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DW660 bouncing of aluminum

Posted: Fri Sep 12, 2014 3:10 am
by philIam
My bit is just bouncing off the aluminum when it hits. First 2 holes when great. 3rd it just bounced off. its set to #7 on speed controller. 45 helix bit carbide tiCN coated.

Re: DW660 bouncing of aluminum

Posted: Fri Sep 12, 2014 6:49 am
by Estlcam
Hi,

how many flutes does the bit have?

Christian

Re: DW660 bouncing of aluminum

Posted: Fri Sep 12, 2014 6:55 am
by PsyKo
Depending on the aluminium alloy you're milling, the material can melt and stick to your endmill, making it useless (unless you manually remove the melted chip. It happens to me once in a while, no big deal).
If this is the case, try to change the cut parameters.
Less flutes, lower RPM, but faster feedrate (so the aluminium won't have time to melt on your endmill). Also try some coolant while milling (water or aluminium specific coolant fluid)

Harder alloys (such a 2017) doesn't have this issue.

Re: DW660 bouncing of aluminum

Posted: Fri Sep 12, 2014 3:29 pm
by philIam
Doesnt seem like anything melted onto it. Maybe too fast for my 2 fluted piece?

Re: DW660 bouncing of aluminum

Posted: Fri Sep 12, 2014 3:36 pm
by PsyKo
We'll need more information.
Endmill diameter, holes diameter, feedrate, plunge rate, RPM (I do not own a DW660 so I don't know what it means in term of RPM)

Are you sure it's a center cutting endmill ?

Re: DW660 bouncing of aluminum

Posted: Fri Sep 12, 2014 9:54 pm
by Estlcam
Hi,

if aluminum sticks to the tool the reason is often (but not always) too high rpm.
A few drops of oil also help to prevent this (it does not need to be something special - you can even use rapeseed oil from the kitchen).

Christian