Rocket Vision - Grymm

Contributed by Kevin Johnson

Manufacturer: Rocket Vision

[Picture] (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 diameter and height in this series of rockets that were around 3 inches in diameter. These reviews compliment my 2.6" and my 4" collection. So, this one, along with the LOC Onyx™ and the Estes Big Daddy™ allowed me to complete a comparison.

Rocket PicThe Grymm qualifies as a "stubby" rocket because it is 15" long and has a 2.88" diameter giving it a less than 10:1 ratio (5.2 to be exact).

The review below describes the kit components and the build of the rocket very well. I will only describe a few findings of my own.

CONSTRUCTION:

My centering rings were not out of round, however, I did need to sand both the inside and outside edges to gain a good fit. Not a lot.

I found the fin assembly a bit tough. It worked out fine, however because the fins did not go all the way to the motor tube they wanted to position themselves based on the cuts in the frame. The instructions say to use masking tape to hold in position. That is a must.

Also, be very careful not to get excess glue on the fins new the back of the rocket. This will prevent you from sucessfully seating the rear centering ring.

The instructions for the Grymm are adequate and have a few illustrations to help with assembly. No real big surprises.

Some major positives include the "spiral-less" body tube. The recovery system and attachment methods (works much better in this larger diameter tube than in their smaller tubes). The included motor retention system was also easy to assember and doesn't limit the motor length like an Estes hook does.

Rocket PicFor finishing, it is simply a prime and paint rocket. No pesty spirals to fill and the nose cone has some level of roughness to it already. I used Plasti-Kote Sandable Primer and then followed it up with Walmart's $0.89 yellow paint. Worked great. (additional comments about Walmart paint). After that I started with the decals. I disagree with the assessment of them by the reviewer below, because I found them thin and had a difficult time with them. I did get the name and one set of fins done and they look very nice.

Overall, for CONSTRUCTION I would rate this kit 4 ½ points. Instructions are adequate and the components are of good quality and fit. The tabbed-through-the-wall fins and motor retention are nice. The decal thinkness takes just a tad off.

FLIGHT/RECOVERY:

This was another of the rockets that got shipped to fly in Arizona. We had planned a vacation to Arizona and it just so happened that there was a launch on 12/23/00. So I packed this rocket and 3 others into a box and shipped them there. I had to rely on the vendor at the launch for motors and since it was a Tripoli High Power launch, there was not much selection for 24mm motors. I was able to purchase a three-pack of E28-7's which allowed me to fly the Grymm.

I prepped it using the provided Heat Shield and was ready to go. Up went the Gyrmm for its maiden voyage. The E28 lifted it off the pad, not a pop as with the lighter Big Daddy™, but a commanding lift off. Straight and no rotation. The big fins made it very easy to see all this. It arched over, a sun bean hit it causing a reflection, it seemed to hang there horizontally, the the ejection charged deployed the 'chute and the rocket came down to be logged as a "picture perfect" flight.

RocketVision's recovery system is nice with the included Heat Shield and the split rings attaching everything. The parachute is above the nose cone and to me, that gives it a more realistic descent (as opposed to a model).

For FLIGHT/RECOVERY, I would rate this kit 5 points. This is only based off of one flight, however, as I am highly confident that others have had good success and if not they will report it in Guest's Opinions. It has a nice recovery system and the parachute was sized correctly.

Overall, the Grymm is another great "stubby" rocket and even more so as it has one of the lowest ratio's I have ever seen, 5.2:1 (note the Estes Fat Boy is 4.9:1). Its quality materials and ease of finishing make it a leader. It is a same that RocketVision has closed . . . but if you ever see this one offered by another company, go for it! I give the kit an OVERALL rating of 5 points.

Flights

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