Dr. Zooch Rockets EFT-1 beta build...

[luke strawwalker]

Hello there...

Well, here's another fine rocket from Dr. Zooch that just arrived a few days ago... The EFT-1, or Exploration Flight Test number one, a rocket modeled after the scheduled upcoming test (in about 2014) of the Orion exploration vehicle (or MPCV or whatever they're calling it this week-- MPCV-- wasn't that a little dinky foriegn-made minivan or something?? ) Anyway, the unmanned Orion capsule is supposed to fly on a Delta IV Heavy rocket, ignite the upper stage of the Delta IV and go into an elliptical orbit, and re-enter Earth's atmosphere at about 80% or so of a lunar-return velocity to test the heat shield. SO, this kit reproduces that vehicle in ant-scale, in the same ant-scale as the recently released (and beta-build-thread reported) Dr. Zooch SLS Exploration Heavy Lift Rocket that was recently released.

The kit consists of quite a few parts, although it's a pretty straightforward and fairly simple build. The Delta IV Heavy itself consists of three BT-50 tubes- a long one in the center flanked by a pair of shorter booster cores, three BT-50 nosecones- two rounded for the boosters like a regular Delta IV Heavy, the third one "pointy" (though this gets modified) for the Orion's "toilet plunger" Boost Protective Cover with the Launch Abort System rocket tower (simulated with a wood dowel and paper "party hat" adapter glued to the BPC cone). The kit uses a BT-20 18mm motor mount, with two BT-20 flamefin mount tubes in the boosters, each embellished with a paper conical transition on the bottom of each booster, just like the Delta IV Heavy. The kit also comes with a Kevlar shock cord, an elastic upper shock cord, a weighted balsa BT-50 stage coupler, a short BT-50 upper stage tube, BT-5 tubes for the flame-fins, and assorted parts and bits for details and such, and the famous Dr. Zooch trash-bag parachute (made from a genuine trash bag!)

So, lets get to it... somehow I even bet we can beat NASA to the pad! (which probably an arthritic snail could accomplish, but hey-- I aim high! LOL)

Later! OL JR

[luke strawwalker]

First we have the motor mount construction... pretty straightforward and standard fare for Dr. Zooch Rockets... although he does add a couple steps to the 'standard motor mount' which has some good ideas easily added to ANY build by any other manufacturer, which will add to the durability of your motor mount in ANY rocket...

First the BT-20 motor tube has to be cut into three pieces... two each 2 7/8 inch long, and the remainder of the tube used for the motor mount. The shorter tubes go into the boosters to hold the removeable flame-fins. The motor tube gets a slit cut in it for the motor hook at the appropriate spot. Cut the "re-enforcement band" from one of the two detail wrap sheets and apply a layer of white or wood glue to the back, and glue it onto the motor tube, just BELOW the motor hook slit. This will reinforce the tube below the motor hook, preventing the shotgun blast ejections from ripping the hook back through the tube wall and screwing it up. Next, put a drop of CA on the reinforcement band just below the motor hook slit to harden the paper and tube a bit. Install the motor hook in the slit and put several wraps of electrical or masking tape around the tube to secure the motor hook. Next, install the motor block ring (BT-5/20 ring) from the kit bag that the motor hook was in, using some white glue to secure it in place. Grab a couple BT-20/50 rings (there's a half dozen in the kit) and lightly sand them on the inside edge til they slide on the tube easy, then glue one on the top end of the motor tube. Take the second one, and cut a pair of slits on the inside surface of the ring, about half the thickness of the ring, and using the hobby knife, carefully carve away and remove the excess paper to create a notch in the ring (a small hobby file also works well for this). This will allow the ring to slide over the motor hook. Next, carefully measure up 7/8 inch from the aft end of the motor tube, and mark the motor tube. Apply a layer of glue ABOVE the mark all the way around the tube, and slide the slotted ring up over the aft end of the motor tube, until the entire ring is ABOVE the 7/8 inch mark on the tube. (aft end of the ring flush with the 7/8 mark).

From one of the wrap sheets, cut the three conical transitions out using a sharp hobby knife and due care and diligence. Pre-curl them over a Sharpie marker and then apply a bit of white glue to the glue tab, and glue them up into their conical shape. Clamp with a smooth-jawed hemostat or something similar and allow them to dry.

