Long, Slow Burn

I’ve been doing some work to prepare for my presentation at the Elementary school tomorrow. One thing I did was to create another water rocket complete with new fins. I took this chance to document how I create my fins. I hope this helps you make a better rocket.

A step by step guide in creating water rocket fins.

A friend and I were preparing for our demonstration at Sawnee Elementary School on Monday and we were test launching a plain bottle. No fins, no doubled up bottle, no nose cone. Just the bottle. We loaded it onto the 1/2 inch launching tube just fine, however, the PVC collar wouldn’t stay up over the cable ties. It kept slipping down.

Now that I look at it today, I see that the flange is much smaller than the normal diameter of the flanges on a 2 liter bottle. A normal flange diameter is approximately 1 7/16 inches (37 mm). This flange measures 1 1/4 inches (32 mm). I think I’m going to sacrifice this bottle to the Fin God. It’s a green bottle so it was probably either Sprite or Mt Dew. I’ll pay closer attention next time I’m ripping off the label.

Moral of the story: (1) watch those flanges or (2) carry a different diameter collar with you. {grin}

I’ve been invited to speak to the science classes at Sawnee Primary school. I’ll be demonstrating the water rockets and speaking on Newtonian Law. I’ll be doing two sessions with each session having 60 kids in them. I’ve got to get over there beforehand and practice which angle and pressures work best in the space given.

April 24th starting at 10:30am. Very exciting.

I’ve had some pictures ready on how to shrink down some 20 oz. bottles for FTC rockets but I haven’t had time to get them together into a form that could be published.

Well, yesterday I started to get it all put together and I finally published it today. Hopefully this is the beginning of getting my FTC water rocket section put together. Now I need to get the ends glued on and pressure tested. Exciting stuff.

FTC Mould to be used to build the rocket ends

U.S. Water rockets has published a picture of a release mechanism that I haven’t seen before. Pretty interesting. The link was broken on their site (of course) but I was able to correct it and pull up the image. Take a look:

Very interesting. It resolves some of the drag issues and yet would give a very low pressure release mechanism that wouldn’t result in a lot of rocket wobble on launch. I wouldn’t recommend this mechanism to anyone that isn’t yet onto the FTC design. The drag using 2 liter bottles wouldn’t warrant this gain of drag from the bottle throat modification.

I’m a little behind the ball on this. I’ve got to monitor their home page better.

The U.S. Water Rockets team has set a new world record in September with their new X-12 design. I’ve placed the entry on my “History” page. Click here.

It also appears as if they have leaked some information on their X-10 rocket. Click here to read about it …

My one criticism is that, even though they have an awesome looking web site, they often have broken links to images and video. Frustrating. If you check the properties of a broken image and you see a “%5C”, switch that to a forward-slash (“/”) and you should be able to pull up the image. I’m not sure what’s going on with some of their videos. They also don’t have a link (that I can find) that will allow you to contact them to ask them to correct a link.

Grrrr. {Green with envy.} When will I have time to run some tests on my FTC rockets? Too much to do, not enough time, need too much sleep.

The student from Wofford College wrote back to me. (I’ll keep his name out of the blog to protect his identity.) He was wanting maximum altitude and was asking me about my reference to T-valves. Crap! Did I write that? I meant T-nozzle. I hate it when I do that.

I wrote to him about T-nozzles and where to get links.

Mental note: create a full write-up of T-nozzles with pictures and everything!

A student of Wofford College wrote me today asking about 2 stage rockets. Unfortunately, I haven’t ever done a 2 stage rocket. I wonder if he’ll write back and let me know how it is going?

I received some inquiries into building parachutes and deployment mechanisms lately. Yesterday I made a tangleless parachute and documented it onto my “Chutes” page on the water rocket site.

Chutes : How To Make A Tangleless Chute

Is “Tangleless” a word?

The U.S. Water Rockets team has broken the world record again. Amazing. From the altitude chart, it appears as if apogee (1,698 feet) was obtained 9 seconds into the flight.

1,698 feet is approximately 0.32 miles. This means that the average speed of the X-10 was 128 miles per hour for the duration of the climb. However, if we look at the first 5 seconds of the flight, the X-10 achieved an altitude of 1,350 feet. This would equate to 184 miles per hour for the first 5 seconds.

Congratulations go out to the whole team! Keep on pushing the envelope!

Click here to view my water rocket history page.