Not an expert, but have been doing hobbyist woodworking for 50 years. I see people talking about the three methods of flattening and thought it would ne nice to have a thread on the pros / cons.
Planer: Probably the fastest, but …
In theory you have to use a jointer to first get the board flat on one side. I don’t happen to have a jointer big enough
There are pressure rollers that feed the boards through the machine. This causes two problems, it can flatten the boards before they are cut and the last couple of inches of a board will suffer from snipe. Snipe is when the board goes past the feed rollers and then can cut at a different depth.
Thickness sander: This is slower. You can’t take as much off as in each pass. This also has a tendency to flatten a cupped board just by the pressure of the sanding drum.
Flattening Bit: Admittedly I haven’t used this to flatten a workpiece. Since the workpiece is clamped into the machine and if the machine is trammed properly this is probably one of the best methods. It may require some sanding.
OK, now every one can tell me I’m soft and or wrong LOL.