# tool marks in mdf wheels



## flyforever (Jan 4, 2013)

I am trying to reduce the tool marks along the contour of my 1" mdf wheels. They are caused by the tool rubbing against the surface when it rises and drops down to cut, especially as it tries to leave out the tabs.
Now, I have a theory as to why it happens. I simply don't know how to eliminate it.
I use a 1/8 tool and a depth of cut of .07. I also use tabs. I suspect that as tool rises to leave tab marks, it rubs against the surface, thereby leaving the marks.
Is there a technique other than multipass that will either clean or eliminate these marks?
thanks
tony


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## harrysin (Jan 15, 2007)

Tony, you haven't given enough information for me at least to visualise what you are making. Why not complete your public profile so that we know what level of experience you have, also your available tools and take and post a few photographs because even one is worth a thousand words!


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## fixtureman (Jul 5, 2012)

try a rough cut a little larger and the final cut to size. It sounds like your bit is deflecting


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## jw2170 (Jan 24, 2008)

I will leave this one for the CNC experts...


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## flyforever (Jan 4, 2013)

sorry for not getting back sooner, but I was out of the country for work. I have several years of experience cutting mostly balsa and Mdf on a small k2 cnc router. I produce small parts and use nothing larger than 3/16 carbide bits, double flute. Most of the marks stem from the fact that I use tabs that are .050 high and .100 wide relative to .375 stock. I suspect that when the tool comes up and over the tab, it leaves the marks. Since my parts are small, I nest them while keeping tabs small so as to make cutting them off easier. If I try mutipasses, I cannot do the tabs. tony


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## mbr72cnc (Feb 15, 2010)

What about using a entrance/exit moves, like ramping in and out?


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## flyforever (Jan 4, 2013)

I suspect that the tool mark is caused by some vibration in the board. I use hot glue to secure the board to another mdf sacrificial board. If, however, there's some clearance between the two boards , the piece being cut will probably vibrate just enough to leave a tool mark. tony


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