Apogee Heli-Roc Build Part 3 Airfoil Rotors and Fins

On the left is a before and after pic of the fin airfoil.

On the right is the rotor blade airfoil (one side flat or chambered) before and after.


The fins are smaller so the airfoil was sanded using a sanding block.

The rotor blade is 10 inches long so a consistent airfoil could be hard to do.
I used the emery board featured in an earlier post, HERE.

TIP: For support, place the trailing edge of the blade near the edge of a hardcover book. Set the emery board over the trailing edge at a slight angle on top of the balsa blade. Sand down the entire length of the rotor blade.

Apogee Heli-Roc Build Part 2 Rotors and Fins

After separating the balsa from the die-cut sheets, alike pieces are stacked and sanded to the same size.

I hadn't seen die-cut balsa in a while. While the cuts were close, you should stack and sand the pieces for uniformity.

TIP: Rocket kit instructions always show fins being "gang sanded" against a piece of sandpaper set down on a table top. I never feel enough control doing it that way.
I find it easier to hold all three alike pieces with my left hand and square them up against a sanding block held in my right hand.

LAUNCH! Schoolyard 11/30/10

Two MicroMaxx downscales, one prototype and a new downscale flew this morning.

There was no breeze, but it was overcast and a very light mist of rain was falling. Good thing I clear coated the carded models.

Here's the newest downscale, plans will be released for free! Follow this blog and I'll let you know when it's available to print out and build.

It's the classic Estes PATRIOT built around a BT-20 body tube. It stands 11 5/8" tall. First flight was with a 1/2A3-2t. Stable with full streamer recovery.

This is the smaller 13mm UP! CUP. It flew pretty high (considering the drag) on an A10-3t. It just takes an extra moment to connect up the igniter leads.

Third up was the MicroMaxx CLOUD HOPPER. Flight was vertical with a slight tail wag on boost. It looks like I'll have to touch up the whiskers, nose and mouth with a fine point Sharpie pen.

Finally the SKY WRITER MMX downscale flew for the 15th time! I've been trying to include it at every schoolyard launch.

In all four launches I used re-cycled MicroMaxx bare nichrome igniters with my six volt controller. A 12 volt controller would probably burn thru these igniters.

You might be asking - Why bother to fly the small stuff?

Large, adequate flying fields are hard to come by. These schoolyard launches are on a soccer field. The small sessions keep me active between flying larger rockets at our Orlando R.O.C.K. and Bunnell N.E.F.A.R. group launches.

Apogee Heli-Roc Build Part 1 Parts

Apogee HELI-ROC

Kit # 05017


Here's all the parts laid out on the floor. This looks to be a fun, different build.
The last helicopter rocket I built was the Estes Gyroc in the early 1970s.

Here's some parts of interest:

Three Du-Bro hinges
.025" dia. music wire for the hooks
Cast urethane nose cone
Three rubber bands
Red Kevlar thread
In the picture above you can see the self adhesive decal sheets

Shaping Tool TIP

Here's one of the best balsa shaping tools available.

I first used an emery board in the 1970s when forming airfoils on the Estes V-2 fins. In the instructions, it was suggested for fin shaping.

Back then we only had the small brown garnet, coarse "files".

I should clarify - a fingernail file is metal, an emery board is like sandpaper glued on cardboard.

This board is much larger, 3/4" wide by 7 1/2" long. There are four different grits, two on each side. The roughness spans (around) 100 grit coarse to 400 grit extra fine.

The great thing is, these boards don't really load up. If they do, they are washable.

The board in the picture is probably one year old and has been used many times. It has a stiff, padded surface.

You can pick them up at beauty supply stores like Sally Beauty for a few dollars each.

Parachute Attachment TIP

Awhile back I read a forum post about tangled shroud lines, asking how to untangle them.
You can eliminate some tangled lines by moving the parachute attachment point away from the nose cone.

With the nose cone so close to the shroud lines, the nose cone can pass through the open lines at ejection.
If you've ever seen a slow motion video of how violent an ejection charge can be, you would understand how the nose cone could get tangled in the lines.

Every low power kit instruction I've seen has you tie the parachute to the screw eye.
I'd suggest tying an overhand loop knot in the shock cord, one third the way down from the screw eye.