Next, following the kit instructions, glue a pair of centering rings at the appropriate places on the other two remaining BT-20 tubes. These will be glued into the boosters for mounts for the flame-fins.


Once the rings have been glued to the tubes and the transitions are dry, test fit them over the motor tube and flamefin tubes. The transition going over the motor tube will have to have a pair of slits cut in the aft end of the transition to allow it to go over the motor hook and allow the hook to open to add/remove rocket motors. If you're careful, you can align the motor hook as per the kit instructions, and "clock" the transition so that the seam on the side of the transition aligns with the reference mark on the tubes (where the boosters will be glued on) thus hiding the seam and making for a neater looking build.

Next, using the doorjamb method (or a handy piece of angle aluminum or brass) put a vertical "reference line" on each of the three BT-50 body tubes in the kit. These reference lines will be used to align the edges of the wraps later on and the seams on the transitions to help hide them, and also to glue the boosters together to make the rocket.

If you "clocked" the motor hook and transition seam, test fit and then glue the motor mount into the core stage (longest BT-50). Otherwise just follow the kit directions relating to motor hook positioning with respect to the reference line, and glue the motor mount in with white glue. Next, glue the two flame fin mount units into the two shorter BT-50 booster tubes, with the transition seams aligned with the reference marks on the sides of the tubes, again, gluing everything up with white glue. Set everything aside to dry...

More later! OL JR

[luke strawwalker]

So, after the cores have their boattails and motor/fin mounts installed, it's time for a quick trip to the paint shop... the bottom ~ 2 inches of the boosters and core vehicle are painted flat white, and the ~2 inches of the top of the core vehicle (that will be above the wrap).

I soaked the nosecones with ultra-thin CA to harden them, and let them dry thoroughly. Then I sanded them with 220 grit sandpaper to smooth them out and remove the rough outer layer of CA. I also sanded the tip off the "pointy" Orion BPC cone that will go on the core vehicle, to ready it for the LAS tower installation later. Just sand the tip down evenly until the top is a flat circle about 1/4 inch in diameter. Then, I brushed a thin layer of Carpenter's Wood Filler onto the cones, let dry, and sanded them down with 220 grit again. Then, after masking off the shoulders and taping the cones down to cardboard painting handles, I gave them 3-4 light coats of primer and set them aside to dry.

Next, cut the wraps for the cores out of the wrap sheets with a sharp hobby knife blade and straightedge. Cut them out one at a time and be sure to write with a pencil on the back of each whether it's a strap-on booster wrap or the central core vehicle wrap, as the boosters are mirror-images of each other, (with one matching the core vehicle) and you want to make sure they're placed on the right tubes.

I pre-rolled the wraps around an 18mm motor case just to ensure that they'll conform to the tube a bit easier. Then, applying a THIN layer of glue all the way around the edge (about 1/2 inch wide stipe from the edge toward the center) and then carefully align them to the central core tube, and ensuring that they're properly aligned with the end of the tube (on the strap-on boosters) or the marks (on the core vehicle) roll the wraps onto the tube, and burnish them down firmly. Set them aside to dry.

Once the wraps are dry, the cores can be lined up to check their alignment.

More later! OL JR

[jetlag]

Looking great, JR!
I love Dr. Zooch kits, so I will be following this build avidly.
Thanks!
Allen

[luke strawwalker]

There's been some discussions and debates lately about wet sanding, damp sanding, and finishing in general of cones and transitions and other balsa parts... here's a perfect opportunity to display some techniques that work well for me and might help someone else if they want to give them a try...

The kit comes with three nosecones. One is "pointier" (the Orion "toilet plunger" BPC cone on the core vehicle) and the other two are more "rounded" for the Delta IV Heavy strap-on boosters. All three are balsa. In the previous post, I mentioned that the first thing I did was apply CA all over the exposed parts of the nosecone above the shoulder, to harden them up. Some inevitably soaks down into the shoulder area, and requires a little sanding of the shoulder the return it to the correct fit with the body tube. The hardened cones are then sanded with 220 grit sandpaper to take off the gritty outer layer of CA (hardened balsa "hairs" and grit from balsa dust remaining on the surface raised by the CA). The cones then get their shoulders masked off with masking tape, and brushed with a coat of Carpenter's Wood Filler thinned to about the consistency of hot dog mustard. When dry, they're sanded down with 220 grit, taking off probably 90% or more of the filler, but filling the grain and any imperfections in the cone, wiped down with paper towels, and attached to paint sticks for priming. I then primed with Rustoleum primer and allowed to dry overnight. The primer says "sandable in 4 hours" but that was optimistic-- we had a cool front move through and the humidity was high yesterday and it was cool, and got a bit chilly overnight, so the drying was MUCH slower. I managed to sand the cones down a bit with 220 grit last night before bed, but they were still quite smelly and the primer was very "soft"... it didn't gum the paper terribly, but it was still just a borderline case... BUT, sanding the cones DID "open up" the primer and allow it to dry thoroughly overnight.

