Dual CIMs and #25 Chain

[AdamHeard]

Originally Posted by sst.thad

Our team plans on prototyping a direct drive this summer. I already have a cadded version, we just need to find a way to machine the side plates. Ill post both the cad of this transmission and a picture of this years drivetrain when i get home.

If we do have to use chain again, we will most likely use #35. Would anyone be willing to help with the math? Because we use 7/16 hex, the biggest sprocket we can buy is an 11 tooth for 35 chain. With this size sprockets what would be the torque load on this?

Why don't you post some pictures of your current setup so we can better offer help.

[Thad House]

Ok Here are some cad pictures that are accurate.

The first picture is from the top, and the second one is from the back. The sprocket coming off of the transmission is the one that is placed closest to the bearing on the pillow blocks. The transmissions are held together with the aluminum rod in the KOP. Chain runs straight down from the transmission to the axle.

[Mr. Van]

Without pictures, this is something of a guess, but I do have a suggestion.

Replace the chain that runs from the transmission to the center wheel with 35 pitch. Keep the other two chains (from the center to the outer wheels) at 25 pitch.

As was posted earlier, the chain from the transmission to the center wheel is going to have 2-3 times the tension as the other two.

Just about everyone (including most of the "WCD" crowd) uses 25 pitch chain, but they do not have a single chain taking the entire load on one side of the robot. Replace that chain with 35 and you should be good to go with little or no other modifications.

- Mr. Van
Coach, Robodox