Apogee Heliroc Part 20 Finished!

Here's the finished Heli-Roc with the rotors flipped up!

The lower half of the rocket with the rotors up.

The full view showing the span of the rotors.

This build was a good stretch! I learned a lot about tissue covering and a new (for me) recovery method.

The instructions call it a Skill level 4 - Challenging. This is a good rating for the kit.

At first I thought the solar panel markings might be a little hokey, but they really look great! The self-adhesive stickers actually strengthen the rotor blades.

If you are looking for a build out of the ordinary, I highly recommend this kit.
I look forward to flying it.

Apogee Heli-Roc Build Part 19 Rubber Bands

The rubber band "cradles" from the last step are glued in place on top of the rotor stops.

I've placed the three rubber bands under the metal hooks and over the top of the rotor stops. This would be a good place to hold the rubber bands between launches. I wouldn't store the model with the rubber bands under full tension.

Apogee Heli-Roc Build Part 18 Rotor Stop Lugs

In Step 18, the remaining launch lug is cut in half and to the length of the top of the rotor stop.

I decided to fill, sand and paint the lug before cutting it to size.

After the lug seams were filled I slid them on the end of a cotton swab for a spraying handle. The lugs were sprayed white.

The lug was slipped over a launch rod for cutting. I wrapped tape the rod for a tighter fit.

The front of the lugs were marked with a pencil for cutting. These lines were extended down the length of the lug.

Before cutting, while the lug was on the rod, I sanded the paint off two (opposite) pencil lines for a better glue bond.

The lug was cut in half lengthwise and sanded flat against 220 grit sandpaper on a block.

Here's the three lug halves cut down to the length of the top of the rotor stop.

You can see where the paint was sanded off for a stronger glue joint.

Apogee Heli -Roc Build Part 17 Burn Thread Holes

Drill two holes, 1/16" diameter by spinning the tip of your hobby knife on the body tube. The hole center should be 2" up from the leading edge of two fins.

Make the hole rounder by pressing and spinning a toothpick in the hole.

I added a little glue around the hole for strength.

Apogee Heli-Roc Build Part 16 Hooks

Three metal hooks are bent from the supplied music wire.

These are small, you'll need needle nose pliers to make the small hook.

Enough wire is supplied to make five hooks. I made five and chose the best three hooks.

A small hole is made in the rotor blade for the wire hooks. This pin turned out to be too big a diameter. I narrowed the hole width with white glue pushed in the hole.

With the flat back of the hook pressed against the blade, thick super glue was applied to the sides of the wire with a toothpick.

Apogee Heli-Roc Build Part 15 Self Adhesive Decor

These ares the supplied self-adhesive panels on the rotors. They look good and will help strengthen the long balsa rotors.

While the face card shows the grey panels all the way back on the trailing edges of the fins, I decided to raise them a bit

A red stripe goes around the nose cone beneath the hooks.

The rotor stops are glued in place. Before gluing, raise the blades and check their position near the body tube. Set the stops in place so the 8 degree side fully butts up over the thread wraps.

Apogee Heli-Roc Build Part 14 Hinges

Here's how the hinges line up.

The corner of the trimmed hinge touches the back corner of the reinforcement strip. Enlarge the picture to see better detail.

Hold the blade steady in the correct position. The free end of the hinge was flipped up and thick CA was applied to the body tube where the hinge made contact. I used a toothpick to transfer the CA to the body tube. The hinge was then folded over and set into the CA.

For the next step, you'll find it easier to tie the blade ends down on the body tube.

I used white shroud line thread instead of the supplied red Kevlar so it would blend better with the white body tube.

The wrapping of the thread went much easier than I thought it would.

The end of the thread was tacked down with a small drop of thick super glue.

Wrap the thread as evenly as you can. After the wraps are complete, use a toothpick to evenly spread out the line spacing.

After spacing the wraps, put a drop of thick CA on a cotton swab and glue the thread to the flat face of the hinge.

