Building the Estes Little Joe II: Tips, Tricks, and Modifications

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James Duffy

Well-Known Member
CRITICAL UPDATE: after this thread was begun it has emerged that adhesive selection on a number of parts is extremely important, so this "read first" note has been attached here. The vacuform body wrap, injection molded fin halves, and injection molded nozzle halves appear to have been molded using acrylonitrile butadiene styrene (ABS) plastic. This particular plastic is somewhat resistant to many traditional solvent cements suggested for plastic model parts, which have traditionally been molded from high impact polystyrene (HIPS). It is critical to select an appropriate solvent cement for certain steps in the build sequence that involve ABS and ABS-to-HIPS bonds, such as the following:

* fin half assembly
* nozzle half assembly
* attaching the launch lugs to the vacuform wrap

Plastruct Plastic Weld has been confirmed to work well on these joints, and can be purchased from most major hobby vendors. Using other solvent cements may result in the failure of these joints, especially the critical lug-to-wrap bond.

http://www.hobbylinc.com/plastruct-plastiweld-1-plastic-model-cement-00002

The capsule, escape tower, and RCS quads all appear to be molded from HIPS, and respond well to traditional model assembly solvent adhesives.

_______________________________

So, the Estes 1/45 scale Little Joe II has generated a degree of interest perhaps not seen before for a model rocket kit, and many of us have started builds. Let's use this thread to share any wisdom gleaned during the process so that everyone can be successful with their kits.

The new LJII kit seems to have a quality not previously seen in a production scale model rocket kit: it combines complexity and accuracy, yet has been engineered for simple assembly and success. So, if you develop any insight that might help others in building their kit, please share it here!

James

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James Duffy

Well-Known Member
In examining the parts and instructions supplied with the kit, it strikes me that filling the spiral airframe tube seam after application of the vacuform wrap would be a fairly unpleasant process. To get around that the initial step in my LJII build is to mask off the lower section of the airframe tube at a point equal to the vertical height of the wrap, followed by the application of primer. The mask point is 7-23/32" (~196.5mm) from the aft end of the airframe tube.

Green Frogtape was used for masking, as was Rustoleum Grey Automotive primer. After the primer has had the opportunity to cure for a few days the surface will be sanded.

James Duffy

Well-Known Member
While we wait for the primer on the airframe tube to dry we can turn our attention to the assembly of the injection molded plastic parts included with the Little Joe II kit. The nozzles and fin parts were not attached to any sprue, but did have some small sprue marks that needed sanding. These parts were then assembled using Plastruct Plastic Weld cement, applied with a small paint brush rather than the large brush attached to the container cap. The RCS quad housings were detached from their sprue, stray flash and sprue marks cleaned up, and assembled. The escape tower aft skirt and nose cone were also cleaned up.

Seams on all of the assembled parts were then sanded using an assortment of sanding sticks sourced from Squadron:

Sanding started with the coarse stick, then moved to progressively finer grits until the seam disappeared. With sanding completed the assemblies were washed with lukewarm water and dishwashing soap and allowed to dry. All parts were then attached to scrap balsa handling sticks for priming. Priming was done using Tamiya White Surface Primer (expensive, but highly recommended!):

Mushtang

TRF Supporter
I've seen a couple of people remark about the big decal wrap that has the black rectangles on it, and how putting such a large decal can be very tricky.

Some have suggested that after painting the rocket white it would be easier to mask off and paint the rectangles black instead of using the decals. I saw on another thread where someone offered a dimension sheet to cut vinyl pieces.

My idea was to cut the black rectangles from the decal sheet and apply them to the gloss white paint separately instead of all on one piece. It would require some measuring and marking, but might be easier than masking. I've never applied vinyl so I can't comment on how that compares.

James Duffy

Well-Known Member
This next tip is COMPLETELY counterintuitive, so hang with me...

Nothing is trickier to paint than a metallic surface, so chintzing out on paint is probably not wise. Over the years the Tamiya spray lacquer paints have always yielded great results for me, and their gloss aluminum color is probably the easiest way to get a realistic metal finish simply and quickly. The trick is to spray a gloss black layer before applying the final aluminum color. The fins have already been primed with white primer, so next we'll shoot on some black lacquer

The primed fins will be allowed to dry for at least 24 hours before shooting on the final gloss aluminum color.

Closing comments on the Tamiya spray lacquers: they are expensive, but nothing will give you better results easier, more reliably, or more quickly. In addition they dry very fast, requiring only 5-10 minutes between coats, and any unpleasant odor dissipates within minutes. I can't recommend them highly enough.

James

http://www.hobbylinc.com/htm/tam/tam85014.htm
http://www.hobbylinc.com/htm/tam/tam85026.htm
http://www.hobbylinc.com/htm/tam/tam85017.htm

georgegassaway

For those who want to reference more information, photos, and drawings of the Little Joe-II&#8217;s, here is a reminder of the link on my website:

http://georgesrockets.com/GRP/Scale/DATA/LJoeMain.htm

NOTE: Except for material by others, the drawings, personal photos, and other information I write are copyright and not to be posted elsewhere without permission.

Every Little Joe-II was different!

Much of the information on my site is based on the Little Joe-II data that Tom Beach and I did for the May/June and July/August 1991 issues of the NAR&#8217;s American Spacemodeling magazine (Now Sport Rocketry Magazine, with Tom Beach as editor). There is more data on the site than the magazines had, including data for the launcher, photos the magazine did not have room for, and more photos found online since 1991.

For those who do not know, the Estes 1/45 kit is mostly an updated re-release of the classic Centuri 1/45 scale kit that went OOP in 1977. It uses the same injection mold for the Apollo capsule/LES tower parts. It is improved by replacing the printed mylar wraps, which wrinkled over time, by a detailed vacuformed wrap. Also, injection molded parts such as fins and fairing assemblies that are easy to build, and Algol nozzles suitable for flight rather than paper cone removable display nozzles the Centuri kit had. I still have my 1/45 model, built in 1975, but wow is it wrinkled and badly worn. I got it at a local hobby shop where the owner offered to sell it to me ($17.95 catalog price) for$5 because the box had been opened (!!!). Turned out that everything was there. Otherwise I might never have had the 1/45 kit (I did have the 1/100 kit, as my 5th-ever model rocket and first to use balsa fins). Here is the first appearance of the Centuri Little Joe-II's in the 1969 catalog:

The Estes kit not only acknowledges the Centuri heritage by including a photo on the box of the original Centuri 1/45 kit box, but also the excellent Little Joe-II Historical Brochure that was included with the Centuri kits.

