Carving Black Cherry spindle shakes

We were carving a catchall tray from 1" Black Cherry wood and the spindle gets to a specific point and it will shake the whole machine. It starts shaking going against the grain but not along the entire length. Have carved 1" Red Oak catchall tray without any issue so this one is a bit confusing. Not sure what might cause this. Step over is small to keep the cuts clean. Don’t recall the speed or cut depth but those shouldn’t have changed from Red Oak. Any advice will be appreciated.

my first assumption will have to be the bit. As it could be dulled which would make it less able to cut against the grain, while cutting along the grain with no issue. After having that amount of back force I would go through and check all the screws and make sure they are tight.

Would agree with that. Was also thinking if there was more oils in the wood at certain spots. We were using a corn meal bit which I should have mentioned, not used too often unless they dull very quick. We also tightened all screws, some were loose.

Were the red oak settings for the corn meal bit? If not, that bit may need slower feeds and shallower passes.

I think so. We’ll try a carve with the same bit to see - may just be that specific chunk of wood (I hope!)

Used a new corn meal bit on roasted ash and it did not go well! Dug into the wood before pulling the 5X9 piece off the platen. Got to think these bits are for another purpose but I know we have used them for other carves, just not certain if it was in soft wood.

Ash is pretty hard. Not sure what your settings are, but perhaps they are too aggressive.