PVC Dreams

[Johnnie]

With rocketry, I have managed to launch a lot of stuff off of PVC, but I have never launch PVC itself...so what do I do with this 2" schedule 40 PVC?

 

[Johnnie]

At work we have a "sister" company that does rapid proto-typing...we can go from design to part in hand in a weeks time. They make molds of parts out silicone, then with that mold make multiple parts from it.

Since they have been slow, I kidded them about making rocket parts, specifically nosecones and tailcones...they said "how many?"

So for my 2" PVC, they have created the following cone, with a shoulder that fits it like a dream...all be it somewhat of an ugly design, it fits

 

[Johnnie]

The 1st run of cones was that made out of rubber

"rubber?" I said, " I need to be able to thread an eyebolt into this cone..." later cones were then cast in a harder plastic material. I should note that the cone is solid, but the shoulder is hollow to conserve weight.

The nice thing about the rubber cone I have, is that it has a color added, and with each pour, the cone could be any color you would want. I am trying to talk them into pouring clear cones, so that I might mount an LED for night launching.

Here is gold rubber

 

[Johnnie]

I do mean rubber...

 

[Johnnie]

Whats a nosecone without a tailcone? I challenged them again, and they produced the following hard palstic tailcone.

The only flaw in the design is that you must first glue in an empty paper towel tube, then glue in a 38mm motor mount. There mounts ended up slightly oversized...but it fits the shcedule 40 PVC like a dream.

 

[Johnnie]

A look down the business end of the tail cone, and one can see the oversized motor mount...too small for a 54mm too

 

[Johnnie]

A view of the shoulder.

 

[Johnnie]

They were cutting some 3/8" clear Lexan, and gave me a few scraps, and I was able to cut a fin design out of it.

 

[Johnnie]

This is some thick fin material, with a solid cone, heavy PVC body, and three of these fins, it may take a "Hoss" of a motor to loft the would be rocket.

 

[Johnnie]

What I have collected so far, are the following items:

(3) cones, one of them is rubber
(3) tailcones
(1) solid piece of PVC for couplers, 4" long
(3) lexan fins

 

[Johnnie]

So that leaves ideas open for disscussion.

I have thought about making (3) strap-on drop away boosters out of the parts, but the weight trade-off would tremendous.

I have a fin set right now, and (1) coupler to make one dual deploy EX rocket, and rest of the cones would be used for spare parts...

...and then theres the whole "epoxy won't stick to PVC thing" so I would probably have to drill, tap and bolt everything down.

So my original question stands, what do I do with 2" PVC and custom cones?

 

[rstaff3]

I think you answered your own question, since you laid out all the parts. Maybe bolt the fins on with aluminum angle stock. It may be heavy but you should be able to find motor to lift it. Low and slow is cool anyway.

Keep challenging them to make parts for other tubes

 

[Johnnie]

Keep challenging them to make parts for other tubes

Amen to that, I have even offered to bring in cones that I have, to make nice solid cones out of, but they seemed to have gotten busy with their day jobs again.

I have looked at bolting the fins down, and using JB Weld for fillets...

 

[rstaff3]

!#$%^ day jobs. Always getting in the way of progress!

 

[brianc]

Originally posted by Johnnierkt
So for my 2" PVC, they have created the following cone, with a shoulder that fits it like a dream...all be it somewhat of an ugly design, it fits

That ugly design looks surprisingly like a <a href="https://www.boeing.com/defense-space/space/delta/dlsfamily.htm">Delta II cone...</a>

And your plan for strap on boosters, is just screamin' "Build Boeing!"

 

[Johnnie]

Delta IV Heavy Payloader/lifter...Hmmm

 

[astrowolf67]

Hey, a rubber nose cone could be a good thing!

Depending on motor choice, if there's enough room, you could use expanding foam to help lock the fins in place.

 

[rstaff3]

The PVC is cheap, the cones were free, go for it! It will take a lot of nose weight to counteract the heavy side tubes and those fins, but the 'strap ons are so long that some of the weight may be in front of the cp? Time for a sim Hey, and then if things aren't working out, just stretch it a bit.

Those cones are too cool.

 

[Karl]

Thats some pretty sweet rubber stuff! If you where to use a rubber nosecone in a cardboard bodytube , if it spacked/lawndarted , the rubber would take the whack and not so much the bodytube. It could reduce damage to the BT....
Karl