#25 Chain Information

[sanddrag]

Originally Posted by 114ManualLabor

If you do that, it will be more than strong enough for any FIRST use.

Go back to 2005 and ask 968 that. "any" is a pretty strong word. But, "many" is definitely true.

As long as you're designing mechanisms to transfer force correctly, there shouldn't be enough force to break the chain. However, I am only speaking from my experience, so if I'm entirely wrong, correct me. It's the best way I learn.

[Travis Covington]

You need to design the system within the limits of the chain. For us, with a few of our drivetrain gearboxes, we were exceeding the maximum reccomended working load for the chain, but were still under the chains breaking load - just barely. We have tested it thouroughly enough to know that there is an obvious safety factor in the chain manufacturers quoted numbers, and as a result have designed our systems carefully enough around that, knowing one small misalignment or potential impact during a match could mean we break a chain. We take that risk, at the benefit of reduced weight and size. It is a fine line to walk, and you have to consider everything before you make that decision yourself.

Transfering 'force' should be clarified, too. #25 chain would probably transfer some force in this picture below just fine, however, the massive reduction in the gearbox means that as soon as you put any sort of 'real world load on the system, the chain will simply fail. The amount of force you wish to transfer has everything to do with what size chain you need. Below, we almost needed a chain larger than #35, but again, we figured if there was some sort of impact or collision during a match, we might actually prefer the chain break rather than the arm or frame of the robot itself.

For drivetrains, it's worth running the numbers every year just to be sure that #25 will work. You can calculate this quite easily. 2 cims at 2ft/s would be safer with #35 chain in my book.

[techtiger1]

Thanks to everyone for your input on this subject. I was wondering if you all could post some of the locations were you purchase your #25 chain and sprockets. 1251 is working on a few new ideas so your opinions and suggestions are much appricated on this subject. Finally, out of curiosity, the person who posted about the load numbers on 25 Vs. 35 chain were did you get those numbers?

Thanks,
Drew

[Tapoore]

If you only need very short lengths of #25 chain, the Electronic Goldmine sells it in 23" lengths for $2.49 each (they come with a master-link too). If you need longer lengths of chain or some #25 sprockets, McMaster is probably your best bet.