As with the Centuri 1/45 kit, this kit models the versions which had moving elevons and long fin root fairings, as the last two Little Joe-II missions used: A-003 which rolled out of control and broke up, causing a REAL abort that safely returned the capsule, and A-004 which did a planned high angle of attack abort and was a total success. The drawing below shows those two, plus A-002 which used the original shorter Fin Root Fairings.

Note that among some differences, the A-003 SM was shorter and used Six Algols (3 at liftoff and 3 that were supposed to air-start), and A-004 which flew a structurally "real" (but empty inside) Block I Service Module and real Spacecraft (SC-002), launched with four Algols (2 at launch, 2 air started), and five small Recruits (3 in center and one in each of the two remaining outer engine bays).

For FAI scale (S7), which requires a one-to-one &#8220;workshop drawing&#8221; of the model, I compiled drawing files to create a 1/39.5 drawing for A-004 which includes rollouts. Link to it is here:

http://georgesrockets.com/GRP/Scale/DATA/Joe_GIFs/LittleJoe-FAI-1-39.5.gif

I realize most will want to build the kit without messing with extra scale details, and that&#8217;s perfectly fine. I just want to make sure everyone reading this knows there is more info available if they chose to either do more or to make some minor mods to reflect a specific mission. As it is, the kit mostly represents A-004 more than A-003, except A-004 did not have Six Algols. Also, the capsules were not smooth, they had Boost Protective Covers over the capsules (BPC&#8217;s) with some detailing. Those covers came off of the capsule when the tower was jettisoned. When I built the Centuri 1/45 kit in 1975, I knew little to none of that. Nor do I fault this kit for not having BPC detailing, especially by re-using the original molds.. The &#8220;smooth capsule&#8221; is therefore a good &#8220;canvas&#8221; for anyone who wants to model other missions and make up the BPC detail that applies to the three that had BPC&#8217;&#8217;s, A-001 which had no BPC but SOME surface detail, and QTV which had no surface detail other than the two narrow vanes.

For building the kit, here are the glues I have used:

Testor&#8217;s Tube Cement (the jelly-like kind in a red squeeze tube)
Plastruct Plastic Weld Liquid Cement (water-like). Tenax 7R also is good. Testor's liquid cement not as good but useable.
Elmer&#8217;s Wood Glue (was out of Titebond)
Thick CA (Foam Friendly, odorless preferred but any thick OK)
5 Minute Epoxy

And now on to the build!

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georgegassaway

First, I want to stress that everyone has different ways of building the same kit. So whatever I mention, is what I chose to do, not the only way or best way. And if I was building this kit for a serious scale model, I would do some things differently and also be aggravated by every &#8220;oops&#8221; that happens. So I&#8217;m building this as a sport model without a lot of intense work or time put into it, so I&#8217;ll feel more free to sport fly the heck out of it as I did with my old 1/45 Centuri model.

But of course, some of the methods I mention may be of use to others. And the discovery of some issues requiring more care, or a workaround, or at the least, awareness.

Now to start from the instructions. For those who do not have the kit yet, or want to review on a computer screen, a PDF copy of the instructions are on the Estes website: http://www.estesrockets.com/media/instructions/007227_LITTLE_JOE_II.pdf

Assemble Main Body Tube, page 2 to 3:

For the Main Body steps, it may be useful to print and refer to this drawing, taken from the FAI 1/39.5 drawing for A004, showing the body rollout.

For more details, see other drawings on my site, especially these:

http://georgesrockets.com/GRP/Scale/DATA/Joe_GIFs/Body-Details-1.gif

http://georgesrockets.com/GRP/Scale/DATA/Joe_GIFs/Body-Pattern.gif

http://georgesrockets.com/GRP/Scale/DATA/Joe_GIFs/Joe-Side-Bottom.gif

http://georgesrockets.com/GRP/Scale/DATA/Joe_GIFs/Body-Details-2.gif

I do want to make note that, from what i can tell, there is an error in the corrugated wrap regarding the orientation of the 120 corrugations (3 degree spacing between corrugation centers). On the real thing, the RECESSED parts of the corrugations are centered on the axes, so the fins, longerons and X-Y axes are centered on recessed corrugations. On the body wrap, they are centered on the flush (positive) corrugations. Due to the fin alignment and gluing lugs on the wrap, it is not very practical to try to shift everything 1.5 degrees left or right to match. Of course, no kit has EVER tried to do those 120 corrugations accurately, and the old Centuri 1/45 kit&#8217;s mylar wrap wrinkled over time, so I&#8217;m not complaining. I just want to make people aware of the situation, why the scale drawings show the corrugations one way (recessed corrugations) and the kit is the other way (positive corrugations).

Step 1 - In preparing the body tube, I marked a lengthwise reference line with a pencil. I used the body wrap to mark off the distance to where the top of the wrap would be. Then I wrapped a piece of paper around the body tube, using tape to keep it rolled together like a slip fit tube. Slid it to the correct location then used a pencil to mark where the top of the body wrap would be.

Step 2 - The gap cut from the short tube (H), needed to be more like 1/8&#8221; than 1/16&#8221;. The purpose of that tube is structural, because the lower part of the vac-formed corrugated wrap leaves about a .015&#8221; gap between the tube and underside of the wrap. Later, a similar spacer (custom-made) was added for the top, see step 4.

Step 3 - Used Elmer's Wood Glue to glue the short tube in place.

Step 4 - As the short tube at the base dried, I added a step. The top of the body wrap will have a gap of about .015&#8221; between the body tube and the top of the wrap. So, I filled it with a 1/8&#8221; strip of .015&#8221; plastic. Poster paper would also be an option, that is about .015&#8221;. What I did was apply 1/2&#8221; double-sided tape along the side of a sheet of .015&#8221; plastic, then used a metal ruler as a guide to cut the plastic to 1/8&#8221; wide. I later wished I&#8217;d cut it to 3/32&#8221; wide. In the photo below, a 1/8&#8221; wide strip is shown held by hemostats&#8230; i was originally going to use a spray adhesive. After the pic was taken, and changing to a plastic strip with double sided tape, then the strip was applied to the tube , to fill the gap that the top of the corrugated wrap would otherwise leave.

