Semroc Little Joe II Build Part 10 Pre-Paint

The fins were glued on and fillets applied.

I tried to pre-plan the fin alignment lines, one was drawn on the lower wrap seam to partially cover it up.

To center the launch lug on the upper wrap:

The upper wrap was marked at the center of it's width with a small pencil tick mark.

The launch lug was marked at it's center.

After a line of glue was applied, I only had to line up the two tick marks.

Semroc Little Joe II Build Part 9 Engine Mount Install

The tube is marked for the fins by placing the body tube on top of a marking guide. You are told to mark the fin lines between two of the corrugations.

I found it hard to do this. I ended up just marking the tube as best I could.

Notice the fin alignment line is continued over the edge of the body tube. There is four small tick marks over the back end of the body tube. When the fin is covering the line, having this extension over the back edge of the tube gives another point of alignment.

You can see the inside of the tube edge is darkened. This is CA glue wiped in the body tube ends for extra strength.

The mount is set back 1" inside the tube. It's not hard to apply and smooth a glue fillet to the mount on this lower end.

Applying the upper engine mount fillet from the top of the body tube is another story.
TIP: To spread the glue fillet, I used a 1/4" dowel with one end sanded round. Think of it as a long, thin fingertip.

One drop of glue is squirted onto the rounded dowel end. Carefully place the drop of glue down inside the body tube onto the engine mount / body tube joint. Set the glue drop on the joint then spread out and smooth it using the rounded end of the dowel.

When getting the drop of glue down to the joint, try not to get glue on the inside of the body tube. Your target is the centering ring / body tube joint.

You can pick up any excess glue (glue outside the fillet area) with a few passes of the rounded dowel end. Pick up some glue, remove the dowel, wipe it off and go back in to pick up more excess glue.

Internal construction can be as just clean as outside surfaces of the model by taking a few extra minutes to do it right.

Semroc Little Joe II Build Part 7 Body Wraps

I built a little out of order from the instructions. The wraps actually should have been put on before the fins were made.

While the instructions say to use glue to attach the wraps to the body tube, I use spray adhesive so I have a little more time to set them down straight.

In the picture you can see I've already filled the body tube seams, primed and sanded the body tube smooth. A line was drawn down the body tube for the wrap alignment.

The lower wrap was rolled into place without any problems. The match of the ends was very close.

The instructions just say to apply the wider second wrap "close" to the first wrap. I probably put the upper wrap a little too close to the lower one. Not a big deal.

This might lead to some problems with the decal and black band placement later on, we'll see.

Semroc Little Joe II Build Part 6 Fins

Okay - everything was going well up until now.

I was only happy with the way one fin out of four turned out.

I was careful not to use much glue to attach the internal balsa ribs, but I still had distortion. I wasn't too excited about all the edge and joint filling I was faced with. So, I took the easy way out.

No handy balsa was thick enough to cut out replacements, so I laminated two pieces of 3/32" balsa. I simply sanded them to a wedge shape - DONE!

The side surfaces were smoother with no distortion or "pulls" from the glue. I don't know why Estes went with a built up fin on the Little Joe kit. I can understand using built up fins on the Saturn 1B, but on this kit, I found it easier to sand the wedge shape from sheet balsa.

On the left is a "test" fin made from balsa above the one built up fin that turned out well. To the right are the four fins I'll use on the model.

TIP: Here's a tool I find helpful.

I'm holding a Little Joe II fin in a Machinist Square.

The square is at a perfect 90 degree angle. I'll lightly sand the fin sides until the root and trailing edges match the 90 degree angle of the square.

On a four fin model this can help the finished rocket stand on all the fins without wobbling. That is, if the fins are all glued on the body tube equally.

On a three fin model, it doesn't matter. It'll stand on all three trailing edges no matter how badly aligned the fins are.

LAUNCH! Small Stuff - September 20, 2010

I walked to the schoolyard to get a few small launches out of my system.

Four were launched, a few parents walking their kids to school got some early morning entertainment.

The picture to the left is like a cheap advertisement for the Odd'l Rockets line.

That's the BIRDIE with an A10-3t in her tail. I'm using the BLAST! ceramic deflector and RAISE Spring to keep it up an inch or two.

The MMX SKYWRITER downscale was up next. A small 1/2" x 8" streamer has been added with no deployment problems.

The card stock downscale STAR SNOOP GooneyBird got respectable altitude for an MMX engine.

Last up was the downscale CHEROKEE T with a 35 year old MPC 1/2A3-3m engine. Great altitude with a 100 yard walk to pick it up.

TIP: I've been re-using Quest MMX Igniters for some time now.

Maybe my batteries are getting old, but I've yet to burn through one.

This is an MMX Igniter after today's launch, still held by the clips. That's the third time I've used this igniter. I'll keep using it until it breaks or burns through.

Semroc Little Joe II Build Part 5 Fins

Here's the ribs glued into one side of the fin cover.

The instructions are right - use just a little glue to set the ribs in place. Too much and it could distort the other side of the cardstock surface.

Click on the picture for an enlarged view and you can see I tapered the ends for a wedge fit. I didn't want to do a lot of filling later on.

This shows how much of the flat, wider inside rib gets sanded down to match the angle taper of the side ribs.

This is the trailing edge after trimming and sanding to the sides of the fin cover.

On EBAY, Martian Patrol For Sale!

I don't have a MPC Martian Patrol kit on EBAY.

This is somebody else.

Mine must have came from the same color batch. All the plastic parts were like mine, green fins, yellow nose cone and gray adapter.

You can check out the auction HERE

The Buy It Now price is only $99.95!

Free shipping - What a deal!

If this seller gets half that, mine will be on EBAY tomorrow.

9/21/10 Update:

The kit didn't sell at $99.95 - big surprise. The item has been relisted.