Buckets v2

Because once is never enough, it's on to the second version of the bucket rocket!

Here are all the parts, ready for assembly....

-Kevin

:eyepop:

That will be a BIG ROCKET!

Where could I find pics of the original?

This should be awesome to see

Will it be going up at LDRS?

eggplant said:

Where could I find pics of the original?

Click to expand...

I'm not sure I have a good picture of the original, though I should take one.

You can find video of the flight of the first one in this thread

-Kevin

troj said:

I'm not sure I have a good picture of the original, though I should take one.

You can find video of the flight of the first one in this thread

-Kevin

Click to expand...

Hmmmm... how appropriate is it that the video is hosted on...


wait for it.....


Photobucket?

cjl said:

Will it be going up at LDRS?

Click to expand...

Yep, yet another rocket for LDRS.

-Kevin

Heh. The first thing that popped in my head was a V2 with buckets for the main body tube. It took me a second to realize you meant "Version 2."

A bucket rocket, so sweet!!
You can make anything fly with a rocket engine lol

I have a feeling this will be harder to bury 12ft under.

But I could be wrong.

Any major changes?

bandman444 said:

Any major changes?

Click to expand...

Some minor changes to the thrust transfer to the buckets.

On the first one, there are two rings that transfer the thrust to the bottom bucket, and from there it goes up the stack.

This time around, the motor mount will be attached to the first and third buckets from the bottom.

-Kevin

And the work begins!

First picture shows the parachute tube and electronics tube, epoxied in to their bulkhead. Both will be trimmed flush. There's a plywood bulkhead that goes over the top of the recovery tube, and recessed inside the center ring.

Second picture is the motor tube, epoxied into the upper thrust plate. This plate will be wedged into the bottom of the 3rd bucket from the bottom, as well as held in place with screws.

-Kevin

More progress today.

Started with cleaning up the parachute and altimeter tubes. Both were too long and needed to be cut/sanded flush with the centering ring. The altimeter tube actually gets cut flush with the step inside, as there's a 1/4" bulkhead that fits on top, to keep the altimeters in place, and keep ejection garbage out.

After that, the two buckets that need holes in the middle were marked. I used a scratch awl to mark around a tube, then used two passes with the Dremel to actually cut out the holes.

Precision isn't important here, as this portion isn't structural.

-Kevin

With the holes cut, the two bottoms need to be connected together. I do this by sandwiching the buckets with pieces of plywood.

On the bottom is a 3/4" ring that gets bonded to the motor mount -- this plate is used for thrust transfer, so I want it fairly full sized. On the top, I used scraps of 3/4" baltic birch. The only real load on these is during recovery.

Two 1 1/2" long plywood screws are used through each block, to hold them to the thrust plate.

If you look closely, you'll see two screw heads visible on the thrust transfer plate. These were used to hold the buckets in position, after everything was aligned, and until the blocks were attached.

-Kevin

Next comes the connection of the 3rd bucket to the 2nd. This is done via four strips of 3/4" baltic birch plywood.

On the original version, I only had the strips of plywood running between the buckets. On this one, because I plan on larger motors, I wanted to have some thrust transfer directly into the third bucket. Thus another 3/4" ring, this one wedged into the opening of the bucket. I notched the ring, so that the connector pieces would fit through.

You'll note there's a hole in the side of the ring. That's because this one was originally meant for the parachute tube, but when cutting for the altimeter tube, I got the cuts backward, keeping me from being able to get the lip on it. So, it because this ring.

The connector strips are held onto the ring via one screw each. These are temporary restraints, to make assembly easier, so aren't overly important.

I then positioned the ring into the bucket, and ran two screws through the side of the bucket and into each strip.

Next, the stack of the 1st and second bucket get slid partway on, to make sure it all fits. I then mixed a batch of epoxy and applied it to the connector strips, to bond them to the centering ring. Not necessary, but it just adds some more strength to everything.

-Kevin

With everything aligned for bucket 3, and the epoxy applied, buckets 1 and 2 (connected together) get slid down into place. Epoxy is then applied to the epoxy/transfer ring joint.

