Tau Zero Leonora Christine

[boomtube-mk2]

Two issues arise with the Bussard Ramjet; first, it turns out that the interstellar hydrogen density is a couple of orders lower than what it was believed to have been back when Bussard first proposed his ramjet, this would necessitate a collection field several times larger than Bussard's design.
Second, anything, even a magnetic collection field, pushed through the interstellar medium at any substantial velocity would act very much like you trying to push a sheet of plywood against a hurricane.

Even Larry Niven, who wrote many stories where a Bussard Ramjet played an integral part, had to admit that they really wouldn't work.

 

[jqavins]

Even Larry Niven, who wrote many stories where a Bussard Ramjet played an integral part, had to admit that they really wouldn't work.

But it's a really cool rocket, so shut up.

Are we going to see this beauty in paint and in the air?

 

[BigMacDaddy]

Are we going to see this beauty in paint and in the air?

In the air soon, I hope, but I do not paint rockets though, no skills or patience in that department

 

[Rob Caswell]

So did you ever get it off the ground? I'd planned to do this same project based on Manchu's design, but you beat me to the punch... and you probably did a better job than I would have as I wasn't planning on using any custom 3D printed bits.

It's really too bad you're not up to giving it a final finish. That'd be the cherry on top, for sure!

 

[BigMacDaddy]

So did you ever get it off the ground? I'd planned to do this same project based on Manchu's design, but you beat me to the punch... and you probably did a better job than I would have as I wasn't planning on using any custom 3D printed bits.

It's really too bad you're not up to giving it a final finish. That'd be the cherry on top, for sure!

I have not tried to launch yet -- hopefully soon and I will post videos!!!

 

[BigMacDaddy]

Successful launch today but hard landing... One chute deployed but other did not.

I can easily repair the damage but I think I will redesign the body tube portion of this. Might make it split in middle of cone with one parachute on either end, might upsize to BT55 in bottom portion of cone, and also think I will bring the BT-50 stuffer tube all the way through 3D printed parts (my wadding got stuck in the bottom BT-55 tube section and continued to burn for a while till I gave it a vigorous shake out and stamped out the embers).

I launched on a single D12 since I did not have the guts to try the cluster setup since I had not figured out how to spring the igniter clips clear so they would not hang up on the fins (well I have some ideas but not sure if it will work - I did get some smaller clips in the mail yesterday for this).



Here is the video of the launch:

 

[jqavins]

What are you using for wadding? It should not burn. Not even a little. The stuff that comes with engines that looks and feels like ordinary tissue paper is, in fact, treated with a flame retardant.

Anyway, congrats on the (mostly) successful flight of a cool and novel build.

 

[BigMacDaddy]

What are you using for wadding? It should not burn. Not even a little. The stuff that comes with engines that looks and feels like ordinary tissue paper is, in fact, treated with a flame retardant.

Anyway, congrats on the (mostly) successful flight of a cool and novel build.

Thanks!

For this launch I was using the Estes wadding and/or dog barf (I cannot recall) and I should have said it was smoldering, not really burning. The way the model landed the part of the body with that smoldering junk stuck in there had a little breeze blowing right through it so it continued to smolder like a pipe.

 

[Raco123]

Very Cool

 

[gdjsky01]

Very cool! Where are the files to recreate this? Thanks!

 

[BigMacDaddy]

I made some good progress this past week on a new version of the Tau Zero Leonora Christine. The latest version stands over 40" (103cm) tall and will fly on a 24mm engine (again has room for up to 8x mini engines in a mid-body cluster).

I made most of the modifications I envisioned after my earlier launch (as well as a few more). I modified my previous version to separate the nosecone in the middle, expanded to BT-55 tube inside bottom portion of nose cone to give more room for chutes, extended BT-50 stuffer tube through the whole bottom portion of the model (goes into base of nosecone), smoothed out model components, and updated design of engine retainer to better match images created by Manchu / Philippe Bouchet for the cover of the book.

Still need to glue the poster-board nosecone on my model but otherwise it is ready to launch. Big Bertha in picture for size comparison.

