Brief:
This is a seasonal oddroc based on a Styrofoam ear of corn. It is a cool-looking, sturdy rocket and looks better in person than in photos. My beta test version flies on 18mm motors but 13mm and 24mm versions were also offered. Unfortunately, all had limited runs and more will not be available until next year. I normally don't submit reviews until I've flown a rocket but, since people are getting the kits now, I thought I'd provide my experience building it sooner rather than later.

Construction:
The parts list:

• Styrofoam ear of corn, pre-drilled with the tip removed
• 4 fins cut from 2 pieces of 1/8" balsa stock
• balsa nose block and screw eye
• BT-50 tube, 9.75" long
• 18mm motor tube, engine block, engine hook, and centering rings
• thick 12" plastic chute, shroud lines, tape discs, and snap swivel
• 150lb Kevlar® and ¼" elastic shock cords
• one 1/8" launch lug
• BBs
• corn husk scraps

The instructions are printed on 7 sheets and include a fin template. They are witty and well illustrated. Although not professionally printed, they are more than adequate for this fun build. Because the body is Styrofoam, you must use foam friendly glues. This is highlighted well in the instructions so there is no excuse to get it wrong. I used wood glue for the motor mount and for attaching the fins and fast Gorilla Glue to main tube and balsa nose block.

The motor mount construction is typical--cut slit for motor hook, tape down, attach the 2 centering rings, insert motor block. Before gluing it into the BT-50 body, you tie the Kevlar® around the mount in between the rings. Remember to put a drop of CA or epoxy on the knot and notch the top ring so it will fit through.

The body tube was quite loose in the husk and I'm not sure how well some of the glues identified in the instructions would work. I used fast Gorilla Glue, which expands as it cures. This worked well. I also plugged the gap on the top using tissue soaked in wood glue. Scrap corn husk material was provided to fill/cover the bottom of the motor tube, but I left it off.

The method of aligning the cone/block/body tube was good. I've faced this issue many times and have responded with varied degrees of success. The answer is simple. Add some glue to the pre-drilled pocket in the nose section, insert the block, slide over the body tube, align the parts, and then turn it on its nose so the glue stays in the nose. I taped the nose to the body while the glue dried. When the assembly was dry, I pulled the nose part way off and used a Sharpie to make a mark on the block and the tube to help with alignment during flight prep.

You cut the fins from the balsa stock using the provided template. The balsa was good quality and the style of the rocket means you don't have to be terribly precise keeping to the lines. I rounded the leading and trailing edges slightly.

Positioning the fins is slightly inexact due to the odd contour of the corn ear. However, it isn't too hard given the pre-marked lines. Use a new #11 blade and go slowly when slotting the corn. As long as the fins are all even, you should OK if you balance the kit as directed.

Although I prefer nylon chutes in general, I am really liking the type plastic provided in this kit. I think it may be a Hartle Engineering Chute Skinz. It seems sturdier than the typical "Questes" plastic.

Since I didn't know if my fins are positioned exactly as expected I couldn't tell if the balancing instructions will guarantee a stable model. I used all the provided BBs and had to add ~0.2oz of lead shot to get it to balance at the fin leading edge with a C6-5 installed (as specified). I think more BB's may be provided in the production kits. Mine weighed in at 3.5oz without motor. I did a quick and dirty RockSim and it shows stability is marginal, but this might be GIGO given the odd contours. Sky Ranger says mine will fly great!

Finishing:
The body comes pre-finished and all you are asked to do to the fins is seal them with your favorite clear coat. Make sure you cover them before installation in case your clear coat eats Styrofoam.

Construction Rating: 4 out of 5

Flight:
I'll ask Nick to add a flight report after I have data to report. With temps <40 degrees and 10-20 mph winds, I'm not hitting the field this month.

Flight Rating: 3 out of 5

Summary:
This is a cool looking rocket and as I said it looks better in the flesh...or in the corn. It really is a straightforward build but the Styrofoam body made it interesting. Two thumbs up for the build!

Overall Rating: 4 out of 5

Brief:
The Corn-Roc is a fall themed oddroc I was asked to beta test. It is basically a conversion of a Styrofoam ear of Indian Corn from a craft store into a rocket.

Construction:
Construction began with the building of the motor mount. A slit was made for the engine hook and the hook was secured in place with several wraps of masking tape. The mount was then marked at each end and the centering rings were slipped into place and glued. One ring needed just a touch of sanding to fit properly. When they were in place, they were glued with yellow glue. The thrust ring was the slipped into the forward end and glued into place.

While the glue on the motor mount was drying, I turned my attention to the fins. The instructions come with a template to be cut out to mark the fins on the sheet balsa stock. I cut out the template and taped it into place on the balsa. I then roughly traced the outline with a pencil. I did not bother being too careful because I figured the individuality of the fins would add to the overall project. The fins were then cut out with an X-Acto knife.

Turning my attention back to the motor mount, I tied a loop of Kevlar® around the forward end of the motor mount and filleted it in place next to the centering ring. A notch was then cut in the ring to pass the Kevlar®.

