Harmonics

Jack O'Neill

Jack O'Neill

Gold Member
Joined
Nov 15, 2007
Messages
7,193
Why am I getting the harmonics while flat sanding on the platen , does not matter if it is the mild steel or the platen with the glass . Been happening for a while now but I do not remember this happening before . I'm getting older and may have forgotten but it is driving me crazier than I already am .

Thanks all
 
Are you saying the belt is setting up a standing wave and leaving a waved finish? Or that the sound of grinding is wailing at perfect octaves?
 
I get that sometimes. Holding the blade in a different place usually fixes it.
 
Frank Niro said:
Please expand on this a bit. Thanks.

Frank
Click to expand...

lets see it this helps , but Ben hit on it has creating a sanding wave but it is LOAD harmonics . It happens in different areas of the blade but I seem to notice it must when I change pressure and the angle a bit at the plunge when I need to raise the grind line .
 
Does it happen with all belts? If I had to make a guess I would say that either the belt has been stretched so it has one side that's longer, which let's it start vibrating aND setting up a wave, or that the tension is too low.
 
Greenberg Woods said:
Does it happen with all belts? If I had to make a guess I would say that either the belt has been stretched so it has one side that's longer, which let's it start vibrating aND setting up a wave, or that the tension is too low.
Click to expand...

Interesting as the belts have been used belts , today anyway . Tension is good , I will check it , and speed does not seem to matter , slow or fast . I will try out a new belt soon but I believe I have done that before . But you got me thinking about vibration , I will check my tension springs but I replaced them last year .
 
You are making me think Ben , it is giving me a headache . Any way , lately I have been pulling the belt tight across the platen assembly wheels and then bringing the platen itself up to the belt . May not be tight enough against the platen . I use to have the platen a little proud of the wheels . Will give it a try
 
ONeill said:
You are making me think Ben , it is giving me a headache . Any way , lately I have been pulling the belt tight across the platen assembly wheels and then bringing the platen itself up to the belt . May not be tight enough against the platen . I use to have the platen a little proud of the wheels . Will give it a try
Click to expand...

That would probably help, that little flap could give enough slack to resonate with any vibration in the grinder
 
When I put a new belt on my grinder, I knock down the grit at the splice with a 60 grit diamond pad. Saw it in a Travis Wuertz video. It reduces the 'bump' and may improve the problem.
 
What kind of grinder?

Make sure you belt tension is as tight as possible, and tighten up any bolts that might be loose. See if putting your hand on any part of the grinder will dampen the harmonics while it's running. That may help narrow down any problem areas.
 
knife to a gunfight said:
What kind of grinder?

Make sure you belt tension is as tight as possible, and tighten up any bolts that might be loose. See if putting your hand on any part of the grinder will dampen the harmonics while it's running. That may help narrow down any problem areas.
Click to expand...

it is a KMG , I think we may have hit on it , the way I have been setting the platen against the belt instead of having the platen set past the wheels and then tighten the belt against the platen . I will find out it that has been the cause soon .
 
What specific note is it singing?

F - Your approach angle is too steep.
G - Your left arm is lifting.
A - The belt is wearing unevenly
B - Your approach angle is too shallow
C - Stop holding your breath
D - Okay, you are breathing but you need to brush your teeth.
E - Don't slouch
F - This is the wrong grind for the knife profile you have chosen.

There are sharps and flats as well... but you aren't ready for that level of understanding.
 
My grinder used to play "Smoke on the Water", but I found removing the bucket from under the platen stopped it.
 
i think a major chord with a minor root note would smooth things out... from what i can gather something is making a screeching noise ? can you tell if it is the machine or the blade making the noise ? i have had blades screech, its always with a used belt. never happened with a new one.
 
Is it possible that the grinder isn't even making any noise and your wife or daughter are just listening to Maria Carey while you're grinding?
 
You must log in or register to reply here.
Back
Top