WVB XR-1 Shuttle

I built this LPR version of the Werner von Braun XR-1 Shuttle about 10 years ago, but I deviated from the plans back then and the model did not fly stably. The plans are available from NARTS and the original model is by Bill Spadafora. The NART article calls for buying a commercial styrofoam cone and wrapping layers of white paper around the cone and pinning them in place with pins. The first layer has wax paper and subsequent layers are applied with a thin coating of white glue and water. The paper shell is then lifted off the cone. As I recall on my first attempt 10 years ago I coated just one layer of paper with epoxy and left it on the foam cone. Somehow I cut out a hole for the BT-50 motor tube through the cone and kept the styrofoam cone in place.

Again, I'm deviating from the original plans and will make a paper shell filling just the forward portion with expanding foam.

Here are some pictures from Walt Disney's interpretation of the Werner von Braun Space Shuttle.

From the original plans I calculated that I needed to swing a 49.3192 degree arc with a radius = 18.7049" to capture the size of the shell. I know that is way too many significant figures and I don't have that kind of accuracy, but that is my way of taking notes. If I can get the same exact numbers later from my notes, I know that I am duplicating the original calculations. Since I don't have a compass that large, I used a tacking pin and a mechanical pencil with a string attaching the two. A smaller arc was drawn using a compass with a radius = 3.5621' to find the end of the shell where the BT-50 exits from the forward end. Later I extended the circumferential distance of the drawn shell about a half inch in order to have some overlap for creating the shell or frustum of a cone. The paper is very large and came from an art store.

Will this help you out?
https://groups.yahoo.com/neo/groups/Space-Paper-Models/files/XR-1 Booster/
https://www.papermodelers.com/forum/vbdownloads.php?do=download&downloadid=207

To support the cone shell I made 4 triangular struts or fins and tacked them in place with super glue gel and later came back and secured them with yellow Carpenter's glue. Sometimes I am a little wary of yellow glue on LPR tubing, because I think I have seen it swell paper, so I tried to not use too much. The fins were cut from light poster board and are 15" long and 2.0745" at the base. The original plans call for a 24 mm D12 motor, but I put in an engine clip for a Estes E motor in case I need such a motor later.

I decided that I needed some circumferential braces or ribs to keep the paper shell in a conical shape. I have a small compass that has a cutting bladed on one end that cuts circles in light poster board very well. I ordered it on line somewhere, but I can't remember where. I tacked the ribs in place with super glue gel and then reinforce them with yellow glue. I also aligned and glued two plastic straws from a fast food restaurant to the side of the BT-50 tube with a little bit of a stand-off to go over the motor mount center rings.

I bought 3/16" hollow core lead from a fishing tackle store that comes in a coil. I cut off 8 pieces, which amounts to 2 oz., and attached them to the forward BT-50 tube, so that they will be underneath the paper shell when it is wrapped around. This will help keep the c.g. forward. I tacked the paper shell to one fin with super glue gel along a straight pencil line. When the super glue had hardened I cut the fin slots.

Very cool project. Good idea to put the ring supports between the cone fins, I would put more rings in, if you can spare the weight. Can you post actual size scans of these plans, or are they available on-line somewhere?

I wonder if this would be possible to make as a two-stage design. Depending on where you split up the cone for booster and sustainer stages, the sustainer might need pop-out fins, but they could be hidden in the cone section of the booster stage. Possibly rubber-band deployed and held in place by a burn-through thread, if that doesn't interfere with the ignition of the sustainer itself.

GlenP said:

Very cool project. Good idea to put the ring supports between the cone fins, I would put more rings in, if you can spare the weight. Can you post actual size scans of these plans, or are they available on-line somewhere?

I wonder if this would be possible to make as a two-stage design. Depending on where you split up the cone for booster and sustainer stages, the sustainer might need pop-out fins, but they could be hidden in the cone section of the booster stage. Possibly rubber-band deployed and held in place by a burn-through thread, if that doesn't interfere with the ignition of the sustainer itself.

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GlenP, I'm a little bit further along than the posts show. I agree more centering rings would be better, but I got lazy. I found that making this model turned out to be more time than I thought, so I tend to think that making a second stage would really be challenging. A second stage would definitely need either permanent clear plastic fins or pop out fins in order to be stable.

You can get the basic plans that I show in post #2 from the NAR website under the NARTS category. It's called The Sentinel from CMASS. It is the first item on the order page and costs $12. There are are about 10 plans in the document.

https://blastzone.org/nar/narts/store.asp?groupid=92400111811376

I used the same full-size fin template that is in the NARTS plans and copied it over to tracing paper. I cut 4 fins from 1/8" balsa wood and cut paper coverings from 20 pound stationery paper. These paper coverings are glued on both of each fin with white glue, covered with wax paper, and are pressed with books on top until the glue dries. The fins were customized a little bit where necessary to fit the model.

