Hi guys.

I've finally managed to source some retracts for my Parkzone T28 of a edf jet and I will be cutting into the fuse and wings to add them very soon. One question I havent been able to answer by reading the many build threads is whether or not you can just use standard micro servos for the retracts.

My plan was to souce some cheap off ebay but seaching retracts alot of people seem to say it is important to get the right servos. Is this just when you are working on large heavy systems?

Any advise would be great.

Thanks
Adam_Fozz

Retract servos are different than standard ones. They have more torque and they travel 180 degrees. They also turn off at the end of each cycle. As for micro applications, I am not sure if they make a retract servo. Have to do some homework on that one. Good Luck, Dave

For something that small you could just use a standard servo. True, they do not turn off like a "regular" servo, but neither does your throttle servo, or flap servo.

The only problem you'll find is that since a standard servo is so fast, the gear will slap up and slap down instead of moving at a nice, slow rate.

But you can avoid that with an inline device to slow the servos, or if your radio has it built in, you can slow the servos through the radio.

Using a standard Micro servos for retracts on a foamy = easily stripped gears...

Don't ask how I know!

Either use a retract servo, or a higher torque servo to help avoid this problem.

Okay OPJOSE, here is the question that begs to be asked.... How do you know???? Dave

Heh...

... servos with broken teeth, that I'm happy to submit for review.

Thanks for the good responses so far.

If I was worried about stripped gears couldn't I just use a servo saver spring like people do on cars to prevent damage when you have servos which stop dead...like on brakes?

yes

Or metal geared servos if you can find them in the size you need.

here is a med weight retract servo http://www3.towerhobbies.com/cgi-bin...?&I=LXPB41&P=0 low profile at 1.2oz its a little heavy for a foamy but it will get the job done for sure.
or this one low profile http://www3.towerhobbies.com/cgi-bin...?&I=LXPB42&P=0