AP Assembly Tutorial

DOME DRIVE Rev. E

The AP Dome Drive was designed with the following objectives:

-- Provide a life-like rotation speed.  The head should snap to any position in a couple of seconds or less.

-- Provide a means to insure constant, even contact with the dome bearing.

-- Make the assembly robust so that it doesn't require frequent adjustment or tinkering.  The individual parts should be durable and of high quality to insure long life.

-- Use a high efficiencey motor to minimize battery drain.

NOTE: This drive was designed for the lighter domes before we started using aluminum for the accessories, periscopes, battery packs, etc in the dome. If you have a fully pimped dome that weighs a lot, you will probably find this motor a bit marginal, and it will need to be replaced every couple of years. We have the new drive for Banebots motors that is much more robust, at the same price. It does pull a bit more on your battery and make a little more noise, but might be worth checking out.

ENGRAVED WHEELS: I designed this drive so that it will accommodate the nice engraved wheels from C4. If you have one of them and want to replace the plastic frame, just order this kit and it will bolt right on.

Specifications:

Pittman GM9413-2 Motor specifications

3D CAD with parts breakdown

Pre-assembly :  Motor holder after debur, cleanup and installation of the bearing insert.

Pre-assembly:  Pivot screw is inserted into the motor holder.   Notice lubricant applied to shoulder screw (petroleum jelly).

Pre-assembly:  I attach two fiber washers to the back side of the motor holder.

Pre-asembly:  Bracket is attached to the motor holder.  There is a nylon insert in the shoulder screw to keep it from coming out, but a thread adhesive could also be added if it does not stay tight.

Assembly:  Attach the motor to motor holder using two 10-32 X 3/8" cap screws.

Pre-Assembly:  The hub is attached to the wheel using four 5-40 socket head screws.  It will be necessary to loosen these screws a bit to attach the wheel to the motor later.

Assembly: Attach the friction ring to the wheel.  We are using a 411 red silicon o-ring.  It gives good adhesion to the rockler with a light spring.

Assembly:  Wheel is attached to the motor.  Once it is in position tighten the for screws in the wheel hub.  Leave the set screw loose until the drive is mounted on the droid.

Using a JAG Version 4 frame as an example here for the next step. We are looking down at the top ring, and I have circled the holes that are premade for the AP dome drive. Two holes for the motor holder T bracket and one for the tension spring.

Here are the dome drive mounting holes in a bit closer shot. Two holes for the T bracket attachment, and one holds the spring. These need to be tapped ¼-20 to use the supplied ¼-20 X 5/8” screws.

Next step: Insert a supplied ¼-20 X 5/8” screw through one end of the spring.

Attach the screw/spring to the frame top ring from the bottom. It needs to come through the tapped hole until it is flush with the upper surface of the top ring. A thread adhesive can be applied if desired.

Next step is to attach the Motor holder to the frame. The remaining two ¼-20 X 5/8” screws are inserted through the motor holder holes from the bottom side.

Attach the motor holder bracket to the bottom side of the frame top-ring. Screws need to be tightened until snug. The bracket is 3/8” thick and the top ring is ¼” thick. The screws should come up flush with the surface. If the screws extend above the surface (as with the JAG version 4 frame), add a washer to each to bring them back to flush level.

Attach the rocklwer bearing to the frame top ring next.

Now stretch the spring over and attach it to the stud on the motor holder frame.

The drive has now been attached to the upper frame ring with two 1/4-20 X 5/8" cap screws.  The third included cap screw holds the tension spring to the frame.  The spring is stretched from the frame attachment screw to the 1/4-20 set stud on the end of the motor holder.

Adjust the height of the drive wheel to be centered on the rockler and then tighten the set screw in the wheel hub.   You are now ready to attach power from your speed controller.  The motor works with 12 or 24 volts (24V makes for a faster rotation).