Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Length: 12.95 inches
Manufacturer: Dr. Zooch
Skill Level: 5
Style: Scale
Dr Zooch Little Joe

Brief:
The original Little Joe has always been a rocket that I like the looks of. I like the LJ2 as well, but the original is the one that fascinated. Unfortunately, there are not very many LJs to choose from. As far as I know, the Little Joe from Dr. Zooch is the only choice. That did not bother me since my previous experience from this manufacturer has been excellent.

Construction:
I was surprised to see that the first step in constructing the Little Joe was painting. The base of the nosecone is to be painted black so that the black protrudes from the wrap that covers the rest of the NC. Upon examining the balsa cone, I found that it was mostly in pretty good shape but that the area right above the shoulder that needed to be painted, was a bit rough. Accordingly, I applied Elmer's Wood Filler to the entire cone, thinking to myself that I would get it all out of the way. What I was not thinking was that all of the rest would be covered by paper and that the fit of the paper wraps would be critical.

When the goop had dried, I sanded the cone down almost to the wood. I then used a brush to apply some acrylic black in a ring around the cone just above the shoulder.

While the paint dried, I cut out the wrap for the nosecone. As the instructions point out, "the better the job on cutting out, the less the rocket will suck." I took the admonition serious and cut it out as best I could. The paper already had a bit of a curl to it from being rolled up and this helped with forming the cone. A small bit of white glue was applied to the tab and the wrap ends were pressed together and allowed to dry.

Now the glue on the cone wrap needed to dry so I turned my attention to the cylindrical wrap that goes on the top of the cone. It too was cut out but this time the direction of the curl worked against me. Eventually, I got it to curl in the right direction and glued it on as well.

By this time the paint was dry (acrylics are nice that way) and so was the main NC wrap. I gave it a test fit and it slid almost, but not quite to the bottom. This is the way it was supposed to fit, hence the black paint.

I removed the conical wrap and tried to test fit the cylindrical one. It was definitely too tight so I started to work with a sanding stick. The next few tries were still too tight so a kept at it until, suddenly, it was a bit too loose. I applied glue around the upper part of the NC and slid the top wrap down.

With the upper wrap in place, I applied glue to the walls of the conical part of the NC and slid the conical wrap in place. I tied to make sure the line on it were aligned with the lines on the cylinder.

I was feeling a little bummed out at this point by the top wrap having a little bit of a gap with the NC and was thinking about trying to fill it when I read the next step in the direction. It told me to look for the weird black circular thing to use as a cap. I looked and looked on the wrap sheet and could find nothing that seemed to fit the bill and took a break. When I came back, I glanced in the box and saw what was intended. It was not on the wrap sheet at all but was a disk of black fiberboard. I applied glue to the top of the NC and set it in place.

On top of this fiber cap goes another cap. This one does come from the wrap sheet and must be formed into a cone. I cut it out and wrestled the curvature back into the direction I wanted it and then glued the tab. There is a bit of a white line that I will want to clean up with a black marker.

An antenna housing for the top of the capsule also needs to be cut out, formed into a tapered cylinder, and glued together. When dry, I gently rubbed its base against some fine sandpaper to ensure that it would sit flat. I then applied a small bit of glue to the base and centered it on the black disk. When I was satisfied with its position, I squirted just enough glue into its core to cover the base.

Now comes the placement of the conical black cap that was formed a few steps ago. I applied a bit of glue to its base and set it in place on the antenna housing. After it sat there for a while, I really did not like the white edges so I got out the black acrylic paint and brushed the entire cap.

The motor mount construction begins with the traditional "cut an 1/8" slit rite, then the hook was inserted and masking tape was used to hold it in place. A few wraps of masking tape were placed under the hook to serve as reinforcement. The instructions suggest the use of electrical tape and point out that masking tape dries out over the years. I used it anyway because I didn't have any electrical tape on hand and the idea that any rocket of mine will last long enough for it to matter is laughable.

With the hook in place, I installed the centering rings. The centering ring with a notch in it goes towards the rear to accommodate the hook. I cut a small notch in the outer edge of the forward ring so I can build a Kevlar® harness. The rings were filleted on both sides.

While sitting around waiting for glue to dry, I cut out the main body wrap and used an angle to draw a line the length of the BT.

Most motor mounts are installed so that the end of the motor tube is even with the end of the body tube. That is not the case with this rocket. It is the aft centering ring which is supposed to be flush with the end of the BT. A ring of glue was made about an inch in, the Kevlar® was fed through the BT and the motor mount was inserted just enough to clear the end. Another ring of glue was applied around the inside of the aft end of the BT and the motor mount was pushed the rest of the way in with the engine hook aligned with the line that had been drawn on the BT.