 

[neil_w]

I would like to see the process for making and attaching the main airframe cone wrap.

 

[BigMacDaddy]

I would like to see the process for making and attaching the main airframe cone wrap.

Sure...

I just test fit the cone pieces this morning (actually the templates -- these are just normal copy paper, will either trace onto posterboard or print directly onto heavier stock for the final product).

The last time I tried to make a template for the entire nosecone (anticipating printing it on a large format printer) but it did not come out correctly for some reason. This time I broke the cone down into 5 parts (basically making each cone wrap cross two gaps between centering rings.

Behind the scenes I am working with a massive 80cm cone in the design software (it gets shorter when I round the tip). I cut this up into multiple centering rings (tried to make them as equally spaced as I could). Then I added in shoulders and other things necessary to allow the three large sections of the nosecone to fit together -- the last 19cm of the tip is fully 3D printed and then there are two sections of poster-board-covered cone, the bottom BT-55 part that will hold the chute(s) and the top BT-20 will be closed.

For making the templates for the poster board wraps, I used my previous design and created small truncated cones (the yellow cones in the picture below) to match the sections that lined up with the centering rings I wanted to land on. Then I used these dimensions to create templates using an online cone template generation site. I did this as 5 separate cones (matching the yellow cones in the picture below).



I printed out the PDF templates this morning and cut them out and test fit them onto the centering ring/tube structure.



For the last build, even though my full size template did not work I tried to create the whole nosecone in a single piece and glue it on all at once. I basically glued the edge of the poster board on all the centering rings and then put glue on the rest of the rings and wrapped the poster board around it. I cut off the bottom at the end. This was really messy and difficult to do. I wound up cutting the poster board in a few spots where it was not fitting tightly ad glueing those sections down and trying to fill everything with wood filler.

This time I am planning to glue the sections of posterboard into conical loops before putting on the model and then want to apply some type of gap-filling glue to the centering rings and slide the complete cone segments down over the nosecone to its placement on the correct centering rings.

p.s., I also remembered to make the front portion of the nosecone a little bigger so that it would be flush with the poster board once installed (on my earlier model the tip part was smaller and I needed to fill with wood filler.

 

[BigMacDaddy]

Any ideas on how to design the nosecone poster board to look like heat shielding?

I can print these templates pre-decorated (I have a color printer). Basically, the only picture I have to guide me is this one (the final book cover only has a picture of the rear of the rocket):



My original thought was to do some type of generic tech detail like a Borg ship.


However, this massive cone is supposed to be a radiation shield. What would look radiation shield-y?


I was also thinking about leaning into the fact that I had multiple sections of nosecone wrap -- for example, printing plate edges or something along the edge of the template/cover or something. Lastly I was planning to include some sensors and other access doors etc... to break up the cone. Here is the description from the book (start of Chapter 2):

"Seen from one of the shuttles that brought her crew to her, Leonora Christine resembled a dagger pointed at the stars. Her hull was a conoid, tapering toward the bow. Its burnished smoothness seemed ornamented rather than broken by the exterior fittings. These were locks and hatches; sensors for instruments; housings for the two boats that would make the planetfalls for which she herself was not designed; and the web of the Bussard drive, now folded flat. The base of the conoid was quite broad, since it contained the reaction mass among other things; but the length was too great for this to be particularly noticeable. At the top of the dagger blade, a structure fanned out which you might have imagined to be the guard of a basket hilt. Its rim supported eight skeletal cylinders pointing aft. These were the thrust tubes, that accelerated the reaction mass backward when the ship moved at merely interplanetary speeds. The "basket" enclosed their controls and power plant. Beyond this, darker in hue, extended the haft of the dagger, ending finally in an intricate pommel. The latter was the Bussard engine; the rest was shielding against its radiation when it should be activated."

 

[neil_w]

So far so good. In my experience, wrapping heavy cardstock (or posterboard, or whatever) into tight cones like that is challenging, and even more so when you need to make five of them come out very consistently, and without creasing.

Would also like to see the exact flavor of posterboard you're using.