Before attaching the papered fins I wrapped the paper shroud for the cone fuselage around the model and used white glue to connect the shroud on the overlap tab. In hindsight this was a mistake. I should have used super glue gel on the overlap tab, because the white glue caused the overlap to wrinkle. This could have been avoided. After completing the shroud I attached the papered fins to the poster board fins and the motor tube.

Thanks for the link! I definitely have to get those plans and try this one out, it's coming along nicely.

I was wondering, could the external fins have been offset from the internal posterboard support fins, i.e. interdigitated? That might give more support to the shroud.

GlenP said:

Thanks for the link! I definitely have to get those plans and try this one out, it's coming along nicely.

I was wondering, could the external fins have been offset from the internal posterboard support fins, i.e. interdigitated? That might give more support to the shroud.

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I am not sure what you mean by this. The fins are really quite large, so it is not possible to wrap the shroud around while the fins are in place. If fact I did a dry fit with the shroud after it was attached to the one light poster board fin and found where the fin slots needed to be cut. There are other possibilities. One could have the large fins in place and apply four quadrants of the paper shroud, but I think that would be difficult and then there would be length-wise seams to deal with.

At the time I was ready to put in expanding foam Public Missiles Limited was out of stock of their expanding foam, so I ordered the foam from Hobby Lobby. I decided that I only wanted to put expanding foam in the forward end mainly, because I wanted to add some rigidity, but not increase the weight of the model too much. I mixed together 20 mls of each of the 2 components and poured it into the model. The first two quadrants filled easily enough, but things were hard to control on the other 2 quadrants, because the foam was expanding too much and getting sticky. In retrospect I might have been better off doing only 2 quadrants at a time. Also, my soda straw lug got out of alignment and I had to replace the rear soda straw with some difficulty.

I put in some more ribs on the aft end to force the shroud outward into a circular shape before applying the aft circular bulkhead plate cut from light poster board.

I attached some small tabs made from light poster board next to the fins prior to putting epoxy fillets on the fins.



The fillets filled in some gaps where the fins meet the paper shroud and also tighten to stiffen the shroud a little bit. Remember that I did not put expanding foam into the aft end. (I still wonder if it would have been better to put expanding foam in to the aft end. It is not good for the c.g. However, the expanded foam section in the forward end is structurally sound.)

I applied MinWax Polycrylic to one quadrant of the model with a foam brush, but it looked like the paper in the aft end wrinkled a little bit, so I switched to DEFT Lacquer Sanding Sealer.

I applied epoxy to the largest indentations and put clear plastic tape over the application to hold the epoxy in place and to make a smooth finish. I have done this before with success. After the epoxy hardens I pull the tape off. Some of the tape adhesive will stay behind. Some of this adhesive can be removed with sanding.

To further remove low spots I applied Green Putty, which my old tube is probably a little too dry, but the shrinkage is low, and Bondo putty, which is moist (perhaps too runny) and smooth to apply, but the shrinkage is bad. This gave the surface a mottled green and red surface. After drying and sanding I applied polycrylic again. It seems that the DEFT (oil based) has stopped the shrinkage from the polycrylic. The fumes from the polycrylic are no where near as bad as the DEFT and the clean up with water is much easier.

I am using the same patterns from the NART plans for the shuttle wings and tails along with the same length of BT-50 tube for the fuselage. I will try to build the shuttle as a glider, so it needs to be light. Rather than use the 3/32" ply called for in the plans, I am using 1/8" balsa with one or two coats of CA for the wings and tail followed by several coats of polycrylic. I modified the plan delta wing slightly by making the aft end straight across rather than with a small triangular indent. It looks like the Glencoe plastic model also has a slight triangular indent on the shuttle aft wing. I weighed a balsa nose cone and a plastic nose cone and found that the balsa nose cone to be lighter. However, after finishing the balsa nose cone it is coming close to the plastic nose cone weight. I am planning on gluing the wing to the bottom of the fuselage as shown in the NART plans. The Glencoe model has the wings in the middle of the fuselage. I am also planning to have elevators that will move upward for gliding after the motor ejection charge fires.

The weather has been unusually warm here for December so I have been spraying the lower model with Rust-oleum Automobile gray primer along with some further applications of bondo in-between sprayings. This model is becoming a bondo wagon, an expression I heard back in high school for car body repairs. The forward BT-50 tube was getting worn and weak from holding, so I reinforced it with a short section of BT-50 cut in half and epoxied to the outside. Also, I took a CA hinge for model airplanes, cut it in half and glued the elevator to the wing with super glue gel.