One of the great things about Dr. Zooch kits is the wraps. This is especially important for people like me who do not enjoy the finishing process. The main body wrap was carefully cut out and test fit. It seemed just right. The instructions said not to smear glue over the whole thing but instead to just smear some around the perimeter. This was to prevent warping. You are also instructed to place some glue behind the markings for the 4 fins.

With the glue smeared on, I aligned one end of the wrap with the line drawn on the BT and started to lay it in place. It came out great.

The Little Joe has 4 fins. The kit provides a pattern to cut out and a slab of balsa from which to cut the fins. I cut out the pattern and used a pencil to trace 4 fins on the balsa, paying attention to the grain alignment. I then used a steel ruler and razor knife to cut them out. A bit of edge sanding was needed to make them uniform.

The main body wrap is marked with the centerlines and edge lines to be used for fin placement. The centerlines extend a bit higher than the edge line because the fins need to have a bevel sanded into them, giving a pointy leading edge. Beveling the fins was accomplished by sanding the edges, 10 strokes on one side and then ten strokes on the other, until a satisfactory result was attained. I was satisfied but only noticed much later that the bevel should have been longer. I could have deduced this from the markings on the body wrap but did not.

The marks for the fins on the BT are present not only to indicate the placement of the fins. They are also used as a guide to cut away the wraps so that the fins can be glued directly to the BT. The process was easy enough in theory. A razor knife was used to cut through the wrap along the lines and then the paper was peeled up. It practice, it was a little more difficult. You need to make sure you cut all the way through the paper but not into the BT. In fear of cutting into the BT, I did not score deeply enough. The glue used to hold down the wrap also contributed to the frustration. This step was not difficult, but it did require one to be careful to keep from tearing the wrap.

After the slivers had been peeled away, I used a safety pin to perforate the BT along the centerlines of the fins. I also pricked holes into the root edges of the fins. The purpose of this was to allow the formation of glue "rivets" the strengthen the construction.

The fins were applied with a double-glue joint and white glue. A bit of glue was put on the root edge and pressed into place on the rocket. It was then immediately removed and the glue was allowed to dry. A bit more glue was then put on the root edge and the fin applied again. This time it was held in place, checking for alignment until dry enough to not move. A small fillet of white glued was applied to the edges after the bonding glue was dry.

I let the glue on the fins set up for a while and turned my attention to the launch lug. A single lug is provided and I was instructed to cut it in half. I did so by inserting an 1/8" rod and using that as a mandrel as I rotated the lug under a razor knife. The two halves were left on the rod and a bit of glue as applied to each. Then, using the rod to maintain alignment, the lugs were applied along the body wrap seam line.

The balsa nosecone is pre-weighted. It is important that you not try and dig out the clay-like yellow stuff on the back end. That meant that I applied the eye screw a bit off center. I twisted it in, removed it, and filled the hole with glue. I then screwed it back in.

All throughout the instructions to this point, there have been warnings, premonitions, and foreshadowing about the wailing and gnashing of teeth that is to come with the commencement of the Launch Escape System tower. That time has now come. It starts out simple enough. There is a fat length of dowel that needs to be filed/sanded into having flat ends. I did a little bit of sanding on mine but, for the most part, it was in good shape and probably did not need this.

After the fat dowel comes the skinny dowels. Therein lie the tribulations. The kit comes with two templates. The first is to cut the dowels to length and get the correct angles. The second is an alignment template to get the pieces in the right places. There are three sides to the tower. I decided to do them one at a time in the hope of getting better at it.

The first step was to cut the pieces to length and get the correct angles on the ends. My method was to lay the dowel over the template and use a razor knife to make the cuts at the appropriate places/angles. Getting the length was no problem. Even getting an approximation of the correct angle was not a problem. The problem came primarily from trying to get multiple angles cut on the same piece. Invariably, some roll would occur and things would be off a bit.

After the pieces were cut, they needed to be assembled. For this, the assembly template was cut out and laid flat. A piece of wax paper was then set over it to keep it from getting messed up by the glue. The vertical piece was easy enough. It was flat at both ends and sat nicely on the template. The top angle was more difficult. I realized that my angles were off a bit. I removed the top angle and tried again.

This time I put a piece of tape on the bottom of the long side to keep it from moving around on me. This does not interfere with the bottom angle because you are instructed to leave that part off at this point. I then glued on the two horizontal members and let them dry. When they were dry, I had another go at the angles. This time it was a bit easier and the glue filled the incorrect angles. I let this dry.