Finally, screws are run into the joining strips, to hold bucket 2 in place.

One the epoxy has cured, the screws holding bucket 3 will be removed. At that point, I'll put in the plywood pieces to connect buckets 3 and 4 together, as well as install the recovery anchor point, which goes through the bottoms of both buckets.

The last picture shows buckets 1 through 3, all connected. The motor tube is still too long; this will be cut to length once the final position of the rear ring is set.

-Kevin

Looking pretty good...Are the handles staying on for the flight?

Pantherjon said:

Looking pretty good...Are the handles staying on for the flight?

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Some do, but not all.

The handle on bucket 1 comes off, because it may catch on the launch pad, which would be bad.

The handle on bucket 5 comes off, because it may interfere with deployment, which is also bad.

-Kevin

This is a very interesting build. I can not wait to see more. I love to watch builds that use non-standard construction materials.

troj said:

I'm not sure I have a good picture of the original, though I should take one.

You can find video of the flight of the first one in this thread

-Kevin

Click to expand...

Oh, Kevin ...

I have lots of photos leading up to the first launch event, including close-ups of the "artwork". I'll bring the laptop when I come up in June - bring a thumb drive.

--Lance.

A bit more progress today...

Motor retainer is attached to the rear ring. Oh, what fun it is to tighten all those little screws....

Second and third pictures show the cover for the altimeter bay, ready to go. The washers and nut are there to create a handle, to make it easier to grab. The length of the screw is dictated by the particular scrap of wood that was used to make the altimeter board -- with that length screw, it's held in place, with no slop. Fancy, eh?

The wires from the altimeter run up under the cover for the bay, then down the side of the parachute tube, and to the bottom. I'll just a sanding drum on the Dremel to make a bit of a divot, so that the wires don't get pinched when the cover is in place.

-Kevin

kevin.... your weird

Ben

BTW, I thought I'd point out that the AeroPac retainer cost as much as, if not more than, everything else I've purchased for this project.

And Stumpy was good enough to make yet another sacrifice for the greater rocketry good -- the parachute tube is yet another piece cut out of Stumpy.

-Kevin

Are all the buckets going to separate? I think that would make this MUCH more exciting.

eggplant said:

Are all the buckets going to separate? I think that would make this MUCH more exciting.

Click to expand...

Only if there's a significant problem, and a level of excitement that I'd prefer to avoid.

-Kevin

Finally, a chance for a bit more progress on the buckets!

First up is gluing a bulkhead in the bottom of the electronics tube. This just helps keep things sealed, plus the electronics board is cut to a length that assumes that the bulkhead is in place....

Next is finishing the recovery attachment point -- I ordered a couple large (5/16" thread dia) forged eyebolts, and bought the appropriate fender washers. The eyebolt goes through the bottom of the parachute tube, through the bottom of the bucket, and down into the third bucket. Thus, it goes through the bottom of two buckets (remember, bucket #3 is upside down) as well as a piece of plywood. This helps keep everything attached together, and spreads the recovery load to two buckets.

The bulkhead for the bottom of the nosecone hasn't gotten much attention. One of the deviations from the original version is the addition of two strips that are notched into the bulkhead. This allows the mounting screws to go through the layers of the plywood, instead of just between them. I'll run two screws into the strips, and a third through the strip and into the edge of the bulkhead. The strips are a tight fit and epoxied in place.

I also (finally) got a 1/4" thread eyebolt which is where the recovery which attach to the nose.

Finally, today I got the motor tube cut to what I hope is its final length. I need it long enough to come up into the bottom ring, but it doesn't have to make it the full way. If anything, it's a bit too long, but until I have fins cut and installed, I cannot do the final fit on this portion.

Work that remains is drilling arming holes for the electronics, attaching the bulkhead for the nose to the nose bucket, epoxying the coupler piece to the nose bulkhead, cutting and installing fins, and installing the rear bulkhead.

Before the fins get done, I need to buy a sheet of plywood....

-Kevin

-Kevin

Tim for everyone's favorite hobby -- cutting fin slots!

The nice thing on this particular project is that accuracy isn't as important as it is on some. Instead, a slightly messy slot just adds character to the rocket.