Don't leave the in one spot for very long - touch and remove. If set down to long, you could glue the cotton tip to the model!

Here's the thread after wrapping, spacing and gluing in place.

Apogee Heli-Roc Build Part 13 Hinges

In Step 12, the hinges are cut to this profile. With one side trimmed down, it better fits the contour of the body tube. Scissors easily cut through the hinges.

The rotor is marked for the untrimmed side of the hinge with the Hinge Placement Guide .

The instructions suggest using a felt tip pen, but a pencil line was easy to see on the tissue paper.

The back of the hinge was coated with thick CA. The thick CA gives you a little extra time for positioning.

Once in place, small drops of the thick CA were applied into the holes on the hinge with a toothpick.

Apogee Heli-Roc Build Part 12 Paint

I decided to go ahead and paint the body before the rotor blades were attached. It'd be to hard to get paint into all areas once the blades were in place.

The main body fins were already filled, primed glued in place and filleted. Then, the white coats were applied.

The rotors hinges will be glued on over roughed up paint. When pre-painting like this, glue joints won't be as strong as when you glue together untreated or unsealed surfaces.

Apogee Heli-Roc Part 11 Trimming Tissue

After all has dried, the overhanging tissue was trimmed off with a razor blade.

Another coat of clear dope and the tissue covering is finished.

I was surprised how transparent the white tissue is. It almost looks like raw balsa.

You could dress up the edges with some very light sanding with 400 grit, just don't sand off the tissue.

The three rotor blades are ready for the hinges.

Now, back to Step 12 of the instructions.

Apogee Heli-Roc Build Part 10 Tissuing Rotors

Ahead in step 22, it is suggested that you can cover the rotor blades with tissue to increase their strength.

I hadn't done any tissue work since the 1970s. I thought I remembered the technique, I just had to buy clear dope and tissue. It took a little searching at the hobby store to find it. By the looks of the envelope, I don't think many people take the time to do this anymore. After some Internet searches I had refreshed my memory on how to do it. I still screwed it up.

I forgot to check the "grain" of the paper before cutting it out. You find the grain by tearing the corner of the sheet. Which ever way it tears easiest - that's the length or run of the grain. The long grain should have run down the entire length of the blade. I ran it the wrong way. Oh well, it's still stronger than it would be without it.

The blades got two coats of clear dope, sanding lightly between coats. You aren't sanding down to the surface, leave a dry coating of dope.

The tissue is cut slightly oversize. Note how it is layed down in the picture. One straight side of the tissue evenly overhangs the front of the rotor. This will wrap over the leading edge and onto the flat bottom.

This overhanging edge insures full coverage of the tissue. (Sorry the picture is out of focus, it's just the way it turned out.)

The tissue is set in place and a light brushing of thinner is applied over the top. The thinner permeates the tissue and goes into the dope on the balsa rotor. This now thinned dope locks the tissue onto the surface.

In this picture, the airfoiled top has the tissue in place. Here I'm rolling over the straight overhanging edge over the edge onto the flat underside.

It doesn't take much thinner to to break down the underlying dope coats and adhere the tissue. I dip my brush into the thinner then take off some excess on a paper towel before going over the tissue.

Apogee Heli-Roc Build Part 9 Fins and Launch Lug

The fins are glued in place, 1/2" from the rear of the BT-5 tube.

Here again a square piece of paper was taped around the tube to be sure all the fins are at the same height. Using a paper guide like this helps when the fins aren't glued even with the base of the body tube.

A launch rod was set beside the two launch lugs for alignment. Sometimes I'll run the rod through the lugs.

Either way, lightly tape the rod to the body tube.

Lug position is critical on this rocket. You can see how the rod passes right beside the balsa reinforcement strip.

Apogee Heli-Roc Build Part 8 Nose Cone Seam

I decided to fill the body tube / nose cone joint.

