[Travis Covington]

Originally Posted by SerpentEagle

Can anyone shed some knowledge based on experience on whether it's safe to use tapped holes instead of locknuts?

Lets say you wanted to attach some square tubing to the side of another piece of tubing like this:



Is it safe to just tap and screw a bolt into the block that I have between the two tubes, or would it be better to just run a bolt through the whole thing and use a lock nut on the end of the bolt? The block is ~.5 inches thick in the middle.

If I'm not being clear enough please tell me.

If you are trying to duplicate what we did on 254, I would heed Adam's advice and simplify things greatly. We make a lot of complicated parts seem easy because we do some unique 3D milling and tabbed machining and have extensive experience doing so. You have changed some of the parts in our design to actually make them more complicated than they were originally. We also do a lot of things design wise on our robot purely from an aesthetics perspective. We could do them simpler, but chose to make them more complicated because we feel that looks cleaner and more elegant. Take a step back to analyze the problem and your chosen solution to decide if you need the complexity you have in there.

Regarding your original question - We tend to use nylon lock nuts in locations where we absolutely do not want something to come loose and do not have a piece of material behind it which we can tap to 1-2x thread diameter. We never use non-locking nuts except for jam nuts on cylinders. 1D (D = thread Diameter) thread depth is about the smallest I would feel comfortable with. We prefer to go thicker where we can. 1/4" thread depth is about as thin as we tolerate for #10 screws, for example.