If you have a SG2100 motor with the smaller 42mm shaft, you can upgrade the shaft to the 50mm size to give you more torque power for heavier dishes. Note the 42mm shaft is easy to replace.
The 50mm shaft will require that your dish has the U-Bolt mounting bracket.
You can view and order the 50mm shaft here (#17 on the list):
HH Motors STAB, Digipower, Moteck, SatControl, Sadoun DisEqC