Attach the parachute's snap swivel to the loop and you are ready to go!


With the parachute tied on 1/3 the way down the shock cord, your rocket will fall in three separate parts, all tethered together by the shock cord. First to hit the ground is the tail end of the rocket, the nose cone and finally the parachute. This is the same way many mid and high power rockets are built for recovery.

If your rocket has a tower or tall nose cone, adjust the distance down the shock cord so the longer nose cone won't be banging against the body tube during descent.

Cruise Blog Update

While the Disney cruise was very good, making blog entries was impossible to do.

I'm surprised I was able to blog what I did while on board!

I'm home now and things should be back to normal. Well, as far as rockets and blogging goes. Thanks for your patience!

Dr. Zooch Saturn 1 SA-5 FINISHED!

Dr. Zooch Saturn 1 SA-5

Here's the mid body with the launch lug standoff.

All the fins and nozzles.


This was another great build from Dr. Zooch. I learned quite a few things in the process. Next time I'll pay more attention to the instructions and scale data sites!

Cruising Update on the Disney Cruise Line

From the Disney Magic Cruise Ship:

I'm happy to say the show went very well. This could lead to more contracts down the road.

When I arrived on board, I received a phone message. John (Dragon Rider 10 on TRF) and family are on board! We got together and talked rockets for about an hour. John is a very active builder and flyer, his customization and detail is amazing.

On the down side, the internet on board is slow. I never know if it'll work when downloading pictures and blog entries. So, bear with me on this.

Dr. Zooch Saturn 1 SA-5 Build Part 37 Launch Lugs

I decided not to make eight of the standoffs. After making the first one, seven more would be a lot of work. It's do-able, but at this point I really wanted to finish up the model.

The lug and standoff were filled with CWF and sanded smooth. A coat of primer followed and sanding with 400 grit.

The instructions tell you to cut the launch lug in half, but it wouldn't match the length of the standoff. I cut it to fit the standoff, the lower lug will be longer than half it's original size.

This is the longer, lower launch lug.

The lug was glued on straight, but it looks crooked. Because of the fin taper, the low end of the lug was glued close to the fin's trailing edge.

I found it easier to keep the white lug against a white fin. I didn't want to do any more masking.

Dr. Zooch Saturn 1 SA-5 Build Part 36 Nozzles

I inserted an engine casing when gluing the nozzles to the bottom plate.

There isn't much clearance around the nozzle bells and the engine.

With the casing in place, it's a little easier to visualize and space out the nozzles evenly.

Here I've added internal fillets inside each bell and bottom plate joint. Don't worry, white glue will dry clear and flat. It'll be invisible when dry.

The glue was placed drop by drop using the blunt back end of a toothpick. I rounded a small dowel to spread out the glue more evenly.

Dr. Zooch Saturn 1 SA-5 Build Post 35 Antenna

This is the back of an antenna panel showing the glue placement.

The instructions show the panels cut apart, but I kept them in one piece for easier gluing.

The antenna panels in place.

I alternated the four panels, yellow squares centered, then the high yellow square panels.

The two panels with the yellow rectangle panels not centered should be positioned as pictured here.

Dr. Zooch Saturn 1 SA-5 Build part 34 Nozzles

Some of the silver paint was sanded off the bottom of the nozzles for a better glue bond.

The inside of the nozzle bell was blackened in with a Sharpie pen. This is much easier than masking and spraying. After the outsides of the nozzles were painted and dried there wasn't any bleeding through of the Sharpie black color.

After the end sanding they were a little out of round. I went back with a dowel and made sure the nozzles were well shaped before gluing onto the bottom plate.

Cruising on the Disney Wonder

Today I join the Disney Wonder. I be doing my act sometime over the next four days.

This is my first time entertaining on the Disney Cruise Lines, so I've had to lighten up the material a bit. I've worked for the Disney organization before, I know what's expected.

I'll keep keep the blog going, but on a ship you never have guarantees about the Internet signal and load times.

No, that's not supposed to be a Disney Ship - they copyright all their licensed images. So you get a Viking boat.

Dr. Zooch Saturn 1 SA-5 Build Part 33 Details

I explained earlier about my mistake on the retro rocket positions.

These steps were done before I realized the error.

