Doing both holes with the same set up makes a lot of sense. Are you a Gingery design purist? If not, you might consider upgrading the bearings to be able to keep the casting.
You can try putting the cutter more towards the canter of the shaft, then extending the shaft out as far as possible. Now set up a third bearing as a tail stock. This will stop most of the chatter and vibration issues. Then cut the bores between the head stock and the third bearing.
Doing both holes with the same set up makes a lot of sense.
Are you a Gingery design purist?
If not, you might consider upgrading the bearings to be able to keep the casting.
Oooof, brutal having to recast the headstock. Hope it goes much easier the next time round!
I'll know what not to do, this time! ;)
You can try putting the cutter more towards the canter of the shaft, then extending the shaft out as far as possible. Now set up a third bearing as a tail stock. This will stop most of the chatter and vibration issues. Then cut the bores between the head stock and the third bearing.
Agree, this is going to benefit from "tailstock" support. Of course needs to make sure the end support isn't pulling or pushing the bar up or down.
Nice work sir