[INDENT]I just bought a medium chassis, and am running into the need for longer axle sections going to my gears and motors. I currently have 4X 12" axles from two starter kits, that I don’t know if I’ll use a lot, and I am thinking about cutting them into 6X 4" sections, and 4X 6" sections. The longest (other than the 12) that comes in the start set is 3".
Has anyone had any need for the 12"ers, and what are the chances that I would regret this for a future project?[/INDENT]
i’ve used the 12’’ axles for shooter mechanisms for an outreach robot resembling robots from the FRC game last year, but that’s about it
Chances are you’ll be fine if you cut them. Remember though that you ca always make something shorter.
also there is always a home depot right down the road or lowes or a hardwar store where you can buy 1/8th inch key stock and cut it down and just sit watching tv for a few hours doing some hand sanding to round off the corners or even faster with a dremmel
I have been thinking about cutting my 12" axles down to 3" or 4" inches. I have seen little and thought of little use for the 12" axles
We (me and my FVC team) have used all 12 inches of axel before, but it can be difficult to do as they can easily bow if not well supported. I can’t tell you what scenarios you might need to use all 12 inches except for the scenario we did where we had a wall of 4 tank tread loops to pick up softballs. It actually didn’t work out well at all…so that’s not even a good example of how you’d use all 12 inches. I’d say go ahead and cut them and enjoy your current project.
i’ve used them for shooters too. i have also used them for front rollers to intake balls, ect. i sugest you dont cut all your long shafts keep at lease one if not 2.
We’ve cut them for other things
During “Round Up” and “Gateway” our team used the 12 inch axels. they are a good way to keep two different objects turming at the same time. dont use unles you need to use them. Hope this helps. 
My team is using 12 inch axles now, which you can see in our robot reveal for Sack Attack. We used 1 to mount our overhead intakes.
Necroed a 5 year old thread…holy moly.
I think that most Threads, like this one are on Life-Support…
This Thread was and still is relevant, besides… Now there seems to be a need for the 12" Axel, in its entirety…
Just showing my surprise at the magnitude of the necro the 12" axles will be important in games like Sack Attack where top rollers (as opposed to the side rollers from Gateway) will probably be popular. The intake mechanism will want as much width as possible, thus necessitating the full 12" and possibly even more.
if it is on a drive train you won`t be able to turn with out breaking them!..
We used them once in gateway on our first bot, but we didn’t stick with it. I think under certain circumstances they may be useful, but it depends on your design. I’ve found most use in 4-6" axles not much more because the longer the axle the more likely it’s going to twist at one end if space is between it.
the longer the axle the more likely it is to twist or bend… support your axles!!!
I hate how weak the 12 inch axles are. I will most likely not be using them.
Omega necro, to be sure. On topic, my team used a 12-inch axle this year on our lift.
I use the 12" axles to store wheels and the larger gears. Keeps everything tidy. 
The one time I used full 12" axles on a bot was to get power to a gripper at the end of a long arm. The long shaft allowed me to position the motor behind the shoulder of the arm to help as counter-weight. The gripper itself used a worm-drive, so having the shaft run through the arm worked perfectly.
Cheers,
I’ve forgotten most of the one mechanics of materials course I had to take, but I’m pretty certain that making an axle longer makes it more likely to bend but not more likely to twist. (Mechanical is not my specialisation.)
The angular displacement will be greater with the same torque, meaning mechanisms may be less precise, but the torque required for failure remains the same.