I needed to give the glue fillets a chance to dry so I took the cut out fins to the spray booth. The instructions recommend to just seal the fins instead of painting them. This is to help prevent warping and leaves the fins a nice straw color to go with the harvest theme. I sprayed with Rustoleum clear. About an hour later, I gave them another coat. The next day, I sprayed the other side. The instruction make clear that any such spray should be allowed to dry fully before trying to install in the Styrofoam ear of corn. I let it dry a full day.

After the motor mount was fully dry, I passed the Kevlar® through the notch I had cut and weighed the end of it with a pencil. I used the weight of the pencil to pass the Kevlar® through the body tube to the forward end. A ring of yellow glue was then swabbed in the aft end of the body tube and the motor mount was pushed into place with but a bit of the motor tube protruding.

Next up, the body tube was test fit into the Styrofoam ear of corn. There were a few gaps here and there but the tube went in easily and was straight. I then removed the tube and mixed a batch of 5 minute epoxy. The instruction indicate that either yellow glue or epoxy should be used in this step and I figured epoxy would do a better job. I used a disposable brush to thickly paint the epoxy onto the body tube and the pushed it into place, leaving just a bit of the motor tube protruding.

The instructions advise to coat the white Styrofoam at the forward end of the corn cob with either epoxy or glue. This is done in order to protect the foam from the ejection charge. Strangely enough, the instructions claim that the problem is only with the main body of the rocket and not with the nosecone. I figure the burning gases get forced back against the main body for a longer period of time and that the NC is protected by brief contact. In any event, I painted over the white foam with yellow glue to give it the protection it needed.

The fin template has a pair of marks indicating the placement of the launch lugs on one of the fins to keep it clear from the corn cob. I duly marked a fin, cut the lug in half and mounted the pieces at either end of the line.

The ear of corn comes with 4 pre-marked lines for fin placement. I set a fin along each line and marked a forward and aft end. I then used a razor knife to cut along either side of the line. The pointy end of the knife was used to dig out the foam and I kept whittling away until the fins fit in their slots.

To attach the fins to the foam, I mixed up some 5 minute epoxy and drizzled it into the slots. I then pressed the fins in and used a gloved finger to smooth a fillet on each side. When done, the rocket was able to stand on its base.

The bottom of the corn ear had a bit of a gap between the Styrofoam and the body tube due to the coring of the foam. This was anticipated in the instructions and the kit came with a few bits of corn straw with which to fill in the gap. I just bent the pieces over double, dipped the middle in some glue and tucked it into the gap. It actually gives a nice appearance, but I wondered how exposed that dry material will be to the rocket exhaust. I tied to make sure that the straw is facing away from being directly in the blast zone. Overall, I like the effect.

The chute for the Corn Roc is hexagonal plastic. I think it is a Hartle Engineering Skinz based chute. Reinforcement rings were put at the corners and the shroud lines were cut into 3 equal lengths. A hole punch was used to perforate the chute material, and the shrouds were tied into place. The kit came with a snap swivel and the ends of the shrouds were passed through it and looped back.

The nose cone of the Corn Roc is simply the end of the ear of corn which has been strategically broken off and modified a bit. A balsa coupler was epoxied into the hole pre-drilled for the purpose. It fits into the body tube the way any nosecone would.

The instruction give precise instructions for balancing the rocket and provide for a margin of safety. The kit comes with a bag of BBs to glue into the Styrofoam of the NC to give the perfect trim after balancing. I know my building habits so I decided to use them all. I also like keeping rockets down where I can see them better. I wedged some of the BBs into the space between the balsa and foam and epoxied the remainder on top of them.

With that, the Corn Roc is ready for her maiden flight. I've enjoyed putting this together even if I did have to listen to some corny comments...

PROs: Easy. Distinctive.

CONs: Sarcastic comments from witnesses.

Finishing:
For the most part, the rocket is pre-finished. Its a Styrofoam ear of Indian corn with a hole in it for a motor. The only real finishing came in two places: the fins and the gap-filling straw.

As recommended by the instructions, I left the fins as a natural balsa color and only applied a clear coating to protect them. That was easy and quick.

I also that the corn straw filler to spruce up the area where too much Styrofoam had been poked out to be a nice touch and showed some foresight. I thought the result looked nice but had some concerns about the stuff being in the exhaust path and igniting. Talking with the manufacturer resulted in the realization that I had misunderstood the manner of application and I trimmed some of the fuzz back to prevent problem in flight. I liked "my look" better but it was obvious, even to me, that it might result in higher NAR insurance premiums.

PROs: Not much too it. Looks good and odd.

CONs: Mistakes are not easily fixed by replacing parts. There is a limited, seasonal run of the corn cobs.

Construction Rating: 4 ½ out of 5

Flight and Recovery:
The Corn Roc finally flew for the first time on 22 Nov 2008, but I forgot to bring the popcorn to use for wadding!

I stuffed it with dog barf and an Estes B6-2. It turned a few heads and the turned in a creditable performance. Its not going to win any altitude or duration competitions, but it's stable and fun to fly. Click here to see a video of the first flight.

