McGrew's MiscellaneaDerby

Four-Lane Derby Track Plans
for a Shape N Race Derby, Pinewood Derby, etc.

Shape N Race Derby, Pinewood Derby, Kub Kar Rally—whatever you call it, a derby is a lot of fun, and it's a great opportunity for learning and for making memories.

This is a set of plans for a four-lane derby track. The track is designed to disassemble for easy storage.

Review these plans carefully to familiarize yourself with the various parts and with the construction process. Construction is fairly simple, and the track can be built with home workshop tools. However, precision is important; sloppy work will produce a track with noticably faster/slower lanes, with section joints that derail the cars, or with other defects that will diminish everyone's derby fun.

Be sure to drill pilot holes for all screws, to avoid splitting the wood. Use carpenter's glue on all permanent wood-to-wood joints, in addition to whatever mechanical fasteners are used.

Overview

List of Materials

One reader said he was able to buy all the materials needed for about US $100.

Lumber

Part #Qty.Item Description
L14 @ ½" × 14" × 8' plywood (base sections)
L216 @ ¼" × 1 3/8" × 8' lattice strip (lane guides)
L31 @ 1" × 4" × 72" pine (brace)
L41 @ 1" × 4" × 38" pine (stabilizer)
L52 @ 1" × 4" × 43" pine (long legs)
L63 @ 1" × 4" × 14" pine (leg cleats)
L72 @ 1" × 4" × 12" pine (short legs)
L81 @ 1" × 4" × 4" pine (brace block)
L93 @ 1" × 2" × 88" pine (base supports)
L106 @ 1" × 2" × 16" pine (section cleats)
L111 @ 1" × 2" × 20" pine (starting bar)
L121 @ 1" × 2" × 14" pine (end cleat)
L134 @ ¼" dowel × 4" (starting posts)
L141 @ ½" dowel × 6" (starting bar handle)
L154 @ ½" × 1 3/8" × 1 3/8" pine (guide risers)

You should be able to cut Parts L3 through L8 from three 8' lengths of 1" × 4" pine. You should be able to cut Parts L9 and L10 from four 8' lengths of 1" × 2" pine. You should be able to cut Parts L11 and L12 from one 3' length of 1" × 2" pine.

Hardware

Part #Qty.Item Description
H13 @ 6" × 14" × 1/8" sheet metal (section connectors)
H224 @ ¼" × 2" flat-head stove bolts (with washers and wing nuts)
H32 @ ¼" × 2" round-head stove bolts (with washers and wing nuts)
H45 @ 2½" × 2½" hinges (with screws)
H51 @ 2½" × 2½" loose-pin hinge (with screws)
H62 @ 1½" × 1½" loose-pin hinges (with screws)
H71 @ 1/8" inside-diameter screw eye
H836 @ 1¼" #10 flat-head wood screws

Other Supplies

Build Track Sections

Lay Out Base Sections

Label the four plywood base pieces (Part L1) Section 1, Section 2, Section 3, and Section 4. Section 1 will be the starting-gate end, and Section 4 will be the finish-gate end.

Secure Lane Guides to Base Sections 1, 2, and 3

The key to a fair track (a track without faster/slower lanes) is the proper alignment of the lane guides and track sections. Do not rush this step. Check, double check, and triple check the alignment of the lane guides before securing them in place.

[Figure 2.1, 1.6k PNG]
Figure 2.1 - lane guide spacing (top view)

Apply carpenter's glue to the lane guides (Part L2). Carefully position the lane guides on the track base sections (Part L1) on 3½" centers. (See Figure 2.1.) Clamp the lane guides in place. Secure lane guides with ½" brads. Allow glue to dry completely.

The centers of the lane guides will be 1¾", 5¼", 8¾", and 12¼" from either edge of the track base.

Secure Lane Guides to Base Section 4

[Figure 2.2, 0.8k PNG]
Figure 2.2 - friction brake (side view)

Section 4 is different from the other sections because the last 3 feet of the lane guides are raised to form a friction brake. The underside of the cars will drag on the raised lane guides, slowing the cars down after they cross the finish line. (See Figure 2.2.)

[Figure 2.3, 1.9k PNG]
Figure 2.3 - Section 4 (top view)

Align and secure the lane guides for Section 4 the same way you did for the other sections, but do not secure the last 3' of the lane guides (the three feet closest to the end cleat). (See Figure 2.3.)

Secure End Cleat to Base Section 4

[Figure 2.4, 0.9k PNG]
Figure 2.4 - end cleat position (bottom view)

Apply carpenter's glue to the end cleat (Part L12). Position the end cleat on the underside of Section 4 along one end. Clamp the end cleat in place, and secure it with two 1¼" #10 flat-head wood screws (Part H8), one at each end. (See Figure 2.4.)