Step 5 - I used 3M Super 77, sprayed only on the wrap. Waited about 2 minutes, it was still a bit tacky, and applied it to the tube. It was not perfectly aligned. I went with it as it was. Strangely, the seam had the edges nearly touch at the top, but there was a little bit of a gap at the bottom. I added pieces of Scotch Tape to help hold the seam tight.
UPDATE - James Duffy found out why the seam was wider at the bottom. Rather than scoop his discovery and solution, I'll let him explain it in one of his updates.

Step 6 - Let dry. A step I wish I had done was to use some CA along the seam to help make sure it stayed secure.

Step 8 - Used the top view on the bottom right of page 3 to find where to locate the long system tunnel. I had expected the tunnel to be placed equally over the seam, but the drawing showed to locate the tunnel left edge on the top of one corrugation and all the rest to the right of the seam. I marked where to place them using a pencil (I used a pencil to mark where to place al the other pieces too). Glued the long tunnel in place using Testor&#8217;s tube cement , applying mostly in the middle so as not to squeeze excess out to the sides. Same for the short tunnel on the other side

Step 9 - Found out later that the edges of the wrap seam peeled up a bit at the top. Applied some thick CA underneath and held in place. Mostly fixed it, but not as good as if I had done the CA before gluing the long tunnel on.

Step 10 - After using the placement guide and marking with where they went, used Plastruct Liquid Cement to apply the tall Longerons (N) and short Longerons (O). Note which way they go, wider end near the bottom!

Step 11 - Used liquid cement to attach the Mini-longerons. I used self-closing tweezers to hold them and put into place. For some silly reason I put them mid-way on the base strip and not even with the bottom like they should have been. Ah, the joys of building this as a lower-key quick sport build&#8230;.so that is an &#8220;oops&#8221; and not &#8220;@#\$%&*!!&#8221;

So, main body wrap and details done. In the image below, bottom centering ring and a couple of Algol nozzles temporarily in place, not glued

End of this chapter. Next time, attaching fins to the body.

- George Gassaway

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samb

Wow ! THIS is a build thread. Thx

James Duffy

Well-Known Member
UPDATE - James Duffy found out why the seam was wider at the bottom. Rather than scoop his discovery, I'll let him explain it in one of his updates.
As George mentioned, the "short tube" serves to fill a gap between the inner surface of the vacuform wrap and the surface of the airframe tube. However, the thickness of the short tube is just a little too thick, preventing the ends of the vacuform wrap from meeting accurately at this point.

The fix is to carefully reduce the thickness of the short tube by carefully removing layers of the paper convolute. Start by inserting a blade tip under the surface of the smooth glassine layer and peeling it away. Dry-fit the vacuform wrap again and check the gap. It probably won't be quite right but it will be closer, meaning we're headed in the right direction. Repeat the process with the outer layer of the tube paper and check again. Repeat the process until the fit of the vacuform wrap over the short tube is acceptable. Here's what the short tube will look like after the glassine layer has been removed:

On my model the process required the removal of the glassine layer and two underlying paper layers to produce the following fit:

The thickness of the short tube was reduced to roughly .015", allowing a perfect fit. Later today I'll add a styrene strip to the airframe tube at the location of the forward end of the vacuform wrap.

NOTE: peeling layers of a standard Estes tube is easy, but practicing on a piece of scrap material first is highly recommended!

More later,
James

rocketguy101

Well-Known Member
As George mentioned, the "short tube" serves to fill a gap between the inner surface of the vacuform wrap and the surface of the airframe tube. However, the thickness of the short tube is just a little too thick, preventing the ends of the vacuform wrap from meeting accurately at this point.

The fix is to carefully reduce the thickness of the short tube by carefully removing layers of the paper convolute. Start by inserting a blade tip under the surface of the smooth glassine layer and peeling it away. Dry-fit the vacuform wrap again and check the gap. It probably won't be quite right but it will be closer, meaning we're headed in the right direction. Repeat the process with the outer layer of the tube paper and check again. Repeat the process until the fit of the vacuform wrap over the short tube is acceptable. Here's what the short tube will look like after the glassine layer has been removed:

View attachment 281064

On my model the process required the removal of the glassine layer and two underlying paper layers to produce the following fit:

View attachment 281065

The thickness of the short tube was reduced to roughly .015", allowing a perfect fit. Later today I'll add a styrene strip to the airframe tube at the location of the forward end of the vacuform wrap.

NOTE: peeling layers of a standard Estes tube is easy, but practicing on a piece of scrap material first is highly recommended!

More later,
James
James, do you know what the final thickness of the short tube is after peeling? It might be simpler to cut a strip of cardstock (~0.005" thick) and wrap that around vs. slitting/peeling a body tube. Also I have seen a picture posted somewhere that the top of wrap has a gap between the tube that needs to be filled...did you find that to be true

James Duffy

Well-Known Member
Next time, attaching fins to the body.
Here's a minor point where careful readers will note a slight difference between the paths taken by George and I. George has elected to attach the fins to the airframe early in the build sequence, simplifying paint application. I have chosen to defer fin attachment until the end of the project, which will simplify detail painting and decal application. Neither approach is "better" than the other, but rather a matter of preference.

Speaking of fins, they have been sprayed with Tamiya TS-17 gloss aluminum lacquer:

James

James Duffy

Well-Known Member
James, do you know what the final thickness of the short tube is after peeling? It might be simpler to cut a strip of cardstock (~0.005" thick) and wrap that around vs. slitting/peeling a body tube. Also I have seen a picture posted somewhere that the top of wrap has a gap between the tube that needs to be filled...did you find that to be true
You are correct, it might be simpler to ditch the short tube supplied with the kit and substitute a strip of cardstock or styrene. The correct final thickness on my kit was .015".

There is indeed a similar gap at the top of the tube, and I'll be documenting the fix for that in a later post (today, I hope).