That said, there are slots that are a little bit off kilter, and there are slots that are an absolute mess. The former is acceptable, the latter is just excessive.

The fun thing is marking it -- no marking gauges that I know of are designed for marking buckets. So, I started with a spare bulkhead and used the center hole to find, well, the center. I then draw one line across the bulkhead. Using a framing square, I created another line perpendicular to the first, then extended it all the way.

Said bulkhead then gets dropped into the bottom of the rocket, and used as a reference for placing marks at the bottom of bucket 1. I then hung my handy framing square over the edge of the bucket, and extended the mark down to the handle ring. From there, I could then use a ruler held on the side of the bucket to get a center line. Voila! One fin marked...

I then used the same ruler to put a mark 1/8" to either side of the center line, both at the top and bottom of the line, then used the ruler to extend those. Voila! A fin slot!

Then out comes the handy Dremel, with a reinforced cutoff wheel, and the material is then cut out. One fin slot, ready for one fin!

One down, three to go....

-Kevin

Time to FINish the project... (Yes, my puns are painful PUNishment for those around me....)

So, the fins were cut from 1/4" floor underlayment from Menard's. This is actually pretty darned nice plywood, with 5 nice consistent thickness layers. 'tis what we use for our big projects.

After the fins were cut, they were slid in from the rear of the rocket, then the tab slipped out. This is because each fin has a tab that sticks backwards, which the rear ring will be bonded to, to help make everything one big solid assembly.

The first picture shows the fins tacked in place with CA. Next came some Aeropoxy (smelly stuff!) which slightly thickened with fumed silica, then drizzled down each side of the fin/tube joint. Finally, thickened (think peanut butter) Aeropoxy was smeared into each joint.

The rear ring was then partially inserted, to help hold things in proper alignment, while it all cures.

-Kevin

I've been lurking in the background on this thread long enough & feel compelled to offer my services should the need arise for any superglueing.
I can whip you up some killer sawdust & CA fillets!
We could cut the bottom off of a few more buckets and make it a tube fin.


Judging by the flange....is that a 75 motor mount?

If so I think you should stuff a small M in it & go for yet another L-3 attempt.

After all....what's the worst that can happen? Turn it into a "Wacky Wiggler"
I'm sure THEY would make an exception for YOU to fly this, instead of a rocket. Now that there's entertainment!

I'm glad I'll be there to see this contraption fly. Good luck and I hope you won't need trash bag recovery.

blackjack2564 said:

I can whip you up some killer sawdust & CA fillets!

Click to expand...

I've done that before. 'tis a great way to help clean out the bottom of the table saw, too.

We could cut the bottom off of a few more buckets and make it a tube fin.

Click to expand...

The problem there is the taper. It could be done, though. I've done it with pill bottles (and obviously much smaller motors).

Judging by the flange....is that a 75 motor mount?

Click to expand...

Er, what makes you say that....

If so I think you should stuff a small M in it & go for yet another L-3 attempt.

After all....what's the worst that can happen? Turn it into a "Wacky Wiggler"
I'm sure THEY would make an exception for YOU to fly this, instead of a rocket. Now that there's entertainment!

Click to expand...

Hey, it's a rocket....it's just a draggy rocket. Four fins and a nose bucket!

I'm glad I'll be there to see this contraption fly. Good luck and I hope you won't need trash bag recovery.

Click to expand...

Thanks -- it'll be interesting, that's for sure!

The original one may well fly on a K975, as well!

-Kevin

Last night, I began a rather tedious portion of the build -- attaching blocks to the fins, which will get screwed to the buckets. This just helps provide another attachment point for all the innards.

Why is it tedious? Because I only have one clamp that will reach... So, I have to glue the blocks one pair at a time.

Here's an exciting photo that shows this in progress. You'll note the "hair ball" fillet attaching the fin to the motor tube. I refer to it as a "hair ball" because of the little bit of chopped CF I added -- if you have a cat, and you've ever used chopped CF in epoxy, you understand the reference.

If not, well, get a cat, and you'll understand...

-Kevin