Project Venn

The Rocketry Forum

Help Support The Rocketry Forum:

boatgeek

Well-Known Member
Joined
Dec 27, 2014
Messages
3,908
Reaction score
2,536
I've teased a couple of pictures on this project. Now that it;s a little further along, I'll start up a build thread.

It all started with a 4' long 6" diameter mailing tube that the sales guy at Rockler fished out of a dumpster and gave to me. It wasn't really long enough for anything but a stubby, and I don't really have room for a 6" diameter 3/4FNC rocket, so it gathered dust in the garage for a long time. I'd wanted to build a tubefin for a while, but again, it would be too big. So I compromised, in the spirit of @neil_w 's ring fins and @Dotini 's plexiglass not-quite-tube fins. And that gave us Project Venn:

1634601843830.png


29mm motor mount, 2.6" LPR tubing for the body, 6" ID rings that are just tangent to the body tube, and a little bit of shaping to the fins to give them a little style. Oh, and while I was at it, I threw a carbon fiber wrap on the outsides of the fins. It probably wasn't strictly speaking necessary, but it looks nice and the final result will be absolutely bulletproof. As you might imagine, marking and cutting this was an exciting job. This is where my copy of Rhino for work came in...

1634602104858.png
1634602280800.png

It's pretty straightforward in Rhino to intersect surfaces, so I made an inside and outside for each tube, marked a constant elevation and the intersections, and unrolled it into a flat surface. And since the cuts where the tubes intersect aren't square, there's a template for the inside and the outside. It all fit on a single 11x17 sheet, so I could print it off on a relatively normal printer instead of a big plotter. The templates were in two pieces, but they weren't hard to tape together. The little square up above is a 1010 rail, so I'm confident that it will slide nicely on to the rail.

Here's two of the rings cut and nested together, plus the process of marking ring #3:
IMG_3694.JPG
IMG_3712.JPG


I marked the outside with Sharpie since it didn't bleed too much over the epoxy. I marked the insides with a pencil since that showed up nicely on the cardboard. Each slot had a cut at the mating line plus two more rectangular windows that I could use to mark lines that I'd join up into full cut lines for the egg crate. This way, the pattern stayed nice and sturdy through marking all three fins. I also marked the center of the pattern so that I could line up the inner and outer patterns. One fin had four bottom cuts, one had four tops, and the last had half and half. Marking the last one was an exercise in measuring five times and cutting once. All cuts were made with a Dremel tool and cutoff wheel.

And this is what it looks like now. I am honestly shocked at how well it fits. The motor mount will have upper and lower centering rings just catching the tops and bottoms of the rings, so it should be nice and sturdy.
IMG_3714.JPG


Next steps:
Drill recesses for rail buttons into one ring fin where it would touch the body tube
Coat the inside of the rings with epoxy
Paint the rings except right in way of the glue lines
Glue the fin can together, make nice fillets where the rings meet
Paint the body tube except in way of glue lines (?, maybe this should be later?)
Glue the fin can to the body tube
Insert the motor mount (and probably a piece of coupler to stiffen the body tube just above the fins)
Touch up paint
 
Last edited:

boatgeek

Well-Known Member
Joined
Dec 27, 2014
Messages
3,908
Reaction score
2,536
This project needs a name, preferably a horrendous pun involving Venn. It was originally going to be themed on the three Elven rings of power, but there were two problems with that. First of all, there's no collective name for those three rings that I could use for the rocket name (Seriously, JRR? How many books of lore and there's no collective name for the rings?! :D ) The second is that the Elven rings are blue, white, and red. While I'm not averse to a set of flag colors, it seemed a little boring. So instead, I'll paint the largest sections red, blue, and yellow. The next sections in will be green, purple, and orange in the manner of a Venn diagram. The center section by the body tube will just be black, and I'm not sure yet what color to make the body tube and nose cone. All of the carbon fiber will be clear coated, since it's a crime to paint carbon fiber. IMHO, of course.

One final thought. I was describing this to my wife, demoing how the rings would go together before the slots were cut. She looked at me for a moment and asked, "Is this... normal?" No, dear, no it is not. At least she knows me by now. :D
 

boatgeek

Well-Known Member
Joined
Dec 27, 2014
Messages
3,908
Reaction score
2,536
This will be a park flyer, well under Class 1 limits, probably mostly high thrust F's and mid-thrust G's. I'll be able to throw in an H easily if I'm at a bigger field and the mood strikes. Estimated altitude ~850 feet on an F79 (CTI 24mm 3-grain smoky), though my mindsim says that's a bit optimistic. I need to rework my sims a little. I think I'll make three tube fins that approximate the inner intersections plus three more that approximate the outer sections. I'm not worried about stability at this point.
 

neil_w

Twaddleposter
TRF Supporter
Joined
Jul 14, 2015
Messages
12,698
Reaction score
5,650
Location
Northern NJ
Funky custom ring-cutting guides that actually work correctly earns the coveted three thumbs up: 👍 👍 👍 I may enlist your help in the future if I ever build one of my intersecting-ring designs.

As for a name... I got nuthin'.
 

tsmith1315

Well-Known Member
Joined
May 16, 2020
Messages
1,327
Reaction score
1,182
Location
Doerun, GA
Neat! For names, there's low-hanging fruit like Venndication, Venndetta. I'm stuck on the rocket being the intersection of the Venn-fin, there's bound to be something good in there.
 

boatgeek

Well-Known Member
Joined
Dec 27, 2014
Messages
3,908
Reaction score
2,536
Funky custom ring-cutting guides that actually work correctly earns the coveted three thumbs up: 👍 👍 👍 I may enlist your help in the future if I ever build one of my intersecting-ring designs.

