Plummer Industries

Drive Rail Selector

The best way to figure out what drive rail is best for your application we recommend asking yourself the following questions.

- Do your need to drive wheels that are on the same side individually? ( ie. Mechanum )

     -If yes, you should be looking at our DR-2 line

- How many wheels do you want per side of your robot?

- How long do you want your robot to be? (direction of drive)

    -We currently offer 24", 30", and 36" lengths

    - With our Brackets it is easy to add one or two inches to any Drive Rail

- How much ground clearance do you need? ( Think about how high you want to mount your mechanisms to as well) 

    - The DR-2 ground clearances are 1/2" with a 4" wheel and 1.5" with a 6" wheel

    - The DR-3 and DR-4 maximum* ground clearances are .5" with 2.5" wheels, .75" with 3" wheels, 1" with 4" wheels, 1.5" with 6" wheels, 2.5" with 8" wheels. 

*Maximum ground clearance is from the rail next to the center wheel to the ground. As there is a 1/8" drop on the center wheel there will be at least 1/8" less clearance on both ends.

- How fast do you want your robot to go?

      - For all our drive rails we offer 3 different gearing options

DR-2 Speeds
Gear Ratios 12.51 to 1 10.83 to 1 8.3 to 1
4" Wheels~7 Fps~8 Fps~10.5 Fps
6" Wheels~10.5 Fps~12 Fps~15.5 Fps


DR-3 and DR-4 Speeds

Gear Ratios for SS-3-775

40.47 to 129.62 to 125.83 to 1
2.5" , 3" , and 4" Wheels~8.5 Fps~11.5 Fps~13.5 Fps
6" Wheels~10 Fps~14 Fps~16 Fps
8" Wheels~11.5 Fps~15.5 Fps~18 Fps
Gear Ratios for SS-2-Cim17.8 to 115.5 to 112.05 to 1
2.5" , 3" , and 4" Wheels~6 Fps~7  Fps~9 Fps
6" Wheels~7.25 Fps~8.25 Fps~10.75 Fps
8" Wheels~8.75 Fps~10 Fps~ 13 Fps


Now, with all those questions answered you should be able to put together a part number for a drive rail.

DR- (Number of wheels per side) - (Length of rail) - (Wheel size) 

   - For DR-2 models the part number also include a gear ratio number as the last part number