Estes Little Joe 1, #7255, Build Part 7, Engine Mount

The engine mount is pretty standard except for the big rings.

On the right is the lower ring. The four nozzles holes are cut. The laser cut lines are the glue positions for the plastic pieces. Notice the off-set notches for the tabs in the motor housings.

The lower ring is glued 1/4" from the bottom of the motor mount tube.

The upper ring is two layers. The smaller ring with the cutouts faces up.

On the left is the finished engine mount.
On the right is the top showing the laminated two rings. The "spoke" holes keep the weight down.

Note that the interior 2" diameter tube fits over the lip of the smaller, spoked ring. Keep this in mind as you don't want glue around the edge (that could affect the tube fit) of the upper ring.

Tools - The Essentials, Sanding Blocks Part 3

After some sanding you should check for build-up on the sandpaper.
These little nubs of filler/primer can get large enough to scar your balsa when sanding!

On the right is a soft brass wire brush I picked up at Home Depot. Be sure to look for a soft brass brush like you could use on suede shoes.

Budget TIP: In the sink, run some water over the sandpaper. Using circular motions, brush off the loaded up gunk.
Your sandpaper is as good as new! Well, close to new and reusable anyway. Each time you clean off the surface the sandpaper becomes a slightly finer grit. You can also wear down the brass bristles over time. My first brass brush lasted for years.

After removing most of the filler/primer from the tube or fins with 220 grit on the block, I lightly sand and smooth out any scratches with a small piece of 400 grit. (Shown below on the left.) This takes off most all of the gray filler primer filling any remaining balsa grain or tube seams.

Here's the same piece of filler/primer loaded 400 grit before -
and after brushing out the filler primer.

These new premium sandpapers are more expensive than the old black sandpapers. But, the new stuff can be brushed off and used over and over again. I'll probably use one single small piece like this to sand a Big Bertha sized model, brushing it off every time it gets loaded up.

OPINION: CWF does not seal the wood! Old style Sanding Sealer does seal the wood surface. Sanding Sealer or Balsa Fillercoat is hard to find today and expensive when you do. Body tubes are rarely sealed before spray painting. Why bring this up?
I sand my models dry - no wet sanding (if I do it at all) until the model has a fairly heavy, dried coat of enamel.
CWF is water based, the balsa can still absorb water when wet sanding and swell up. Kraft tubes will absorb water. Wet sanding will slow down the "loading" of sandpaper with filler/primer. If you decide wet sand, do it only after color coats are sprayed using very fine sandpapers. Keep the water away from the open ends of the body tube and engine mount.
Watch a video of someone clear coating a guitar or piece of furniture. The wet sanding is only done after a few color or clear coats have dried. Be very careful not to sand through the color or clear coats.

Estes Little Joe 1, #7255, Build Part 6, Skinning The Fins

I using my favorite re-purposed tool, a Sharpie barrel to burnish and set the skin onto the glued sides.

The picture to the right shows the slight overhang at the root edge. this will better fit the body tube curve. At the bottom you can see the skin overhang.

You can carefully cut off the overhang, but don't get too close to the balsa. Use a new blade to shave it close.

Then use a sanding block to take the card stock edge down to the balsa form.





Here's the finished assembly.
Notice the wedge shape and thickness of the trailing edge.

There will have to be some CWF applied to fill the notch recesses around the outside of the fins.

Tools - The Essentials, Sanding Blocks Part 2

Here's my favorite sanding block - The Great Planes Easy Sander. It's made of aluminum, the top fits your hand very well.

The problem - 
Hobbico hasn't sold them for a while. Remember that bankruptcy? CLICK HERE

EDIT: Dubro is selling these sanding blocks. They seem expensive, but are worth it. CLICK HERE

If you find one at your local hobby store - BUY IT! I liked these enough to buy three when they were still available. Two new 5.5" long Easy Sanders are still in the package.

You can still find the adhesive backed sandpaper rolls made for the sander. Their 220 grit seems a bit finer than what you'd find at Home Depot. Home Depot does sell sticky backed sandpaper rolls:
220 grit CLICK HERE, 400 grit  CLICK HERE
25 yards for $20.00 seems very reasonable.
The Great Planes rolls were 12 feet for $11.00.
The inset picture shows the overlap when the sticky strip is set down on the flat bottom plate. This overlap is cut off with scissors.

When I sand I set a old towel in my lap.
One pass is made on the primer/filler sprayed balsa, then the bottom of the block is wiped off on the towel. This prevents build-up of the primer on the sandpaper. I am dry sanding here.

More on this in the next post - 

Tools - The Essentials, Sanding Blocks Part 1

Here's how we all start out, a block of wood with some sandpaper wrapped under it. It's hard to keep the sandpaper tight around the block as you are sanding with it.





I used a Warner #436 sanding block for a few years. It's a wood block meant for drywall sanding.
This block used 1/4 sheet of sandpaper. The upper block locks down on the sheet with a wing nut at the center.




I still use one of these blocks today, it's always loaded with some 400 grit.
One side of the lower block is rounded, the other is a wedge shape. The sides of the block come in handy for shaping.