Searching for something to do while the first tower panel dried, I decided to apply the bottom wrap to the LES motor casing. This is nothing more than a long black band. It was cut out and the end was tacked onto the bottom of the fat dowel. After I was sure it had stuck, I applied a small bit of glue to the backside of the rest of the strip and began to wrap it around the dowel. This allows the band to be built up and give some 3D definition.

Strictly speaking, the fins should have been finished before they were installed on the body tube. It says so right in the instructions. I neglected to do this and decided to work on them afterwards. The balsa had been a bit fuzzy, however, it had been sanded down and 4 coats of balsa filler coat had been applied. While still waiting for the glue on the LES to dry, I sanded down the filler coat and began to brush the paint onto the fins. I used Tamiya aluminum. It came out well, even brushing and complemented the body wrap well. The photos do not do it justice.

Dr Zooch Little Joe Since I had problems keeping the cuts on the dowels oriented in the right planes, I tried a different approach with the second panel of the LES tower. I cut the long vertical dowel and taped it in place over the template as before but I did not cut any of the others at this point. Instead, I made a beveled cut in one end of the dowel and dipped it in a spot of yellow glue and then put it in place against the vertical one. This was the top angled dowel. I fussed with it until everything lined up right on the template and then left it to dry. When dry, I used the template as a guide to slice the opposite end at the right place and at the correct angle. I then took the flat end of the dowel stock and glued it in place as the top horizontal member. I continued in this fashion, allowing each segment to dry before cutting and making the next piece. To me, this was much easier than cutting all the pieces at once.

Waiting for the elements of the third panel to dry left me with time on my hands to look ahead. I decided to return to the stubby, fat dowel. It was going to need some black paint applied so I went ahead and painted a band around the top opposite the paper band and the top and bottom surfaces.

The tower panels are assembled with the use of 2 triangular jigs cut from the balsa. A template is provided on the wrap sheet and I cut the triangles out. These triangles are supposed to be tacked with a small amount of glue to the horizontal members of the truss system. The adjacent panel is then glued into place and, when dry, the triangles are removed so that the final panel can be put into place. Mine did not fit. I had to do some rethinking and some trimming.

I trimmed away at the triangles, trying to keep them equilateral and congruent while also trying to make their sides the same length as the horizontal members. It was a losing battle but I gave it the best I could. Eventually, I had something I could live with and tacked the triangles onto the horizontals. When they were stuck, I laid the second panel in place and glued it at what I hoped would be a reasonable approximation of the correct angle.

When the 2 panels of the LES space frame were stiffened up a bit, I removed the triangles. I wanted the system to still have a little play in it in order to fit in the third panel. It fit better than I expected but not as well as I had hoped. I glued it in place and hoped for the best.

The tower was going to take a while before it was safe to work with so I decided to do the wrap for the motor casing. This is a simple orange rectangle that is wrapped around the fat dowel. The ends of the fat dowel had already been painted black so all I had to do was glue an edge, wrap it around and glue the other edge. It makes more than 1 complete revolution.

When the tower had dried completely, I took a close look at it. The first thing I noticed is that I needed to "fillet" some of the truss joints and fill them out a bit. That was easily done with more yellow glue.

The instructions say to stand the tower up to ensure that it is fairly plumb. I did and it had a definite lean in one direction. The instructions also warn that the tower will tend to look like it leans even when it does not. I fabricated a "plumb bob" from a piece of silk thread and a #7 1/2 piece of lead bird shot. It was definitely out of plumb. I laid the tower on its side and used an X-Acto knife to cut the merest sliver from the end of the long vertical member. When I stood the LES tower up again, it still looked a bit out of plumb but the bob said otherwise. Then it was a waiting game as the fillets dried.

When the glue was dry, I painted the entire tower with acrylic black. This is actually supposed to be done after the motor housing is glued on but I had jumped the gun and already applied that wrap.

The acrylic dried quickly and I was ready to mount the tower to the motor housing. This was done simply with 3 spots of white glue.

When the motor housing was safely joined to the tower, it was time to mount the entire thing on the antenna housing of the capsule. It just slides on the top but it does not go all the way down. When satisfied that it would sit properly, I took it off, applied some white glue and then set it back in place. I kept rotating it to make sure it was straight from all directions.

A toothpick gets mounted on the top of the LES motor housing. I double glued it in place. I used to double glue method mainly because the thing kept falling down. I let the glue dry then applied just a tad and it held.

The LES tower is safely glued to the antenna fairing on the capsule and I allowed myself the pleasant illusion that the LES was done...for a while. It was not. There were still the 3 diagonal members from the original template which had not been put into place. I painted these black and, while I was at it, also painted the probe at the top of the tower black at the same time.