SO, this morning, upon close inspection, the 220 grit sanding scratches were VERY evident from the soft primer... Clearly this surface is nowhere NEAR smooth enough for paint. Upon raiding the sandpaper supply bag, I found some 320 and did a quick sanding, and still found that it was too rough. A smoother finish is needed. Upon some searching, I found the last of my 440 grit wet/dry paper... time for some damp sanding...

Now, lest anyone think I'm somehow violating a fundamental law of nature by wet sanding primer, here it is... right there on the can-- WET SANDABLE. Now we've gotten that out of the way...

Here's all you need... a small bowl with a bit of water, a couple small squares of 440 grit wet/dry paper, and a couple paper towels.

Dip the paper in the water a couple times, and tap it against the side of the bowl to shake off as much excess water as possible. Sand in small circles around the circumference of the cone, slowly turning the cone in your other hand as you sand. DO NOT sand in straight lines, or sand in one spot-- keep turning the cone very slowly as you sand in a small circular motion. After a couple revolutions, move up the cone, overlapping the area you sanded before. Make another couple revolutions. Then work your way up to the tip, sand just below the tip all the way around a couple times.

As the cone is sanded, the moisture will be absorbed by the sanding dust and turned into "sanding mud". This gradually dries the paper out as the moisture evaporates and is absorbed, making the "mud" thicker and thicker until it starts to get dry.


Later! OL JR

[luke strawwalker]

Dunk the paper in the water again, rubbing a finger over the grit to release the trapped paint particles, and shake it dry. Take the paper towel and wipe the cone off thoroughly. Inspect your work, looking for any spots that need more attention. Take the damp paper and work CAREFULLY over the tip-- since it's small in area (even worse on "pointier" cones) and rather small-radiused, you have to be VERY gentle when sanding it to avoid sanding in flat spots or wearing completely through the primer... keep sanding in small circles as far as you can, and MAKE SURE you keep turning the cone CONSTANTLY as you sand... for the very tip, it's best to hold the paper almost like a violin bow (sorta like the Vulcan "V" hand sign, with the paper stretched across between your fingers) and let it gently curve over the tip of the nosecone, sanding back and forth as you constantly turn the cone.

Wipe the cone down again thoroughly. The sanding scratches are nearly gone, and the surface is MUCH smoother, but we can do better... time to repeat the process... it only takes 5-10 minutes per cone...

After another pass, with a close inspection and a bit of "spot sanding" of some grain that was peeking through, and another thorough wipe down, we can inspect the cone in daylight... look at the reflection-- it will show far smaller defects than you can see looking directly at it. When the reflection is smooth and unbroken, you have a nearly perfect surface ready for paint...

Notice the TINY blemish in the reflection at the "11 o'clock position" in the second photo, in the reflected light off the surface of the cone?? This one is just small enough not to bother with, especially for a BT-50 cone...
Later! OL JR

[luke strawwalker]

Looking great, JR!
I love Dr. Zooch kits, so I will be following this build avidly.
Thanks!
Allen

Thanks Allen! I appreciate it!

Later! OL JR :)

[evil ed]

IMPRESSIVE..............

Can't wait to see the finished product!

[nukemmcssret]

I soaked the nosecones with ultra-thin CA to harden them, and let them dry thoroughly. Then I sanded them with 220 grit sandpaper to smooth them out and remove the rough outer layer of CA.


Does this mean you actually poured enough CA in a container, and dipped the nosecones in it ? Or do you mean you brushed CA on until the balsa quit taking the CA. If you dip it in what do you do about fumes? How ling do ou leave the nose cone in the CA? I cannot stand the smell of CA. I have to have a fan going.

[luke strawwalker]

I soaked the nosecones with ultra-thin CA to harden them, and let them dry thoroughly. Then I sanded them with 220 grit sandpaper to smooth them out and remove the rough outer layer of CA.


