Because uprocessor-based servos are attempting to achieve and hold a commanded position "much" more aggressively than non processor-based servos, component matching (proper servo for the job at hand) and set-up is much more critical.
Jittering (poor RF communication causing servos to hunt), surface binding, too heavy (too big) control surfaces, insufficient surface travel that causes binding, etc will all put undue strain on the motor, especially the brush structure. If the servo is having trouble just holding the control surface up while sitting on the ground, and then asked to go to a commanded position repeatedly can cause overheating. Overheating causes the brushes to fail, or the ciruitry supplying the current. If as you state there is no binding, the first failure should have pointed to an issue of this sort. The second should for sure. Putting a "non-digital" servo in where a "digital" servo failed (like on your rudder) is masking the problem. The non-digital servo is fighting the very same battle, just with less resources (as in update rate and current). Any "digital" servo asked to hold a position it can not achieve will experience heat build-up. Now depending on whether that servo so a Ferrari or a Yugo will dictate whether it gets compromized or just sits there and hums. All things being equal (no binding, proper servo for the job at hand, etc), I would rather have the Ferrari, er I mean Hitec 5125. It is not normal for these servos to fail in this manner, unless you are exceeded their design parameters. Buying servos based on advertised torque is only a part of the equation. Quoting "Albert E. Wedworth" <[EMAIL PROTECTED]>: > Hi All > I'm building a HM Ventus 2ax 5 m model sailplane. > I've used Hitec digi servos thought. > HS-5245MG digi Mini & HS 5125 MG Digi thin wing servos. > What I've noticed is they burn out very easily.. > What's up !!!! > I haven't gotten my plane in the air yet and I've burned up 5 of the servos > already!!!!! > > What burned out so far... > 1. rudder servo; on a pull pull system HS-5245 MG Digi > ( to tight ) my fault... Non Digi now. > 1.Tip aileron HS-5245 MG Digi servo. > 2. Flap servos HS-5125 Thin Wing Digi servo. > 1. Spoiler servo HS-5245 MG Digi servo. > None of my surface's are tight! > 5 cell battery pack. > > Should I be concerned??? > Is this normal??? > Could it be too much throw? > > I like that Hitec replaces then without a questions, But..... > > I've never had this happen with non Digi servo before.. > > So let me know if this is happing to others out there. > > Cheers > AL > > > > > Albert E. Wedworth ( AL ) > ERA Capshaw Realestate > REALTOR- ASSOCIATE > Cell 530-228-9445 > Fax 530-343-1715 Radius Systems Cogito Ergo Zoom RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