I'm using a favorite glue transfer tool, the tip of a toothpick. A drop of glue was set on the top of the lower LH2 duct and at the underside of the centering ring and fairing edge.

The retro rockets are in position.

I added some glue over the joint to fill in the seam and touched up with white paint. Not my best work, but it's done!

Dr. Zooch Saturn 1 SA-5 Build Part 32 S-IV Motors

The S-IV motors are very small. You'll need tweezers to help get them into position.

The instructions don't specify a color. When at the Meatball Rocketry site I saw they were red and white. Working this small, I decided to just go with the red.

According to the pictures on the Meatball Rocketry site, the red motors go in the center of the upper band, not beneath it like shown in the Zooch instructions. Either way would look fine, it's ant scale! Nobody is going to tell you your model is right or wrong.

I decided to glue the nozzles in the pictured position. It's a stronger bond gluing the wood dowel to the paper wrap. If I were to glue the dowel to the white spray painted area, I'd have to remove some paint.

Dr. Zooch Saturn 1 SA-5 Build Part 31 Upper LH2 Ducts

Read the Scale mistake note below before doing what I did!

I tried to sand an angle to the bottom of the retro rockets to match the top end of the lower LH2 ducts.

Be careful how much you sand, don't make them too short like I did.

I got the angle as close as I could. I'll fill the gap with white glue and touch up the joint with white paint later.

Scale mistake note: The retro rockets didn't connect to the lower LH2 ducts! They were set on four of the eight standoffs. On this model, the upper launch lug is glued to a standoff.
You can make all eight standoffs and glue the retro rockets to every other standoff if you'd like. This was my mistake, I didn't look close enough to the S-1 drawing inset in the instructions. But on the positive side, this way the retro rockets are stronger with two gluing areas instead of just glued to the upper centering ring alone.
Check the Meatball Rocketry site for a better pictorial explanation.

The upper LH2 ducts go a little to the left of the lower duct placement.

Sight down the body tube to get them just to the left and straight.

While the nozzles were drying, I glued on a new bottom plate.

This time the position of the engine hook notch was rotated so the hook movement wouldn't bump up against the nozzles.

I blackened in the edges of the body tube and the old plate so when the new one is glued on the first try will be less noticeable.

Dr. Zooch Saturn 1 SA-5 Build Part 30 Lower LH2 Ducts

The instructions don't give enough information about placement of the lower three LH2 ducts.

You only make three dowels, 4 3/8" long. But it seems there are four places the duct dowels could go - between the tanks, above the stub fins.

I checked the Meatball rocketry site again and found which side doesn't get a LH2 duct dowel.

It's shown in the picture on the left. There is no fourth LH2 duct above the fully black area of the fins.

Dr. Zooch Saturn 1 SA-5 Build Part 29 F.G.P Tips

Step 9-A-prime: F.G.P. (Funky Glue Putty)
I've never had much luck making the Funky Glue Putty for the Zooch kits.
But, like everything else, you usually get better results if you keep trying!

I don't have the recommended yellow glue, so I'll give it a try with white glue.
In the first attempts, I found I was spreading out the glue to far when rubbing it between my fingers.

In later successful tries, I pressed my fingers together, spreading out a drop of glue. Pull your fingers apart and let it the thin glue sit for 10 seconds. This lets it tack up a little before rubbing again. Rub the glue for a few seconds.

Again, hold the fingers open and still and wait again. Then more rubbing.


The glue was starting to "thread up".

I rolled these small, drying pieces into a ball.





Here's the F.G.P. in place, on the turbo pump dowel. I haven't done any forming of the putty yet. It'll be smoothed out and feathered into the engine bell.

LAUNCH! Schoolyard, November 21, 2010

I got up a little earlier than normal for a Sunday, why not launch a few before the winds pick up?

This is the Hot Rod Rockets BELL BOTTOM won on Ebay.

It's a conical stabilized model with streamer recovery. Great flight on a A3-4t engine.

It came back close enough I caught it before it hit the ground.

I made up a larger UP! CUP from a 16 oz. styrofoam cup.

I had great success with the earlier 13mm version, this one would fly with 18mm engines.

Look to the bottom left of the cup. I added too much clay to the lower end hoping it would lift the nose and "glide" down, lifting body style.