Does this mean you actually poured enough CA in a container, and dipped the nosecones in it ? Or do you mean you brushed CA on until the balsa quit taking the CA. If you dip it in what do you do about fumes? How ling do ou leave the nose cone in the CA? I cannot stand the smell of CA. I have to have a fan going.

Well, I didn't post pics of that operation, but here's how I do it...

I use ultra-thin (pink bottle) CA from Hobby Lobby (buy the small bottles so it doesn't go bad before you use it all)-- especially cheap with the 40% off coupon... I grab a cardboard "flat" (can goods) shipping box and go outside on the porch, and work CROSS-WIND-- if the wind's at your back, it forms turbulence that tends to whiff the fumes right into your face, of course if the winds in your face it will sends the fumes straight at you, so cross-wind is definitely best to minimize fume sniffing... ) I take the nosecone, and holding it by the back of the shoulder, with the tip of the nosecone down at about a 45 degree angle, I pull the cap off the CA bottle with my teeth, and using the tip of the CA bottle, start applying the CA directly to the surface of the cone, just above the shoulder of the cone (which is lower remember since the cone is inverted). I simply "rub" the CA out onto the surface of the cone as I slowly turn it, allowing the balsa to "drink it in" to the pores and grain of the wood. I keep turning the cone slowly as I work my way toward the tip of the cone. Any excess CA tends to run down toward the tip, which is really where you need the thickest layer of CA anyway...

Be advised-- the wood grain does tend to soak up the CA and pull it back toward the rear of the cone, to the shoulder/base of the cone, which is where you're holding it, so keep your fingers moving and if you feel ANY sensation of warmth or dampness MOVE YOUR FINGERS to prevent them from getting glued to the cone! It's probably a good idea to use wax paper to hold the cone, or nitrile gloves, or a ziplock baggie to prevent your fingers from getting stuck to the cone. Usually I get the "stickies" doing it barehanded but I haven't actually glued the cone to my fingers (yet). The secret is to keep moving and not give the stuff time to actually "grab" your fingers... (or do it the "right way" and use gloves or something... LOL:))

I have gloves, just never remember to use them... :rolleyes:

It REALLY hardens the cones up substantially, the outer layers anyway (eventually the cone will quit 'drinking in' CA as the pores and grain fill and the glue sets, sealing off the deeper grain from absorbing any more. It doesn't make the cones "bulletproof", but then again I'm not aware of anything that really does (short of glassing them, but if you're gonna glass a cone why use balsa to begin with? :confused: ) The worst part of the process is the fumes, as you mentioned. The other thing is, the CA tends to "raise" any stray fibers or grain on the surface of the cone, and any dust or grit from the cone being turned (and no you can't get rid of it all by cleansing the balsa-- it ALWAYS has some dust/grit hiding down in the pores of the balsa so it seems). This takes a little elbow grease with 220 grit sandpaper to get rid of, but the results are worth it... (IMHO)

Later! OL JR :)

[nukemmcssret]

[QUOTE=luke strawwalker]Well, I didn't post pics of that operation, but here's how I do it...

I use ultra-thin (pink bottle) CA from Hobby Lobby (buy the small bottles so it doesn't go bad before you use it all)-- especially cheap with the 40% off coupon... I grab a cardboard "flat" (can goods) shipping box and go outside on the porch, and work CROSS-WIND-- if the wind's at your back, it forms turbulence that tends to whiff the fumes right into your face, of course if the winds in your face it will sends the fumes straight at you, so cross-wind is definitely best to minimize fume sniffing... ) I take the nosecone, and holding it by the back of the shoulder, with the tip of the nosecone down at about a 45 degree angle, I pull the cap off the CA bottle with my teeth, and using the tip of the CA bottle, start applying the CA directly to the surface of the cone, just above the shoulder of the cone (which is lower remember since the cone is inverted). I simply "rub" the CA out onto the surface of the cone as I slowly turn it, allowing the balsa to "drink it in" to the pores and grain of the wood. I keep turning the cone slowly as I work my way toward the tip of the cone. Any excess CA tends to run down toward the tip, which is really where you need the thickest layer of CA anyway...

