QuoteBTW; does anyone know the current a tortiose motor will draw?  I lost the specs I had.  Any feedback is appreciated.
Rich

Circuitron Tortoise -- During operation, the draw is approximately 3ma. Stalled it will draw up to  25ma.

QuoteA 1:20.3 locomotive is moving a lot slower in scale than even a 1:29 locomotive travelling at the same actual speed would be going in scale....
Matthew (OV)

To cover the same distance in the same time
1:20.3 scale is 7 MPH
1:29 scale is 10 MPH

You used the MPH formula correctly (6.98 rounded 7.0 MPH).

Too many variables to state all Bachmann Large-Scale 1:20.3 38 Ton Shays will be running 7.0 MPH at 10 Volts.

Quote from: Mark Damien on February 14, 2007, 06:36:03 PM

OR  if you don't have a calculator handy

Divide MPH by 5 to give Inches per second.

60MPH/5 = 12 Inches/Second.

Multiply Inches per Second to give MPH.

18 Inches/Second X 5 = 90MPH

Mark, your method works for HO scale only.

The following can be used to calculate scale miles per hour for any scale and any timed length of travel. Best to use a stop watch to time the travel over a measured distance.

L = length of travel in inches
F = scale factor
T = time in seconds for locomotive to travel length.

Scale MPH = ((L x F/12)/5280) x 3600/T

Example: If it takes 5.2 seconds for a HO locomotive to travel over two straight pieces of Bachmann sectional E-Z Track.
L = length of travel in inches: 18 inches
F = scale factor: 87.1
T = time in seconds: 5.2

Scale MPH = ((18 x 87.1/12)/5280) x 3600/5.2 = 17.1 MPH 

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To use   Microsoft EXCEL
Cell A1 enter length travel in inches
Cell A2 enter scale factor
Cell A3 enter time in seconds
Cell A4 enter the scale MPH formula  =((A1*A2/12)/5280)*3600/A3