Hi Bruce,
Please see the main Radio forum and check the links in post #3.
I hope you find this information helpful. You can also reach our Futaba support technical team at 217-398-8970, or via fax at 217-398-7721.
Sincerely,
Krysta Hunt
Product Development & Support Specialist
Futaba Service Center USA
http://www.rcuniverse.com/forum/m_4765498/tm.htm
ORIGINAL: bruce88123
Will you please tell me the exact differences between the S3001 and S3004 servos? Bearings, motors, circuitry? What accounts for the difference in weight? Thanks.