Be advised-- the wood grain does tend to soak up the CA and pull it back toward the rear of the cone, to the shoulder/base of the cone, which is where you're holding it, so keep your fingers moving and if you feel ANY sensation of warmth or dampness MOVE YOUR FINGERS to prevent them from getting glued to the cone! It's probably a good idea to use wax paper to hold the cone, or nitrile gloves, or a ziplock baggie to prevent your fingers from getting stuck to the cone. Usually I get the "stickies" doing it barehanded but I haven't actually glued the cone to my fingers (yet). The secret is to keep moving and not give the stuff time to actually "grab" your fingers... (or do it the "right way" and use gloves or something... LOL:))

I have gloves, just never remember to use them... :rolleyes:

It REALLY hardens the cones up substantially, the outer layers anyway (eventually the cone will quit 'drinking in' CA as the pores and grain fill and the glue sets, sealing off the deeper grain from absorbing any more. It doesn't make the cones "bulletproof", but then again I'm not aware of anything that really does (short of glassing them, but if you're gonna glass a cone why use balsa to begin with? :confused: ) The worst part of the process is the fumes, as you mentioned. The other thing is, the CA tends to "raise" any stray fibers or grain on the surface of the cone, and any dust or grit from the cone being turned (and no you can't get rid of it all by cleansing the balsa-- it ALWAYS has some dust/grit hiding down in the pores of the balsa so it seems). This takes a little elbow grease with 220 grit sandpaper to get rid of, but the results are worth it... (IMHO)

Later! OL JR :)[/QUOTE

Thanks, I will give that a try. I like those 40% off coupons at Hobby Lobby. I get my wife to go in and use also. Thanks for the tip. :)

[luke strawwalker]

Next we start building the Orion capsule BPC (Boost Protective Cover-- the so-called "toilet plunger" or "Kaiser hat" if you prefer). Originally, Orion was to have a form-fitting BPC quite similar to the one used for Apollo, which rode basically almost touching the skin of the Apollo capsule. Due to problems with the performance of Ares I, NASA found it advantageous enough to cut drag by changing the shape to an ogive shape, which puts the Orion capsule sorta 'suspended' inside the hollow BPC much as Soyuz capsules are inside their large hollow BPC. Hence the shape change (note the Zooch Ares I-X for the 'old shape'). Now with the history lesson behind us, we'll continue.

The "pointy" nose cone in the kit is the Orion BPC. Of course the point isn't needed, and is sanded or filed off until the top of the cone is about 3/16 to 1/4 inch flat, even and round and perpendicular to the cone's long axis. Next, using a small drill bit as specified in the instructions, using FINGER POWER alone (don't whip out the power drill for this one) drill a shallow vertical hole in the top of the nosecone, centered in the flat spot, about 1/16 to 1/8 inch deep. Fill it with yellow glue, grab the wooden LAS rocket tower from the kit bag, and insert it flat end down into the hole, squeezing out the glue around it, and then fillet the squeezed out glue around the tip of the nosecone and the shaft of the LAS dowel. Pop the cone into a booster or a scrap piece of BT-50 and roll it across the work table, carefully observing the tip of the dowel-- if it wobbles, adjust it until it "rolls true" when the cone is rolled across the table. Set the cone and tower aside to dry.

Cut the "party hat" from the wrap sheet (which is actually a fairing on the real BPC designed to reduce supersonic drag-- another improvement over the old "open strut" towers used on Apollo). Apply white glue to the glue tab, and curl the thing around a pencil or pen tip into its conical shape and glue it together, clamping it in place with a smooth-jawed hemostat or equivalent. Set it aside to dry.

Once dry, fit the party hat over the dowel. I had to trim my upper end of the party hat a TINY bit to get a smooth fit over the dowel, apply a layer of white glue to the dowel about 3/8 inch up from the tip of the nosecone and lay a thin layer of glue around the top of the nosecone, and then slide the party hat over the dowel and slide it down into place against the top of the nosecone, and wipe away any excess glue. I went ahead and put a THIN layer of white glue over the party hat itself to seal the paper and smooth out the glue seam.

Next, from another kit bag, grab the four small LAS rocket nozzles, and trim them at an angle, and glue them to the LAS tower dowel 7/8 inch below the tip, spaced evenly around the dowel at the four cardinal points... I then filleted them with some yellow glue just for a bit of extra insurance.

The core vehicle gets a green band glued around the top of the BT-50 tube. Cut the green band from the wrap sheet using a sharp hobby knife, and apply a thin layer of white glue to the back of the band, and carefully apply it to the rocket, lining it up with the seam on the lower orange tank insulation foam wrap. This band serves to not only represent a color band on the vehicle, but also to prevent sooting of the white paint on the top of the core vehicle at parachute ejection...

