uncomfortable number of links

[tgurapter]

if i need a #35 chain with 47.7317333333 links, how many links do i realy have to use?
do i have to use a little bit less then the exact length? or a little more?

[tgurapter]

sorry. i need a 71.1976949157 links chain.

[Tem1514 Mentor]

You will always have to round UP (never down) to the next whole number of links.

Merry Christmas

[MechEng83]

To clarify, because it's a rather confusing bit when dealing with roller chain: technically, one link is 2 rollers. There are half-links, which are just 1 roller long. You always should round up to the nearest number of rollers. Of course, a better option would be to design your system to need just slightly less than a whole number of rollers. If that's not possible, a tensioner could help remove most of the slack in your system.

[magnets]

You need to either use too many and add a tensioner, or move your two sprockets to the exact center to center distance. From my experience, the easiest and lightest chain runs for FRC are exact center to center and have #25 chain.

[artdutra04]

As much as possible, try to design for an even (multiple of two) number of links; this way you can use the chain breaker/resetter tools or normal master links without any need for tensioners until the chain starts to wear in. Once the chain starts to wear in, cam tensioners or using plastic floating idlers are my preferred ways of tensioning roller chain.