Rocket Vision Grymm

Rocket Vision - Grymm {Kit}

Contributed by Kevin Johnson

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Rocket Vision

Brief:
Short and fat Rugged Rocket.

Rocket PicConstruction:
Component List:

  • 1 2.88 inc ABS nose cone
  • 1 2.88 inch phenolic body tube 11.75 inches long
  • 1 1.2 inch phenolic motor tube 5.5 inches long
  • 2 1/8 inch G10 centering rings
  • 4 1/16 inch G10 fins
  • 1 1/4 inch plastic launch lug 3 inches long
  • 1 24 inch rip stop nylon parachute
  • 1 10 inch square Nomex® chute protector
  • 1 24mm cardboard motor tube insert
  • 1 Engine hook
  • Kevlar® rigging
  • Cardboard shock cord mounts
  • Color waterslide decals

Rocket PicI ordered the Grymm direct from RocketVision via their web site. The kit came bagged with a cardboard insert protecting the decals. The sub-assemblies (recovery, centering rings, fins, etc.) were individually bagged as well. The instructions are color printed and include a lot of text for the 13 steps and 3 illustrations. The instructions give you a web address for general assembly photos and animations, but it is not up and functioning yet on RocketVision's new site. The construction steps are straightforward and well described. With the exception of using epoxy throughout, the kit goes together much like any model rocket.

Rocket Pic In dry fitting the parts in my kit, I found the centering rings were oval and not true circles. I had to mark and sand them repeatedly to get them to fit into the body tube at all. Because I don't have access to power tools, it was very laborious to hand sand those thick fiberglass rings. The nose cone fit was also a little tight and required some sanding.

Other than that, the remaining components fit well and the build went smoothly and quickly (with waits for the epoxy to set). The tolerances on the through the wall slots in the body tube were much better than on the previous 2 rugged rockets I have built. They required only rough sanding to prepare them for epoxy. Tools required were sandpaper, 6 minute epoxy, hobby knife, and paint.

Finishing:
The color decals included in the kit are awesome. They are big and thick and look great. I highly recommend RocketVision's decal service, and hope they get it up and functioning on their new web site soon.

Construction Rating: 4 out of 5

Flight:
Unfortunately, due to high wind on our launch days, I have only logged 1 flight with the Grymm. The recommended motors are AT 24mm E15-4, F72-10 and G55-10. Predicted altitudes are 1100, 2200, and 3000 feet respectively. For the maiden flight I chose the E15-4. Prep was very easy using the included Nomex® protector. It fully sealed the BT and made a pocket just right for the 24 inch chute and Kevlar® rigging. Boost was fast and straight, with ejection past apogee (darn bonus delay!). I can't wait to fly it on an F!

Rocket PicRecovery:
The final length of my 3/32 inch braided Kevlar® shock line was about 42 inches. I was a little wary about the shock cord anchor, cardboard epoxied to the inside of the BT and nose cone, but it held up well. The rocket was travelling pretty fast on ejection, and the chute filled with a loud POP! The descent rate was just about right and the model landed about 25 yards from the pad, in some tall brush. The hot pink chute made it easy to find.

Flight Rating: 4 out of 5

Summary:
All in all this was a great kit to build. I love the big fat tube and stubby appearance of Grymm. High quality components and "fly it through a wall" ruggedness will make this one a frequent flyer at our club launches. PRO's: Ease of construction and simple layout. Great looks and decals are top notch. CON's: Centering rings out of round, iffy attachment points for shock cord.

Overall Rating: 4 out of 5

Other Reviews
  • Rocket Vision Grymm By Kevin Johnson

    (01/20/01) Well, as I write my third review in this series of "stubby" rockets, I am a bit disheartened since just before I flew this bird, RocketVision closed their doors to business. Once the Grymm was announced I immediately ordered one anticipating "Rugged Rocket" in a design that I very much enjoy . . . "stubby". This is the smallest in dia ...

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