Weight Loss Strategies

[thefro526]

In my experience, the big secret to keeping weight in check is to start losing it in the design phase. After an experience in 2011, where the team I was with at the time needed to 'find' 3lbs or so before our second event, I've been actively trying to design everything I'm involved in to be as light and efficient as possible from the beginning.

Some of my favorite techniques are:

- Use 10-32 SHCS/BHCS and 1/8" Rivets as standard hardware instead of 1/4-20. Most of the time, especially in FRC, 1/4-20 is used in situations where it's way overkill. Swapping out a 1/4-20 Bolt for a 10-32 nets ~20% weight savings per fastener, which adds up over time.

- Use 1/16" Wall Extrusions when possible instead of the standard 1/8". There are numerous instances where I see 1/8" Wall Extrusions used because they're common and 'easy to find' - but aren't really needed. Swapping this out to the equivalent extrusion in 1/16" Wall thickness nets a ~50% savings. (* try to avoid thin 6063 extrusions though, sometimes they end up being a nightmare)

- Use .060 (nominal) Wall 6061 Tubing instead of PVC/ABS/Etc for rollers. This can really add up on a system with a lot of rollers.

- Swap out larger gears in COTS transmissions for their aluminum equivalent. West Coast Products makes 7075 versions of many of the AM gears, swapping out two or three gears can add up to a pound of weight savings really, really quickly.

- Avoid thick polycarbonate and other plastics. Many people think that because plastics are relatively light, they can get away with using thicker sheets which often leads to 'hidden weight'.

The list goes on and on from here, but I hope you get the idea. Also, sometimes, it's worth trying the 'lighter' version of something first. If it fails, you'll know that you can easily replace it with something stronger/heavier. If you do the opposite, sometimes it's hard to replace that part because it's been on the machine for too long and/or is too well integrated to make it easy.