Loctite vs press fit

[Cory]

Originally Posted by Munchskull

648 is a primerless loctite.

Primer is still recommended for 648, particularly for aluminum. It both cleans the surfaces and decreases cure time until maximum strength is reached.

[Mr V]

I do not recommend press fit bearings for a couple of reasons.

Too tight of a press fit or a hole that is not perfectly round can cause an increase in friction of the bearing and possibly cause it to fail sooner than it otherwise would. Bearing failure is another reason to not use either a press fit or a sleeve retaining compound. If the bearing fails and I have seen them fail then replacing it on a fully assembled robot can be difficult to do in a quick manner.

On the WCD drives I've been involved with the mechanism that retains the sprocket and wheel also retains the bearings. On those the chain runs were on the side of the tube facing the inside of the robot and the wheels are on the outside. Those are retained by either a bolt threaded into the center of the axle or an E-clip or snap ring in a groove on the axle. The sprocket and wheel then retain the bearings though you'll want a spacer between the bearing and wheel. Then if the bearing does fail you can remove the wheel or sprocket and slide the bearing out by hand, with the axle still in place.