Thread Tools
This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Jan 01, 2016, 06:12 PM
Registered User
Jack Crossfire's Avatar
Thread OP
Discussion

14 year old servos


These Tower Hobby servos date back to the DVD robot of long ago. They were $6 in those days, but should have held up. It went hundreds of miles, then snapped during a mild crash after 1 mile. There are no metal gears for standard servos. Now going through all the Futaba servos in the apartment until they need new gears. The Hitec servos won't fit in the lunchbox's servo saver. Only Futaba & generic Towers will.

The trick with servos is the screw needs to go down past the case. That should transfer the load from the screw to the case, rather than from the screw to the gear to the case. Unfortunately, servo horn screws are yet another extremely rare hobby screw size with no more local shop. It would be more effective to eliminate the "servo saver" so the lone existing screw from 1988 can reach far enough.

After some grinding & 2 stripped screws, managed to get a custom horn loosely fitting where the servo saver went. The screws would never be a perfect fit. These servos arrived from China with only the Futaba S3003 sticker but nothing else matching the photos, no screws or attachments. Only stray Sanwa mounting screws & Sanwa horns from 1988 fit.

The screws are 1.6mm inner diameter, 2.2mm outer diameter, at least 9.5mm long, 0.825mm thread spacing.

After test driving in manual mode, it was time to drill out the Chinese gear & use a standard screw size to get the steering horn flush. It drifted quite a bit.
Last edited by Jack Crossfire; Jan 02, 2016 at 08:46 PM.
Sign up now
to remove ads between posts


Quick Reply
Message:
Thread Tools