James

James Duffy

Well-Known Member
The upper section of the airframe tube was primed with automotive primer in an earlier step. Before beginning this step the masking was removed and the primed surface sanded with 400 grit sandpaper.

Next up is a fix that will prevent a gap between the airframe tube and the back of the vacuform wrap at the forward end of the vacuform wrap. To do that we'll be attaching a 3mm wide strip of .015" thick styrene sheet to the airframe tube at this location. First, we cut the strip from a larger sheet of .015" styrene sheet:

Next the styrene strip is positioned on a piece of double-sided tape (I used 3M Type 465, but any variety should do). Excess tape is trimmed away from the perimeter of the styrene strip.

The backing is removed from the double-sided tape, and the strip is positioned on the airframe tube.

The styrene strip is slowly and carefully wrapped all the way around the airframe tube.

We now have both upper and lower strips in place to augment the circumference of the airframe tube to optimize the fit of the vacuform wrap. Take some time to dry-fit the wrap, rehearsing the process before adhesive is used.

Next step: attaching the wrap into place!

James

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James Duffy

Well-Known Member
I suspect that lots of folks are looking over their Little Joe II kits and stressing about the wrap attachment step. It really isn't difficult at all, but turns out best when a bit of planning and practice has taken place. If you have done the suggested prep work to the aft short ring and added the forward styrene ring everything should turn out well.

We'll be using 3M High Strength 90 adhesive for wrap attachment. There is no requirement to use this adhesive! Others, including George elsewhere in this thread, have used the 3M Type 77 adhesive with great success. Type 90 is a sprayable contact cement that will allow a bit of repositioning time, but will cure quickly. Both the interior surface of the wrap and the outer surface of the airframe tube will be sprayed with this adhesive, so you'll need to mask off the upper Service Module section of the airframe. I have also masked off the internal surface of the tube to catch any overspray.

Next both surfaces are sprayed with the adhesive. The 3M 90 adhesive comes out with a splatter, yielding a web-like appearance that may lead you to think that something has gone horribly wrong. Don't worry, that how the stuff works.

Let the parts set for 5-6 minutes, allowing the solvent to flash off. An easy test to know when the surfaces are ready is to press a knuckle into some overspray. When your knuckle comes up clean without any solvent, you're ready to move on.

Carefully attach one edge of the wrap along the reference line drawn on the airframe tube in step one. Slowly work the wrap around the tube. If you find a misalignment, just gently peel up the wrap and start again. Eventually you'll end up back at the reference line with a well-positioned wrap.

That's it! Let things settle for a couple of hours, and if an edge threatens to pull up you can fix it with a tiny bit of thin CA wicked under the edge. At this point I elected to test fit the long cable raceway to get a preview of how things would look with the seam hidden.

Next, we'll attach the injection-molded lower airframe details using the procedure described in the kit instructions.

James

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MALBAR 70

Build Mode Activated
Thanks James and George, I was wondering how I was going to get rid of the gap in the wrap. I'd already glued the small ring on so I had to carefully peel it down. The wrap fits much better now.

georgegassaway

Assemble Engine Mount - Page 4

Step 1 - Cut out the rings as in the instructions, but did not remove all of the discs for the outer holes for the Algols. This is because I am going to do A-004 nozzles (Four Algols), and may leave two of the disks in place for mounting a custom-made Recruit in each one.

Step 2 - The lower pair of discs were slightly curved, and any white glue will shrink some and promote warpage. So, I used 5 minute epoxy to bond the two discs together, laid onto a sheet of waxed paper. I oriented them as much as I could so that warped curve faced warped curve, so that the two would hopefully cancel the curve out after gluing. I carefully inserted two Algol motors in opposite holes to hold the rings aligned, and pressed onto the rings to hold them flat while the epoxy cured. This is so that the ring hopefully will be flat, as a warp would make it look funky.

Step 3 - Also used epoxy to glue the two upper centering rings together (open-web and solid disc). And temporarily inserted a 24mm tube into the center hole to assure alignment while it cured.

Step 4 - After both sets of rings were cured, they fit a bit too tight onto the 24mm engine mount tube. I wrapped some scrap sandpaper into a narrow cone and twisted it inside of the hole to enlarge the hole a little bit for a nice slide fit as well as to de-burr.

Steps 5, 6, & 7 - Marking engine tube, attacking engine hook, and gluing on external collar tube to secure the hook, done as in the instructions.

Step 8 - The ejection charges for D12 and composite motors are so hot that they eventually fry engine mount tubes that extend beyond the thrust ring. So, I cut a piece of 24mm tube coupler to glue inside in place of a thrust ring. This way, the heat has a lot more to burn thru. I have found that applying some thin CA to soak inside of the coupler will help to reduce burn damage. If a step like this is not done, then eventually, after a lot of flights, the whole engine mount tube ahead of the ring will have burned apart from repeated ejection charges, and only be held by the aft centering ring.

As I type this, I have not completed the engine mount assembly, so will have to update later. I am still using the rings temporarily with a longer tube to hold the model for painting. When I am done with painting the main body, I will paint the rear ring flat white, to simulate the white RTV that was applied as heat protection to the bases of A-002, A-003, and A-004, then glue the mont assembly together. I will also add either a wire cable shock cord mount to the upper ring, or some very strong Kevlar cord, which will later have 1/4&#8221; elastic tied to the other end for the real shock cord.

For those who may be building before I complete the mount, I want to note that the engine hook&#8217;s rear extension sticks down far enough that it will not allow the model to sit flat on the 4 fins. So, after the above photo, I used a Dremel cut-off wheel to remove most of that extension, leaving about a 1/16&#8221; long stub, rounded off to remove sharp edges. Before & After pic

Of course&#8230;. it is best to have a display stand for the model, not stand it on the fins. But a display stand is not always available.

When I do glue the engine mount in place, I will use 5 minute epoxy. Not Elmer&#8217;s, Titebond, or any water-based glue as those tend to shrink as they dry, which can cause the body tube to shrink where the centering rings are.

