pic: 80/20 Flanged Button Head Fasteners
 

Re: pic: 80/20 Flanged Button Head Fasteners
 

Yup, flanged screws are great for retention on the ends of shaft. Also dropping a washer into the depths of your robot is never fun. We buy ours at Mcmaster.

http://www.mcmaster.com/#91355a080/=vozj62

Re: pic: 80/20 Flanged Button Head Fasteners
 

Totally missed these! What a headache saver....thanks, Greg.

Re: pic: 80/20 Flanged Button Head Fasteners
 

Note that you can strip the hex out of a button head much easier than out of a socket head, especially when the screw is retained with Loctite as should be done on a spinning shaft like this. We had this problem numerous time on our drive last year and have since switched to socket heads with washers. If only socket heads with flanged didn't cost $4 PER SCREW.

Re: pic: 80/20 Flanged Button Head Fasteners
 

Assuming you're using a reasonable size like #10-32 or larger, you're putting some mean torque into the bolts, using junk wrenches, or using junk bolts. We haven't had issues with buttonheads stripping out.

#8-32 and smaller on the other hand, much easier to strip.

Re: pic: 80/20 Flanged Button Head Fasteners
 

I've never stripped out a hex socket screw, button or socket. Maybe getting some new allen keys could help.

Re: pic: 80/20 Flanged Button Head Fasteners
 

Don't use the ball end of the allen wrench. If the straight end is getting too worn, grind it shorter.

Re: pic: 80/20 Flanged Button Head Fasteners
 

Standard 10-32 black oxide from McMaster...I can't comment in the meanniss of the pit crew last year :p , but I will take a close look at our wench tips, I know some of them are at least 10 years old...