Dean,

What is needed to cycle retracts on the bench?

I have the Chinese version of the servo tester which cost about 10-12 bucks (had it for years!). Never tried it on retracts but don't see why it wouldn't work.

Search for servo tester on eBay.  A bunch of choices will pop up.  For $8 this one looks good.

http://www.ebay.com/itm/5-6V-DC-Digital-LCD-Servo-Tester-ESC-Consistency-Tester-For-RC-Helicopter-/390658427100?pt=Radio_Control_Parts_Accessories&hash=item5af50e88dc

One thing you need to remember is that just about all servo testers require a 5V power input unless you are testing a speed controller that has a BEC.  What I have used in the past is a Radio Shack 4 cell battery holder with a servo lead attached.  If the retracts get their power from the receiver or speed controller BEC make sure the BEC is rated with enough amps to drive the retracts.

By the way all servos, speed controllers, and retracts operate on the same pulse, so a standard servo tester will test most any device.  The only exception are some of the very expensive digital interface servos.  It's not likely you would run into any of these.

Tom,
 This trick worked for me(got it from Will Hubin). If you are using a FM retract timer you only need a 3 wire servo extension lead,clip the white wire on the lead, connect it to the FM retract timer and ESC(make sure you have the polarity correct). If I recall the motor will need to be connected also but will not turn.  You will have to program the FM retract timer so it will cycle up and down. Then hit the start button.
Bob

Hi Gang This looks good, and has a built-in tachometer too.

http://www.innov8tivedesigns.com/product_info.php?cPath=30&products_id=1249

Dean P.

If I read it correctly You can put a battery in this unit and it becomes self powered.  This is a great feature.  Especially for field use.