HPR-1 Large Rocket Constructor
For Your Bigger Birds
HPR-1 is the big brother of the Rose Fin Jig - a longtime favorite of NAR Model
rocketeers for rockets in the Model class. Designed to meet the special needs of larger,
High-Power vehicles, the
HPR-1 uses the same principles as the smaller fin jig which
greatly simplify attaching fins and other details by just laying them in place and gluing
them. The parts do not have to be awkwardly held in order to keep them properly
positioned while the glue dries, or held or clamped vertically making it nearly impossible
to get satisfactory fillets. Having the rocket conveniently at hand in the HPR-1 makes
its construction much simpler, quicker, and more satisfying.

Fin slots used on many large rockets make for very strong fin attachments, but they do
not guarantee perfect fin alignment. HPR-1 readily provides accurate fin placement and
alignment, with or without slots, thereby assuring optimum flights. Use with kits or
scratchbuilt vehicles for super high, straight-up flights.

Each fin rests on the
Fin Plate with its root edge in contact with the body tube, or thru a
slot, in contact with the motor tube, aligned with the center axis of the body by proper
offset to allow for the fin thickness. The offset may be easily and precisely set to within
a few thousandths of an inch, putting the center plane of the fin exactly in line with the
center axis of the body. The lower edge of the fin plate may be adjusted to a
convenient distance from the airframe. It is set at a 45 degree angle so that glue will
flow to form symmetrical  fillets. Fin slots are readily laid out using the edge of the fin
plate as a guide.

The rocket airframe is held by its motor tube. Two
Mandrels are used which slide on
the main
Spindle to adjust for different lengths of motor tubes or adapters. Precision
turned Delrin mandrels up to 54mm dia can be ordered with the HPR-1. For larger
diameter or multiple motors, lighter weight adapters can be used to fit the airframe to a
smaller mandrel.

The airframe is rotated with the index wheel and locks into position for three or four fin
configurations, corresponding to 0, 120, and 240 degrees, and 0, 90, 180, and 270
degrees, respectively. Any other angle from 0 to 360 degrees may be set and held
using the precision
Angular Position Dial with the index wheel.

The HPR-1 will accomodate vehicles with up to 32 inches diameter total fin span, and
airframe diameters to over 8 inches.

An external,
Adjustable Work Holder is included for additional support of the rocket
body, maintaining accuracy.

Wrenches and other tools are furnished and no additional tools or parts (other than
mandrels) are needed to use the HPR-1.

New rocket designs are easily developed, starting with a body tube, laying out fin slots
or directly attaching fins, and then completing the assembly, all on the HPR-1 fixture.

Individually, hand fabricated in the United States from stainless steel, aluminum, and
various woods, the rugged HPR-1 offers you convenience, time saving, and accuracy
for your high power rocket constructions.

HPR-1 Complete with External Work Holder, Tools, Base, Instructions: $825 USD.
HPR-1 Mandrels: 29mm $55, 38mm $65, 54mm $75
Contact us for more information and ordering data:
HPR-1 shown with section of 4" dia Endeavor rocket