my mover matt brown spring tx feb 2009. outline 1.track & wheels 2.motors / battery / electrical...

My MoverMatt BrownSpring TXFeb 2009

Outline1. track & wheels2. motors / battery / electrical

o drive train optionso battery sizeo Recharging

3. lighting o where to get 12V leds cheap!

4. general construction o how to make your mover look like a traino smoke stacko cow catcher

5. security & safety1. making sure your mover is still there the next night2. keeping little ones out of harms way or from them harming your mover

Track

• Built from plastic lattice – available in the molding section of Lowes/Home Depot

• 2 widths used: ¾” & 1 ¾” (8’ lengths)• 5 pieces per rail were laminated together to form

a groove• Ties are standard 1x6” treated deck board• Rails attached to ties with gusset plates• Track built in a circle, then cut into two 180°

sections

Track

Wheels

• Drive wheels are 7” lawnmower wheels from Lowes. One directly attached to motor and the other attached via a lag screw.

• Smaller wheels were plastic (intended for robotic use) and attached via a lag screw. These quickly wore out and were replaced with solid rubber caster wheels attached to a steel shaft.

• All wheels are attached to a piece of ¼” plywood that rides in the groove.

Wheels

Original wheels – attached to trucks with lag screws

Drive wheels

New wheels

• New wheels are much better!

• 2 ½” diameter• Grizzly.com #G7079

Motor

• Windshield wiper motor purchased from monsterguts.com

• Directly attached to wheel• Wiper motors have two +12V connections:

one for high speed, one for low speed, so DC motor controller is not required.

Motor

Battery

• Purchased a new 35ah (U1 size) deep-cycle battery on eBay (no taxes, no recycling fees)

• Automatic battery charger from Walmart• We removed the battery from the train every

night and brought it into the garage for charging. Charged at 4 amp rate.

• Sealed AGM batteries are safest and longest lasting, but more expensive. In case of an accident, you don’t want battery acid on your lawn or on the hands of your neighbor’s children.

Schematic

Lighting

• Great deals on 12V LEDs at dealextreme.com, however they ship direct from Hong Kong so plan on a long delivery time. Lots of options, so get creative!

• Also found battery operated lights that require 4 cells (6V) at Target. Two of these can be wired in series and powered directly from the 12V battery.

Construction• 5-gallon paint bucket for the boiler• PVC pipe and funnel for the smoke stack• Melamine dinner plate for the front of the boiler

(yes, I took my measuring tape to HEB and measured the various plates until I found exactly the right size).

• Cow-catcher made from tongue depressor sticks from Michaels.

• Battery rests in the cab. This is very important! The battery’s weight improves the traction of the drive wheel.

Construction

Base Cab attaches to base with 3 screws.Boiler attaches to cab with 1 screw.

Fully Assembled

Security & Safety

• When we brought the battery in for the night, we also locked the train to a steel cable wrapped around a tree.

• The track was surrounded by rope light suspended from candy canes. This allowed the train to be seen, but kept children from getting too close.

What worked?

• Modular construction of engine made it quick to assemble and disassemble.

• Direct drive motor was very quiet.• Electrical system was very reliable.– Battery had plenty of capacity and charged

reliably– When mechanical problems occurred, the fuse

blew, protecting the motor and battery.

What needs improvement• More lights!• Too much friction using grooved track, made

worse by tight radius. Plywood that rode in the groove would warp when it got wet.

• Lag screws don’t make good axels.• Reduce weight of cars that get pulled.• May continue to use plastic lattice for rails

because it makes curves/circles easier, but will use gusset plates on both sides of each rail to limit rail deformation.

Next Year: The Kindla Method

Notice the casters that face outward, keeping the train on the track.No grooves. Much less friction.

Dimensions-Front View

Dimensions-Side View

Dimensions-Top View