The JonRocket.com Fin Wrap Tool generates custom, printable guides which wrap around a rocket's body tube creating a marking guide to ensure equal spacing when attaching fins.

Paper Size: Select Letter, Legal, A3, A4, or A5 based on the size of the paper in your printer.

Number of Fins: Select the number of fins (three to eight) that will be on your rocket.

Include Launch Lug: Select "Y" (for "Yes") to include a guide line for placing the launch lug on your rocket.

Body Tube: Select the body tube you are using or "Other" to manually enter the diameter.

Body Tube Diameter: If you selected "Other" for the Body Tube, then enter the outside diameter of the body tube. Be sure to select the proper units in the next field.

Units: Select the units for the Body Tube Diameter ("inches," "millimeters," or "centimeters").

After you click the Submit button, the guide will be downloaded as a PDF file. When printing the guide, make sure to select the "Actual Size" setting. The QR Code in the bottom left corner of the printout should be just slightly smaller than one-inch tall and one-inch wide.