My Build - I blame you lot for this....!

[HiltonSteve]

I have been profiling a couple of 20mm aluminium router sideplates at the weekend and been playing with different speeds and feeds to see find out what works best and gives the best finish.

Ended up at around 4000rpm with a feedrate of 600mm/min with a 2 fulte HSS slot drill, roughed the profile first stepping down 2mm at a time and leaving 0.5mm on all round, then did 2 finish pass's at 10mm deep with the same cutter but dropped the feedrate to 350mm/min, cutting time around 45 mins.

Finish is OK but still room for improvement, i have a couple of ali-master 10mm cutters which have completely different geometry to a standard slot drill so may give that a go to see if it improves the finish.

But overall still quite happy with the results!!

[Jonathan]

I don't fancy cleaning up the machine after that!

I was also experimenting a bit on friday with feedrates on 20mm aluminium plate. I'm using a nearly new 20mm 4 flute HSS cutter. With a maximum cut width of roughly 5mm (plate was allmost to size, just machining the edges), stepdown of 2mm and 2150 RPM I found 720mm/min to be good. It would go faster, but I'm only putting the cutting fluid on with a brush and I didn't want to push it...

For finishing I tried various speeds still at 2150rpm. I left 0.5mm for the finishing pass and did one 20mm deep climb milling pass. I couldn't really see any improvement in finish below 300mm/min, so I stuck with that.

On the first of the attached photos you can see the difference between accidently running the finish pass at 600 compared to <300.