Woodland Mills Grindlux sharpener issue

[Bucksaw]

Has anyone else had their sharpener head not stay tightened in the 7,10,14 positions?
I have tighten the locking knob as tight as I can by hand and the grinder head is still not secure and will move from the detent positions. 
I haven't used it yet due to this issue because if it moves during sharpening it certainly will ruin a blade. I contacted Woodland Mills and they advised to add a washer which made no difference.

[Stephen1]

Maybe add a lock washer?

[TroyC]

Yeah, that doesn't appear to be a strong point on that sharpener.

There is a tab sort of thingy with a dimple on it  (if I remember correctly) that hits the degree positions. I tweekek mine a little and made it slightly tighter. Haven't looked at strengthening the tightening knob but that is next. One of those lock washers with the teeth all around the outside might be in order.

[rusticretreater]

Hi,

The first thing to check is if the motor brace is firmly against the back of the control box.  If the bracket hole does not fully clear the protruding boss and the brace fully seats against the control box, the motor assembly will not stay put no matter how much you tighten the lock knob.

If it doesn't, either enlarge the hole in the bracket or sand/file down the boss until the proper clearance is obtained and the brace fully contacts the control box.  This will also allow the detent tab to fully seat in the adjustment holes.  Still, a lock washer under the knob is a good thing to do regardless.

Another thing you might try is to put a bolt sleeve inside the brace to keep it from bending when you tighten the knob.  This will apply more downforce to the brace.  Another good enhancement to do just because.

As all of my saw blades have the same tooth angle, I carefully drilled a hole through the tang and the back of the control box and put a self tapping metal screw in there.  It holds the detent in place and is rock solid for me.

[Tristen]

I just tighten the knob with a pair of channel locks and it has held nicely.  

[Bucksaw]

I ended up trying a rubber washer I made from a thick inner tube. Helped a lot but I could see that it would still move.
I drilled and tapped the detent of the arm and put in a bolt that now goes into the hole(s) in the back. NOW it's rock solid and still adjustable to any of the three positions.
It has been frustrating that I should have to fix something that is a design flaw in my opinion, but it's certainly better than new now.