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georgegassaway

Fin and Nozzle assembly (Page 4)

Step ZERO - There are some circles sticking out (inwards), probably where the ejector pins are located in the mold. One in the lower bay, and two a couple of bays up (to the right in the photo). They interfere with the fit of the alignment and glue tabs on the body wrap, try to push the fin assembly away. So, I recommend carefully cutting out those circles (6 per fin assembly), at least for the depth needed to no longer interfere. I did not trim them until after they were glued because I did not find this problem earlier. But it would be better to trim them before gluing the fin halves together.

In the image below I played with the contrast and brightness to make those other two circles more visible.

Step 1 and 2 - I carefully used liquid cement to attach the fins together. Be careful not to let any run in the wrong place! What I ended up doing was to only apply liquid cement to the halves of the fin item, the leading edge, trailing edge, and tip, and using the brush i na way so that any excess wild get on the inside, not the outside. I did not apply liquid cement to the Fin Root Fairing portions at first, in order to be able to apply the glue to the other areas and press the halves together before the liquid cement dried too much. After that, then I went back ,and carefully on the INSIDE of the assembled fin, applied liquid cement along the seams of the front half one fin root fairing as well as other seams on the inside that had not bene glued before.

After allowing time for the glue to dry completely, I used some 600 grit sandpaper to carefully sand along the outer seam of the front of the fin root fairing, the tip of the fins, and trailing edge of the fins. This was to reduce the visibility of the seam. But I didn&#8217;t go to extremes to try to totally get rid of the seams, just to clean them up. Later I finished off with some 1000 grit. I will note that there are some sunk-in spots on the fins that some builders may want to apply putty to, and sand to get a smooth uniform surface.

Step 3 and 4 - The nozzles were simpler to glue. I just pieced each half together, and applied liquid cement to the inside. It wicked into the seam to bond the halves well. As I type this I have not done anything else with the nozzle, probably will sand the same a bit with 600 and 1000, but not go as far as I would if I was doing a model for judging.

For those considering clustering, I found that an 18mm motor won't fit inside the Algol nozzle assemblies. So if someone wants to cluster 18mm in the outer 6 Algol locations, they either need to make up some custom nozzles (could be cardstock) that are reasonable without being too big looking (and perhaps also simulate the dark covering over the throat region), or make those nozzles removable for display only.

Now, 13mm motors will fit inside of the Algol nozzles, see picture with 13mm tube. However, any model that used 13mm motors would need a big engine in the center to fly properly.

Fin Attachment (Page 5)

John Boren provided a link to this Top View which can be printed out and used to check that the fins are aligned properly: http://www.rocketryforum.com/attachment.php?attachmentid=280780&d=1453847413

Step 1 - With the ejector pin circles trimmed, the fit of the fins was good. I used Testor&#8217;s Tube glue, applied mostly to the inside of the bays that touch the alignment and gluing tabs. I also applied tube glue across horizontal parts of the root area. Was careful not to let any ooze out.

I held the first fin in place, double-checking to make sure that the curved part of the base of the fin root fairing had no gap on the left or right, that it was flush to the curved base of the body wrap. I waited several minutes for the glue to set up, holding it while I watched TV. When it had dried enough, I glued the second fin on, 180 degrees apart. I did the same sort of visual check, but now with two opposing fins on I could look down the trading edged of both fins to see if they were parallel to each other (the middles parallel), and did make an adjustment when I saw one was a bit off.

When I glued the third fin on, and held it long enough to be decently set up but still possible to adjust, then I was able to use the top view printout.

I placed the model on it, to see if I needed to adjust the position of any of the fit, especially the newest one. They were fine. Then the last fin, same method, holding it several minutes, then placed it onto the printout. Did need to make a tiny tweak. Once tweaked, I held it again for awhile, rotating it slowly. When I was ready to set it down for good, I turned it upside down to be supported by the top of the Service Module. If I had set it on its fins, that would have applied some stress that could have caused the fin glue joints to shift a bit.

Launch Lugs - Attached carefully using Testor&#8217;s Tube Glue, as described in the plans. Make sure of course that they are aligned to the same corrugation and not tilted either.

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georgegassaway

Capsule Assembly, Page 6

Step 1 - Used liquid cement to bond Escape Rocket nozzle halves "Y" to each other. The nozzle halves do not have alignment pins, so before the cement sets, move them until both nozzles lower edges of the halves are as even as possible.

Step 2 - Same process as above for the other set, "Z". In the image below, both sets have been glued but are a bit rough.

After the sets dry fully, use a model knife to try to scrape excess plastic along the seam away, on mine there was a pretty good bit of unevenness that required scraping to get it close. Also, use a knife to scrape away flashing and other excess plastic that may be along or inside of the nozzles. I also used a sanding block on the bottoms of the nozzles to get them cleaned up. Then, back to the seams, use sandpaper, I used 400 grit along the seam edges, later used 600 grit. Also used a rolled-up cone of sandpaper twisted back and forth inside of the nozzles.

Step 3 - The set I had, would not fit together all the way. I had to do some trimming with a model knife to enlarge the slot in the &#8220;Z&#8221; nozzle set. Also had to do little bit of trimming on the &#8220;Y&#8221; nozzle set. Finally got them trimmed so that they would fit together with all 4 nozzle edges touching the table top evenly. I then used liquid cement to permanently join them, and let dry (step 4).

New Step - I cut a hole into the tip of the nozzle assembly and temporarily glued a 1/16&#8221; dowel into it. I painted the nozzle assembly flat black. Also,worked on the LES skirt (Part DD). After trimming away sprue and sanding a bit to remove a bump, I masked off the front end that fits inside of the Escape Motor tube, attached a balsa handle, and painted the LES skirt flat black. After drying, I removed the dowel for the nozzle assembly and sand off some of the paint to get to bare plastic. For the LES skirt, I used a 3/16&#8221; drill bit, by hand, to scrape away paint deep inside to get to the raw plastic.

After checking to be sure it fit well, I applied some Testor&#8217;s Tube glue deep inside the LES skirt, along the bare plastic, and put the nozzle assembly in place. I checked the alignment to make sure the nozzles were equally spaced (and 45 degrees ot the tower leg locations) and let dry.

Purpose for doing this is that the LES nozzles and skirt are flat black. So it is a heck of a lot easier to paint them first, then glue together, than to assemble the whole capsule/LES and try to mask everything off.