Construct the Friction Brake on Base Section 4

[Figure 2.5, 1.0k PNG]
Figure 2.5 - friction brake construction (side view)

After the glue has dried, create the friction brake by supporting the loose ends of the lane guides with the guide risers (Part L15). Apply carpenter's glue to one guide riser, then position it under the loose end of the lane guide and clamp it in place. Secure the lane guide to the guide riser with ½" brads. Secure the lane guide to the base with one 1¼" #10 flat-head wood screw (Part H8), driving the screw through the guide riser. position (See Figure 2.5.)

Repeat the process for the other three guide risers.

Cut Slots for Starting Posts in Base Section 1

[Figure 2.6(a), 0.6k PNG]
(a) closed
[Figure 2.6(b), 0.5k PNG]
(b) open
Figure 2.6 - starting gate action (side view)

Section 1 is different from the other sections because it has a slot in the center of each lane to allow the starting posts to swing down. (See Figure 2.6.)

[Figure 2.7(a), 1.2k PNG]
(a) drill holes
[Figure 2.7(b), 1.0k PNG]
(b) connect holes
Figure 2.7 - cutting slots for starting posts (top view)

Begin by marking the center of each lane. Next, mark each lane 8" from the starting end. Next, mark each lane again 3" beyond that.

This give you two points in the center of each lane, one 8" from the starting end, and the other 11" from the starting end. Drill a ½" hole centered on each of these points. (See Figure 2.7(a).)

Next, use a keyhole saw, a jig saw, or a similar saw to cut a slot connecting the two holes in each lane. This will create a ½" wide slot down the center of each lane. (See Figure 2.7(b).)

Join Track Sections

Prepare Section Connectors and Cleats

[Figure 3.1, 1.2k PNG]
Figure 3.1 - Part H1 construction (top view)

Drill four ¼" holes in the section conectors (Part H1), one in each corner. Locate the center of each hole 1¾" from the 6"-long side and 1½" from the 14"-long side. (See Figure 3.1.)

[Figure 3.2, 0.8k PNG]
Figure 3.2 - Part L10 construction (top view)

Mark the midpoints of the section cleats (Part L10). Drill four ¼" holes in each section cleat. Locate the center of the holes 1½" on each side of the midpoint and 6½" on each side of the midpoint. (See Figure 3.2.)

Secure Base Supports

[Figure 3.3, 1.2k PNG]
Figure 3.3 - base support positioning (bottom view)

Apply carpenter's glue to one base supports (Part L9). Carefully center the base support on the underside of Section 2 and clamp it in place. (See Figure 3.3.) Secure the base support with five evenly spaced 1¼" #10 flat-head wood screws (Part H8). In the same way, secure the remaining base supports to Sections 3 and 4. Allow glue to dry completely.

Fit Section Connections

The key to a fair track (a track without faster/slower lanes) is the proper alignment of the lane guides and track sections. Do not rush this step. Check, double check, and triple check the alignment of the section connections as you work.

Carefully align the ends of Sections 1 and 2, then clamp them face down to the work surface. It is a good idea to place scrap wood between the track sections and the work surface, to protect the work surface from the drill bit.

Carefully align a section connector (Part H1) over the ends of the two track sections. Clamp the section connector in place. Using the holes in the section connector as a guide, drill two ¼" holes in each track section. The holes should be located 1½" from the end of the section, and centered in the outside lanes (1¾" from the edge of the base), but the exact positions are less important than the fact that the holes exactly match those in the section connector.

[Figure 3.4, 1.3k PNG]
Figure 3.4 - section connection (top view)

Carefully position two section cleats with their middle holes over the holes you just drilled in the track sections. Use ¼" bolts (Part H2) to check the alignment of the section cleats, then clamp the section cleats in place. Using the outer holes in the section cleats as a guide, drill two more ¼" holes in each track section. The holes should be located 6½" from the end of the section, and centered in the outside lanes (1¾" from the edge of the base), but the exact positions are less important than the fact that the holes match those in the corresponding section cleat exactly.

Unclamp everything. Countersink the holes in the lane guides.

[Figure 3.5, 0.6k PNG]
Figure 3.5 - section connection (side view)

Assemble this section connecton with eight ¼" × 2" flat-head stove bolts, eight washers, and eight wing nuts (Part H2). The section connectors should be sandwiched between the underside of the track sections and the section cleats. The wing nuts should be on the underside of the track. The heads of the stove bolts should be flush with the surface of the lane guides. (See Figure 3.4 and Figure 3.5.)

