Tag Archives: Center Servo

How To – use RC Logger Digital Pitch Gauge To Center Servos

Want that perfect zero on your servo horns? Here’s how to do it using your RC Logger Digital Pitch Gauge.

This build is based on the RC Logger Digital Pitch Gauge 2 kit as it requires the use of the tail blades mounting adapter.

Very quickly. Yes I know that:

  • This method only centers the servos relative to the servo case and not the main shaft.
  • Some FBL units can compensate for servos that aren’t perfectly centered.

STEP 1.

Get yourself one of these protractors from your local office supplies store. I chose this one because it has plenty of horizontal lines measurements already on it to use as references for cutting later.

Cost me $2 AUD.

Cost me $2 AUD.

STEP 2.

Next you need to determine the minimum width of the mounting plate for you pitch gauge. You will need to add the width of the servo horn at the output shaft to the width of blade grips on the pitch gauge tail blade adapter.

Measure the width of your servo horns.

Measure the width of your servo horns.

Measure the width of the blade grips.

Measure the width of the blade grips.

To allow for a little extra clearance I rounded up the width to 30mm.

Step 3.

Cutting the plastic down to size. For this I simply used a trimmer knife to score my line a few times and then snapped it off by hand. So far, every time I’ve done this it’s resulted in a good clean break.

I used the 30mm graduation line. No measuring required.

I used the 30mm graduation line. No measuring required.

Again. Used the pre-printed meausrements. Used this square on the factory edge to to get it neat.

Again. Used the pre-printed meausrements. Used this square on the factory edge to to get it neat.

Step 4.

Now take some sand paper and sand the edges using the square to clean up the cut. Start with the factory edge as your reference point. Keeping it square is very important.

Step 5.

Now measure:

The diameter of the horn retaining bolt

The diameter of the horn retaining bolt

The diameter of the ball retaining bolt, and

The diameter of the ball retaining bolt, and

Step 6.

Drill the hole for horn retaining bolt in the center of you mounting plate (In my case it was 3mm). Then mount the horn and line it up perfectly, mark and drill the hole for ball retaining bolt (In may case 2mm).

Drill Center Hole

Drill the center hole and mount horn.

Note:

Note the gap between plate and horn once mounted. Retain this gap when the ball retaining screw is installed to avoid bending and cracking the plastic mounting plate you’ve just made.

Keep this gap to avoid bending and breaking the plate.

Keep this gap to avoid bending and breaking the plate.

Step 7.

Mount your plate and servo horn back on your servo at the point closest to zero. This can be done visually. Of course ensure no trims are set in TX and/or your fbl unit is also at default (zero) trims and/or your offset is at zero if using servos with programmable centers.

Plate mounted on servo.

Plate mounted on servo. Note that servo not powered hence not showing even close to center.

Step 8.

Choose a flat and solid reference surface and zero your RC Logger Digital Pitch Gauge on it.

Zero the gauge on a reference surface.

Zero the gauge on a reference surface.

Step 9.

Mount the pitch gauge to your mounting plate using the tail blade mount and blade grips. Place the servo against the same reference surface and simply adjust your trims or offsets until zero or very very close to it. Your done.

Trims adjusted to read zero.

Trims adjusted to read zero.