Bits keep breaking

Hi @Loren what settings do you recommend for 3/8 and 1/2 bits? Decided I could use bigger bits for roughing passes. Perhaps there’s an app you pull settings from?

I use GWizard for speeds and feeds. It does what it needs to but my needs are not all that demanding. I don’t like the UI on GWizard. I have been looking at HSMAdvisor, but haven’t tried it yet.

No app, just experience . As a rule with cutting hard wood I will use 100-150% of cutter diameter for DOC and 25% cutter diameter for WOC (step over). That is for non-slotting type cuts. Reduce if slot cutting.

3/8" diameter cutter I would start with .008" feed per tooth chip load. Adjust upward if the machine and fixturing does well with the load.

1/2" diameter cutter I would start with .010" feed per tooth chip load with same conditions as above.

Slow your spindle down for these larger diameter cutters. 10-12k. Look up cutting speed or Surface Feet Per Minute for the material you are cutting and the type of steel the cutter is made of Carbide …HSS…etc

Hi Loren - do you feel my feed and plunge rate are excessive with this 3/8" roughing bit? Tried to get the chipload down to .008" and speed down to 12K as you mentioned but these variables are all linked.

I think your feed rate is okay. For plunge feed rate I start at 25% of my normal feed rate. For ramping I start with 50% of my normal feed rate.

OK thanks!

Your feedrate looks really slow in this screenshot, check your units. 300mm/min = 11ipm = Burning up.