Mark the ends of these track sections, the section connector, and the section cleats with red paint. Disassemble this section connection.

Repeat the process for the connection between Sections 2 and 3 (mark with yellow or green paint) and for the connection between Sections 3 and 4 (mark with blue paint).

Build Legs

Secure Brace

[Figure 4.1, 1.8k PNG]
Figure 4.1 - Section 1 with brace (bottom view)

On the underside of Section 1, mark a line 9" from the end that joins Section 2. Apply carpenter's glue to one side of the brace block (Part L8). Center the brace block on the underside of Section 1 with one end on the mark and clamp it in place. (See Figure 4.1.) Secure the brace block with three 1¼" #10 flat-head wood screws (Part H8). Allow glue to dry completely.

Attach one end of the brace (Part L3) to the brace block with a 2½" × 2½" hinge (Part H4).

Build Long Leg Unit

[Figure 4.2, 1.4k PNG]
Figure 4.2 - long legs (rear view)

Mark each long leg (Parts L5) 12" from its bottom end, and 8" from its top end. Position two leg cleats (Part L6) across the long legs, with the top edge of each leg cleat along the corresponding marks on the long legs. The leg cleats should be perpendicular to the long legs, with the outside edges of the long legs even with the ends of the leg cleats. (See Figure 4.2.)

Apply carpenters glue to the joints, restore the proper position and alignment of the parts, and clamp the parts in position. Secure the leg cleats to the long legs with two 1¼" #10 flat-head wood screws (Part H8) at each joint. Allow the glue to dry.

[Figure 4.3, 1.3k PNG]
Figure 4.3 - long legs with stabilizer (rear view)

Position the stabilizer (Part L4) centered across the bottom ends of the long legs with the ends of the long legs even with the bottom edge of the stabilizer. Clamp the stabilizer in position.

Drill one ¼" hole through each joint. Unclamp the stabilizer and secure it with two ¼" × 2" round-head stove bolts, four washers, and two wing nuts (Parts H3). (See Figure 4.3.)

Remove stabilizer and store bolts in holes.

Attach Long Legs to Section 1

[Figure 4.4, 1.7k PNG]
Figure 4.4 - Section 1 with long legs (bottom view)

On the underside of Section 1, mark a line 12" from the end with the slots for the starting posts. Position the top end of the long leg unit on this line. (See Figure 4.4.) Attach the top ends of the long leg units to the underside of Section 1 with a pair of 2½" × 2½" hinges (Part H4).

Build Short Leg Unit

[Figure 4.5, 0.4k PNG]
Figure 4.5 - short legs (front view)

Position the remaining leg cleat (Part L6) across the bottom ends of the short legs (Part L7) with the ends of the short legs even with the bottom edge of the leg cleat. The leg cleat should be perpendicular to the short legs, with the outside edges of the short legs even with the ends of the leg cleat. (See Figure 4.5.)

Apply carpenters glue to the joints, restore the proper position and alignment of the parts, and clamp the parts in position. Secure the leg cleat to the short legs with two 1¼" #10 flat-head wood screws (Part H8) at each joint. Allow the glue to dry.

Attach Short Legs to Section 1

[Figure 4.6, 1.5k PNG]
Figure 4.6 - Section 1 with short legs (bottom view)

On the underside of Section 1, locate the line 9" from the end that joins Section 2. You drew this line during the previous "Secure Brace" step. Position the top end of the short leg unit on this line. (See Figure 4.6.) Attach the top ends of the short leg units to the underside of Section 1 with a pair of 2½" × 2½" hinges (Part H4).

Note that the hinges must open more than 90° for the short legs to be vertical when the track is set up. If the hinges are attached flush with the ends of the short legs, they will be able to open only 90°. Here are some ways to allow for this.

Attach Brace to Long Legs

[Figure 4.7, 2.0k PNG]
Figure 4.7 - Section 1 with legs and brace (side view)

Turn Section 1 right side up and stand it upright on the extended leg units. Position the brace so that the loose end of the brace rests on the lower leg cleat of the long leg unit. (See Figure 4.7.) Attach the loose end of the brace to the lower leg cleat of the long leg unit with the 2½" × 2½" loose-pin hinge (Part H5). The loose-pin hinge allows the long leg unit and the brace to be detached from each other and folded flat for storage.

Build Starting Gate

Attach Starting Posts and Handle

[Figure 5.1, 0.9k PNG]
Figure 5.1 - Part L11 construction (top view)

Mark a line along the length of the starting bar (Part L11). Locate this line 1" from the rear edge of the starting bar.

