xsTECH Router - CO2 Dragster Demo

This tutorial demonstrates how to use the xsTECH Router can be used to make TSA competition sanctioned CO2 dragster bodies.

CO2 Dragster Body Demo 1 is a 1-setup demo program that introduces the basic CNC workflow. there are 2 programs attached to this demo:

CO2 DRAGSTER DEMO 1 ROUGHING.nc
CO2 DRAGSTER DEMO 1 FINISHING.nc, an optional finishing program that can be run after the roughing program to provide a smooth finish.
CO2 DRAGSTER DEMO FIXTURE.nc, a program for cutting the fixture plate from a 1/4" piece of MDF or Plywood.

The roughing program has a run time of approximately 12 mins. The finishing program is optional and has a run time of approximately 30 mins; if you choose not to run it, the dragster body will require hand sanding at the end. After running the the finishing program, you may need to do some light sanding to blend a few areas, depending on the exact width and height of the dragster blank you started with.

The CAD/CAM files created in Autodesk Fusion 360 are included at the end of the demo.

Before you begin

You will need the following for this demo:

For the CO2 Dragster car body:

12-inch balsa wood CO2 dragster kit, like this one
Chop saw or Band saw to cut the balsa wood blank to size
PN 39172: 4 mm carbide burr (included with your xsTECH kit)
PN 39171: 2 mm carbide ball end mill (included with your xsTECH kit)

For the Fixture:

0.25 inch x 2 inch x 12 inch MDF or plywood to make fixture.
Flat head wood screws and countersink drill, or masking tape and super glue
PN 39173: 4mm compression cutting end mill (included with your xsTECH kit)
M6 bolts, washers, and nuts (included with your xsTECH kit)
M6 or 1/4 in. drill bit

For modifying the demo programs or designing your own dragster bodies:

Autodesk Fusion 360 (free license for educators)

1. Prepare the workpiece

Modify a 12 in. CO2 Dragster Blank to the following dimensions. This can be done done with a chop saw or band saw.

When preparing the blank, the height dimension is crucial. Anything shorter than 1.5 in. will not meet the TSA Competition design specifications. Taller than 2 in. will not leave enough room for tool clearance.

2. Make the fixture

The fixture is used to hold the balsa wood blank to the table. There are a couple of ways to approach the fixture.

A. Method 1: Machined wood and screws

This fixture above can be made from 0.25 in. thick dimensional lumber, such as a MDF or plywood.

Using a saw, cut the board to width and length. Mark and drill the holes with a a 1/4 in. drill bit.
Use a layout square to locate the center of the board and mark it. This is X0Y0 location.
Attach the board securely to the xsTECH Router table using bolts, washers, and wingnuts.
Load the CO2_DRAGSTER_FIXTURE.nc program.
Install the 4mm compression cutter, PN 39173 as Tool 1 (T1)
Reference, and then set the work offset X0Y0Z0 at the location marked on the board.

Press Cycle Start to run the program and cut the fixture
Remove the plate. Use countersunk wood screws to secure the dragster blank to the plate from the bottom.

Pay attention to the placement of the screws so they will not interfere when cutting the final design of the dragster body.

B. Method 2: Thin plywood with masking tape and superglue

This super glue and masking tape method is a technique that can deliver strong and secure workholding as long as the contact area is relatively large.

Prepare the fixture plate from 1/8 in. plywood cut to size.
Cover the entire top of the fixture plate with masking tape, taking care to avoid any wrinkles. Firmly press the tape into the surface by rolling a dowel over the tape repeatedly. Do the same with the bottom of the dragster blank.
Cover both taped surfaces with a generous amount of superglue. Use a popsicle stick to spread the glue evenly.
Carefully align the pieces and press them firmly together for several minutes until the glue has bonded.

C. Method 3: 3D Printed Fixture

3D printers are excellent tools for creating customized fixturing solutions. If you have access to a 3D printer with a 12 in. print bed, you can also print the fixture.