BT-56 Centuri Groove Tube

[ronhill]

Just looked at the Rack One photo again up close. My memory of the first stage engines was wrong. The first stage had two D18-0 engines straped to one E5-0 engines. With the E5-6 upper stage, it had a powered boost of 10 seconds.

The D18 engines got it off the pad fast, but the velocity bled off rapidly with those draggy fins. By the time the upper stage lit, it was going pretty slow. The upper stage actually was still thrusting when it went horizontal. It was quite high, but not high enough.

In the 1970s, we couldn't figure out a good use for the E5-0 engine. Obviously, in 2004, I didn't solve that problem.

 

[rokitflite]

Hi Ron,
I do not think I have seen square carbon fiber rods but I will look when I go to the RC show in New York where I get my round rods from. The round should work though, I make stilt type video rockets and just rough up the carbon fiber rod a bit where it is to be glued. I then strip off the glasine coating off of the body tube and glue the rod to it with medium CA. I then come back and put a fillet of 30 min. epoxy over it. The one crash I had proved that the joint was stronger than the cardboard tube. Oh, I think the Centuri Groove Tube was the best looking tube fin rocket so far (had to bring the thread back a little). I have attached a picture of my video rocket that has been flown about 15 times, the long rods are carbon fiber attached in the manner I described above. I think they are superior to wood dowels in that they will not warp.

 

[rokitflite]

I am VERY familiar with the performance of FSI motors! Back in the 80s the popular phrase was "fly and die with FSI".

 

[ronhill]

Scott

Your ideas about carbon rods are attractive, and I'll have to look into it. Your photo testifies to the effectiveness. The joints look about the same as the ones on my Racks. You've developed an effective method of attachment, and I've captured it for my use.

I'm down to about 8 FSI motors from a total of about 30. The newest one was dated 1974. Out of the batch of 22, I've only had one CATO, although I think I did have a blow-through on a D20-0 booster on Sunday. I'm burning them fast.

In 1978, we launched a cluster of six F7s around one F100. Lots of smoke and fire.

Ron

 

[ronhill]

Scott

Your Proteus is a fantastic design. I have two questions:

1. Is there a web site where I can view your design and your videos?

2. What is source of your carbon fiber rods, i.e., where can I buy them? I can imagine making the booms a bit longer but the fins a bit smaller. It would still create the same moment arm to keep the CP aft. The light weight of the carbon fiber rods would enable this.

Ron

 

[rokitflite]

Hi Ron,
Oh Jeeze, I was afraid you might ask me the name of my supplier of carbon fiber tubes next! I can't for the life of me remember the name of the one I got the longer ones from. It is a vendor that shows up at the WRAM (Westchester Radio Aero Modelers) show in NY every year. I would be happy to forward you their information, but I am afraid I won't get it until the last weekend in Feb. You may ask at your local RC airplane enthusiasts hobby store for carbon fiber pushrod material, or if there is a kite manufacturer around they use them for spars. you can also get carbon fiber arrow shafts fron sporting goods stores. I have a few extra ones I could sell but they are kind of awkward to ship so it might be easier to find them locally. I am working on a website to post my videos on, but as yet have nothing. If you want to PM me your mailing address I can send you a CD of a couple of flights in MPEG format.

 

[ronhill]

Scott

Just looked at my "Into the Wind" kite catalog. They have graphite tubes and rods. I assume the graphite rods are the same as the carbon fiber rods you use. I also believe I've seen them in the R/C shops (something I used to do in a former life). I'm sure I can get them locally.

Don't worry about sending me the CD. I'll wait until you get your website up and running. But thanks for offering.

Ron

 

[Fishhead]

Dateline - VOA, November 21, 2004
After a month in the wilderness, my Groove Tube was returned yesterday by a kindly rocket hunter. As you can see, it won't fly again in this version, but the good news is that the tube fins had enough paint on them to allow them to survive almost two months in the wilds of West Chester, OH. The rebuild starts as soon as I track down another length of BT-56.

 

[rokitflite]

Go Bill!

 

[ronhill]

Originally posted by Fishhead
Dateline - VOA, November 21, 2004
After a month in the wilderness, my Groove Tube was returned yesterday by a kindly rocket hunter. As you can see, it won't fly again in this version, but the good news is that the tube fins had enough paint on them to allow them to survive almost two months in the wilds of West Chester, OH. The rebuild starts as soon as I track down another length of BT-56.

Bill

Glad you got it back. I guess I blamed the soccer players a bit prematurely.

Same thing happened with my tube rocket. Found it after 6 weeks. The only things that could be salvaged were the six tube fins and the plastic nose cone. As you said, the paint inside and out saved them. Here it is on flight number 10 on a D12-5. It had 5 flights before being "lost" and 5 flights after being rebuilt

Ron
(fellow tube fin fan who persuaded you to launch it with a little clay in the nose)

 

[Fishhead]

Mine is in the final stages of painting as we type. It's among the rockets I plan to bring to this weekend's launch, IF I make it. It will have a LOT of clay in it this time. ;-)