The second motor I wanted to try was the recommended C6-3. The only Cs I could find were C6-7s and C11-3s. Tim Reidy was kind enough to provide me with a C6-5, which is not a recommended motor, but I was willing to try. It actually performed well. The delay was too long but it was still safe. Click here to see a video of the second flight.

They say the third time's the charm. Well, at least the Corn Roc seems to have a charmed life. It survived being built by me and now came its ultimate test. The instructions say you can try an A8-3 if you're feeling really lucky. I was. The Corn-Roc was not. It boosted to a stunningly low altitude, nosed over and headed down aerodynamically. I later found out that the ejection charge went off right as the nosecone impacted the ground. The bouncing lawn dart flight can be seen here.

Examining the rocket after its sudden deceleration trauma revealed surprisingly little damage. The ejection charge had gone off just as it struck the ground and this resulted in a lot of internal pressure that had to go somewhere. It did manage to eject the chute, a moot point by then, but the rest of the force was directed towards inducing a zip from the engine hook. This one is a friction fit from now on. Examination of the nosecone revealed just a slight bit of cracking. The rocket conceivably could have flown again.

Two weeks later, I got another chance to fly the Corn-Roc. The only 2 changes made were to take the A8-3 off the schedule permanently and to replace the engine hook with friction fit tape. It performed flawlessly.

PROs: Interesting oddroc. Bounces well.

CONs: None.

Flight Rating: 4 ½ out of 5

Summary:
Nota bene: This was a prototype. The manufacturer did successfully fly the rocket on an A8-3. We attribute that success to a probable early ejection. He has since taken it off the recommended list. No significant changes were needed for the production model, just a few spelling corrections for the instructions.

All in all, this was a fun rocket and will continue to be flown. It is fairly easy to build and, because of the odd design, it is easy to hide construction blemishes. It is definitely...odd.

Overall Rating: 4 ½ out of 5

Brief:
The main stay of the Corn on the cob shaped oddroc collections by First Flight Hobby. This 18mm rocket once complete is interesting and fun. It promises to be a head turner and also a great flier.

Construction:
The parts include:

• One styrene foam corncob
• One body tube
• MMT 18mm tube
• One engine block
• 2 centering rings
• Small bag of bb's
• 12" parachute
• 2 sheets balsa fin stock
• Kevlar® shock cord mount
• Elastic shock cord
• Motor hook
• Instructions
• Snap swivel
• Small screw eye
• Nose block
• Chute reinforcing tapes
• Launch lug
• Bag of bb's with corn husk scraps
• Shroud line

One of the things that really showed me that this company cares about its customers is that each small bag of parts was signed after the parts where placed inside. Also the fact that they hand drew the corn in the instructions when explaining the insertion of the stuffer tube into the corn body.

Reading the instructions you almost laugh at the thought and humor put into them at a few points. Well worded and thought out, easy to follow. Though I suggest the fin pattern being on its own sheet.

To build this oddroc you first need to assemble the engine mount and stuffer tube assembly. After building the engine mount, the instructions say after gluing the cord to the engine mount to feed the Kevlar® cord through the stuffer tube. A better means is to feed the free end into the MMT so that it is hanging out the back then gluing the mount in place. This allows you more control when the times comes to tie the shock cord to the Kevlar®.

Next part is to carefully cut the four channels into the foam corn for the fins. I used and would suggest a Dremel with a 1/8" cutting wheel attachment on its second to lowest setting while using a piece of angle iron for a guide. This to give you a good clean cut.

Once that is done, you want to mount the stuffer tube. Test fit first! I found I needed to wrap 5 turns of masking tape aroung the middle to get a snug fit before gluing. The next thing you do is sand and fit the nose block. Making sure it fits well enough so that when you put the cap on it matches with the orientation of the corn.

Using foam safe 5 or 15 minute epoxy, glue the block in place while the block is in the tube to aide in the alignment.

Let the rocket dry nose down for a least an hour before going on.

While the nose and body are drying, cut out the fins sealing and sanding until you are happy. Leave them natural to match the husk on the corn. Once complete, I used Great Stuff foam to fill the body gaps around the stuffer tube.

All in all this rocket was one of the most enjoyable build I have done in a while.

Finishing:
The only finishing needed is a touch of flat or matte non-corrosive paint to protect the rocket and maybe using some epoxy paint on the inner exposed foam to protect it from damage.

Construction Rating: 4 ½ out of 5

Flight:
I flew this oddroc twice on C6-3 engines. The first flight was great and cleared the pad with no issues. It screamed into the sky and landed 120 feet from the pad. I lost sight of her during the coast phase due to over cast so she got some good height.

The second flight was a mirror of the first.

Recovery:
It came down slightly faster then I liked so I will be increasing the chute to a 16" with a controllable spill hole.

Flight Rating: 4 out of 5

Summary:
This rocket is a head turner, and I feel that it is a must have for anyone who like oddrocs or, like me, just likes to take strange things to the range and fly them while others look at you like you are crazy.

Overall Rating: 5 out of 5