Der Big Red Max Plywood Fin Upgrade Set of 3

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SKU:
RW-FIN-BIG-RED-MAX-PLY-3MM
Availability:
In stock items ship within 1 business day
  • Rocketry Works plywood Der Big Red Max upgrade set, including 2 or 3 centering ring options.
  • Compared to the stock multi-part fin assembly requirements shown on the right, the Rocketry Works plywood upgrade set is simple, clean and ready to assemble.
$14.99

Description

These 1/8 inch thick plywood replacement fins for the Estes Der Big Red Max kit are a great option to improve your build strength and durability over the stock multi-part balsa fins that can be damaged in transit or during assembly.  Laser cut to the original specifications for accurate fit in the stock fin slots, with the stock motor tube. You can use the stock cardboard centering rings or replace the 3 cardboard centering rings with either 2 or 3 plywood centering rings. The Plywood centering ring option works nicely with just a pair of rings, but it is available with the original design of a 3rd centering ring in the middle to interlock the fin to ensure straight alignment.  The forward centering ring includes a sturdy and accessible shock cord mount. You can also add common additional components for this retro build.

The 3 plywood fins weigh in at 4.15 ounces (116 grams, compared with 1.8 ounces (51 grams) for the stock balsa fins.

The 2 plywood centering ring configuration weighs 0.5 ounces (14 grams), compared with 0.25 ounces (8 grams) for the stock 3 cardboard centering rings.

The 3 plywood centering ring configuration weighs  0.7 ounces (21 grams), compared with 0.25 ounces (8 grams) for the stock 3 cardboard centering rings.

Be sure to evaluate the impact of the additional weight in the fin can as you build--you may need additional nose weight to compensate. And be aware that by flying higher power motors in this kit, you do need to consider stability and fin flutter as a part of the equation.  These are relatively large fins for 1/8 inch balsa or plywood, so be mindful that at a high enough speed, your rocket's fins can flutter so much that they shear off the airframe tube. Using this kit with high power motors likely requires fiberglass reinforcement of fins and airframe.  Also, as you fly larger motors,  your center of gravity moves farther back, closer to the center of pressure, which can destabilize your rocket, particularly in strong winds. You can use the Rocksim files below to determine best motors for your particular build, but the Aerotech E20-4 and Aerotech E30-4 stand out as nice motors with this kit.

 

More specifications are available in the Additional Information tab.

 

Simulation Files

rocksim-logo.jpg Design File with Balsa Fins
rocksim-logo.jpg Design File with Plywood Upgrade Kit

 

 

 

 

 

 

 

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Additional Information

Weight (per centering ring):
0.25 ounces (7 grams)
Weight (complete set of 3 fins and 3 centering rings):
4.85 ounces (138 grams)
Weight (per fin):
1.35 ounces (38 grams)
Root Edge:
5.55 inches (141.0 mm)
Semi Span:
6.00 inches (154.8 mm)
Trailing Edge:
4.89 inches (124.2 mm)
Leading Edge:
7.40 inches (188 mm)
Tip Chord:
4.39 inches (111.6mm)
Thickness:
1/8 inch (3mm)
Tab Depth:
0.879 inches (22.3 mm)
Tab Length:
2.84 inches (72.3mm)
Tab Offset:
2.14 inches (54.3mm)
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3 Reviews

  • 5
    DBRM fin upgrade

    Posted by Phil Bridges on 28th Apr 2021

    Excellent quality and quickly shipped!

  • 5
    Worth the price

    Posted by James Buckley on 23rd Apr 2021

    The factory fins are in 3 pieces and impossible to get flat without a lot of work. Paper rings. Work long for big motors. The rings fit perfect. The shock chord mount was wonderful. Get the Kevlar shock chords. So worth it. The wooden fins sand up smooth. Mount great in the precut slots on middle ring. Very strong and are sure to survive hard landings. I'm convinced to use wooden fins and rings on all my large model rockets.

  • 5
    Der Big Red Max upgrade package

    Posted by John on 16th Feb 2021

    Everything fit really well. No sanding of the centering rings or fin openings necessary. The whole kit only added 30-40 grams to the back end of the rocket. I don’t think any additional nose weight is required. It’s a solid upgrade. I can’t wait to fly it.

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