Later! OL JR

[luke strawwalker]

Next we'll find a short piece (about 1 inch long) of BT-50 tubing in the kit, and the pre-weighted balsa tube coupler plug.

The tube serves as the "kick stage fairing" covering the Delta IV Heavy upper stage. The tube should have been painted white earlier when the tubes got painted white before the orange foam insulation wraps were applied to the boosters and core. The short tube is put on the BPC nosecone shoulder til it's seated, then insert the balsa plug, weighted side up, into the bottom of the tube until it's seated against the bottom of the cone shoulder. They'll be glued together like this later on-- I'm just test fitting them now.

Next, grab the two BT-5 tubes from the kit and the four BT-5/20 centering rings. Lightly sand inside the centering rings til they fit the tubes nicely, then glue one ring on the very end of each of the tubes, and the second ring below it with a 3/8 inch gap in between. Glue the rings in place with white glue.

Cut the Flame Fin pattern from the wrap sheet with a sharp hobby knife. I tend not to bother with the "ragged edge" effect since it's the general shape that's visible on the pad anyway, and just cut them out just past the tips of the "ragged edge". Another trick I've found is to cut a bit outside the lines at the bottom of the Flame Fin pattern so the bottom edge of the fin is rounded instead of a sharp point, which is very prone to breaking at landing IMHO. Be sure you cut the fin a bit larger if you want to make the bottom rounded-- don't just lop the tip off-- we don't want to reduce the actual fin area, just make the tip rounded so it's less likely to crack a fin or something. Align the grain pattern handily drawn onto the pattern with the grain of the two included balsa sheets and trace the pattern, making THREE Flame Fins for each of the two Flame Fin insert units. This makes SIX fins total... Carefully cut the fins from the balsa sheet using the hobby knife, and stack sand them.

The finished Flame Fins are ready to glue to the tubes...

Later! OL JR

[luke strawwalker]

Back to work on the Flame Fins...
We've already cut them out of the balsa sheets in the kit, and stack-sanded them to identical size/shape. Now we're ready to glue them on the BT-5's to make the flame-fin units themselves. The Flame-Fins are meant to be rather 'rough looking' so I don't bother airfoiling them or papering the fins... they're strictly for flight not display so I deliberately leave them "au naturale" as far as finishing/filling/etc. Later they'll get painted.

I put all the fins root side up into the slitted egg cups of an old egg carton, and apply a thin even coat of wood glue to the root edges of all of them and allow it to dry for double glue joints.

I then take the BT-5 tubes and, marking the fin locations using a paper wrap and fin reference lines put on with a small brass angle, I sand the lines a bit with 220 grit to roughen up the glassine and promote adhesion. Then I apply a thin layer of yellow wood glue to each of the lines, and put them aside to dry.

When about dry, the fin's root edges get another light coat of wood glue, and then are carefully aligned with the marks on the tube, and then pressed in place. The glue grabs "almost instantly" and whatever excess glue is squeezed out, I use to gently fillet the fins, sometimes with a bit of additional yellow wood glue. I usually do the opposing fins first, and clamp them to a ruler with clothespins to ensure they remain straight while the glue hardens up, and then "eyeball" the last fin centered 90 degrees between them. There are ONLY THREE fins per unit, arranged 90 degrees to each other (like a four fin rocket with one fin missing-- DO NOT put them on like feathers on an arrow or a regular three-fin rocket spaced 120 degrees apart!)

Next, it's time to join the cores together. I test fit them to ensure the arrangement and alignment, then set them up on another egg crate and apply a thin layer of white glue to each core's wrap seam, where they'll join with the other cores. Let this thin layer dry for a double-glue joint.

Apply a second layer of glue to the seam and then carefully mate the cores together, ENSURING their alignment of the seams-- eyeball it from the ends to ensure that the seams are both 'clocked' together (at the 3 and 9 positions on the left (main vehicle) and right (strap on booster) cores, respectively). Also make sure they're both flat and even on the table work surface-- they must be parallel to each other. Let them dry.

Later! OL JR

[luke strawwalker]

Well, let's get back at it...

