Chip-out on lead in with compression Spiral

[bstern]

I have been tweaking my bot a bit and am now achieving a great cut on 3/4 melamine at 9 ips.

However, I am getting some chip out doing a lead in move.
It comes from the up-cut part of the bit during the lead in move.

I have heard that the 4hp HSD spindle is used on boring machine and the bearings can take plunging.

If I leave out the lead in move and just plunge straight down before starting my cutting, how fast can I safely plunge with a 3/8 compression spiral?

If I go too slow I get burning.
If I go fast I feel like I'm pushing the spindle.

Thanks

[Gary Campbell]

Bob...
Even tho it may do a ramp to final depth, when you use a compression bit you need to plunge to a depth that allows the downspiral section to engage. Hundreds do this every day. We plunge at 2ips into sheetgoods, never had any problem.
Gary

[bstern]

Thanks Gary,

After posting, I thought that might be the answer.
Changing my code as we speak.

[bstern]

I was plunging at 1 ips.
Going to try 2.