Troubleshooting Chatter Marks

Imperfect cuts are traced to alignment and bit issues. December 10, 2007

When determining our feed speed for melamine, I have noticed that before the melamine starts chipping, I get a pretty wicked chatter mark on all sides of the particleboard core. Could this be due to an out of adjustment router head? I have not really seen this before in our cuts, just recently, plus when I fly cut the spoil, I can feel the machine lines where I could only faintly see them before. Any guesses?

Forum Responses
(CNC Forum)
From contributor J:
It sounds like two problems. The fly cutter marks are because your spindle is not 100% square to bed. The cutter marks sound like the tool itself. Some tools leave chatter marks much more than others. This is the most common reason. Try a different tool. I guess it is spinning the correct direction and traveling anti-clockwise.

From contributor T:
Could be your spindle is out of tram to the table.

From contributor D:
Are you using a 3/8 tool? What brand? I've tried to save a few bucks on my common tools and it never worked out. I always got runout, chatter and that awful screaming. Now I just stick to 60-126 3/8 comp spirals from Onsrud. Also, how many operators do you have on your machine? Sounds like someone crashed it. There's not a whole lot of ways to throw a spindle out of sweep. Bad forklift drivers and crashes are most common. Seen both before... Not the end of the world, but sucks anyway.

From contributor M:
It could be that the spindle is out of tram, or it could be the tool, or both. When the pattern of cuts on a spoilboard change, that is often an indicator that either the spoilboard cutter needs knives turned, or the spindle is no longer perpendicular to the table. However, from my experience, when stock tools suddenly start cutting bad, it is often caused by inferior sharpening. I would simply put in a brand new tool and see if that helps. If the cuts are still bad, then you have eliminated a possibility.

From the original questioner:
I am using a 1/2" compression spiral with 3/16" of upshear from Southeast Tool. I believe they have about 1 3/16" of carbide on them and we are cutting mostly 3/4" melamine. These bits do get sharpened. The shop has one programmer and I am the only operator. The training that I received was the five days that the tech was here (pretty scary, huh?). Could this be a collet issue? The shop supervisor has been a tough sell on collet replacement and I have been trying to get tools for checking the tram (no luck yet). Any easy ways to check tram without having to petition for tools?

From contributor M:
I wouldn't think it is a collet issue. My advice would be to get a technician in to check tram and fix it. If you pay attention and stick with him, you will be able to do this yourself in the future. It isn't too difficult if you have someone good show you how and with what tools. The other option is to find someone local that knows how to do it, or get detailed instructions from the manufacturer. Hopefully it is a machine that allows easy access to the spindle mounts.

From contributor G:
If both items you mentioned, from chatter to lines on the fly cutter, it's a good chance it's not the tooling. It sounds a head may have crashed and needs to be fixed. Chatter marks means the tool is dull or RPMs too slow.

From contributor R:
What kind of machine are you using? What type of tooling, ISO or HSK?

From the original questioner:
I am running a 5 x 12 Anderson Stratos Pro. It's HSK.