As for a name... I got nuthin'.
Any time. This went a lot faster the second and third time...
 

Funkworks

Low Earth Orbit, obstructing Earth's view of Venus
Joined
Jul 28, 2018
Messages
2,359
Reaction score
2,222
Venn-turi effect(s)
Venn-turi tube(s)
Venn-turi fin(s)
Ad-venn-tures in fins
or
"The one with fins that look like a Venn diagram"

This is the kind of thing where you go:
"Venn diagrams and rockets have existed separately for over a 100 years, but it took 2021 to bring them together. That is nuts!"
 

Dotini

Well-Known Member
TRF Supporter
Joined
Mar 2, 2021
Messages
513
Reaction score
436
Location
Seattle, Washington
Barnum & Bailey - Three Ring Circus
One Ring Good; Three Better
Dunlap - Three rings Dun Lap over each other
In Venno Veritas
Caesar's Rocket: Venni Vidi Vici
Triple the Rings; Third the Altitude
Belt, Braces and Brassiere
Venndication Cubed
 

boatgeek

Well-Known Member
Joined
Dec 27, 2014
Messages
3,908
Reaction score
2,536
Barnum & Bailey - Three Ring Circus
One Ring Good; Three Better
Dunlap - Three rings Dun Lap over each other
In Venno Veritas
Caesar's Rocket: Venni Vidi Vici
Triple the Rings; Third the Altitude
Belt, Braces and Brassiere
Venndication Cubed
Oh, so many of these are good. I'm leaning toward Venni Vidi Vici or In Venno Veritas. Belts, Braces, and Brassiere is awfully hard to pass up though.
 

Sandy H.

Lifetime Supporter
TRF Lifetime Supporter
Joined
Mar 20, 2009
Messages
1,055
Reaction score
469
If it were a 2 motor cluster, I'd say 'Two Yutes'. The Vinn(y) correlation would be for a select few. Possibly a very select few. Possibly just me. . .

Sandy.
 

Rktman

Eric
TRF Supporter
Joined
Mar 5, 2017
Messages
1,445
Reaction score
323
I've teased a couple of pictures on this project. Now that it;s a little further along, I'll start up a build thread.

It all started with a 4' long 6" diameter mailing tube that the sales guy at Rockler fished out of a dumpster and gave to me. It wasn't really long enough for anything but a stubby, and I don't really have room for a 6" diameter 3/4FNC rocket, so it gathered dust in the garage for a long time. I'd wanted to build a tubefin for a while, but again, it would be too big. So I compromised, in the spirit of @neil_w 's ring fins and @Dotini 's plexiglass not-quite-tube fins. And that gave us Project Venn:

View attachment 486233

29mm motor mount, 2.6" LPR tubing for the body, 6" ID rings that are just tangent to the body tube, and a little bit of shaping to the fins to give them a little style. Oh, and while I was at it, I threw a carbon fiber wrap on the outsides of the fins. It probably wasn't strictly speaking necessary, but it looks nice and the final result will be absolutely bulletproof. As you might imagine, marking and cutting this was an exciting job. This is where my copy of Rhino for work came in...

View attachment 486234 View attachment 486235
It's pretty straightforward in Rhino to intersect surfaces, so I made an inside and outside for each tube, marked a constant elevation and the intersections, and unrolled it into a flat surface. And since the cuts where the tubes intersect aren't square, there's a template for the inside and the outside. It all fit on a single 11x17 sheet, so I could print it off on a relatively normal printer instead of a big plotter. The templates were in two pieces, but they weren't hard to tape together. The little square up above is a 1010 rail, so I'm confident that it will slide nicely on to the rail.

Here's two of the rings cut and nested together, plus the process of marking ring #3:
View attachment 486236 View attachment 486237

I marked the outside with Sharpie since it didn't bleed too much over the epoxy. I marked the insides with a pencil since that showed up nicely on the cardboard. Each slot had a cut at the mating line plus two more rectangular windows that I could use to mark lines that I'd join up into full cut lines for the egg crate. This way, the pattern stayed nice and sturdy through marking all three fins. I also marked the center of the pattern so that I could line up the inner and outer patterns. One fin had four bottom cuts, one had four tops, and the last had half and half. Marking the last one was an exercise in measuring five times and cutting once. All cuts were made with a Dremel tool and cutoff wheel.

And this is what it looks like now. I am honestly shocked at how well it fits. The motor mount will have upper and lower centering rings just catching the tops and bottoms of the rings, so it should be nice and sturdy.
View attachment 486238

Next steps:
Drill recesses for rail buttons into one ring fin where it would touch the body tube
Coat the inside of the rings with epoxy
Paint the rings except right in way of the glue lines
Glue the fin can together, make nice fillets where the rings meet
Paint the body tube except in way of glue lines (?, maybe this should be later?)
Glue the fin can to the body tube
Insert the motor mount (and probably a piece of coupler to stiffen the body tube just above the fins)
Touch up paint
That is a freakin MASTERPIECE!
 

boatgeek

Well-Known Member
Joined
Dec 27, 2014
Messages
3,908
Reaction score
2,536
Let's not get too romantic about it. And make sure the parachute is big enough, or it'll get baroque when it lands.
I can always depend on you to keep a pun stream going. You're an old master at this.
 

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
9,408
Reaction score
4,110
You could go white and sparkly and call it “Taste of HeaVenn”
 
Top