My 8 year old grandson, having just solo-ed his MAD Highlander successfully, following a "one-point landing" which was spectacular, felt he needed all the "things" grand-pa had, to charge, and check, batteries, so I started putting together some cabling for an ESV and found I needed a plug from a servo. I dug into the junk box and found a "Hobbico" which had failed during one of my own "spectacular" landings about a year ago. I opened it up just to see how many teeth I could find floating around inside, and discovered something interesting. And just a little confusing. The servo is a Hobbico mini, CS-31 which I did not see listed in the Tower catalog. Interesting point number one. The case parts have identification numbers "HS101x". ("x" =T, M and L, referring to "top", "middle", and "lower" respectively. But the "HS" prefex got me wondering, thinking that "HS" referred to "Hitec Servo" and "CS" would refer to "Command Servo", the Hobbico. Maybe "HS" is "Hobbico", or both are the same with different labels on the outside? Interesting point number two. Looking for a "HS101" under "Hitec" in the Tower catalog showed nothing either. Interesting point number three. I noticed a plastic (?) gear replacement repair kit at the hobby store which was labeled for Hitec, and appeared to be the same size, but passed it up as I figured as cheap as these servos are, there is no sense making a repair and taking a chance, over the long run. But I am still curious about the numbers. Anyone know? - No guessing now! Last surprise was finding the servo motor labeled "Mabuchi". Guess they are pretty much the "standard" in low end motors? I keep seeing "Mabuchi style motor included", or "-with Mabuchi 550 motor", advertised with some of the electric sailplane kits. Oh, yeh, before you ask, there were three teeth floating around. By placing the transmitter trim and stick full over, with the servo hooked up, I was able to rotate the potentiometer gear, driving the damaged "idler" gear to mesh the teeth. With the transmitter trim centered, plus and minus, and normal stick throw, the servo would be salvageable in an emergency. So, maybe it's a good idea to include a very small phillips screwdriver in your tool kit for the rare occasion you are in dire need. After very careful inspection I would not hesitate to use this "emergency" repair to salvage a day lost without a spare servo, and who carries "spares" anyway? :-) Just make sure with trim and stick centered, the gear is centered on the good portion of the teeth arc, and normal stick / trim doesn't cause the damaged gear to rotate past the good teeth. Later - Larry ( [EMAIL PROTECTED] ) RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]