AM Shifter (Gen 1) am-0001

Product Overview

The AM Shifter includes hardware for both pneumatic shifting and servo shifting (the pneumatic cylinder is not included). Hardware for the pneumatic shifting method is installed for shipment while the servo-shifting hardware is packed in the hardware baggie.

This transmission is a two-speed, shift-on-the-fly gearbox, using a dog shifting method. Motor input includes two CIM motors, or two AM Planetary Gearboxes or a combination of either. The output shaft is contained within the side plates of the gearbox. Two 12-tooth sprockets are mounted to the output shaft. The overall ratio between high and low gear is 2.56:1.

Shift Style:

Two shifting methods are available for the AM Shifter. The pneumatic method is much stronger and faster than the servo method.

Pneumatic: A pneumatic cylinder, Bimba model 04-0.5-DP, 3/4" bore x 1/2" stroke, (not included) shifts between high and low gear. This cylinder mounts with a 5/8-16 nut (not included). This is a strong, fast method of shifting, lasting under 0.5 seconds and pushing with 26 pounds of force (if using 60 psi). This pneumatic shift can be done while a robot is accelerating.

Servo: A Hi-Tech Servo, model HS-322HD is included, using an actuation fork to shift between the 2 gear settings. This is a slow, weaker method of shifting (compared to pneumatic), taking 1.5-2 seconds and pushing with up to 5 pounds of force. A robot driver may need to back off of the throttle to let a servo shift gears while moving.

Weight: 3.4 lbs.

Hardware:

Shielded, flanged ball bearings

4140 steel 20 dp gears, w/ 14.5 degree pressure angle

3/32" thick steel side plates with zinc plating

encoder, cable and servo included

Output sprockets: 12 tooth, 35 series steel

Loose Hardware:

(shipped in a bag, with gearbox)

Two - CIM gears (12 tooth)

Two - 5/16" retaining clips

Two - 2mm x 2mm machine keys

Four - #10-32 screws, for motor mounting

One - servo w/ aluminum servo arm

One - Servo shaft with shoulder bolt and washers, for servo actuation

One - 3/16" id, 1/2" long bushing for servo actuation

One - 1/4-28 nut to lock cylinder to shift block

Four - 5/16" id washer to space out CIM gear (2 for each motor)

#8-32 screws and nuts, for mounting servo

One - US Digital CA-3285-1FT encoder cable

Encoder alignment

The encoder wheel fits on the back end of the Output Hex Shaft so that the outer face of the encoder wheel is aligned at the same level as the tips of the encoder clip posts, as shown in this picture:

 

Motor Input:

Designed for 2 (or 1) motor inputs

Use CIM motors or AM Planetary Gearboxes or a combination of both

Gear Reduction:

STANDARD GEARING

Ratio between High and Low gears: 2.56:1

Low Gear: 10.67:1

High Gear: 4.17:1 OPTIONAL GEARING
(available as optional parts)

Ratio between High and Low gears: 4:1

Replace the standard 35 Tooth Small Output Gear (am-0023) and the standard 28 tooth Medium Cluster Gear (am-0025) with the 28 Tooth Small Output Gear and the 35 Tooth Medium Cluster Gear, to get these new output ratios below

Low Gear: 10.67:1

High Gear: 2.67:1

Optional side plates

Aluminum inside and outside replacement side plates are available

NOTE:

The AM Shifter Gen. 2 is the same version as this Gen. 1 gearbox, except there are different side plates on the Gen. 2. These side plates were used for a larger motor provided to FRC teams in 2005-2007.

Layout Drawing

Print showing dimensions and shifting methods (.pdf)

CAD Files

These are in .stp format, right click and "save as", then open them in your solid modeling software.

AM Shifter, pneumatic setup, with motors and air cylinder

AM Shifter, servo setup, with motors and servo