Custom P.O.N.G. at Seattle Museum of Flight

Bill Stine referred my name to Custom Rockets about building a Custom PONG kit for the Seattle Museum Of Flight rocketry display. I had one upstairs, finished and never flown! CLICK HERE
The is the same model that was built on the blog. It was to sent to Custom Rockets for consideration.


At the last NARAM, submitted models were voted on to be included in the Model Rocketry display. CLICK HERE 
Along with the chosen NARAM models, each major rocket kit vendor will have a model from their product line. This PONG model will represent Custom Rockets.

Custom PONG Finished

This was the toughest 13mm build I've ever done!
Like the face card says it is "Super Detailed!"
If you are looking for a smaller challenge, this is the kit.

Tall for a BT-5 model, it stands 19 1/2" tall.
While I don't like stick on decals these do add a lot to the looks of the model.
Just remember, when you set one down you can't reposition it!

TIP: There is no engine hook, you are told to friction fit the engine.
I don't like friction fitting engines, especially on a thin walled BT-5 tube.

The engine mount tube and engine both extend beyond the end of the body.
A simple wrap of masking tape will hold the engine in place throughout the entire flight. Remember earlier how the extended tube got a coat of CA glue to keep it from peeling? This is why.
When the tape is pulled off there is less chance of the tube delaminating.
Be sure to press the tape down before launching.

EDIT: This model is on display at the model rocket exhibit at the Seattle Museum of Flight.

Custom PONG Build Part 16, Nose Cone Canopy Paint

I experimented with an extra ping pong ball before applying paint on the model.

This is a permanent marker from Staples Office Supply store. The ball took the marker ink well, whether painted or not.

The outside was drawn first. Stay just on the pencil lines, making slight correction to the line as you go.

We're just starting to fill the the drawn border.
I had to go over the interior area twice to get good coverage.

The black marker areas were smoother than I could have ever got with a brush.

I went a little outside in a few spots.
You can lightly scrape away any rough edges with a sharp knife tip.
The marker didn't soak into the white paint and could be scraped off.

You'll probably have to go back and forth between the marker and knife a few times to get it right. Just don't scrape too deep with the knife.

Custom PONG Build Part 15, Nose Cone Canopy Paint

The face card shows an oval canopy on the side off the ping pong ball nose cone.
Step 24 says to draw it with a pencil and paint it with gloss black paint.
I didn't think that would give a smooth enough surface.
I took a gamble and it worked very well.

Go to the Custom Rockets PONG review at RocketReviews.com - HERE
Dwayne Surdu-Miller came up with a great way to mark the circular canopy on the ball nose cone. Trace around some body tube ends!

The inset picture shows the faint initial base line. This straight line is just below the mid point of the ball. The straight base line gives you something to attach the right and left side curves onto.

The right side of the picture shows the body tube you trace around for the round right and left sides of the canopy. I used a BT-20 tube.
The midpoint of the tube touches the penciled base line. Draw around the tube with a pencil.

The smaller arc at the top was simply drawn by hand.

Before filling in the canopy with black, double check to be sure the baseline is straight and the sides are evenly drawn.

Custom PONG Build Part 14, Ball Nose

The ping pong ball nose cone had a deep, noticeable seam.
The kit ball is on the left.

I tried to fill it with a bead of medium CA.
After it dried it melted through the ball plastic a bit. After sanding it smooth it thinned the (already thin) wall of the ball.
I didn't want to use it now.

I've got a few new ping pong balls in my spare parts box.
The ball on the right was one of six bought at a sporting goods store.
It is smooth with no real seams.
Only one ball out of the six had a seam, not as wide as the one in the PONG kit.

Custom PONG Build Part 12, Center Section Dowels

In Step 2 you are told to glue the BT-50 sections to the BT-5 with 3" of space between them.
The two supplied dowels are exactly 6" long. Those are cut in half leaving two 3" sections. If the dowels ended up a little short the dowel ends wouldn't reach the BT-50 assemblies.

I glued the upper assembly a little closer to the bottom (2 15/16") to allow a sanded friction fit of the dowels between the two BT-50 sections.

Cut the dowels in half by rolling a razor blade over the 3" mark.
Roll only one turn of the dowel forward, then roll back toward you keeping the blade in the cut you just made.
If you roll too many rotations forward you run the risk of the cut traveling down the dowel in a spiral. You don't have much dowel length to play with, make the cut correctly.