TOWER assembly

Step 5 - I used liquid cement to attach tower part AA (no legs) to part BB (two legs). First applied the liquid cement to the areas with locator holes in part BB, then moved AA into place and let the liquid cement do its thing. In one spot I had to force the top of an AA strut into the hole in BB and hold it there till it set up better. I checked that the parts were at 90 degrees, and let set up for awhile. Later, I came back and applied more liquid cement to those areas, including the lower diagonal strut that has no locator pin or holes, allowing the liquid cement to create a proper bond at all the joints. Do note there is a fine line between adding liquid cement that improves the joint, and applying too much too soon such that the liquid cement acts like a &#8220;debonder&#8221; so the parts begin to loosen up.

I REPEATED step 5 with the other pair of AA and BB struts, instead of doing it the way shown in step 7, so I had two identical sets of half-built towers.

Step 6 - Added the ring strut (CC) to two of the &#8220;X&#8221; struts in one of the assemblies.

Step 7 - revised as per the end of step 5 above. Applied liquid cement to the locator holes of both parts BB, and put into place, making sure the pins were aligned and that the ring strut was also connected properly. Later, applied more liquid cement to improve the joints, and also to the areas of the ring that had not been glued. So, then the tower was complete. The photo below was taken before before the nozzles were glued to each other, shortly after they were cleaned up.

Steps 9 thru 12, not done yet, and step 13 already done (gluing nozzles into LES skirt). When I do put nose weight into it, I am going to use something denser, such as 1/8&#8221; diameter plumber&#8217;s solder, or Lead Shot. Reason for that is that clay is not very dense. I think that enough nose weight can be added to the Escape Rocket to not require any nose weight inside of the Capsule. I have seen bad results when nose weight is inside of a capsule and its lands hard nose-first, the mass of the capsule having a pile-driving or hammer effect on the tower assembly. Also, the nose weight is more effective that way, either the model will need less overall nose weight, or for the same total nose weight it will be more stable.

And anyone who clusters, or uses a reload, or does anything else to make it heavier in the back, you are going to HAVE to add more noseweight!

Step 15 - I put the LES Tower into place on the capsule without applying any glue. Turned the capsule upside down, and applied liquid CA on the inside, brushing the liquid cement into the joint of the holes and the protruding parts of the LES struts. Made sure that the tower was even before the glue set up. Later, on the inside, applied some Testor&#8217;s Tube glue along the joints to back up the liquid cement glue.

So, this is the current Capsule , Tower, and LES status:

Step 16 & 17, not done yet. I need to paint the Capsule/Tower flat white first. When ready to glue the LES skirt on, will scrape paint from the top 1/16&#8221; of the tower legs, and use a small drill bit to remove any remaining black paint from inside of the holes in the LES skirt, then apply Testor&#8217;s tube glue and put the LES rocket in place. I&#8217;ll have the rest of the LES rocket tube on temporarily, so I can rotate the whole assembly and make sure it does not wobble around as I rotate it. Otherwise, tweak it until it does not wobble when rotated, and let dry.

Next time..... body painting. And hopefully something gets some markings...... not sure what or how many yet

- George Gassaway

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K'Tesh

OpenRocket Chuck Norris
Man I am loving this build thread guys! Thanks!

JumpJet

Well-Known Member
Please don't forget to put the clay inside the escape tower tube before gluing it in place. This model needs all the weight up front it can get.

John Boren

tab28682

Well-Known Member
Please don't forget to put the clay inside the escape tower tube before gluing it in place. This model needs all the weight up front it can get.

John Boren
Not going to use clay for the nose weight. Not real compatible with the hot Texas sun. But will add the appropriate amount of something denser that is not prone to melting when fresh or drying out and getting crumbly when old.

georgegassaway

Please don't forget to put the clay inside the escape tower tube before gluing it in place. This model needs all the weight up front it can get.
Defintely. Always good to be reminded of that. As I said I am going to use something denser, like surplus 1/8" plumbing solder or lead shot, to try to concentrate mass in the Escape Rocket tube since that is more forward of the CG and more effective (so hopefully no weight needed for the capsule). I'm going to complete the model before gluing the tube on, and check the CG location with engine and such, and add enough dense noseweight into the tube to be sure it is stable.

Nice find. That one is at Johnson Space Center. It is a 12-50 series, with a Block-II SM and the actual BP-22 capsule flown by A-003. Several oddities about it (12-50 series had fixed fins, Block-II SM was never flown on a Joe). So for anyone who might use photos from that as a reference for building, here is an excerpt from Tom Beach&#8217;s article, mentioning the remaining Little Joe-II&#8217;s:

Remaining Little Joe II Hardware

A total of eight Little Joe II vehicles were built by General Dynamics. Airframes 12-50-3, 12-50-4, and 12-51-4 were not flown and two of them still exist on display. One of the 12-50 series vehicles is on display at the Lyndon B. Johnson Spaceflight Center near Houston, Texas. The vehicle is sitting on the Little Joe II launcher used in White Sands, and is mated with the Boilerplate capsule BP-22 (flown on A-003), a Launch Escape Tower, and a Block II Service Module. Strangely, the vehicle is not equipped with the fixed fins that would be expected on a 12-50 series model, but instead sports the movable-elevon fins and the lower part of the fin-root fairings that belong on vehicle 12-51-4. A bit confusing, but still an excellent opportunity for photographing details of the body, fins, and fairings (as long as you understand the situation). The short wiring tunnel cover plate is not on the aftbody. The roll patterns on the LES and SM are incorrect, and the CM lacks a Boost Protective Cover. Because the vehicle is sitting atop the launcher, modelers cannot reach it to make measurements.

Little Joe II number 12-51-4 is on display at the International Space Hall of Fame Museum in Alamogordo, New Mexico, topped by a Block II SM, dummy capsule, and dummy escape motor. A set of fixed fins and just the tops of fin-root fairings (the bottoms of which are on the Houston Joe) are mounted on the vehicle. The display provides excellent photo opportunity for those interested in body details and fixed fins, and the vehicle is mounted low enough to allow measurements of the bottom sections.

The Boilerplate BP-23 Command Module (flown on A-002 and Pad Abort-2) is on display at Marshal Space Flight Center at Huntsville, Alabama. It lacks a BPC and has an incorrect paint pattern, but the LES tower framework and the lower part of the LES motor provide useful scale data.
Very sad thing is that there was a third left over Little Joe-II, one of the 12-50 series, which cannot be accounted for. It was built though, so apparently it was scrapped.

A composite image of the JSC Joe and Alamogordo Joe.

UPDATE - There are many internet sources for photos of those two Little Joe-II's on display, practice your Google-Fu. Here is just one such example, many pics of the JSC Joe.

https://commons.wikimedia.org/wiki/Category:Little_Joe_II_rocket_on_display_at_Johnson_Space_Center

As for the image below, it is one I shot last summer on the way to NARAM. Some detailing near the bottom of the Alamogordo Joe. And for QTV and A-001, that is exactly what the fixed fins looked like when attached. No fairings, those open slots and gaps for bolting the fins on, were left open in the breeze, not covered in any way. More "fun" for building accurate QTV and A-001 models.....

- George Gassaway

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tab28682

Well-Known Member
Defintely. Always good to be reminded of that. As I said I am going to use something denser, like surplus 1/8" plumbing solder or lead shot, to try to concentrate mass in the Escape Rocket tube since that is more forward of the CG and more effective (so hopefully no weight needed for the capsule). I'm going to complete the model before gluing the tube on, and check the CG location with engine and such, and add enough dense noseweight into the tube to be sure it is stable.

.............
George, any worries about having all the denser weight up in the escape rocket and having that entire escape rocket assembly being snatched right off the capsule with a hard opening chute? I was still leaning towards having some of my (not clay) weight in the peak of the capsule, for security reasons. In fact, the extra nose weight for a possible RMS 24-60 launch with mine will be in the peak of the capsule on a temporary basis, for sure.

Certainly there are ways to mitigate this possible issue with a good shock cord and recovery setup. Might be worth having a separate shock cord from the chute to the capsule and then another one from the capsule to the airframe.

I know it is not much of an issue, if any at all. with the stock amount of nose weight with John proofing the models.

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georgegassaway

George, any worries about having all the denser weight up in the escape rocket and having that entire escape rocket assembly being snatched right off the capsule with a hard opening chute?
Well, I can see your concern but that would have to be quite a hard shock and a very high speed deploy that ought not to happen unless the delay is way long, the model weathercocks badly, or something else it wrong.

The opening shock is mostly axial load. I can see though that the usual attachment method along the inner wall of the CM Capsule does introduce a side force that could try to snap the joint.

I WISH I had a 36" flare parachute, like Estes used to sell in the 1970's (I see them on eBay but wow they are pricey). Those chutes are light and thin, the typical 36" hobby rocketry parachute is way thicker, overkill, heavy, and take up too much room. I used that in my 1/45 model, it landed slowly, yet the chute opened slowly too, no big shock. What I will probably do with this new model is to use a Semi-Drogue set-up. 18" chute to the Apollo CM/LES, and 24" chute on both the Joe body and the Apollo CM/LES, on a long shock cord.

The Semi-drogue being that the 18" chute is packed last, inserted last, so at ejection when the nose comes off, the 18" chute comes out first and will deploy, and in the process, acting like a drogue, yank the main (24" or more) chute out in case it did not get ejected out.. I do that with nearly all my scale models and larger models. The photo below is my 1/39.5 Little Joe, using IIRC an 18" chute plus two 24 or 30" chutes. Now, normally I had the two main chutes with longer shock cords of their own, not connected together like that. In any case, a good photo showing semi-drogue in operation.

Also, BTW, I tightly wrap the lines around the chutes. So, the lines have to unwrap, usually delaying deployment a bit.

And now for something completely different.

I laid down some yellow masking tape on a body wrap from a second kit, so it could be removed later without damage to the wrap. CA&#8217;ed some 1/8&#8221; thick balsa to the tape to create a &#8220;dam&#8221; around all the edges. Mixed up some RTV rubber as used for making molds for casting, and poured it in so as to make a rectangular RTV negative mold of some of the corrugations.

Other than James Duffy and John Boren, anyone want to guess why?

- George Gassaway

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Mushtang

TRF Supporter
Other than James Duffy and John Boren, anyone want to guess why?

- George Gassaway
Are you making the radiator panels for the outside of the Service Module?

JumpJet

Well-Known Member
having that entire escape rocket assembly being snatched right off the capsule with a hard opening chute?
Not saying in can't happened but of all the flights we've put on test models, it's not happened yet.

John Boren

georgegassaway

Rocket Finishing, Page 8

Step 1 says to use white primer until smooth. Any use of primer on tubes ought to be done before any work with the tubes, such as primer on the Service Module area if the SM is to be painted, and the LES motor tube.

Also, my personal preference is to avoid using primers on white plastic detailed parts. As the primer will fill in some details and cause some detailing to lose sharpness. So if I did use any primer on detailed parts, I would use model-type primers which have finer pigments and go on finer/thinner. Best of all would be to airbrush fine coats of any primers. But even if I was going all-out on this, I would not use any primer on the Little Joe body. I would only use a non-buffing aluminum metalized lacquer, as I&#8217;ve used for past contest models without using any primer, keeping the details crisp.

So, choices for paint needs to be planned out before starting the build. Or else you might get too far down the road to do some of the steps more easily. For example, you'd want to do any priming, and paint the Algol nozzles the two colors (white nozzles and dark gray covers) before gluing the nozzles on after the rest of the main body painting was done.

That said&#8230;.

I painted the body, using my new DIY Spray Paint Booth for its first real model.

I did not install the engine mount because the bottom ring will be painted flat white to represent the white RTV coating applied to the base due to the greater heating of the later flights. So, the rings were used temporarily with a longer 24mm tube. The SM was masked off, and rear portion of the inside of the lower tube was masked off

For painting, I used Krylon metallic silver. I had done a test spray that looked OK, better than Testor's Silver had tested, but am not happy how it turned out on the model. So I do not recommend it.

What worked great for me in the past was SNJ Aluminum, and later Model Master Metalizer lacquer, the non-buffing Aluminum.

