I don’t currently own any digital servos but I do own the HiTec HFP-10 Digital Servo Programmer.  So is this just another piece of technology that is actually useful or did I just buy it to throw money away?

This is one of those tools that you don’t really need but once you have it, it is so handy.  The unit is a rather handsome, compact device made of brushed aluminum.  On the face we find 4 buttons, an LCD display window, an adjustment knob and power switch.  The unit comes with its own rechargeable 4 cell 1100ma NICAD battery pack built in. 

 

 

 

 

 

 

 

 

 

 

There are 2 ports located on the right hand side.  One for plugging in a servo and the other to plug in a receiver channel  output OR for charging the internal battery. 

 

 

 

 

 

 

 

 

 

 

Upon turning on the unit, the display shows the current firmware version installed in the unit.  There are a total of 10 test routines built into the unit, 6 of which are strictly for digital servos (HiTec servos of course) and the other 4 tests are for any servo, any brand.  The tests are setup in an endless loop that you page through with one button and then select with another.  Depending on the test chosen, there can be several sub-tests.  This all sounds rather difficult already, but once you play with the unit for about 5 - 10 minutes, actually it isn’t.  HiTec has also printed a handy flow chart of all the tests, on the bottom of the unit for easy referral without having to worry about losing a piece of paper.

 

First, I’ll briefly describe the 4 tests that aren’t just related to digital servos (the other 6 tests are for digital servos):

 

1. Transmitter Pulse Width

With this test, you can see the pulse width time being supplied to any servo.  Merely plug any receiver

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servo output jack from the receiver  into the tester and move the transmitter control.  Neutral or center position for any channel should show 1500ms.  Then move the stick/pot/switch on the transmitter to each extreme and you can see the end point pulse width time (or any position in between) displayed.  These values should be pretty much the same for each channel, assuming that all adjustments have been returned to the original factory settings.  The difference in time for each extreme should be symmetrical also.  If the stick decreases by 400ms when moved in one direction but only 300ms when moved in the other direction, something is wrong.

 

2. Measure Voltage

This will measure the voltage supplied to any servo from the receiver.  Again you plug any receiver channel into the unit.  By pressing one button you can read the actual voltage supplied to the servos while resting.  By moving the servos and pressing a button again, you can also read out the lowest voltage delivered to the servo.  This would be a good test to see if any servo is drawing excessive amounts of current and thus pulling the voltage down excessively.

 

3. S-Test Manual

Here you can test the servos manually by plugging the servo into the unit’s servo port.  If you press a button, one end point is tested by supplying a 900us pulse width.  Another button press tests the other end point position of the servo by supplying a 2100us pulse width.  One further button press gives you the neutral servo position by supplying a 1500us pulse width.  You can also control the servo position by use of the adjustment knob to dial in whatever pulse width you want. 

This test is especially helpful when setting up a new plane.  By using the centering 1500us pulse width on each servo, you get the exact neutral position without having to power up the receiver and transmitter.  This then makes setting up the physical neutral of the control surface attached to the servo very easy. 

You can also setup your throws with this setting.  For example, if we want to set up 1/2" up and down for the elevator.  Just turn the knob till you get the throw you want up and down, then write down the pulse width values for

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