Minitrac™
Document: UMDC013503.docm
Revision: A13
Created by: JSS
Date: 17 Nov 2019
3072929-A13
Source Location: C:\ePDM\ISLEng\products\dc-minitracs8000\manuals\UMDC013503.docm
Page 9 of 26
User Ma
nual
Differential Steering
Differential Steering
means steering by varying the speed of two tracks such as with a tank or bulldozer.
During the steering process the tracks are dragged sideways in addition to forward / backward
movement. The sideways movement adds to the total track load and requires extra torque from the
motor. The greatest increase in loading occurs during a spot turn; the load being calculated as per the
figure below. A typical 41 kg (90 lb) VT150 MKII vehicle on a surface with friction coefficient µ = 0.5 will
experience an additional 12 kg (27 lb) load per track to execute the spot turn. The same maneuver done
on fine dry concrete or low-pile carpet will result in over 23 kg (50 lb) of extra motor load! When steering
on a vertical surface include only the magnetic down-force for the differential steering load calculation.
Curved Geometry
Curved Geometry
inside a pipe will increase the payload on a track depending on the angle of contact
with the pipe. For nearly flat tracks the increase is small. For a contact angle of 60°, the load is doubled.
The same calculation is used for a track contacting the outside of a pipe. Include both vehicle weight
and magnetic downforce for this calculation.
