PT785-S Pan & Tilt System

SKU:
$349.99

This is the point and shoot PT785-S pan and tilt system.  This precision, closed-loop system is designed to manipulate cameras and devices up to 6lbs even though the entire head weighs a mere 1.85lbs. Each axis is driven by a Hitec HS-785HB servo that is geared down for more power and precision. 1" diameter hollow aluminum shafts supported by ABEC-5 precision ball bearings allow video and power wires to be cleanly routed through the points of rotation and remain tangle free.  The framework is constructed of black anodized aluminum to create a sleek and robust structure. The stock Hitec HS-785HB servos that drive the pan and tilt can rotate several turns in factory form. By coupling the servo to an external gear set, the amount of rotation is decreased by the ratio but the torque and precision is increased by the ratio.

This system is a simple plug-and-play with any servo controller.  Perfect for still photography, amateur videography, security applications or even antenna tracking stations.  The PT785-S can easily be mounted to various jib-cranes in the hanging or upright position using the JM-1100 jib mounting kit (sold separately).  Balancing your camera or device is easy using the vertical slide adjustment.  Camera, controller, power supply, and servo extension leads sold separately.  Manufactured in the USA.  Patented.

Features:
• Adjustable Framework
• Aluminum Hollow Shafts
• Aluminum Construction (Anodized)
• 32 Pitch Gear Drive
• Precision HS-785HB Servos
• 4.8-6.0 Volt Operation

• Fully Assembled with 1/4-20 Camera Screw

PT785-S schematics

PT785-S Plate SchematicsMPT1100-SS & PT785-S bottom plate

Tech Tips:

Calculating Travel

I am going to use a servo controller with a 1000-2000usec PWM signal range and am using the stock 7:1 ratio.

2000usec-1000usec = 1000usec

1000 x 1.525 degrees = 1525 degrees. This is the amount of rotation the HS-785HB servo itself will rotate.

1525 / 7:1 ratio = 218 degrees. This is the amount of rotation that each axis on the pan and tilt will rotate given the stated signal range.

Creating a Faster Ratio

The stock PT785-S Pan & Tilt System uses a 7:1 gear ratio. If your use-case calls for a faster ratio you can separately purchase different gears and swap them out for the stock gears. You can use a 76 tooth hub-mount gear and a 20 tooth servo gear (with a C24T spline) to achieve a 3.8:1 ratio. 

If the servo controller you intend to use transmits a standard PWM range of 1050-1950usec, the 3.8:1 ratio will achieve just over 360 degrees of rotation on each axis. On the same controller when running a 7:1 ratio, each axis would rotate approximately 196 degrees.

If you run a servo controller capable of a 675-2325usec signal range, you can achieve just over 360 degrees on each axis running the 7:1 ratio or approximately 662 degrees with the 3.8:1 ratio. 

*Figures are calculated by multiplying the PWM range by 1.525 to get the number of degrees the servo will rotate.

The speed, torque and precision of the PT785-S are altered by the external ratio. The 7:1 ratio will yield higher torque and higher precision but will be slower than a 3.8:1 ratio. The 3.8:1 ratio will have more rotation given the same signal but will have less torque and less precision when compared to the 7:1 ratio. 

    • 6V max speed with 3.8:1 ratio: 68 degrees/sec
    • 6V max speed with 7:1 ratio:  37 degrees/sec
    • 6V stall torque with 3.8:1 ratio: 695 oz-in
    • 6V stall torque with 7:1 ratio:  1281 oz-in
    • Precision with 3.8:1 ratio: 1 pt every 2.8 degrees
    • Precision with 7:1 ratio:  1 pt every 1.5 degrees

Specs

Maximum Payload 6 lbs
Weight 1.80 lbs (28.8 oz)
Servo Included (2) Pre-installed HS-785HB servos
$349.99