Once the core vehicle and one of the strap-on boosters have set up, glue the second strap-on booster to the stack. Apply a thin layer of glue to the booster and slowly slide it into place against the core vehicle. Ensure that the glue is centered against the contact point between the booster and core, and that the entire stack is perfectly flat on the work table... this will ensure both cores are completely aligned and true with the core vehicle. Also double-check the lengthwise alignment down the long axis of the vehicle and ensure that the booster is aligned at the bottom and along the wrap lines... Once you're satisfied everything is straight, true, and level, let the glue dry.

Next, grab the three slender dowels from the kit box and cut them to length as indicated in the instructions. Save the remaining bits cut off the dowels as they'll be used for aft struts on the boosters. Cut them to length per the instructions and set them aside. Round over the ends of the long dowels as indicated to turn them into LOX lines for the rocket, extending from the intertank area to the thrust structure. Cut two 3/16 squares of balsa as instructed for the forward strut attachment. Grab the four cut toothpick forward struts from their kitbag and then take all these detail parts and get them ready for paint. I find it easiest to paint these parts by rolling some tape into a double-sided loop, sticking it down to some scrap balsa, and then sticking the parts to be painted down onto the tape. Then they can either be spray painted white or brush some white paint on them using a bottle of Testors (or equivalent).

Once the core and boosters have set up firmly, you'll probably want to fillet the boosters a bit to the core to ensure everything has a good strong glue joint. I've found this tool to be EXTREMELY helpful for putting mini-fillets down in the crevasse between the boosters and core vehicle... it's a kid's medicine measuring syringe (I get one every time Keira gets a prescription so I have a few stockpiled) with a "Testors Gluing Tips #8805" tip popped onto the end of the syringe. The glue tips were cheap at Hobby Lobby, but I'm sure they can be found at nearly any hobby shop or online... they're small plastic tips that are made to wedge onto the tapered end of a model airplane glue tube tip, for applying thin, fine lines of model airplane glue to plastic models. The syringe tip is the EXACT same size as the model airplane glue tube tip, and the gluing tip will snap right onto the end of the syringe securely. Pop the plunger out the back, squirt in a few CC's of white glue, and presto you're ready to apply thin fillets anywhere, even deep in grooves between body tubes! When done, squirt the remaining glue back into the bottle,and clean the thing out under running water-- easy as pie! I spread the fillets and pop any air bubbles using the point of a bamboo skewer... another VERY handy tool to have!

Next we apply the detail parts... run a hobby knife to cut the paint where it overlaps the tape, and then pull the detail parts off the tape, and scrape off any paint lines. Of course there's no paint where it was stuck to the tape, so keep this side of the detail part facing down against the rocket... Carefully glue the small balsa squares centered on the core vehicle, and then glue the two toothpick forward struts from the strap-on boosters to the core vehicle's small balsa square on either side... apply a bit of white glue to shore everything up and set it aside to dry...

The aft struts are cylindrical bits cut off the end of the long dowels we turned into LOX lines... each is cut to length per the instructions, then tapered on the backsides to nestle down tight against the body tubes, and finally painted. Cut the paint and pull them off the tape, daub white glue on each end, and stick them in place between the strap-on boosters and the core vehicle at the aft end directly in front of the aft transitions on the thrust structure. Finally, the three LO2 lines are glued into their proper places on the rocket, just below the SMALL intertank doors, which should all be on ONE SIDE of the rocket... The LO2 lines reach from the intertank down the side of the LH2 tank to the thrust structure at the bottom. Make sure they're all even (ensure they're equally spaced below the small door printed on the wrap) and that they're parallel with the long axis of the booster and not slanted, and centered on the booster as best you can get them. The launch lugs should go on the opposite side, the side with the BIGGER intertank doors. (yeah I screwed up) Set it aside to dry.

Later! OL JR

[luke strawwalker]

You'll probably want to put some TINY fillets along the sides of the LO2 lines just to make sure they stay put... The syringe applicator shown earlier and a bamboo skewer are EXTREMELY handy for doing this...

Once dry, flip the rocket over and install the fwd and aft struts identically to the opposite side.

The glued up flame fins were slid into a spare BT-20 and shot with a few coats of white paint, allowed to dry a few hours, then masked off the fin tips and bright yellow paint shot on the centers of the fins and tube to simulate the rocket exhaust and smoke. Works for me...

Next, grab your Gen-You-Wine Dr. Zooch trash-bag parachute from the kit and assemble it per the instructions... sticky dots on the corners, cut the "poly-coated Popeilium" shrouds into even third, and apply to parallel corners, even them up, and attach them to the snap swivel.