The problem - 
Warner no longer makes this block! There is a new style but it doesn't have the wing nut to tighten it all up. The new plastic version has plastic clips that hold it together. Under the wrapped sandpaper there are holes in the bottom plastic.

Here's the closest block I've found, based on the older Warner design. It's plastic, the same size and has the center wing nut.
You can find it on Amazon: CLICK HERE

Estes Little Joe 1, #7255, Build Part 5, Skinning The Fins

The leading edge fold was sharpened with a burnisher.

It doesn't have to be razor sharp, it still has to roll over the front of the fin assembly.





The instructions say to put glue on the folded card stock skin. I didn't do it this way, I was concerned that wet card stock might distort.

Instead I applied glue to one side of the balsa frame being sure to get good coverage on all the contact areas.

This was smoothed out and excess removed with a Q-tip. Be sure there isn't any drops of glue pooled up in the corners. Heavy glue can shrink and distort the flat card stock skin.

Set the fold over the sharp leading edge. Glue down only one side  and burnish the card stock over the sides.
TIP: It's hard to see in the picture, but I set the skin to overhang a very slight amount at the root edge to better fit the curvature of the body tube.
The card stock is a little larger than the balsa frame and will overhang at the outside and trailing edges.

Estes Little Joe 1, #7255, Build Part 4, Creasing The Leading Edge Skin

You shouldn't fold the fin cover skin without pre-embossing the center line.
I wouldn't recommend creasing the line on corrugated cardboard, the interior wavy layer runs one direction. Unless the scribe line is lined up with the interior cardboard layer you'll crease dips in the skin.

TIP: Practice some crease lines outside the printed skin borders to get a feel for how the card stock embosses.

I use the tip of a butter knife to score the embossed line. Find a knife with no serrations near the tip. This is how the old Estes Saturn 1B fins were embossed to be folded.

Do a soft fold down the middle line of the fin skin. To get a clean final sharp fold you should make the crease in short steps. Don't try to make an immediate sharp fold.

Continue working the fold.
Here I'm increasing the angle over the top edge of my triangular engineer's ruler.


When the sides are getting close, do the final sharp fold using a burnisher like the barrel of a Sharpie pen.

Tools - The Essentials, Straight Edge Rulers

Here's what most of us start with, the cheap wooden ruler. That thin strip of metal set into the edge won't last as a metal straight edge. After you've cut out a few fins, the thin edge will slip out of the slot. Once it's gone your knife will cut into the wood ruler that remains.

Here's a metal ruler that's good but not ideal. The 1/32" markings are a little hard to read.
This metal edge would work to cut straight lines and fins using a hobby knife.

Notice the rounded off left end. There is a border margin before the measurement markings start.

Get a 18" long metal straightedge with a squared end.
You can double check the spacing of a centering ring. Rotate the ruler around tube at the base of the centering ring before the glue dries. Here the ring is set 3/8" from the end of the engine tube.

The cork back helps the ruler grip. If you were using Rapidiograph pens it raises the edge so the black ink won't run underneath.

TIP: If you use a straightedge to cut out parachutes, flip over the ruler with the cork side up. A raised ruler edge can allow the plastic to flex and you could end up with wrinkled cuts.

TIP: Here's a great ruler for marking, manufactured by Incra.
Those small holes are made for a metal scribe but a .5mm mechanical pencil will fit.
To learn more: CLICK HERE

Estes Little Joe 1, #7255, Build Part 3, Fin Assembly

Here's the fin assembly from the bottom.
I wish the tabs were a little longer so they would stick above and could be sanded to surface. On these built up fins there is always something to fill with more CWF.

The leading edge is sanded to a taper to match the root and outside edge pieces.
The lowest line of the taper goes into the top of the "O" cut outs.

Here's the before and after:
On the left, the root and outside edge pieces are sanded to match the bottom pieces.

On the right, the top fin is before sanding the leading edge wedge.
Below is the sanded leading edge taper.

If you don't have one - GET A GOOD SANDING BLOCK! You'll never be able to get a sharp taper with sandpaper wrapped around your fingers.

Estes Little Joe 1, #7255, Build Part 2, Fin Assembly

It might be tempting, but never punch the fins off the balsa sheet. Use a sharp knife and cut through the tics to free the parts.



It seems balsa is wasted in some kits. Hang onto the big leftover pieces for 3/32" thick repairs later on.

Laser cut parts are great except the cuts aren't clean. The beam gets diffused cutting through to the bottom side of the balsa.

Square up the sides with a sanding block but don't sand too much off or make the pieces any smaller.
This picture shows how the sanding block cleans up the "wedge" laser cut.



When gluing the sides onto the center piece, be sure they are glued on at a 90 degree angle, perpendicular to the large middle piece.

The picture on the left shows the center piece at an angle. The picture on the right is correct showing the piece sitting square on the tab.
Also on the right notice the light sanding on the (facing) center piece edge to square up the angle of the laser cut. Don't sand the pieces any smaller! Sand so the sides are squared up and adjoining pieces will glue on straight.

