, yes. I've used it quite a bit playing around! Could you weigh in on the wheel profile? Is the radius too much like Brad was saying?

[Bradm]

I run an almost square corner on the grinding wheel and adjust the angle on the OD if needed.  I also lightly dress the profile with a Desmond dresser every band/pass.  I never dress the inside face as doing this will add that taper to the wheel.

Barbender's drawing shows it quite well on the left.  Even though there is a fairly large angle on the OD, the left hand side of the grinding wheel is parallel to the tooth face while in your picture the deep profile shows what I'm talking about at the bottom of the tooth to where it transitions into the gullet.

[AaronS]

Wow, well then maybe that explains it... thanks for pointing this out Brad! I'm going to reprofile the wheel to square up that inner radius and take another shot at it.

[SawyerTed]

If the stone matches the profile of a new blade then the stone profile is correct.  Otherwise, the stone needs to match the new blade profile.

[Bradm]

Before changing the profile of the wheel, compare the profile you are getting when sharpening with a new, never been sharpened band (flat pack them and line up the tooth faces).

[RAYAR]

I noticed a tiny bit of sway side-to-side of the whole grinding wheel assembly, but I can't get the hinge any tighter... could that be it?

Sounds like you likely found the root of the problem. This has to be taken care of, there should be no side to side movement as that will cause the problems you are experiencing. Cutting down on a piece of tin, the full face of the wheel is grinding, but on the blade, you're just catching the left edge of the grinding wheel and it's being deflected to the right as it grinds down the face of the tooth.

[ladylake]

 One other thing to check, in some of your pics it looks like the tip of the tooth is flattened out right at the tip like the sone isn't. lifting high enough. I had that happen once when a spring on my grinder go weak not lifting  the stone high enough flattening out the tip of the tooth.  Even with power feed the mill wouldn't feed. Put a stronger spring in my grinder and it fed good again

[Joe Hillmann]

In a previous post you said you were setting a 19-21 thousandths.  I find when cutting pine that isn't enough.  I aim for 15-27 thousandths.

And since I dislike setting blades I will often push it all the way out to .030 of set so I can get 2 or 3 very light touch up sharpening out of it before I have to set again.

Although when the logs are frozen .030 leaves too much sawdust behind that causes the board to freeze back to the can't once the blade passes through.

[AaronS]

For those looking for a resolution to the mystery... I wasn't crazy!

Turns out that somehow or other the main hinge on the sharpener had slowly loosened over time, so no matter how careful I was setting everything, it would move a bit as it sharpened and ruin the angle. The bolt which held it was tightened to it's limit, so I ended up sending it to New Brunswick to the Woodmizer dealer there. Didn't have to pay a dime because it was still under warranty. All they did was add a few washers to either side of the hinge and tighten it up again... but it's working good as new now!

Still don't know if it was a manufacturing defect or just normal wear but a few months of use seems pretty quick for a problem like that to arise...

Anyway, I appreciate everyone who pitched in with advice! I now know a lot more about sharpening than I would have 

[RAYAR]

Good to hear you got the problem fixed. Mine, a custom built, had a similar issue, but only needed shim stock to remove the sideways movement.

[Peter Drouin]

Good for you