When the paint on the diagonals was dry, I used white glue to place them on the LES tower. They are, in effect, glued to the bottom horizontal member of the tower and the side of the antenna fairing.

The LES tower was almost finished at this point but there still remained a little be to do. The vertical member of each panel is not supposed to just terminate at its end. Instead, a pair of struts like an inverted "V" are supposed to connect the tower to the top, flat edge of the capsule. These are cut from the same dowel stock as the rest of the LES but I did not find a template for them. That is probably fortunate because at this point, my accumulated error would have made any piece I had cut useless. Instead, I measured each piece of stock against where it was supposed to go and then cut it. I immediately painted these pieces black as well.

For some reason, I did not like seeing the bright white of the motor tube protruding from the bottom of the rocket. Since I had some time on my hands, I decided to do something about it and brushed on some Tamiya bronze acrylic.

The struts having dried were glued into place at the bottoms of the truss vertical members. While tweezers are essential for just about all of the LES build, they are even more so here. They are also a source of frustration. While trying to grip the last piece, it flew into an almost full garbage can and an hour of searching did not suffice to recover it. Another had to be cut.

A final strut was cut, painted and glued into place. Then white glue was used to smooth out many of the imperfections of the LES tower. When the glue was fully dry, it was touched up with more black paint.

The final assembly step was the installation of the three rocket nozzles to the LES. These were cut from the wrap sheet, rolled, and glued to form cones. This was actually one of the more difficult steps. My large fingers and large hand did not handle it overly well but, eventually, I coaxed them into a semblance of the proper shape. White glue was then used to apply them to the tower.

All that was left was some touching up. I painted the inside of the rocket nozzles black and put some touch up paint on the glue gussets of the LES tower. With that, it seemed like the Little Joe was finally complete.

I looked at it from a distance and was rather pleased with myself. I saw plenty of problems with the tower but, I didn't think to was too bad for a first attempt. The feeling lasted until I went to help out with the Cornfield Classic. There, I saw Tim Reidy's Saturn IB. It too had an LES tower and his looked perfect. Those molded parts really look good. Trouble is, I found out that it was scratch built and I think he said it was his first one.

PROs: Unique product. Looks good. Good introduction to modeling of fine parts.

CONs: The LES Tower really is a challenge. This is not really a con but builders should be aware of it.

Finishing:
Almost all of the finishing for this rocket was very simple. It consisted mostly of painting background color and applying paper wraps. The result looks good. I chose to add a little bit of paint in some places indicated above but that was not strictly necessary. It would have been fine as a stock build.

PROs: Wonderful quality paper wraps.

CONs: None.

Construction Rating: 4 out of 5

Flight:
The opportunity to fly the Little Joe finally came and it was taken out to a club launch. When it was taken from its box, it was in good shape. While handling it though, I grew careless and brushed the spike at the tip against something sitting on the launch control table. That was enough to break the glue seal and bend the probe over. It would never survive a flight like that so I removed it and resolved to fly it uncovered.

The rocket was loaded with a B6-4 and placed on the pad. At ignition, it streaked up straight and was lost to my sight except for the smoke trail. Then the chute opened up and I followed it down to what seemed like a good landing.

Upon examining the rocket though, the landing was marred by a popped fin. It will be easy to fix and it will fly again but I did not get to fly it again this day.

A video of the flight can be seen here.

The flight was a good one. I have no reason to suspect anything less than a good performance on a C as well.

PROs: This little rocket really climbs well and looks good doing it.

CONs: The size of this one makes for the potential for long walks.

Dr Zooch Little Joe

Recovery:
As stated in the build section, I deviated a bit from the kit. Instead of using a tri-fold mount, I fixed a Kevlar® harness to the motor mount and then attached that to the elastic, etc. I also replaced the plastic chute with a nylon one because I simply do not like messing with them.

On a build thread on TRF, Dr. Zooch himself weighed in on the matter and endorsed my attachement method, if not my chute.

Flight Rating: 4 out of 5

Summary:
The "Ant Scale" little Joe is a nice rocket from several perspectives. It is unique--all other Joes are of the Little Joe 2. The rocket itself is easy to build. The LES tower is difficult but doable by somebody with patience. Its also a good learning experience. The wraps are first rate and really do more for the appearance of the model than I could ever do with paint.

Oh, it flies well too.

Overall Rating: 4 out of 5

Flights

Comments:

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J.L. (October 31, 2008)
A free 19" version of the LJ1 that can print out on a regular-sized desktop printer is posted on EMRR. http://www.rocketreviews.com/reviews/all/scratch_little_joe_6.shtml

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