Estes M.A.V. #7283, Build Part 3, More Interesting Things

Continued from the last post:

Here's the top of an engine sitting in the motor mount/fin can. Notice how it is centered, just inside the upper centering ring hole. The ejection charge would clear the plastic lip of the ring.








I did a dry fit of the fins.

Against a back light you can see the airfoil taper.

Here's the launch lug again.
The left side of the base is right down the seam of the wrap.
Usually on a factory installed wrap, the detail lines don't match. On this one - everything lines up!

It looks like the lug was glued on with a hot glue. There is a little clear glue squeezed out on each side.

Fill & Finish Questions From TRF, Part 1

On TRF, Neil W had some questions about how I fill and finish. I tried to  answer all his questions. Neil's quotes are in italic -

I am mostly using the finishing strategy that hcmbanjo has documented on his blog. In this strategy, filler/primer is functioning primarily as filler. So you sand off just about all of it except what remains in the various cracks and indentations, and then it has done its job. The reason to remove as much of it as possible is.... well, I guess it's mostly about weight, but perhaps also a bit of thickness, although I can't attach any numbers to either of these. A good area for experimentation."

Hi Neil,
I do a two step fill. First is the CWF to fill 80% of the balsa grain and tube seams. The second step Duplicolor Filler/Primer fills any remaining grain and seams after sanding.
Removing most all of the filler/primer is not for weight reduction. I'm a sport flyer, a little extra weight doesn't bother me or my flights.
This two-step fill process is something that works for me - In my teens, I hated the four passes of brush on and sand steps using sanding sealer. I read about some multiple step process some builders employ and wonder how long it takes them to finish a rocket.
My fill and finish steps are probably quicker. What slows things down is the paint dry times between finish colors.
I have used every available filler/primer out there and have found the automotive Duplicolor Filler/Primer to be the best. Some filler/primers sand like rubber!

"In general, I'm not as obsessive about removing filler/primer as Chris is; his body tubes in particular have *very* little grey left on them when he's done with them. I tend to run out of patience before I get to that point, but my mindset has still been to remove "most" of it."

You probably don't have to take it down to the tube and balsa surface like I do, but this works for me. When you sand to surface you will see gray filler/primer left in the remaining seams and balsa grain.

"I am definitely leaning towards the idea of leaving a bit more primer on in areas where scuffing is a danger. That might help avoid problems. However, sand-through is still possible at high points. I guess if I can just minimize them, then a bit of touch-up here and there with CA is no biggie."

Occasionally I do sand too much and can scuff the surface. This shows up when I shoot the first gloss white coats. I usually do a gloss white undercoat. Take the undercoated model out in the direct sunlight and you'll see the rough spots that require smooth sanding. There are always some rough areas and glue boogers that need to be smoothed out.
If an area was rough or sanded through, I do some light sanding of those areas of the white base coat. These (sanded) rough areas disappear with the second white undercoat.

"I can't imagine leaving filler/primer unsanded. After a heavy coat, it's usually quite rough and bumpy. However, the idea of performing minimal sanding only to smooth it out definitely is something I'll explore, rather than trying to remove most of it."
"Are you talking about filler/primer or regular primer? As mentioned above, I find it hard to envision leaving filler/primer unsanded. Regular primer, though, I usually don't sand (in fact I usually apply it in the same painting session as the base coat).

The Duplicolor Filler/Primer I use drys dull and slightly rough. At a minimum you do have to lightly sand to smooth it out.
I only use the CWF first, then the Duplicolor Filler/Primer (FP101) and sand to surface. No other "Primer" after that, just the white undercoats.

Estes M.A.V. #7283, Build Part 2, Interesting Things

The shock cord is already installed!
This is a different attachment - the low end goes through a slit in the body tube, then folded up along the outside. The launch lug strip is glued over the shock cord holding it down against the tube.

The nose weight is already in place.
Under a bright light you can see the clay weight inside the nose cone.

The nose cone weighs just over one ounce.

The engine mount doesn't have a traditional motor mount tube.
On the left is 1/2 of the fin can/motor mount assembly. Notice the two central vertical ribs. There are two more ribsi n the opposite half of the fin can.
When the engine is slid in from the bottom - the wedge shaped ribs direct the top of the engine to fit and "lock" into that circular groove in the upper centering ring.

Estes M.A.V. #7283, Build Part 1, Parts

Here's probably the most interesting of the "Beginner" rockets, the new Estes Mars Ascent Vehicle or MAV.

It has a Space X Dragon style nose cone and fins that look a little like upside down landing legs from the old Mars Lander kit. The tube wrap is already applied.

In the center are the three stickers that go on the lower fin can, placed between the fins. 

The yellow square is a clear sticker that goes over and reinforces the installed launch lug strip.

This one is heavy at 3 ounces! Somehow I would expect it to get higher than 250 feet on a C6-3 engine. The parachute seems large at 18" diameter.

This same design will be available in the "Colonizer" Starter set with red fins and nose cone trim.

Why feature a "beginner" build? There are some new manufacturing twists that make it very interesting.

Older Centuri Kit - First Impressions

The first rocket kit I ever ordered was from Centuri.
Why didn't I order from Estes, like the other kids in the neighborhood? I liked the Centuri print ads better. The art layout was more visually appealing to me.

My first order was for the Centuri Javelin. (The fins and guides pictured below are from the Centuri Honest John kit.)
While watching a few Estes kits being assembled by friends, I did notice some differences in the way Centuri produced their kits.
The small notches at the top and bottom of the Centuri fin positioning guides made it easier to mark body tubes.
The fin alignment guides helped coax the fins to a 90 degree spacing. Both the guide pieces were printed on card stock, not 20 lb. paper.

Then there was the fins.
The cut lines were silk screened onto the balsa sheets. No cutting out of a template and pencil tracings needed. I do wonder now if the printed ink might bleed through a light color paint.

ASP MMX Micro Corporal Build, Finished

Another good addition to the Micro-Maxx Fleet!
These are always good "first launch of the day" rockets.
Small and still a good challenge.

ASP MMX Micro Corporal Build, Part 8, Paint & Decals

The model gets an overall shot of gloss white paint. No masking!

The painting wand is a plain 1/4" diameter dowel.






Here's how the instructions show the decal placement.









The roll pattern decal on the upper section doesn't extend the whole length of the upper tube as shown in the drawing above.







This shows cutting the low end of the decal -

The top side should be cut close to the print so there won't be any clear overhang over the nose cone seam gap.