Thread: CNC Router

Hi Guys.
A friend has a CNC router and has been making me some buttplates out of 4mm Ally. The edge has some chatter even though he did it in four passes 1mm at a time. He is using a 3 or 4mm bit at about 24000rpm.
Any ideas please.
Kim

Hi Kim,

Lighter cuts, especially the finishing cut, maybe 0.1mm, rather than 1mm.

The chatter is most likely being caused by tool deflection.

Regards
Ray

Thanks Ray.
The 1mm was deep but I get it.
tool deflection was my guess so mabe a larger dia cutter
Kim

If the edges are what I call gummy it is remelt and a coolant should be used. At 24,000 RPM you generate a lot of heat unless you have a good chipload which takes the heat away. A spray of WD40, CRC or your own brew will help.

It the edges are smooth but have toolmarks then it is deflection of the tool / machine or the head needs tramming depending on how the marks are arranged. If a 3mm bit is being used then likely to be deflection in the tool. One method is to offset the cut 0.1mm and cut the job in increments and then do a full pass to your line. You will need tabs to do this.

What sort of cutter are you using?How many tooth?
I assume you are effectively cutting a slot around the butt plate?
What feed per tooth?

Stuart

Thanks Guys
I think it is a one tooth cutter but it is not my machine just my job and he is new at ally. He is a kitchen man on the day work and whatever at night.
Kim