Here's the dowels in place, friction fitted with no glue.
Don't make the fit too tight, you could bend the center BT-5 tube.
The dowels will be glued with a spot of white glue first on the ends.
I'll follow with some medium CA applied with a toothpick at the inside area of the joint.

Custom PONG Build Part 11, Stick On Decals!

You are given four decals that go on the body tube between the fins.
There is no way for them to fit around the launch lug standoffs.
Instead off cutting and pasting, I left them off.

I did put the black bands on the sides of the rear standoffs.
It's tight but do-able.

The lower end of the upper section tube is painted orange.
Rusto 2X "Real Orange" was a good match to the orange stickers.

No measurements are given but I settled at 3 1/2" below the lower ring.
The picture shows the simple mask.

Here's the upper decals in place.
The black band is already starting to lift up.

Custom PONG Build Part 10, Stick On Decals!

This is another tough one - the adapter decal.
The straight sides are cut with a blade and straightedge.

The arc is cut with scisssors.

Leave this decal on it's backing paper and dry fit it to see how it rolls around the adapter.

The black band at the bottom goes right along the joint.

Be sure you start the decal edge on a straight line. Some light pencil ticks might help with alignment.
If the start isn't straight the decal bands won't meet up on the other side.

Once you start this one there is no turning back. You can't pull up and reposition the decal.

With any luck, the bands should match up when they meet.

The first square (towards the bottom) is wider than all the others.
Your finish under the shroud doesn't have to be perfect, this stickon almost covers the entire shroud.

Custom PONG Build Part 9, Stick On Decals!

There is a LOT of stick-on decals in this kit.
You are best off cutting these out right on the color lines.

Start with the easiest ones to get a feel for them.
Lift the decal off the backing with the tip of your hobby knife. Don't handle them with your fingers. The oils on your fingertips will transfer and show up under the clear areas.
Once you set these down, they are stuck! If you try to lift them you could lift some paint with it.
Visually center the stickers before pressing them in place. "Float it" before sticking down a corner.

This band decal is a hard one.
Draw center tick marks on the forward BT-50 section and on the decal itself.

Set the center down first. Check the sides to be sure the edge is running straight down the body line.

Press in place from the center to the sides working out any bubbles as you go.

The rounded black bars to on the lug standoffs.
I had to place the wide edge right into the fillet area.

Custom PONG Build Part 8, Fillet Fixes

This is a tough model to spray evenly.
There are too many nooks and crannies!

I did have to go back and smooth out some of the Titebond M&TG fillets.

The ping pong ball is glued in place using a hot glue gun.

I did my best to make a clean joint with the glue gun but after painting the joint didn't look good.
This is a tight joint, you'd never get your finger in there to smooth out a fillet.

Titebond M&TG was applied and the fillet smoothed with a Q-tip.








After painting the end result is much better.

Custom PONG Build Part 7, Fin and Dowel Prep

The fins and lug stand-offs are centered between the ends of the BT-50 sections.
After all the fin lines were marked the primer was sanded off, not any wider than the root edge thickness. The pencil alignment line was redrawn.

The centers of the BT-50 sections were marked and measured.
The fin centers were also marked.

It's simpler to set the center marks on top of each other when gluing on the fins.




While the instructions have you glue on the fins first, I glued on the lugs and standoffs.
I thought it would be easier to glue on the lugs first. It's easier to align them without the fins in the way.
There are four lug standoffs, two on each side.



The dowels are cut in two and glued between the two BT-50 assemblies.
I decided to spray them black, then cut them in two.
After fitting they are glued between the two BT-50s.

The dowels are held between my thumb and index finger for spraying.
There is a little space between the dowels. I can spray the upper half then roll the dowels between my fingers to the next unsprayed area.

I sprayed the upper 2/3rds and let that dry.
The dowels were flipped over and the remaining third sprayed.

Custom PONG Build Part 6, Fin and Dowel Prep

Before the dowels are cut in half, I sealed the dowels with varnish.
I simply dipped a paper towel in the varnish and wiped it on the dowel.

After drying the dowels were smoothed over with 400 grit.

The fins were taped down to a piece of cardboard for primer spraying.
Notice the root edges are  butted together. This keeps the primer off the gluing surface.

Instead of using the fin marking template on the instructions, I used my (yet to be released) Odd'l Rockets FinTool to mark the tube. It was slid into the back and lines were drawn using the marks on the base of the tool.
The lines were extended down the body tube using an aluminum angle.

Custom PONG Build Part 5, BT-50 Assembly Glue

I didn't mark the lines from the instruction sheet template. The template seemed small and hard to align the tube for marking. I'll mark it later.

Looking ahead, there are four dowels that fit between the the two BT-50 tube assemblies.
The two supplied dowels are cut in two making four 3" dowels.
The lower assembly was glued 1/4" from the bottom of the internal BT-5 tube.
I glued the upper BT-50 assembly just inside the 3" spacing. This way I can sand the 3" dowels for a friction fit. A 6" dowel cut in two might come up short of the space between the two BT-50 sections.

I won't be friction fitting an engine inside the thin BT-5 tube. There has been too many crimped tubes over the years.
Instead, for retention, the engine will get a wrap of tape over the 1/4" of BT-5 extending out the back.
That tape could pull off a layer of the tube wrap. I applied a coat of CA glue using a Q-tip to protect it.

The BT-50 assemblies are glued in place.
A piece of paper was rolled and set into the back to keep the primer out of the engine tube.

Note: I haven't glued in the engine block in yet. This model uses a tri-fold shock cord mount. In a BT-5 it's a tight fit. I'll use Kevlar tied to the engine block.

Custom PONG Build Part 4, Coupler Assemblies

With the CA coat on the ends you can lightly sand the paper smooth.
Just remove any roughness, you don't want to remove the paper. The paper is helping hold the loose fit rings in place.

With the tip of your knife, cut a "star" pattern in the center hole of the centering ring.

Wrap some 400 grit around a dowel (or Sharpie pen here) and sand off the inside paper pieces. Sand up and down and around the perimeter of the inside circle.

This is a good and stronger fit over one of the internal BT-5 tubes.

Enlarge the picture to see some of the thin yellow covering sanded off.
I was surprised at how thin the yellow layer was.

Custom PONG Build Part 3, Coupler Assemblies

From the last step, set a small weight over the tube, ring and paper until it dries.

Run a ring of glue inside the other end of the BT-50 tube.

Repeat the last step. Set a light weight over the assembly and let dry.

On a Q-tip spread a coat of medium CA glue over the dry paper ends and coupler.
This will harden and strengthen the ends.
Don't worry about the BT-5 center hole yet.

With a sanding block, take down the hardened edges.
Sand at a very slight angle trying not to sand off the yellow coloring on the tube.
Sand on side at a time. The paper will flex and eventually sand off.

Custom PONG Build Part 2, BT-50 Segment Assemblies

These yellow BT-50 segments feel thin compared to standard brown BT-50 tubing.
If the inside diameter is thinner, the fit of the die-cut centering rings would be loose. These fell right through the tubes.
They are too thin to be built up.
I could have glued a liner of 20 lb. paper on the inside of the tube to make the inside diameter a bit smaller.

The rings should glue just inside the tube edge. This would leave a joint to be filled.
The method shown here strengthens the assembly, no seam to fill and gets the rings in the edge of the tube. It makes a "shelf" out of the 20 lb. paper edge giving a larger gluing surface.
I'll glue the thin centering rings to a piece of 20 lb. copy paper.

TIP: Lately I've been using a glue stick for many paper to paper joints. It stays put, doesn't run or wrinkle thinner paper.

A line of glue is run around the BT-50 tube edge.

Set the tube over the glued down ring.
To smooth out the internal glue bead, turn the tube over the ring.
You'll end up with a even, smooth internal fillet.

Custom PONG Build Part 1, Parts

EDIT: This one is a challenge!
The face card lists this as a Skill Level of 3. The Custom website mentions a Skill Level of 4 but no listed models have that level. This borders on the Master Modeler's Level 4, maybe a level 3 1/2.
For a smaller "T" engine kit this build took a LOT of time. To paint it like the facecard you have to build and fill in subassemblies.
If you are looking for a inexpensive challenge, add this one to your want list! It's an impressive  design.

I bought two of the Custom P.O.N.G. kits on Ebay at a pretty good price.
Shipping was cheap! There was a reason why.
The kits were shipped in a padded envelope, no box! Most all the body tubes were crimped and bent.
Luckily I have extra tubes and cut some new ones to size.

For a 13mm "T" engine model, this one is detailed.
Lots of tubes and some very small BT-5 couplers.

The parts of interest:
A 65 lb. paper shroud (I'll scan and print more on heavier stock)
The pink streamer (maybe a 6" parachute might be better)
The ping pong ball nose cone
8 (yes, eight) 5/50 centering rings
Two yellow BT-50 sized tubes. These look like the thinner BT-50 pre-colored tubes that come on some RTF models.





Three stick on decal sheets.
The model is interesting enough without the decals, but these will really dress it up.