Very cool, I just got my booklet of plans in the mail. I hope to try this one out sometime over the winter building season. I was thinking of building up a framework from balsa, i.e. frames and stringers, kind of like how a fuselage is built up in a Guillow's balsa airplane kit, to support the conical fairing. Not sure if that would get too heavy. If the paper cone is thick enough, the stringers won't cause a faceted appearance, hopefully.

Aerostadt....sorry I missed this over here...its been a rough week or so...but.this is COOL! I think you are doing a great job on this...I was a little nervous on the early photos wondering how you would get the wrinkling out...but she is coming along great I think!

I love watching the masters on this board pull things together!

aerostadt said:

The weather has been unusually warm here for December so I have been spraying the lower model with Rust-oleum Automobile gray primer along with some further applications of bondo in-between sprayings. This model is becoming a bondo wagon, an expression I heard back in high school for car body repairs. The forward BT-50 tube was getting worn and weak from holding, so I reinforced it with a short section of BT-50 cut in half and epoxied to the outside. Also, I took a CA hinge for model airplanes, cut it in half and glued the elevator to the wing with super glue gel.

View attachment 248547 View attachment 248548 View attachment 248546

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Very cool, I just got my booklet of plans in the mail. I hope to try this one out sometime over the winter building season. I was thinking of building up a framework from balsa, i.e. frames and stringers, kind of like how a fuselage is built up in a Guillow's balsa airplane kit, to support the conical fairing. Not sure if that would get too heavy. If the paper cone is thick enough, the stringers won't cause a faceted appearance, hopefully.

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GlenP, that might work. As I mentioned before sometimes I wish that I had used expanding foam on the whole thing. If you find something better, let us know.

Aerostadt....sorry I missed this over here...its been a rough week or so...but.this is COOL! I think you are doing a great job on this...I was a little nervous on the early photos wondering how you would get the wrinkling out...but she is coming along great I think!

I love watching the masters on this board pull things together!

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Thanks, NJ, I'm still hanging in there. I am continuing with spraying primer, sanding, and spotting with bondo, while the weather is nice. I noticed that the weight for the conical booster has grown from 7.8 oz to 9.2 oz, which is not too bad.

I drew ink lines for attachment of the short BT-50 section to the shuttle wing. The BT-50 tube does not extend over the elevator. I attached the two pieces with 5-minute epoxy. Later, I glued a short section of 1/64" ply to the elevator on both sides with yellow glue. This will be the general location where I plan to drill a small hole for an elastic string attachment to pull the elevator up. I am becoming more partial to the plastic nose cone versus the balsa nose cone. The balsa nose cone is lighter, but it did increase in weight with finishing.

I drilled two small holes in the elevator and threaded an elastic string through the holes and tied a knot. I printed out a template from Rocket Reviews under Tools for making a 45-Degree slant cut in an Apogee BT-50 coupler tube (red).



Wrapping and securing the template with scotch tape to the coupler tube, I traced the pattern onto the BT-50 coupler. I then put this on a wood dowel (actually an old broom handle I sawed off years ago) and then cut out the desired notch in the coupler tube.



I then threaded the elastic string through the notch and inserted the coupler into the glider (shuttle) aft end for a test dry fit. The notch was not quite larger enough, so I cut the notch slightly larger.

After threading the elastic string through the open coupler tube notch, I pulled the elastic thread through the glider BT-50 tube. I inserted the unglued coupler tube into the BT-50 and when I was satisfied with the fit, I wicked in some very thin CA around the outside location where the two tubes met. This was easy to do and was strong enough to hold the coupler in place. I then tied the other end of the elastic string to the plastic nose cone.



So, when the glider (shuttle) is not attached to the booster, the elevator is in the up-position. When the glider is mounted on the booster, the elevator is in the down-position.

Very neat,

this is begging for a large foam version.....I'll wait for you to confirm a good CG position...........

burkefj said:

Very neat,

this is begging for a large foam version.....I'll wait for you to confirm a good CG position...........

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Frank, I am sure that you could do an excellent job on this model. I'm in the winter building season, so it may be awhile before I can confirm a good c.g. location.

I tried a few tosses in the basement and the glider ability looking wanting, so I taped on some larger temporary flaps (1/64" ply). The basement gliding is better. I tried outside tosses with some breeze in the air. The gliding was not so good, but it seems that the flaps are breaking the fall. Hence, I am going to increase the size of the flaps.

I thought the original elevator flaps looked a little small. If you don't want to extend them aft that much, you can cut a portion of the wing tip and add some elevator area in front of the hinge line. I was looking for a picture to better describe this, something like this: