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

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?? :confused2 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

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

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

do you happen to have a picture of the kit?

RocketManDan said:

do you happen to have a picture of the kit?

Click to expand...

If you look in the background of one of the pics above, you can see the end of the kit box sitting on the work table... basically it's shipped to me in the same ~ 4x4x12 cardboard mailing box the Doc uses to ship all his kits, except the beta kits rarely come with the pretty white box art stickers that the regular kits have... this one included. This one was just wrapped with plenty of regular mailing tape...

Later! OL JR

PS... do you mean the parts of the kit?? No, sorry... no pic of the parts loose in the box... but I will promise pictures of the parts assembled into the finished product... Basically the inventory of the parts in the box was 3 BT-50 tubes, one longer than the others (core vehicle), 1 BT-50 balsa plug, pre-weighted, 1 BT-50 bit 1 inch long (upper stage of the core vehicle into which the weighted plug is installed), 2 rounded BT-50 nosecones, 1 "pointy" BT-50 nosecone, 1 long BT-20 tube (later cut into three parts for the motor/fin tubes), 2 half-sheets of balsa fin stock, 6 BT-20/50 centering rings, 4 BT-5/20 centering rings, 3 long slender wood dowels, 4 partial toothpics used for the strap on booster struts, 2 BT-5 tubes for the flamefins, 2 wrap sheets, trash bag parachute, kevlar shock cord, elastic upper shock cord, length of shroud line, sticky parachute dots, and 2 kit bags- 1 with 4 LAS nozzles and the LAS main tower motor dowel, and the second with the screw eye, launch lug, motor hook, motor block, and snap swivel. I think that's it... Well, and of course the instruction sheets and wrap sheets, which I unrolled and put under a stack of books for a couple days to flatten them back out.

nice work!

An important note here folks; this is the actual beta build, the kit will not be released until the beta is complete, the instructions are printed, and I get the kits made up.

To make matters worse I recently had shoulder surgery for a torn rotator cuff and currently have one arm immobilized until further notice. The recovery process after such surgery is quite long. As a result making up kits is a very slow, awkward, exercise in pain. In fact, the simple act of rolling up instructions can leave me a hurting puppy. So everything here at Dr. Zooch rockets is moving at a slow pace to say the least. With any luck I hope to be out of my sling and making kits at a better pace by mid-December. I'm hoping to get this kit released in December, but depending on therapy it could push in January. All of the components needed to make the kit are currently in stock, however.

In the meantime, don't worry about me they've given me REAL good pain medication.

Wes,
hope you get better soon!!

Rick


ps- This is going to be an awesome kit!

Luke,
this is a great build thread! I am going to bookmark this one!!! keep up the good work! Always fun to watch a craftsman at work. Your kits always turn out fantastic!

Rick


ps- Did your daughter ever get a chance to fly her Gumball lifting rocket? That was a great build thread...I have thought about buying that and painting it in the colors of the Pershing 2 missle...olive drab with orange bands....I feel bad though because I don't think Dr. Zooch intended for someone to militarize that kit ....

NJRick said:

Luke,
this is a great build thread! I am going to bookmark this one!!! keep up the good work! Always fun to watch a craftsman at work. Your kits always turn out fantastic!

Rick


ps- Did your daughter ever get a chance to fly her Gumball lifting rocket? That was a great build thread...I have thought about buying that and painting it in the colors of the Pershing 2 missle...olive drab with orange bands....I feel bad though because I don't think Dr. Zooch intended for someone to militarize that kit ....

Click to expand...

Thanks Rick...

No we haven't had the opportunity to fly here since last spring... March or April to be exact. We've been in a particularly dry spot of probably the worst drought Texas has had in the last 50 years AT LEAST. We've operated under a permanent burn ban since the last launch, and while I don't mind "sneaking one under the radar" despite the burn ban, conditions have been SCARY dry and fire-prone... everything tinderbox dry, extremely hot (until a few weeks ago when "fall" arrived) and very windy. I just don't risk it in those conditions... We've been hoping against hope for rain... we got 1/2 inch today, which brings us up to 7.5 for the year, which is 16% of our normal yearly rainfall of about 44 inches or so. The club (Old Rocketeers #724) guys have asked about flying, and if we could get just ONE good rain, now that fall is here and the heat is over, it would green things up enough to fly. Unfortunately it just KEEPS MISSING us... other areas around Houston, and heck even with 20-30 miles of here, have gotten pretty good rains, but here we just keep staying dry and missing everything. Hopefully we can get Keira's Gumball Lofter up soon, and her Fat Boy as well...

I like your idea about the GLV... it'd be cool to see one painted up like a Pershing... the fins are kinda "Pershing II" looking but the Pershing I paint schemes are usually more interesting. I don't think the Doc would mind... If he didn't mind me turning a Zooch shuttle into Moonraker 5 I don't think he'll sweat it out over having a GLV painted like a Pershing...

Good luck! OL JR

Dr.Zooch said:

To make matters worse I recently had shoulder surgery for a torn rotator cuff and currently have one arm immobilized until further notice. The recovery process after such surgery is quite long. As a result making up kits is a very slow, awkward, exercise in pain. In fact, the simple act of rolling up instructions can leave me a hurting puppy. So everything here at Dr. Zooch rockets is moving at a slow pace to say the least. With any luck I hope to be out of my sling and making kits at a better pace by mid-December. I'm hoping to get this kit released in December, but depending on therapy it could push in January. All of the components needed to make the kit are currently in stock, however.

Click to expand...

D@mn buddy, there must be something in the water in the mid-atlantic region.... I'm scheduled for my surgery on 12/21...My right shoulder has a massive tear in the rotator cuff, they're doing it open and not laproscopic...Sad part is, I am extremely right-handed....Food ends up in my lap as much as in my mouth, I have a Robert Hayes-esque drinking problem, and I can't even unzip my fly left-handed (kilts are in my future, I think)...

On the plus side, during the Christmas holidays with my entire family at my parents house, I'll be drugged to the gills!!! Little victories....

Heal well,

G.D.

Luke....7.5 inches for the YEAR?? Holy smokes. we got that up here in September in one day...that is scary....in essence, you haven't gotten any rain for the past year. I hope it comes your way.

your build threads are always great reads....I learn everytime I read yours...(and others too....Foose, Banjo.....just some really good builders on here) just amazing what you guys can do. keep it up!!

Rick

Yes, we all wish Wes a speedy recovery and hope things go well with him!

Sorry to hear of your shoulder problems too, G.D. Best wishes!

I don't go to the doctor unless I gotta be carried in... sure hope I can keep it that way!

Wes, sounds like you need to train your daughters to help pack kits... (either that or recruit and train more ants!) I'm training my daughter to work in the shop with me, finding wrenches and stuff... she helped me replace the gas pump in the gas tank in the 96 Roadmaster a couple weeks ago. She's learning fast. Right now she's engrossed in Punkin Chunkin and coming up with all sorts of ideas for building a punkin chunker... :y: Oh boy... may have created a monster... She's also gotten pretty good working cows...

Later! OL JR

NJRick said:

Luke....7.5 inches for the YEAR?? Holy smokes. we got that up here in September in one day...that is scary....in essence, you haven't gotten any rain for the past year. I hope it comes your way.

your build threads are always great reads....I learn everytime I read yours...(and others too....Foose, Banjo.....just some really good builders on here) just amazing what you guys can do. keep it up!!

Rick

Click to expand...

Yep... unholy smoke... that's been the problem... Had a BIG fire just a couple or three miles from here that burned a few hundred acres and took out a couple barns and outbuildings... no fun. Even worse north and west of here...

Later! OL JR

PS... just to update the build, I'm waiting on paint to dry...

SO back to the build of the EFT-1...

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

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

PS... click the photo to see it in "full res" outside the dinky black "pop up box" the forum displays them in... click the full res view for an enlarged view of the pic at full size in full res... click the "back" arrow of your browser to return to the thread...

luke strawwalker said:

SO back to the build of the EFT-1...

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...
View attachment 63568
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...
View attachment 63569
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.
View attachment 63570
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.
View attachment 63571
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.
View attachment 63572

Later! OL JR

Click to expand...

JR that's the way I always do it. Nothing wrong with wet sanding. Nice work as always!

RocketManDan said:

JR that's the way I always do it. Nothing wrong with wet sanding. Nice work as always!

Click to expand...

Thanks Dan... I appreciate it.

Seems some folks thinks wet sanding ("wet sanding" is IMHO what we do on antique cars-- sanding the color coat with a garden hose constantly dribbling water on the area to remove the paint particles and keep the area cool and lubricated) primer is of the devil...

If you use a garden hose I'd probably agree... that's why I call this "damp sanding"...

Later! OL JR

Ditto JR...You always put up some nice builds...looking forward to seeing the set of pictures.

RocketManDan said:

JR that's the way I always do it. Nothing wrong with wet sanding. Nice work as always!

Click to expand...

I've been using the same technique for quite a spell. I highly recommend this method!

I actually have some wet sanding to do tomorrow...it will be nice to work on some rockets!!

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...

Late! OL JR

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,
this is a great build ......quick question regarding the wet sanding....is there an advantage to wet sanding over regular? do you have to use the plastic backed sand paper? I hope these aren't dumb questions....but does the wet sanding give you a smoother finish? Are there times that you prefer wet sanding vs. regular?
I appreciate your build threads! I hope you have great thanksgiving!

Rick

NJRick said:

Luke,
this is a great build ......quick question regarding the wet sanding....is there an advantage to wet sanding over regular? do you have to use the plastic backed sand paper? I hope these aren't dumb questions....but does the wet sanding give you a smoother finish? Are there times that you prefer wet sanding vs. regular?
I appreciate your build threads! I hope you have great thanksgiving!

Rick

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Wet sanding is virtually mandatory when you go down to very fine grit sandpapers... otherwise they simply clog the paper so completely they don't sand at all. The moisture provides a lubricant and a solvent to remove the sanded off paint particles and keep them from clogging the paper. As you can see, VERY little water is actually required, as shown in the photos. Given the rather "non-waterproof/non-water friendly" materials we use in LPR, that's why you want to limit the amount of water you use to a bare minimum and be very careful... that's also why I call it "damp sanding" to differentiate it from true 'wet sanding' as commonly done on classic cars and such that have no concerns about waterproofing... You can see for yourself the difference in the finish between the 360 grit sanding I did on the cones dry, and the 440 grit wet sanding. You CAN dry sand with 440 grit, but it really tends to clog up the paper, IMHO. I can do several parts with even a small 2x2-2x3 inch piece of paper using wet sanding, where dry sanding usually completely clogs the paper to the point of uselessness after only one cone. The results speak for themselves.

As for paper, well, wet/dry paper is what you want to look for... backing materials I don't know... I just picked up some paper at Walmart... the stuff I use looks like a paper backing, maybe 'waterproofed' with something...

Later! OL JR

PS... only dumb question is the one that isn't asked...

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

I guess if I could some it up in one word I would say IMPRESSIVE, but your skills go beyond that!! You definitely have talent and your attention to detail is by far one of the best I have seen in any of the build threads...

RocketManDan said:

I guess if I could some it up in one word I would say IMPRESSIVE, but your skills go beyond that!! You definitely have talent and your attention to detail is by far one of the best I have seen in any of the build threads...

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Thanks Dan... Don't give me a big head... everything else is already big enough... LOL Seriously I don't do anything special-- most of the stuff I do I've learned from other folks right here on the forums... I just take my time and don't get in any HUGE rush...

I'd post more about the build, but I'm kinda waiting for paint to dry and stuff... turned cool and quite humid, and I mainly focused on filleting the three bodies together and primered the LAS tower... still gotta sand it down again now, then shoot it with paint.

Just got home from going up to my sister's for T-giving supper... enjoyed the visit, but I think I'm gonna hit the sack. Figure on going to the Texas Renaissance Festival tomorrow so I'll need sleep. Do more build work later...

Happy Thanksgiving to yall!
OL JR

I hope you're going to "flame-up" those fins a bit so they don't look like flower-fins :wink:

Dr.Zooch said:

I hope you're going to "flame-up" those fins a bit so they don't look like flower-fins :wink:

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Yep, I'll give them the "yellow center, white smoke" effect that I did on the last build (SLS) with some success... probably try partial masking this time... the plain old "shoot the edges with white from the rattlecan" didn't work too well...

Later! OL JR

PS. Yeay!!! RAIN! A whole whopping inch or so, but at least it's WET! We'll take anything we can get!