But they come in expensive little bottles and require using an airbrush..... I wanted a simpler paint job out of a spray can. Should have tried some others or just gone with the lacquers and drug out the airbrush stuff.

I later sprayed it with a clear gloss lacquer (Testor's), after doing a test. The clear gloss makes it look a bit better. And the clear helped that finish work better for decal application (Normally I would never apply a clear coat before decals) In this pic, green paper is masking the SM.

Step 2 - Decals - UNITED STATES Decal

In preparing, I got some Micro Scale's &#8220;Micro Set&#8221; setting solution which helps decals slide into place, to soften them and &#8220;snuggle down&#8221; into crevices. Especially important for getting the lettering to fit down into the corrugations.

Another thing to help get the decals to snuggle down was shown in a previous post. The RTV that was poured to make a rectangular negative mold of the corrugated body wrap, was made for the purpose of squeezing the decal into the corrugations. However, it was not needed much. On my 1/39.5 models, I cut out each letter by hand (ah, the fun&#8230;.) from black decal sheet, applied each letter one by one (ah,even more fun...) and used the same kind of molded RTV strip to press each letter into the corrugations during the final stages.

Before I first committed to building serious scale Little Joe-II models, I identified three critical things I had to succeed in prototyping first or the project was dead. One was to scratchbuild a good looking tower (worked out a way, using a jig, and the scale factor worked well for using styrene 3/32" tubing and 1/16" rods). Second one was to do the corrugations correctly (used Evergreen plastic sheet with a "Metal Siding" pattern curled into a tube). And the final hurdle was to do the UNITED STATES lettering correctly into the corrugations. So that RTV corrugated pattern trick has been around a long time.

I cut out one UNITED STATES decal strip, then cut it into three pieces. The longest piece being &#8220;UNITED STAT&#8221;, with lower 1/8&#8221; of the last &#8220;T&#8221; cut away, for the 2nd piece, and &#8220;ES&#8221; as the 3rd piece. I slobbered a lot of the Micro Set into the corrugations and wet out the &#8220;UNITED STAT&#8221; strip and waited for it to be able to slide it lengthwise. I got it a bit crooked in the application and in trying to move it around, accidentally got it folded into itself and it was not possible to get it unfolded. So, a ruined decal. Not the kit&#8217;s fault, I screwed it up. Cut out the other decal and with more care, got it in place, with the shortened part of the last &#8220;T&#8221; at the top of the STA-227 splice ring . Then applied the &#8220;ES&#8221; below the splice ring.. And after that, applied the short 1/8&#8221; bottom part of the &#8220;T&#8221; onto the STA-227 splice ring.

I used the model brush (cheap plastic type) back and forth along the corrugations to get the decal to snuggle into the corrugations. Often worked from the middle of the decal towards the top and middle towards the bottom, which also squeezed out excess Micro Set. I did this without the use of the molded RTV pattern.

For the other side, I opened a 2nd kit and used one of the UNITED STATES decals for that. I scanned it first, so I can make up copies later. For that one, I did not cut into three pieces I left it as one piece. I applied it carefully, making sure the bottom of the last &#8220;T&#8221; was at the bottom of the STA-227 splice ring.

Then I went back to check on the first side. It was snuggling down but needed some more Micro Set to be brushed in. I later carefully used a 1&#8221; long segment of the molded RTV pattern to help press a few trouble spots in place.

After drying, the results look pretty good.

Here is a photo taken after the early application but before final snuggle-down.

If things go as planned, I will use paper wraps for the SM, CM, and LES. I hope to get at least the SM drawing completed to post pics Monday night, hopefully more.

- George Gassaway

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Brent

Well-Known Member
This next tip is COMPLETELY counterintuitive, so hang with me...

Nothing is trickier to paint than a metallic surface, so chintzing out on paint is probably not wise. Over the years the Tamiya spray lacquer paints have always yielded great results for me, and their gloss aluminum color is probably the easiest way to get a realistic metal finish simply and quickly. The trick is to spray a gloss black layer before applying the final aluminum color. The fins have already been primed with white primer, so next we'll shoot on some black lacquer
View attachment 280934
The primed fins will be allowed to dry for at least 24 hours before shooting on the final gloss aluminum color.

Closing comments on the Tamiya spray lacquers: they are expensive, but nothing will give you better results easier, more reliably, or more quickly. In addition they dry very fast, requiring only 5-10 minutes between coats, and any unpleasant odor dissipates within minutes. I can't recommend them highly enough.

James

http://www.hobbylinc.com/htm/tam/tam85014.htm
http://www.hobbylinc.com/htm/tam/tam85026.htm
http://www.hobbylinc.com/htm/tam/tam85017.htm

Never tried Tamiya paints before. Will one can of Aluminum and the White be enough? I would think the one of the black will be enough.

James Duffy

Well-Known Member
George seems to be sprinting ahead of me, but I did get a couple of minor tasks accomplished yesterday that may be helpful to others...

First, I primed the LES motor tube with Rustoleum grey automobile primer. Nothing sexy there, but I should note that a section of standard BT-5 tube makes a great holding fixture for the LES motor tube part, as the BT-5 sleeves cleanly within the LES part.

Next, the detail parts were added to the vacuform wrap, after which the assembly was primed. I used Tamiya White Primer for this step:

Do not use a high-solids primer such as the Rustoleum product for prepping the vacuform and injection-molded parts of this kit, as you'll be unnecessarily obscuring the fine detail contained in these parts.

I also assembled the escape tower, and can offer the following tip based on that experience: integrate the circular piece into the build before you "box in" the assembly, as George did after two sides were glued together. I failed to do so, and getting that little booger in there after the fact was quite a chore.

One final general model-building tip: for years I purchased large packs of sanding paper from an assortment of sources, yet never seemed to have exactly what I needed on hand when it was needed. During a ukulele building project years ago I learned of a vendor called Stewart-MacDonald, who are kind of the Apogee Components of the lutherie trade. One of the items carried there is a sampler pack of sanding papers and films, covering grits from 150 to 2000. For just over twenty bucks you'll have just about any grit you might conceivably need in a single pack.

http://www.stewmac.com/Materials_an...Papers/Sandpaper_Finishing_Paper_Sampler.html

More later,
James

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