I have previously pondered an all-conical design, and have been very uncertain how to construct it, which is why I'm so curious about the details. Thanks for the write-up so far, it's a beautiful rocket even if I do worry about the survivability of those fins.

 

[kalsow]

I've never tried rolling paper cones. But if you have 3D printer access, you could print inside and outside conical sections to use as a mold while forming and gluing the paper cone. Just a thought...

Once upon a time I made a large Nike Smoke nose cone from fiberglass. I started by turning a 10" wooden cone on my lathe. Then I wrapped mylar around the wood and laid up the first bit of fiberglass. After the initial piece cured, I could use the existing partial fiberglass cone and mylar to lay more fiberglass and grow the cone larger. After 4-5 enlargements, I had my nose.

 

[BigMacDaddy]

So far so good. In my experience, wrapping heavy cardstock (or posterboard, or whatever) into tight cones like that is challenging, and even more so when you need to make five of them come out very consistently, and without creasing.

Would also like to see the exact flavor of posterboard you're using.

I have previously pondered an all-conical design, and have been very uncertain how to construct it, which is why I'm so curious about the details. Thanks for the write-up so far, it's a beautiful rocket even if I do worry about the survivability of those fins.

Thanks for feedback and interest!

I am hoping that I can "hide" the seams with the design on the cardstock and a sharpie.

I also worry a bit about the fins (although they are plywood and last time they hit the ground but the 3D printed part broke before they did).

After I made this prototype of my revised version (which is already like the 5th iteration I printed in the last couple of weeks). I added much deeper / wider fin tab notches so that the fins have quite long tabs that are 5mm deep and have support along their full surface area on both sides inside the rocket. They also should more or less sit against the motor tube but I am not sure how essential (or possible) getting wood glue in there will be.

 

[jqavins]

[T]hese are just normal copy paper, will either trace onto posterboard or print directly onto heavier stock for the final product).

Suggested for your consideration: whereas tracing can be error prone and many printers will fail to handle very heavy paper well, it is therefore suggested that you use glue stick to apply the paper pieces you have to the posterboard.

Any ideas on how to design the nosecone poster board to look like heat shielding?...

My original thought was to do some type of generic tech detail like a Borg ship.
View attachment 561714

However, this massive cone is supposed to be a radiation shield. What would look radiation shield-y?
View attachment 561715

The Borg ship look is pretty good. For a shieldy look though, I like the Kapton blanket's texture best, but not the color. One could start with a flat picture of such a thing, then in the paint software of your choice apply a grey scale "filter". A technique for this comes to mind, though it would certainly need testing on scrap. Print the pattern you want on regular paper, then apply it to the outside of the cone as if you were papering fins. (Glue stick will not suffice this time.) Then clear coat.

On the other hand, real world satellites are often covered with little squares of Optical Solar Reflectors (OSRs) that appear deep blue and violet, and that might also be a good look. Which could also maybe be applied as above.

They also should more or less sit against the motor tube but I am not sure how essential (or possible) getting wood glue in there will be.

You could maybe reach in with a glue applicator (that is, a stick) to put glue on the motor tube before inserting the fin. I don't know how much good it would do. I'd use epoxy for that. No, not for strength, but because epoxy will make a strong joint even of the parts are not mated as well as wood glue wants.

Really? At least for 110 lb cardstock, I have had no trouble with multiple different printers. I always print my transitions directly on the cardstock.

(@neil_w, posts are out of order because I was adding to this one by editing as you read and replied to the unedited initially posted version.) I don't know the actual weights, but I've seen printers fail to take the thickness of some stuff between the rollers, or have the rollers bind, or something like that, and jam. I've also seen very heavy paper come out with a very tight curl after being successfully going all the way through the paper path. None of that was in relation to rocketry.

 

[neil_w]

many printers will fail to handle heavy paper well

Really? At least for 110 lb cardstock, I have had no trouble with multiple different printers. I always print my transitions directly on the cardstock.

