Bearing Blocks/Chain Tensioning

[ollien]

My team has never used chain before, and I'm doing some last minute research to ensure we will be able to this season.

I was looking into calculating the C-C distance, and found this calculator. How do I use this correctly? The example I was looking at was if I had a #25 chain, a 36t sprocket and a 12t sprocket, and I wanted to run chain over a 10" distance. According to this, I would need 104.36 links. Clearly, this is physically impossible. Should I just play with the number of links up top until I get a number close enough to 10"?

Secondly, my team doesn't have a mill. Therefore, we figured the best way to use chain would be to utilize Versablocks. Of course, I can measure the distance I need to put the sprocket centers from each other using a tape measure, but I won't get a super high level of accuracy. How do I determine that my versablocks are sufficiently spaced, such that my chain is tensioned?