Spindle Speeds

[JAZZCNC]

I'm sorry but all this talk I keep seeing about keep winding it up until the tool breaks is total B@##~ks.! . . Just because the tool breaks doesn't mean you have found the limit. Tools can break for multitude of reasons which have nothing to do with speeds n feeds. Spindle runout, machine vibrations, material hard/soft spots, tool geometery, DOC etc etc.

just a simple tweak of any, one parameter can cause a tool to break, esp small tools, like wise a simple tweak of any one parameter can Stop the tool from braking and allow you to push far higher than you probably realise.
No two machines and work/material setups are the same so it's very difficult for anyone to recommend speeds n feeds unless machines are very closely matched. Even then materials and the quality of them play a huge part.

For instance MDF, most people think MDF is just MDF and all are the same, they are very much NOT, the cheap nasty stuff you find in B&Q etc cuts Soooo much diffferent to a quality grade MDF. So much so you can easily double the feeds with the same tool and machine setup because of how it chips and clears the cutter.

I have one particular customer who cuts nothing but MDF letters & shapes, 10hr days, 6 days a week using 4mm SF cutters with 4mm DOC @ 7mtr/min and hardly breaks a tool.
Before changing grades and using cheap MDF they were breaking cutters all the time and cutting at half the feeds.

Now the OP is battling with several fronts, Crappy material, Crappy machine design and probably using Crappy cutters going at least 6 times too slow and I'd also take a guess not even able to achieve the feeds required to cut correctly due to lack of power.!

The only thing I'd say is to ramp up the feeds and play with the parameters until you get cutting something like your happy with. Then push it some more if you want, but be prepared to break tools but don't think because the tool broke it's the limit, keep tweaking the parameters a little at the time and you'll get more, how much depends on many factors and just like a womens mind, it could all change again tomorrow when you get a different grade of material.!!