Now, as far as the "posterboard" goes, I'm not sure, because I'm not sure exactly what sort of paper we're talking about here. For that matter, I'm not sure in this sort of design how heavy it needs to be... it's pretty well supported all the way up and down; each segement doesn't look much different from a typical paper transition. Long and skinny gets more annoying and difficult the heavier the paper.

A two-layer design using lighter cardstock (65 lb, even) would probably be best. I wonder if it would be possible to do a first layer of cardstock, then use much larger pieces to overlay the whole thing.... gluing would be an adventure.

Anyway, we will see what @BigMacDaddy does here... maybe it's all not as bad in practice as it is in my head.

 

[Hobie1dog]

I doubt if I'll ever post up any builds on here as I will be to embarrassed to share the company of guys like this who are "master modelers". I just wish I lived near you so that I could paint it for you as I like the painting part the best.

 

[Daddyisabar]

Preventing fin hang up on wires/clips from clip whip and igniters.

Use long igniters.

Tape up clips smooth.

Careful connections made at pad with no wind or force to rotate before launch.

Pray.

 

[BigMacDaddy]

Preventing fin hang up on wires/clips from clip whip and igniters.

Use long igniters.

Tape up clips smooth.

Careful connections made at pad with no wind or force to rotate before launch.

Pray.

Thanks -- I was thinking about how I was going to ignite those booster engines.

I was originally thinking of using springy skewers on either side that I thought might bounce outwards to pull clip whips out of the way.

However, more recently I was thinking about something like what you suggest -- basically taping thin wires to sides of model and running them up to igniters so I could clip to them below the fins.

 

[Daddyisabar]

Silly, mid canted rockets will eventually snag a clip whip, especially if there is a long wait on the pad before launch. The rocket gods can be cruel, punishing the mortal flyer for disobedience to their sacred 3-4FNC maximum.

 

[Daddyisabar]

The strong canted exhaust is great at pushing the clip whip wires away and has worked for me 99% of the time, even with lots of silly bits trailing behind.

 

[Daddyisabar]

Keep the clip whip long, loose and unattached.

 

[Rob Caswell]

Any ideas on how to design the nosecone poster board to look like heat shielding?

I can print these templates pre-decorated (I have a color printer). Basically, the only picture I have to guide me is this one (the final book cover only has a picture of the rear of the rocket)...

My original thought was to do some type of generic tech detail like a Borg ship.
View attachment 561714

First - 40" tall?! WOOOOOO!!!!!!!!! Nice. That should deliver some impressive (if sublight) launches on a 24mm. Has the potential to be "majestic"!

Good idea... and good question on printing a texture. Ideally a printed metallic would be nifty, but that's outside the capabilities of even the average pro large format inkjet. Incidentally, running a large format inkjet is my day job. Just on the physical parameters of the cones, I'd recommend a stock like Epson Enhanced Matte (which is 10.3 mil thick and 192 gsm) or easily as good but cheaper, Lexjet Premium Archival Matte (9.5 mil and 230 gsm). Any way you go, it's probably best to print on matte stock and then recommend the modeler seal it with a clear varnish like the Krylon UV Archival Giclee spray. Inkjet print surfaces are chemically sensitive and can discolor if the wrong chemical recipe clear coat is used, so it's best to stick with products designed to work with giclee (aka inkjet).

So is your idea to the the various conic elements overlap by a small bit or would they edge butt? The latter seems trickier for the modeler to get precise without small rifts.

On the artistic side, I'd keep any texture kind of subtle and as this is a near FTL heat shield, the art should probably show some indications of streaked scarring, I'd guess. Regarding the Borgy details... it's interesting, but I'm guessing it's gonna look strange as details compress as you get closer to the nose. At this I'm inclined to recommend doing the whole cone as one piece of art, then breaking it down from that into the various conic sections. The whole cone could be done as one digital painting before being broken up for production. I like the idea of incorporating various hatch and panel detail in the art.

Were you thinking of including decals for the radiators?

 

[jqavins]

First - 40" tall?! WOOOOOO!!!!!!!!! Nice. That should deliver some impressive (if sublight) launches on a 24mm. Has the potential to be "majestic"!

