What is the maximum diameter I can have on the bit used for the 65mm VFD Spindle Kit-110V? I have a 1.5" surfacing endmill bit but it locks up when it plunges down to cut.
The “Max” depends. Plunging straight down is one of the most stressful things a spindle has to endure. That same tool would likely perform better if it ramped into the material at an angle, or started outside of the stock (as shown in a recent video about surfacing bits). It’s not always the bit, it’s also the technique. That being said, 1.5" would be at the upper limits of what I’d want to try on a 65mm spindle. Maybe stick to 1-1/4" or smaller, and explore alternate toolpathing techniques to minimize the shock and torque loads on the spindle.
1 Like
I have a 1” fly cutter and I design the tool path to start outside the material so I’m not plunging with it. It’s easier on both the bit and the spindle. I know I may not do what others do but it works for me.
I also don’t use a 1.25” to 1.5” bit on a trim router either. Too much rotating mass on the smaller router.