Surface grinder question

Jarrett Fleming

Jarrett Fleming

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Knifemaker / Craftsman / Service Provider
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Jun 5, 2011
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I just recently purchased a surface grinder and I am really enjoying it. The only downside to using it is the chatter marks. Does anyone have any tips on how to get rid of these? I know that some say trizact belts don't leave them as bad, but honestly I can't hardly tell a difference. I have tried a few different ways to get them out without much success. Any advice would be greatly appreciated.
 
It was already done. I bought it from another knifemaker.
 
12345678910 said:
It could be related to balancing the contact wheel.

Perhaps ask the last owner,?
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The last owner passed away. His wife was selling his equipment and I bought the surface grinder as well as a few other things.

The drive wheel doesn't sound out of balance and I have used various belts all with the same result. I was under the impression that "chatter marks" were normal from using a surface grinder. I would like to know if there is a way to prevent the marks from being as bad, and how some you guys go about removing the marks from the blade.
 
Jarrett Fleming said:
The last owner passed away. His wife was selling his equipment and I bought the surface grinder as well as a few other things.

The drive wheel doesn't sound out of balance and I have used various belts all with the same result. I was under the impression that "chatter marks" were normal from using a surface grinder. I would like to know if there is a way to prevent the marks from being as bad, and how some you guys go about removing the marks from the blade.
Click to expand...

I have a few surface grinders that use stone wheels. The only time I get chatter marks is it the stone is not dressed correctly after changing the wheels, or if someone came along and put too much pressure on the wheel causing it to go out of round. Do you have a way to measure the run out of your wheel? Maybe the wheel was not mounted correctly and needs to be trued.
 
I don't have one, but what about how much are you taking off in a pass and how fast are you feeding? Frank
 
The contact wheel that comes with the TW90's surfacing attachment has helical grooves which are meant to make the wheel a more aggressive cutter. I believe it would also make them much less prone to chatter marks.

Helical cutters for milling machines, routers and wood surface planers leave much smoother surfaces. I think it would be applicable to any similar operation, on any material.

Just my 2 cents.
 
Thanks everyone for the help. Carl how could I measure the run out of my wheel?
I am not taking off much per pass and I'm feeding it pretty fast. The wheel on my surface grinder is a 90 durometer 6" serrated contact wheel if that helps.
 
Jarrett Fleming said:
Thanks everyone for the help. Carl how could I measure the run out of my wheel?
I am not taking off much per pass and I'm feeding it pretty fast. The wheel on my surface grinder is a 90 durometer 6" serrated contact wheel if that helps.
Click to expand...

If you have a dial indicator you could measure it or just run the wheel down until you get a slight spark. Then turn it off and move the wheel by hand. You may see that your wheel may be out of round? I do not have any experience with "belt" surface grinding so I may be way off here. :rolleyes:
 
You might try dressing the wheel to take out any runout I just put a piece of sandpaper on the magnet and held it with a metal strip at one end and the ran the wheel lightly into the sandpaper to dress the wheel if I remember I used 120 grit..

Tim
 
Have you tried dressing your belts?Get a diamond point dressing tool and dress the belts.
Mine runs stones but have a friend who has one that runs belts and he dresses them like a stone.Belt surfaces are uneven for that kind of precision.
Stan
 
Is there any play in bearing shaft...... Even a little.... Does the wheel up and down by hand without a belt on it?
 
Don't forget that the wheel for a belt converted surface grinder needs to be a higher duro than for hollow grinding.

Is your wheel 90 duro?
 
blades&grace said:
Is there any play in bearing shaft...... Even a little....
Click to expand...
Yeah....that's a good indicator spindle bearings are going out. Usually there will be some irregular noise involved also.
Put an indicator on the shaft and see if you can move it with light hand pressure, if that seems good check the wheel. A flat spot could cause chatter.
I have never dressed a rubber wheel on a surface grinder, Maybe you could use a lathe bit in a vise lock down the x and feed across with the y ?
Most chatter is caused by a lack of rigidity. Also is your magnet good and strong....parts sliding any ?
 
Ok thanks for all the comments guys. I will check for movement tomorrow and I'm also going to try dressing the wheel to see if that helps.
 
I don't even remember how I did it, but when I got my new wheel all assembled, I made a holder that held a broken end mill with a sharp jagged end.
I placed this on the magnet and VERY CAREFULLY!! dressed/cut the face of the new wheel until it was perfectly smooth.
Don hit on a really important point, that the area with the splicing tape is just a tad bit thicker than the rest of the belt. This will give you bumps. as well.
 
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