Good idea... and good question on printing a texture. Ideally a printed metallic would be nifty, but that's outside the capabilities of even the average pro large format inkjet. Incidentally, running a large format inkjet is my day job. Just on the physical parameters of the cones, I'd recommend a stock like Epson Enhanced Matte (which is 10.3 mil thick and 192 gsm) or easily as good but cheaper, Lexjet Premium Archival Matte (9.5 mil and 230 gsm). Any way you go, it's probably best to print on matte stock and then recommend the modeler seal it with a clear varnish like the Krylon UV Archival Giclee spray. Inkjet print surfaces are chemically sensitive and can discolor if the wrong chemical recipe clear coat is used, so it's best to stick with products designed to work with giclee (aka inkjet).

This is why I love TRF!

 

[BigMacDaddy]

First - 40" tall?! WOOOOOO!!!!!!!!! Nice. That should deliver some impressive (if sublight) launches on a 24mm. Has the potential to be "majestic"!

Good idea... and good question on printing a texture. Ideally a printed metallic would be nifty, but that's outside the capabilities of even the average pro large format inkjet. Incidentally, running a large format inkjet is my day job. Just on the physical parameters of the cones, I'd recommend a stock like Epson Enhanced Matte (which is 10.3 mil thick and 192 gsm) or easily as good but cheaper, Lexjet Premium Archival Matte (9.5 mil and 230 gsm). Any way you go, it's probably best to print on matte stock and then recommend the modeler seal it with a clear varnish like the Krylon UV Archival Giclee spray. Inkjet print surfaces are chemically sensitive and can discolor if the wrong chemical recipe clear coat is used, so it's best to stick with products designed to work with giclee (aka inkjet).

So is your idea to the the various conic elements overlap by a small bit or would they edge butt? The latter seems trickier for the modeler to get precise without small rifts.

On the artistic side, I'd keep any texture kind of subtle and as this is a near FTL heat shield, the art should probably show some indications of streaked scarring, I'd guess. Regarding the Borgy details... it's interesting, but I'm guessing it's gonna look strange as details compress as you get closer to the nose. At this I'm inclined to recommend doing the whole cone as one piece of art, then breaking it down from that into the various conic sections. The whole cone could be done as one digital painting before being broken up for production. I like the idea of incorporating various hatch and panel detail in the art.

Were you thinking of including decals for the radiators?

Thank you very much - great advice. My wife is a graphic designer and will do the design for me -- she also pointed out the issue of making the Borg details work for the cone. She always reminds me she is not an illustrator so I hope I can find some sensors and panel pictures for her to use.

I have a color laser printer at home so will likely print the heavier stock I can at home (direct through feeding can put pretty thick stock through). I will probably print matte and recommend that people clear coat / dullcoat depending on the finish they want (have had issues with toner sticking perfectly to satin finish paper).

My tentative plan was to do the cone in sections and design with some edge detail -- lean into those separations instead of trying to hide them. I am not sure if the poster-board could overlap the prior section and still have a good hold on the other centering rings (particularly the middle one). However, I am also not sure about finishing the gaps if the parts butted against each other.

I don't actually print decals per se so I wonder if I print paper for the radiators if the plywood could be "papered" with pre-printed designs. Have not tried that before.

 

[BigMacDaddy]

Keep the clip whip long, loose and unattached.
View attachment 561800

Does that just slip through all those wings and fins on your models?

My current clips have massive V shaped backs that would catch just about anything so I guess it is key to seal off the back of those clips.

 

[Daddyisabar]

Does that just slip through all those wings and fins on your models?

My current clips have massive V shaped backs that would catch just about anything so I guess it is key to seal off the back of those clips.

Yes, just slip sliding away. Each rocket and launch is different. Keep your mind on where you are at, what you are doing. Feel the force flow through the clip whip, the igniter, the pad, the rock. Get a Master Jedi to help out when you have designed silly claw fins on your rocket that are nasty clip whip wire catchers! Had to put narrow red tape on front claw to avoid it catching a wire.