VEX Chains
 

Does anyone know what the amount of strength that a VEX Chain can handle. Like how many pounds of force can it take without breaking a link.


Thanks,
Ethan

Re: VEX Chains
 

We were wondering that too. Even though it's not important any more I'd like to know too.

Re: VEX Chains
 

We haven't run tests, but we had vex chain lifting 3 pounds of mini tetras on a two stage elevator that weighed another 3+ pounds. The vex chain is plenty strong. Most of the time when the chain parts or occasionally breaks it's due to shock loads or bad alignment of the sprockets causing uneven stress on one side of the chain. Shock loads like sudden starts or stops caused by sticky mechanisms or hitting a wall or robot, etc.

To test the chain strength fix one end of a length of vex chain to something solid connect the other end to a hanging fish scale and slowly pull on the fish scale until the chain parts. Repeat a few times and you'll have a good idea of how strong the vex chain is.

Re: VEX Chains
 

...and please be sure to share your findings with the rest of us!

Don

Re: VEX Chains
 

My chain keeps breaking. We use it to lift our conveyer pickup, but I don't think it can handle it...

Re: VEX Chains
 

What about doubling or trippleing the chain?

Re: VEX Chains
 

That's similar to what we tried to do with ours. We had an elevator-type lift to pull us up onto the bar. It worked a few times (at Ramp Riot), but then it broke and then didn't work again. After trying to fix it multiple times (none worked), we tried using string (didn't work) and then just gave up. We decided we would use tank tread instead (way sturdier), and left it at that. After VEX was over, we were sitting in the stands watching the FRC competiton, when a VEX team member realized the clutch (I think that's what he said it was- the green thing on the end of the motor) was stripped.

To wrap up this jumbled post, if you're using the chain to lift your robot, and it's not working, try using the tank tread instead, and check your motor clutch.

Re: VEX Chains
 

There is one main problem with the treads. The chains held tension even after the power is cut off to the motor. With the tank treads, they will slide down very easily. Thats why i personally think that by putting two or three rows of chains, that will hopefully solve our problems, but we will find out soon....

Re: VEX Chains
 

And yes, it was the clutch, so we dont know if the string doesnt work for sure. But i guess that we will test that too.

Re: VEX Chains
 

That we will. To quote National Treasure (we watched it in History today) and Nicolas Cage, who quotes Thomas Edison in the movie: "I did not fail 2,000 times at making a lightbulb. I just found 2,000 ways how not to make a lightbulb." (or something like that).

My food for thought for the day.

Re: VEX Chains
 

I kept breaking chain when I tried to go too far and my lift stopped but I didn't. We put in a limit switch which stopped that issue but still broke some chain. I doubled up the chain and had no more problems.

Another tip. After pulling chain apart remove the stretched link and replace with new. Once weaken they never work the same.

Re: VEX Chains
 

Yeah, that is the exact same problem that we were having, when the operator of the chain lift went too far either up or down, it would break. That problem however could easily be solved by adding a limit switch, but we still have chain breaking problems. Thats good to hear that 2 chains work fine. Maybe we will even go up to 3 chains as backups in case the others break...

Re: VEX Chains
 

I think the reason ours kept breaking with the stripped clutch may have been because it caused the sliding part to come thudding back down and put the stress under awkward, undesigned force and therefore breaking it. I think a good thing to remember with this when you're frustrated is that the chain's meant to be more of a drive train/power transfer device, rather than part of a robot-lifting device...then again, neither is tank tread, but c'mon- it's tank tread, it's sturdier!!!! :D

Re: VEX Chains
 

The other main advantage to using the treads is that if you go too far or too short, it will not break, you will probably just strip a clutch. always use a clutch so the motor doesnt get damaged.