Another Toilet Tube Rocket

[El Cheapo]

I decided to build my boy a scratch rocket for his birthday and wanted to use one of the two nose cones I built trying a method learned here. I also wanted to do a cluster that was different yet easy to build considering my time constraints and only having a day and half to build prior to his birthday. I was definitely not the early bird in making this decision. I settled on modifying the Y-Wing design from Astrosaint's Recycled Rocket Page of which I've alrady built one previously and is a great, stable flyer.

The long and short is this build consists of two paper towel tubes (These are considerably stronger than most I've come acrossed. They are from a pack of recycled paper towels purchased from Costco) five toilet paper tubes, a few pieces of 1/8" balsa, scrap BT50 tube, cardboard, cardstock, two screw eyesy, 3/8" elastic shock cord and one very late night.

Power for this is one 24mm Central and two 18mm outboards in the tube fins. The 24mm motor mount was cut from an extra piece of tubing left over from my 6yro boy's Fireflash kit bash that he built on his own. Centering rings were made from cardboard and coated w/epoxy. The foward thrust ring was a piece cut from a spent 24mm casing.

The two outboard motors were rolled using 110lb cardstock and the Fliskit's motor mount method. They were fastened to the outboard tubes by cutting four pieces of balsa to center it between the TP tube.

The BT's were joined by making a coupler out of part of the fifth tp tube. A three chamber baffle was made out of the other piece of the fifth tube and cardboard. The baffles were glued in using titebond and protected w/a thin layer of epoxy. A screw eye was also attached to the top of the baffle and set in w/epoxy. The baffle was set 3" up from BT tube joint to help shift the CG.

The tube fins were attached using titebond wood glue and the bottom 1/2" was reinforced w/thin CA. Once assembled it was swing tested and determined about 1.5oz of nose weight was required which I epoxied bb's into the nose cone, glued in a cardboard shoulder which was epoxied on both sides. The second screw eye was also affixed to the shoulder using epoxy. I'm not sure if so much nose weight is really necessary as this thing is probably over stable but I don't have Rocksim and wanted to make sure it would fly in it's heaviest configuration.

The first flight was on a D12-3 and two A8-3's in the outboards. All three motors lit and recovered perfectly. The second flight was on a D12-3 and two C6-3's in the outboards. This proved to be too short of a delay but it still recovered just fine. Only damage was a slight chip in one of the tube fins on landing.

I also have in the works an 18mm booster which will allow this to initially stage on 3 18mm and light the 24mm in the sustainer. Pics of the booster will follow in the next week.

All in all, this was an awesome project, cheap, and flew amazingly well. Included is are two pics of the rocket, nekid, and a pic of the original Y-Wing we built at my daughters rocket slumber birthday party a few months ago. Sorry, no flight pics.

 

[El Cheapo]

Here's the 18mm booster. It'll light the three 18mm, one in the booster and the two outboards in the tube fins and then stage the single 24mm in the sustainer.

 

[El Cheapo]

One more from the business end of the outboards and 18mm booster. At first glance the upper left tube fin looks out of whack but I realized it's the back of the cusion for the porch swing.

 

[El Cheapo]

Here's the finished product after clear coat. I still need to do a little sanding on the booster as I extended the paint a touch too far and it's grabbing a bit. No, problem. Too bad it's so windy today, I'd love to send it up on three C's and a D12-5 in the sustainer. It came in at 7.45oz after paint which is a bit heavier than I wanted. It has a ton of nose wieght in it which is probably pretty overkill but I couldn't get it to swing test otherwise with all four motors loaded.

 

[UfO]

Very cool! Not bad at all for toilet paper tubes.

 

[Rocketman52]

I really like your tube fin .I have built a few tube fin & ringfin rockets also.