It didn't! After it left the rod with a B6-2 engine, it went horizontal. Landing about 100 feet away, there was no damage. It'll fly again, but without the clay weight on the tail end.

On a positive note, the engine ejected and the attached streamer did unfurl.
After two launches of the smaller 13mm UP! CUP there was soot and slight melting of the inside foam wall. On this larger cup the inside of the cup was coated with white glue to protect the foam from engine flash. That seemed to protect the inside wall. It wiped up clean with a damp paper towel.

On a sad note -

Here's that old Quest MMX igniter right after it's 14th launch!

I was going to use a 15th time today, but it broke when inserting the retention toothpick.

Here's the math -

14 uses X $.40 (per igniter) = $5.60 - $.40 (one time use) = $5.20 savings!

I subtracted the first, one time use of the igniter and only calculated the repeat uses and savings.

Gee, now I can afford those other more expensive igniters.

I'm using a six volt Estes controller with the MMX igniters. I would see more burn through if I had been running a 12 volt system.

The MMX SKYWRITER it's 14th flight on a Quest Micro Maxx engine. I also caught this one on recovery.

Also flown - The downscale GALAXY GUPPY and MICRO BIG BERTHA had successful flights on MMX engines.

The Micro Bertha should be rebuilt, next time for 13mm engines. It doesn't get the altitude to make it worthwhile using MMX engines.

TIP: A note on the Micro Bertha - Two years ago, Instead of Kevlar, I was using hemp shock cords. The hemp has held up very well after quite a few ejection charges. Hemp is cheap and works fine, it just isn't very pretty.

All five rockets (MMX, 13mm and 18mm engines) were launched using my surplus Quest Micro Maxx Q2 igniters! No pyrogen, just thin bare nichrome.

Dr. Zooch Saturn 1 SA-5 Build Part 28 Details

The S-IV Ullage Motors are angled at 30 degrees.

You should sand the end of a dowel to 30 degrees before cutting it to the 1/8" length.

I printed an online protractor. You can find one HERE

The dowel was set parallel to the bottom of the protractor base line on the print.

My sanding block was set to 30 degrees on the protractor.

Both were held at this angle and lifted from the protractor.

The angle was sanded by moving the sanding block back and forth against the steady, held dowel.

The angled dowel was cut to a 1/8" length.

Be ready and hold both ends down while cutting.

When the first piece of 1/8" dowel was cut free, it flew across the room!

The lower end of the 1 1/4" pieces of LH2 continuation ducting have to match the angle of the fairing.

This is simply a trial and error process. Sand, then check the fit.

In the picture at the left, I still had to change the angle by sanding a little off the tip side to get the proper fit.

After you get the angle right, then round the top.

Dr. Zooch Saturn 1 SA-5 Build Part 27 Details

Before cutting any of the dowel pieces, you might want to seal the wood. I used two coats of varnish, rubbed on with a paper towel. Lightly sand between coats.
The sealed dowel "ducts" will look much smoother when the paint is applied. I'd recommend sealing and sanding everything in one piece before cutting the ducts to length. It's easier to sand the dowels when the piece is longer.

In Step 10 you add all the dowels and trim pieces.

The upper LH2 Ducts glue against the body tube. I decided to sand down the side a bit so they would have a better gluing surface.

I wasn't going to sand these to a half round, but just take a little off one side for a flatter gluing area.

Dowels can be hard to sand, they'll want to roll.

To be sure the dowel would be sanded on one side only, I darkened the edge with a Sharpie. This thick line was drawn down one entire dowel.

When sanding, this line lets you know the dowel is still facing up. The line also works like a depth gauge, the more you sand off, the less of the line is left.

This is what the line looks like when a just little of the line is left, a thin line on either side of the sanded, flattened area.

Dr. Zooch Saturn 1 SA-5 Build Part 26 Fin Gluing

The larger fins are glued on the four printed lines.

The stub fins center between those.

If you masked the root edge before painting you should have a strong enough bond without cutting through the lower wrap.

I didn't think about the inside fin overhang on the root edges. I'll have to touch that up.

The color separation on the outside edge of the far right fin will need some cleaning up.

Here's all the fins are glued in place.

A shot of clear coat will help blend the painted and printed surfaces.