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