Brief:
The face card of this most unusual offering from FlisKits proclaims it is "nearly 6 feet tall and weighs only 6 ounces". This rocket is built out of Styrofoam coffee cups!

Construction:
The kit includes:

• 1 Nose Block
• 1 BT-50 Body Tube
• 1 BT-70 Body Tube
• 1 Launch Lug
• 2 Centering Rings
• 1 Engine Hook
• 1 Engine Block
• 1 16" Parachute
• Shroud Line
• Tape Disks
• 36" Shock Cord
• 36" Shock Line
• Foamboard Fin Stock
• 12 16oz Foam Cups

To build this kit, you will need to make sure you have a high temperature hot glue gun available.

The build starts out with constructing the motor mount. No surprises here, just follow the well illustrated instructions and you will have no difficulty with this part of the build. The elastic shock cord is attached to the upper centering ring and has a loop on one end to attach to the parachute. The other end of the elastic is tied to the Kevlar® shock cord in a later step.

Next, you shorten the 17.50" BT-70 tube by 2.25". Personally, I do not like cutting body tubes but this turned out fine. The instructions have you mark the tube, wrap a piece of paper around the tube at the mark to act as a straight edge so you can draw the line around the tube. I decided to use card stock so I could let my knife follow the edge of the paper as a guide. Tip: I inserted the 1" nose block to act as a mandrel for my cut. This worked great for me and gave me a nice, smooth edge. The leftover piece is to be discarded according to the directions but I saved mine for a rainy day.

The 1" nose block is glued into one end of the modified BT-70 along with a piece of Kevlar® attached to the block which is the second part of the recovery system. The other end of the Kevlar® attaches to the elastic cord from the previous step. Once this is done, you attach the parachute and slide the motor mount up into the BT-70. It will not be glued since the entire mount is ejected during recovery.

Now for the coffee cups! Three cups are modified by cutting out their bottoms. There is a ridge around the bottom of the cups. If you cut by following this ridge, the BT-70 tube will have no problem fitting in the holes you make. I lightly sanded my cuts with some 150 grit sandpaper to remove the rough spots but I was very gentle because Styrofoam sands down very easily. The first two cut cups are then hot glued to each other at their tops. Instructions say to use High Temperature hot glue. It took some getting used to and I had some excess squeeze out on my first attempts--do not use your finger to wipe up the excess! I used some scrap balsa to clean up the edges, which worked quite well.

The first two cups are slid onto the BT-70, 1/2" from the bottom. A fillet of hot glue is used to tack the cups in place. At this point, it is time to make a decision. You have the option of either making your fins surface mount (easier) or through the wall (stronger). I chose TTW for strength. I attached the shroud/fin marking guide, made my marks, then used a ruler to extend the marks from the top edge of the first cup to the bottom of the cup. You essentially are cutting out a narrow strip of the cup from the top to the bottom. I had a little trouble cutting through the hot glue fillet at the base of the cup but a sharp X-Acto knife and some patience did the trick. I cut all three slots and then proceeded to the fins.

The fins are made from foamboard. You must follow the fin layout pattern exactly or you will not have enough foamboard to make all three fins. All lines on the fins are straight, so I used a straight edge and several passes with my X-Acto knife to make the cuts. I lightly sanded the edges of the fins with a sanding block to remove any burrs. Once completed, I used hot glue along the root edge of each fins and pressed them into place, making sure the fin is straight while the glue sets up. The hot glue sets up very quickly, so I only had to hold the fins for 30 seconds. After all the fins were in place, I added hot glue fillets. Take your time with this and keep in mind the tip of the glue gun is hot enough to melt Styrofoam!

My fins were about 1/4" too long. If you look at the pictures provided in the instructions, the bottoms of the fins should be even with the bottom of the BT-70 and the top of the fin should only go as high as the top rim of the first cup. I knew that the fins were too tall, so I left them hang over the bottom of the tube. It looks just fine. Then you hot glue the rest of the cups together, making sure the third cup with the hole cut in it is at the bottom of the assembly.