Drill a ½" hole through the starting bar. Locate the center of this hole along the marked line and centered between the ends of the starting bar. Drill four ¼" holes through the starting bar. Locate the centers of these holes along the marked line and on 3½" centers. (See Figure 5.1.) Double check the spacing of the four ¼" holes by positioning the starting bar under the slots for the starting posts in Section 1.

[Figure 5.2, 0.7k PNG]
Figure 5.2 - starting gate (rear view)

Apply carpenter's glue to the ½" hole in the starting bar (L11) and to the end of the starting bar handle (L14). Insert the end of the starting bar handle into the ½" hole. The starting bar handle will protrude from the bottom of the starting bar, and will be flush on the top of the starting bar.

Apply carpenter's glue to the ¼" holes in the starting bar (L11) and to the ends of the starting posts (L13). Insert the ends of the starting posts into the ¼" holes. The starting posts will protrude from the top of the starting bar, and will be flush on the bottom of the starting bar. (See Figure 5.2.)

Mount Starting Gate

[Figure 5.3(a), 0.6k PNG]
(a) closed
[Figure 5.3(b), 0.5k PNG]
(b) open
Figure 5.3 - starting gate (side view)

Position the starting gate under Section 1, with the starting posts sticking up through the slots. Position the starting gate as close to the end of Section 1 as the slots allow. (See Figure 5.3.) Attach the starting gate to underside of Section 1 with the pair of 1½" × 1½" loose-pin hinges (Part H6). The loose-pin hinges allow the starting gate to be removed from Section 1 for storage.

Attach the 1/8" inside-diameter screw eye (Part H7) on the underside of Section 1, downhill from the starting gate and centered between the left and right edges of Section 1. The distance between the starting gate handle and the screw eye should be a couple inches longer than the length of your heavy rubber bands.

Loop a rubber band over the starting gate handle, then loop secure the other end of the rubber band in the loop of the screw eye. (See Figure 5.3.) To open the starting gate, the starting gate operator reaches under the track and pulls the starting gate handle back quickly and smoothly. You may need more than one rubber band to keep the starting gate from opening when four cars are in place.

Final Details

Finishing the Track

Sand all surfaces and sharp corners.

Remove any residual dust with a tack cloth. Paint the top and edges of the track base sections with white enamel, and allow to dry.

Mask the lane guides for Lane 1 and paint them with red enamel. Repeat the process, masking Lanes 2, 3, and 4 and painting them with yellow, green, and blue enamel respectively. Allow all the lanes to dry.

Finally, coat all track surfaces with clear gloss polyurethane. Rub with fine steel wool between coats. Three or four coats of polyurethane will give a long-lasting, durable finish.

If you prefer, you can paint the base black, grey, or some other neutral color instead of white. You could also leave the base (or even the entire track) unpainted, and just apply the clear polyurethane finish.

Using the Track

Use the red section connectors and cleats to join Sections 1 and 2. Use the yellow or green section connectors and cleats to join Sections 2 and 3. Use the blue section connectors and cleats to join Sections 3 and 4.

Extend the legs of Section 1 and secure the loose end of the brace to the long leg unit with the loose-pin hinge. Attach the stabilizer to the long legs with the stove bolts and wing nuts. You may want to help stabilize the track by placing one sandbag over the cleat of the short legs, and one sandbag over each end of the stabilizer of the long legs.

[Figure 6.1(a), 0.6k PNG]
(a) closed
[Figure 6.1(b), 0.5k PNG]
(b) open
Figure 6.1 - starting gate (side view)

Attach the starting gate using the loose-pin hinges. Loop a rubber band over the starting gate handle, then loop secure the other end of the rubber band in the loop of the screw eye. (See Figure 6.1.) You may need more than one rubber band to keep the starting gate from opening when four cars are in place.

To open the starting gate, the starting gate operator reaches under the track and pulls the starting gate handle back quickly and smoothly. It is important to open the starting gate quickly to avoid giving some car designs an advantage over others. It is important to open the starting gate smoothly to avoid suddenly bumping the track.

Design Modifications

Enhancements

The following enhancements to the basic track design will produce a track that is better overall.

Variations

The following variations of the basic track design may allow the track to fit the needs of different groups better.

Credits and Disclaimers

This track plan was adapted for the web (with permission) from the derby track plans distributed by Christian Service Brigade. I have never built a derby track from these plans (or from the original plans), and the original plans were a bit vague in places.

I am grateful to Derik S. <ViperZZoom@aol.com>, to <Civilfun@aol.com>, and to Carl L. Strickler <CarlStrickler@upr.com>, who provided valuable feedback based on their units' derby tracks, which were built using these plans. If you use these plans to build a derby track, please let me know if you discover any problems, or if you can suggest any further improvements or clarifications.

See Also