Why are most cutters so crap?

[Tenson]

I don't believe it's a problem with the machine, I have done nothing that should knacker the spindle that was working fine with my other cutters, even 3mm dia. ones.

That said I've asked Trend what feeds and speeds they recommend and they said 4.5mm DOC, 4,500mm/min and 18-24K rpm. Im my mind that is a very small chip-load that I'd expect to cause re-cutting of chips and excessive heat build up.

Anyway I've got these on order, so it's a temporary problem. http://www.ebay.co.uk/itm/2316880456...%3AMEBIDX%3AIT

[JAZZCNC]

I find with cutters you really do get what you pay for and the higher quality Carbide are worth every penny. Trend I don't exactly class high quality.

There's also much more to cutter than just HSS or Carbide. Flute type, angle etc play massive part to how the cut on CNC machine and with different grades of material. The grade and quality of Board for instance can make big difference, high glue content or low grade cores etc can kill cutter quick.
Cutters designed with CNC in mind and aimed at specific materials have flute profiles and angles etc that deal with the extra forces imposed much better.

Then you also have spindle to throw in the Mix.? . . . . You say 16000rpm but are you actually maintaining 16000rpm in the cut.? Has the spindle got enough guts so it's not bogging down when the going gets tuff.?

All these things make up the Big picture and it's easy to blame the cutter when it's actually some other reason.!!