I would change step 23 slightly. It says to run a liberal bead of hot glue along the top of the uppermost cup and then quickly slide the rest of the cups onto the tube. Two problems. One, a liberal amount of hot glue oozes all over the place once you assemble the cups, so I had a bit of a mess to clean up. A thinner coat would have worked just as well. Second, I had the assembly slid well down the tube before I applied the glue, that way I just had to close the gap once the glue was applied. The body tube is a tight fit on the cups, so I did not want to mess with trying to get the upper assembly slid down while my glue was quickly cooling off.

Last step is to attach the launch lug to the cups with hot glue and you are finished! This kit took me all of one hour to build and 4 glue sticks.

Finishing:
No finishing is required for this kit. However, FlisKits does offer a variety of shroud patterns that you can download and print on label paper to jazz up the cups a bit. I will leave mine bare for now but I do like the option of dressing it up later down the road.

Construction Rating: 5 out of 5

Flight:
Preparation is quite simple and you do not even need any type of baffle or recovery wadding. Simply wrap the shock cords around the upper part of the motor tube above the top centering ring, fold the parachute (it does not need to be rolled up), lay the parachute against the motor tube between the upper and lower centering rings and slide the whole assembly into the BT-70. That's it for prep!

My first and only flight was with a C11-3. It was a bit windy. Although the liftoff was perfect, the wind caught the rocket and it took a nasty arc. Good thing there was only a three second delay because she only got to maybe 200 feet before it nosed over. The motor tube assembly/parachute ejected just before it hit the ground. Fortunately, this is a light weight rocket, and it had a nice soft landing in the grass with no damage. I will be flying it again soon on a calmer day.

Recovery:
I believe the recovery system is perfect the way it is. I like the fact you do not need wadding so prep is very easy. I just do not recommend flying on windy days.

Flight Rating: 5 out of 5

Summary:
This is an inexpensive, easy to build rocket with superb instructions that I am sure will be the talk of any launch even though you will be using materials foreign to most experienced rocket builders. Coffee cups? On a rocket? Next thing you know, they will start having rockets with ping pong balls for decoration!

You will have no troubles building this kit. The instructions even include a variety of configurations, one that uses 116 coffee cups! My hot glue gun is ready for some more coffee cup action!

Overall Rating: 5 out of 5

Brief:
This is a 2nd Opinion review of the Fliskits Decaffeinator, a foam cup rocket with a 24mm motor mount. I made a couple of minor modifications to the design.

Construction:
This kit is pretty basic. At its core is the lengthy 24mm motor mount configured for rear ejection from a BT-70 body tube. Around that mount are a collection of foam core fins and Styrofoam cups. The assembled rocket stands over 6 feet tall but weighs just a few ounces.

This rocket is a very quick build. The motor mount is built traditionally using yellow glue. The rest of the rocket consists of variation on foam and is assembled using a hot glue gun.

One change I made was to set the motor mount thrust ring to allow for the longer Estes E9 engines. This meant that the provided engine clip would be too short. I modified the clip to bring the upper end of the hook out of the motor mount tube and bent it back over an additional ring I placed outside the MMT.

I chose to use the through the wall fin mount technique rather than the easier and less strong surface mount. Templates for both styles of fins are provided. One thing I noted was that I needed to extend my TTW slots up into the second cup in the stack on the motor mount. This wasn't obvious from the instructions but would be necessary if you don't want the fin roots hanging below the body tube.

I did run into a little trouble getting the hot glue to coat the cups lips quickly enough so that the beginning of the ring was still melted while the end of the ring was still being laid down. I found that ignoring the glue gun trigger and pressing my thumb directly on the end of the unmelted glue stick jutting out of the rear of the gun, resulted in a quicker glue flow and more working time to position the cups.

I also used an old trick in a new way. Hot glue can be resoftened using heat from a standard hair dryer. I used a hair dryer to resoften some of the glue joints and reposition the cup edges for better alignment. I do not recommend using a heat gun for this procedure as the Styrofoam cups themselves would likely melt.

Another tip is for stiffening the edges of the fins. If you don't have a very sharp razor knife when you cut out the fins (as I didn't), you will likely gets snags and holes in the foam core between the posterboard layers. To fill those voids and toughen up the fin edges, I used a coating of Gorilla Glue. This glue foams up slightly as it hardens so that it expands to fill the uneven foam core edges.