Grab the pre-weighted balsa plug from the kit. Put the weighted end down, and apply a little CA to the center of the balsa end grain (don't get it on the sides of the plug) to harden the balsa a bit. Get the screw-eye from the kit bag and screw it into the wood, then remove it, apply some yellow wood glue into the hole, and then screw the eyelet back in. Get the Orion BPC nosecone, and insert it into the short (1 inch) piece of painted BT-50 kick stage cover tubing after putting a layer of white glue inside it. Next insert the weighted stage coupler, WEIGHTED SIDE UP, into the glue-lined kick stage tube below the Orion BPC nosecone, gluing the entire thing together into an assembly. Once dry, tie the shock cord elastic to the screw eye. Clip the parachute to the snap swivel, insert the flame fins, and presto your done!

Later! OL JR

[luke strawwalker]

So, after allowing the glue and paint to dry thoroughly over night, here's the finished product... The EFT-1 is ready to soar into space to test the Orion capsule on high speed reentries, and you didn't even have to deal with all the messy politics of putting the capsule on the EELV...

Enjoy! OL JR

[luke strawwalker]

A few more glamour shots... OL JR

NOTE: Some pics show the rocket without flame-fins on the pad-- DO NOT attempt to fly the rocket like this-- these are strictly display pics...

[luke strawwalker]

And a few more glamour shots... Later! OL JR

Note: display pics only-- don't attempt to fly without flamefins!!!

[luke strawwalker]

Last two... OL JR

Note: Don't fly without flamefins!

[tbzep]

Hey, JR....can I fly it without the flame fins? :chuckle:

The kit didn't really hit home as "ant scale" until I saw how big the motor looked sticking out the back. :p That looks like it's going to char up the flame fins, but it will get the job done, especially since it it won't be displayed with them on. :cool:

[jharding58]

Most of the damage to this type of fin comes from the flame bounce from a flat plate. I learned the hard way with the Atlas and Titan models to move the model about six inches up the rod you balance damage with stability. With the launch stand that you see here it will defelct nicely to the sides. It would be interesting to see a slow motion as the exhaust flame propagates with this stand.

Shouldn't you have a little sprinkler head for sound suppression also?

[luke strawwalker]

Hey, JR....can I fly it without the flame fins? :chuckle:

The kit didn't really hit home as "ant scale" until I saw how big the motor looked sticking out the back. :p That looks like it's going to char up the flame fins, but it will get the job done, especially since it it won't be displayed with them on. :cool:

Well, I figured better to point out the obvious rather than have some newb dingus complain later that "well the pics showed it on the pad without flamefins" while complaining to Wes wanting a free new kit because theirs just pinwheeled through the air before darting into the RSO's table and disintegrating...

Better safe than sorry... :) (Legal disclaimers and all). OL JR :)

PS. Yeah, it's ant-scale-- bout the size of three Alpha III's strapped together... :chuckle:

[luke strawwalker]

Most of the damage to this type of fin comes from the flame bounce from a flat plate. I learned the hard way with the Atlas and Titan models to move the model about six inches up the rod you balance damage with stability. With the launch stand that you see here it will defelct nicely to the sides. It would be interesting to see a slow motion as the exhaust flame propagates with this stand.

Shouldn't you have a little sprinkler head for sound suppression also?

Meh... then ya gotta run the plumbing for it, build an ant-scale water tower, etc. etc. etc... We just launch 'em dry out on Pad 34Z ("Z" for Zooch).

This is my favorite pad... a rocket LOOKS like a rocket sitting on and launching from this pad... and you're right... the hole allows the motor to exhaust down through the open area and off the soup can flame deflector to the side at liftoff... while STILL getting the benefit of full length use of the launch rod...

All that and looks cool as heck doing it! OL JR :)

PS. got pics of my Zooch Shuttle and Zooch Saturn V launching off this pad in their respective build threads... and some in the club flight reports by yours truly in the 'events' section...

[jharding58]

Should anyone be intersted in some laser cut flame fins they can be obtained from this email address.

jfranco@dietandtraining.com

He cuts them to the specification of the majority of the kits (Atlas, Titan, Shuttle, Aries 1-X) and has also cut some up-scale (five inch on the root). With the irregular LE you need to infuse thin CA into the wood prior to finishing.