2 Stage Water Rocket - Part 38 - Top Ring

[@AscenderRockets]

Enjoying the consistent updates, can't wait to see it fly!

[@michaelsilva7085]

Agree 100%!

[@AirCommandRockets]

Cheers :)

[@simonabunker]

That master template was definitely a very good idea!

[@AirCommandRockets]

It's definitely been useful in getting things lined up and sized correctly.

[@Calenardhon314]

The launch is gonna be epic

[@kayboku7281]

Beautiful work! 14 years in the making!

[@AirCommandRockets]

Cheers! :)

[@TonyLambregts]

Thank you for bringing us along on your endeavor. It is truly appreciated.

[@AirCommandRockets]

Cheers!

[@teamlucrockets]

Great engineering George.This is going to be a superb flying waterrocket.👏

[@AirCommandRockets]

Thanks Luc! I hope we get more than one flight out of it. Actually I'd be happy with even one flight. :)

[@lonl123]

Awesome George, fantastic Engineering Mate....cannot wait to see the launch!

[@AirCommandRockets]

Thanks! ... not long now until the launch so I am panicking a little bit, there is still so much to do.

[@jimgraham6722]

Couple more stages and into orbit

[@sgriffett541]

so nice to see the old rocket George! looking forward to August the 10th!!

[@AirCommandRockets]

Cheers! Yup it's been a few years since we've flown it. Fun times :)

[@Ranger_Kevin]

I am constantly impressed with the creative fabrication techniques that you come up with. Well done!

[@AirCommandRockets]

Thank you for following along. :)

[@JTapselicious]

Looking mint, staggering the carbon on the corner reinforcement is clever. Hot glue is great for those temporary wooden fixtures, would recommend.

[@AirCommandRockets]

Cheers, thanks for the tip.

[@IT-sq5rj]

Hexagons are the bestagons!!!

[@jasonsaj.3]

When are we looking for a launch? Being following this project since part 1!! Can’t wait super interesting!!!

[@AirCommandRockets]

The current plan is around 10th August or so.

[@shere_kan8329]

😮😮

[@BrendaEM]

Your experience and design techniques are excellent. I have learned a lot from your channel. I might be inclined to do an experiment to in which the booster slide pads hold internally onto the sustainer. Then short segments bridge from the tangnet of the booster tube connecting at a peak, letting the sustainer pass. Though, the trick is, the internal pads must keep the sustainer from rotating, which might be a issue with your design, too. If the sustainer turns axially, it may hook to the support ring of either kind. Perhaps delrin/UHMWPE or even felt or even fuzzy Velcro will make the sustainer slide nice. Perhaps the ring edges could be teardropped. BTW, you know that Freecad can use CFDof, which allows the use of OpenFoam for aerodynamic studies. It will probably do transonic, too.

[@AirCommandRockets]

Thanks for your comment. The ring geometry here is set up so that the sustainer is free to rotate on the way out of the booster and not clip the ring. The reason for this was that we didn't want to add any more gap than necessary between the sustainer and booster segments. We may loose some paint though. We could have had a guide rail on the inside, but that would have added weight and the rail buttons would have added drag to the sustainer. (The best part is no part) Thanks for the tip on FreeCad that is something I will need to look into in the future.

[@robertsteinbeiss8478]

Cool cool cool

[@gsestream]

not directly water rockets but still, solid-liquid hybrid rocket, where bottom container is rigid nozzle shaped plate oxidizer and top tank is fuel, say anfo hybrid rocket. then you only need to pump the liquid fuel spray to the solid oxidizer plates and ignite/react. also gravity linear acceleration going up can do the pumping after ignition.

[@saxus]

Why did you orefered to put the boosters in the middle of a segment instead into a corner of too? Maybe there is something but if you rotate it by 30° then you could have two glue line with the curved plates and it's also could stiffen the ring. I didn't checked it on comouter but also aren't it give more clearance for the fins too? The other edge of the hexagon would be where the 2nd stages fins is. Also only one glued edge would be in the "air" instead of two. Or it would require that longer panels?

[@AirCommandRockets]

This is a really good question, and it was one of the options we explored when designing it. When you have a look at the geometry of that setup and where the sustainer fins extend to, there wouldn't have been enough clearance for the fins over the entire range of possible positions of the fins. The size of the sustainer fins is fixed as the sustainer is already built. In order to get the full clearance you would have had to offset the the hexagon away from each of the booster segments. We compromised a little and the hexagon isn't a true hexagon three of the sides are shorter than the other 3.