When doing the final assembly of the cups, I chose to use a mid-body seam to make transporting the rocket easier. Suggestions for how to do this are included on the back page of the instructions. An extra cup is needed, but those aren't hard to come by.

Finishing:
No finishing is required for this rocket if you like white Styrofoam. It reminds me of the classic NASA and gleaming Sci-Fi ships of years gone by so I left it as is.

Construction Rating: 4 out of 5

Flight:
My first flight for the Decaffeinator was on a D12-3. I needed to use a spacer to bring my total engine length up to that of an Estes E9. Prepping this rocket is very simple. The rear ejection motor mount is partially inserted into the rocket. The parachute and shock cord are then tucked in around the motor mount. The motor mount is then fully seated into the rear of the rocket. Take note that the parachute and cord should not be wrapped around the MMT. They should be loosely tucked between the two centering rings. Because I incorporated a mid-body seam in my rocket, I needed to use a ring of masking tape to attach the top of the rocket to the bottom half.

There were a few scattered chuckles when this pile of coffee cups went out to the pad. The crowd (and I) were pleasantly surprised by just how nicely this rocket flies. It had a very straight boost on the D12.

Recovery:
Everything stayed together right up until the ejection charge. At that point, one of the glue joints on the upper cups failed and the rocket came down in two pieces. Due to the light construction, the "nose" fell at the same rate as the rest of the rocket under chute. The tethered motor mount and lower airframe were right next to the upper section in the field. A little hot glue and this rocket will be ready to fly again. At this point I think I'd rather have the glue joints failing then having the cups breaking, so I don't think I'll be strengthening the joints much. Perhaps a little more glue, but no extra tape seems warranted.

Flight Rating: 4 out of 5

Summary:
Most people are dubious as to how a stack of hot glued coffee cups is going to perform. They don't stay doubting long when they see how a D powered foam rocket can give a good show. Then again, it might be a good idea to get a portable hot glue gun to add to your field box. Those cups might need a little TLC on a regular basis.

Overall Rating: 4 out of 5

Brief:
I opened this package to try and build it quite some time ago but stopped when reading the instructions. Most of the construction is done with a hot glue gun and I didn't have one. When my brother in law asked about it sitting on my desk, I told him I didn't have such a tool. A few weeks later, one magically appeared. Thanks Toby!

This kit is made from Styrofoam coffee cups, foamboard, and a few more conventional pieces in the area of the motor mount. It is definitely different and quite tall. I built it in a single sitting.

Construction:
Construction began with the motor mount. It uses a very long BT-50 tube as opposed to the short tubes that are just over standard motor length. A quarter inch was marked off on a spent motor casing, some white glue was swabbed around the interior and the spent casing was used to push the thrust ring into place.

A razor knife was used to make a slit for the engine hook and the hook was put into place. It was secured with several wraps of electrical tape.

The kits came with 2 fiber centering rings to mount the BT-50 motor tube into the BT-70 airframe. Each needed to have a notch put into its inner hole. The instructions recommended using a hole punch and that worked great.

Each of the rings was slipped over one end of the motor tube and glued in place with white glue. The notch on the bottom ring was to align with the motor hook. That on the upper is to pass the recovery harness. A fillet of white glue was placed around both sides of each ring.

The kit has both elastic and Kevlar®. Usually, the Kevlar® gets attached to the motor mount but that is not the case here. An loop was tied into one end of the elastic and then an overhand knot was tied in about 10 inches down the line. The long, untied, end of the elastic was then passed through the notch in the upper ring and the elastic was pulled through until the overhand knot acted as a stopper at the ring. Some glue was then used to fasten the harness into place.

The tube that receives the motor mount is a longish piece of BT-70 that has to have one end trimmed by a few inches. I marked the cutting line and then inserted a mandrel to support the tube. The tube was cut with a razor blade since my hobby knife was missing at the time.

The forward end of the BT-70 is to be blocked by a balsa coupler. The Kevlar® is supposed to originate in the tube, pass along one side and over the top of the coupler, and then back into the tube to emerge at the other end. I should have checked for fit first but did not. I smeared white glue around the end of the tube and inserted the balsa and Kevlar®. The balsa was a tight fit and I could not get it all the way seated flush with the end of the tube before the glue grabbed.

