Originally Posted by
63rickert
How to engage the two mating flats is the whole problem. There has to be a simple way to do that. Every attempt so far engages the edge of spindle to a line on the cotter. Or at least that is what the damage says to me.
Think of cotters as a game. To win the game, you need as much of the filed face of the cotter to come in contact with the flat face of the spindle as possible. The more surface area of each flat you have in contact, the more chance you'll have of success and thousands of miles of creak-free, loose-free riding. If you're seeing a significant linear gouge, you're not engaging the flats well enough, deep gouge means you're catching the edge of the spindle before the flats can engage nicely, or after you're too far past engaging.
You need to press or punch in the cotter enough to see where you're making contact, then adjust the angle of the cotter so the flats match. Sometimes you'll get lucky and you'll get good engagement without touching a file - it happens! But more often than not, especially with the French stuff I'm wont to work on, I'm filing a good bit of the face.
Best I can do is throw together a picture to visualize it. Blue line is where you're meeting the spindle. You want contact flushly across the face for a long blue line, engaging across a lot of the surface. If your angle isn't steep enough to meet the face, you'll gouge at the blunt end. If you over-file, you'll gouge a line into the threaded end. It's that simple. File things flatter on the end you're gouging, or if you're gouging on the threaded side, you might've over-filed already (it depends on how much blunt end is exposed after a full press!)
Make any more sense? Just make sure you file evenly, flatly, because the spindle face should be perfectly flat also, you want flat to flat.