[@saxus]

@@AirCommandRockets Ah right, I forgot that it's not a true hexagon. (I had to watch the video in two part). Thanks for your answer!

[@Mourkain]

Hey George, it seems our last comment disappeared somehow. Hopefully we didnt violate any rules. At first we'd like to thank you for your amazing work. It inspired us (me and my son), to build our own high Pressure Water Rocket. Today we've done the first Testflights with lower Pressure and it worked out amazing. We got one question which you are surely able to answer easily... we use a hand pump to pressure our rocked right now. Thats a big struggle to even get 15 or 20 bar. In your videos you seem to use a big compressed air bottle and somehow reduce the pressure so that you are able to pressure your rocket slowly. Can you explain us how you manage to do that? That would be AWESOME! We are looking forward to finally see the horizon rocket launch!! Many greetings from germany!

[@AirCommandRockets]

Hi, glad to hear you are having fun with higher pressure rockets. :) To fill our rockets we use a scuba tank which certainly cuts down on the effort required, but a Nitrogen bottle would work just as well. You technically don't need a pressure regulator, you just need a very tiny hole in the air supply hose (less than 1 mm) that delivers air to your rocket. When you open the valve a little on the bottle, air starts to flow slowly into the rocket and you watch the pressure gauge. When you reach the desired pressure you turn the air off. It's nice and simple, but you need to make sure your pressure gauge is on the rocket side of that tiny hole.

[@Mourkain]

@@AirCommandRocketsThank you for the fast answer. We will try it exactly as you discribed!

[@Ded_Yz]

does this hex amp weigh 398 grams? I think this is too much. You used 3mm thick plates. Are there really such heavy loads there? You have fabric. Why didn't you make the amplifier out of fabric by wrapping and impregnating a hex template with resin? I can assume that a thickness of 1mm is more than enough.

[@AirCommandRockets]

Yes, the loads on this ring are enormous. I hope even as is it is now that it is strong enough. You have a 2m long lever (the portion of the sustainer above the ring) trying to force it's way sideways during acceleration especially if the rocket has any kind of angle of attack which it will have. With the acceleration ~50G just before staging imagine the amount of force on that lever if say the rocket has a AOA of just 5 degrees and air speed of 360km/h pushing on that. Saving a few grams here isn't significant in terms of performance as the booster produces about 1 ton of peak thrust. The weight forward on the rocket also helps keep the rocket stable. Another way to look at it, sit on a bullet train and stick a 2m piece of wood out the window and angle it at 5 degrees from the direction of travel. Now hang on to it while the train gets up to 360km/h in about 1.1 seconds.

[@hunnybunnysheavymetalmusic6542]

Will the ring get any face-on chamfer along the leading edge for streamlining? Or is that amount of surface area discounted as inconsequential to the Cd of the whole rocket?

[@AirCommandRockets]

No, the edge will stay as is. In the whole scheme of things this makes very little difference on the booster. If it was on the sustainer than we would probably streamline it.

[@hunnybunnysheavymetalmusic6542]

@@AirCommandRockets Understood. Great job as usual though.

[@morphles]

Hm, so, I assume when stuff is pressurized booster will squeeze sustained real good in that ring? But as booster looses pressure it will be much less compressed, though still even in template seems like it's very snug and quite "frictive" setup?

[@AirCommandRockets]

Yes this is correct. I think from the tests we did the booster segment increases about 1-2mm in circumference so let's say 0.5mm in diameter. The sustainer will also increase slightly , perhaps 0.3mm? There is about 1-2mm clearance for the sustainer between the booster segments. So yes a squeeze when pressurised and under acceleration which is good, and by the time of staging we should be back to the right clearance. The ring does have a little bit of flex under those loads so I am hoping we should be OK.

[@alienbeef0421]

I'm curious about how you'll go with protecting the booster and sustainer from friction as the two stages separate. Vaseline maybe? 😂

[@AirCommandRockets]

Some paint may rub off during staging.

[@ozy1994]

when will we see this rocket in action?

[@AirCommandRockets]

We hope to Fly it 10th August. Not long now. :)

[@mstreich]

How often do you have to replace the dremel diamond saw blade?

[@AirCommandRockets]

We haven't needed to replace it yet. I'd say we've cut perhaps 10 linear meters with it so far and it still looks fine.