Next up was work on the cups. Three of the cups are singled out for special attention. They need to have the bases of the cups cut out to accommodate the passing of the BT-70. This too was done with a razor blade. By cutting just at the mold line, a very tight, almost too tight, fit is achieved. I had to open the holes a bit with some sanding.

Now came something really new for me. I had never used a hot glue gun before and two of the cups which had their bottoms cut out were to be joined mouth to mouth with a got glue gun.

I plugged it in and let it heat up for a while. I gave some test squirts to see how it fed over a piece of scrap cardboard and I burned myself several times. Did you know that globs of glue at 400 degrees look almost identical to ones at room temperature?

Ready to take the plunge, I placed two of the cups together and began to pump out a bead of glue around the circumference. The feed was not steady and some parted got more than others. I burned myself some more. I worried about melting the foam. I eventually got them together and, surprising me, they seemed solid enough.

I gave the glue a few minutes to harden up and then fit the BT-70 into the joined cups. I pushed it down so that the cups were at the end opposite to the plug and allowed the body tube to protrude from the cups for just a little bit. The glued gun was then used to glue the lower cup into place.

Included in the kit is a template for marking the fin locations. I was cut out and taped into place on the bottommost cup. The lines for each face and each side of the three fins was then transferred to the cup. The template was removed and a steel straightedge was used to extend the lines.

The kit also came with a template to cut the fins from the foamboard. At this point, a decision had to be made. The fins could be mounted on the cup or they could be mounted directly to the BT-70 hiding inside the cup. The latter, naturally, yields a stronger connection and that is what I chose to do. That being the case, I laid the full template out on the foamboard, transferred the outline, and cut the fins out with a steel ruler guiding a razor blade. Had I elected to do a surface mount, the same template would have been used but a shaded area would have been removed from the template first.

A razor blade was used to cut slots for the fins in the bottom cup, following the lines transfered from the marking template. The template was sized so that it fit around the cut right up to the lip but did not extend onto the lip. I learned at this step that the lines should have been extended all the way to the edge of the cup. This was simple to do.

The fins themselves were mounted by the simple expedient of running a bead of hot glue along the root edge and pressing them into place through the slot cut for the purpose. When in place, a fillet of hot glue was run along the seam between the cup and the fin on each side. It was all much easier than I had supposed.

You will recall that there were three cups which had their bottoms cut out. Two had been used thus far and it was time for the third one. It was mated with an unmodified cup in the same way that the first two were. The cut end was then slid over the projecting section of BT-70 so that its base was flush against that of the upper cup of the first pair. Hot glue was then used to join the two sections together.

From there on, it was just a matter of hot gluing pairs of cups together and then gluing the butt end of a pair to the butt of the preceding pair. It was easy.

The last construction step was the installation of the launch lug, a long, heavily built 3/16" job. It was just hot glued into place at the seams of the two lowest pairs and with that, construction was complete.

Finishing:
No finishing is really needed on this rocket. I suppose that I could find some foam safe paint and get rid of the yellow from the glue but its not all that noticeable from any distance. I decided to leave mine bare.

Not long after completing this rocket, I saw a post from Jim Flis on TRF about finishing. He mentioned that electrical tape can be used to provide a little color and the strengthen the joints between cups. That seemed like a good idea to me and would cover up much of the glue mess.

I didn't have any colored tapes but I decided that I would be satisfied with black. Accordingly, I wrapped each cup joint with tape and the appearance was greatly improved.

Construction Rating: 5 out of 5

Flight:
I was a bit worried when the time came for the maiden flight. The wind had kicked up a bit. Mostly, I was worried about the rocket being torn away from the lug on the launch rod. That did not occur.

I mounted a 12" chute and a C11-3. It was not a kid magnet because there were no kids present at that time, but it sure magnetized the adults. It took off well, did not weathercock at all, and ejected very nicely. It looked kind of funny coming down. Usually the rocket hangs under the chute canopy. This one kind of let its chute droop down below it. There was no damage. A video of the maiden flight can be seen here.

The second flight was on a D12-3. It was a repeat of the first one except higher. A good time was had by all. A video of the second flight can be seen here.