To fit, the ends of the long bottom piece must be tapered.

In the top picture, I shaded the ends to show what has to be sanded at an angle.

The bottom picture shows the fitted piece making contact with the base of the center piece.

Tools - The Essentials, The Hobby Knife Alternative, Part 4 Changing The Blade

I realize most would know how to change out one of these knives.
But for those who haven't used one before -

On the left is a dull blade tip. Notice the diagonal break-off scored lines.

On the right is the back end of the knife. Press the ribbed button and slide off the end clip.

Only extend the blade "one click" outside of the wrapped metal end. You only want to break off one segment of the blade, down the score line.

The end clip piece has a slot molded into the back end. Slide this over the end of the blade. Press down on the clip and the blade should break off down the score.

When you've broken off all the available tips, the blade is replaced.
Remove the end clip again. Slide the black center hold piece out the rear.

There is a single round pin that goes into the hole on the blade strip end. Remove the old blade. Install a new, long blade over the round pin.
Slide the blade strip back into the center of the of the knife. Click the yellow rear clip in place.

You're ready to go!

The inset picture shows the back of the rear clip. the yellow overhang can be clipped on your shirt pocket.

Estes Little Joe 1, #7255, Build Part 1, Parts

I always thought it was a matter of time before Estes produced a Mercury Little Joe kit.
Here's the face card and parts in the bag from the back.

Here's the parts for the booster. All seem to be of high quality.


The red plastic parts are the capsule and tower.
The white parts are the new scale nozzles.





Some interesting parts, clockwise from the left:
All the centering rings. Notice the wheel spoke cutouts to keep the weight down.
The decals with the stenciled "UNITED STATES".
Multi-pieced balsa fin parts.
Card stock fin covers.
Laser cut card stock shroud.

Tools - The Essentials, The Hobby Knife Alternative, Part 3

X-Acto #1 handles are dangerous - They roll!
Years back I worked in a print shop doing old-school paste-up on a slanted drawing table. One day a heard a scream. Another artist ended up at the hospital for stitches when her knife rolled off her drawing board and stuck in her thigh!
X-Acto does make handles that are "anti-roll", but you don't normally find those at hobby stores. The large majority of knives are rolling #1 round metal handles.

I still use a #11 blade in an X-Acto knife for cutting tight curves.
But for straight cuts, why dull an expensive knife blade? Most all kits come with laser-cut balsa parts. You don't need a fancy knife to cut through small hold down tabs between the long cuts.

It occurred to me that on a #11 blade, the tip gets dull while three quarters of the blade is still sharp! If the tip breaks off and the blade is no longer usable.

The solution seemed to be a carpenter's break-off blade knife!
It is one long flat knife with a break off score about every quarter inch. Break off the dull top segment, and you've got a new sharp knife.

Here's my personal favorite: CLICK HERE
9mm blades strips fit it. It doesn't roll off the workbench!

TIP: On Amazon, break-offs are less expensive than the Excel blades. CLICK HERE
10 blades with 120 break-off tips are $6.59.
Divide $6.59 by 120 tips, it's like paying a little over $.05 each!

These cheap break-off blades knives are okay in a pinch. They won't last long in everyday use.
TIP: Carry a few of these in your range box. Leave your good knives at home.

Tools - The Essentials, The Hobby Knife Blade, Part 2

They aren't kidding when they say their blades are "surgically sharp!" I couldn't count the many times I have cut my fingers.
TIP: Keep Band-aids at your work bench!

For years I removed and changed the blades incorrectly. I'd twist the ferule, then pinch and pull up on the blade.

Try this (if you don't already) -
Turn the ferule until there is a small space at the base. Don't remove the ferule.

Press down on the ferule and you'll hear a "snap". The blade is now loose in the handle.

Lift up on the blade from the flat back.

If you don't have a blade disposal container -
Fold a few wraps of masking tape over the sharp side. You don't want to find a blade when you are smashing things down in the trash can!

Blades can be "sharpened" or stropped. Stropping a blade that starts to lose it's edge will extend it's useful life. CLICK HERE
I don't bother with stropping, I'll usually change out for a new blade.

These blades are brittle, a little side pressure will snap off the tip. When the blade tip breaks off, there is not much you can do. The blade should be changed out.

Semroc Andromeda Build, Part 17, Applying The Decals

In the instructions you are given placement measurements.
Here I'm leaving most all of the decal on the backing paper. The right side of the "A" in Andromeda is set on the 9/16" spacing before the backing is slid back to the left with the decal remaining on the surface.

Always, always, always wet the area where the decal will end up. You want to have some water underneath the decal surface so it will slide for positioning, especially on this textured, metallic finish.

The largest "wing" decal is in two pieces. Be sure to set the decal into the root edge/body tube joint.

Again, use a damp Q-tip to work out the air bubbles and get a better surface seal on this textured paint.
At the bottom the two decals butt up at the fin root edge.








Be very careful with the metallic wrap.
When I peeled off the back, the stripes were starting to split.