The tip of a older X-Acto blade was dipped in thinned Carpenter's Wood Filler. The blade tip was set in the seam and the small drop of CWF was dragged around the joint.

Doing it this way keeps the filler right where you want it and the blade tip guides the filler right into the seam.

After sanding down the primer, I had to add some more filler into some recesses above the body tube.

That filler was sanded down using a block.

This is a cast resin nose cone and not very porous so there isn't much for the filler to "grab" onto. I applied some thin CA glue with a Q-Tip to keep it in place.

After the masking tape strips were removed, the masked area was lightly sanded to remove any paint ridges.

The balsa reinforcement strips were glued down. Enlarge the picture and you can see how the center tick marks were lined up.

Under the two reinforcement strips in the picture is a wrap of paper. This is another way to guarantee all the bottoms of the strips are at the same height.

Apogee Heli-Roc Build Part 7 Prep and Priming

Before gluing the balsa parts to the body, I also wanted to prime the body tube. The body tube seams were already filled with thinned Carpenter's Wood Filler and sanded smooth. Next, the spray primer will fill any of the remaining seam.

I cut thin strips of masking tape to cover the root edge gluing surfaces on the body tube. As mentioned in the last post, I am filling and priming the balsa pieces before gluing them to the body tube.

Notice the center tick marks between the ports. The balsa reinforcement strips will also have a center mark.

It's just easier to to match up the marks before the glue has a chance to set up.

NOTE: This is not as strong a glue bond as gluing the fins directly to the body and THEN priming and painting. This is just another way to "pre-finish" a rocket.

Masking off the root edge areas of the tube will give me a stronger gluing surface. I'll have a raw balsa root edge glued to the masked areas on the body tube. I've also stuffed small pieces of paper towel into the ports to keep paint out of the body tube.

The base of the nose cone got a coat of 15 minute epoxy to protect it from the ejection charge. After drying, the nose cone was glued in the body tube with epoxy.

BE SURE THE HOOKS IN THE NOSE CONE ARE CENTERED BETWEEN THE PORTS!

Apogee Heli-Roc Build Part 6 Filling Balsa

Looking ahead to Step 17, the rotor stops should have a dihedral angle of approximately 8 degrees.

I got out my protractor and drew up the angle to check the rotor stops.

After "group sanding" the stops I wanted to be sure the angle was still at 8 degrees.

Note: These steps are not in the instructions. You are directed to seal the balsa surfaces with two coats of sanding sealer. This is just how I chose to fill the balsa.

With the balsa surfaces sanded smooth, I wanted to fill the grain off the body tube.

The three reinforcement strips are small and would be tough to hold on to while brushing on the Carpenter's Wood Filler. I used a pin stuck in the root edge to hold the strip.

After all the wood filler was sanded off, primer was next.

Here's all the balsa pieces stuck on a piece of cardboard for primer spraying.

Masking tape is laid down sticky side up. The root edges of all nine pieces are stuck down with the fin standing on edge. This keeps the root edge clean with no paint on it for a better gluing surface.

Apogee Heli-Roc Build Part 5 Ports

I used a strait edge to cut the slots.

Be careful not to over cut the corners. I pressed the tip of the blade into the corner and stopped the cut before reaching the end of line.

The tube was turned around and the cut was finished from the other side.

To strengthen the body tube and the cut out ports, thin CA was applied to a cotton swab and rubbed inside the body tube around the cut port edges.

A small amount of CA was also run around the ports from the outside. Any buildup of the super glue is easily sanded smooth.

Here's a finished port after sanding the CA glue smooth.

Apogee Heli-Roc Build Part 4 Ports

On my BT-5 tube, the fin marking guide was a little to wide. It over wrapped by about 1/32".

I knew the fin marks and ports (or slots) would be critical, so I made a new marking guide.

After the three fin marks were made, I centered the ports over the three lines.

I only cut one box out and rotated the same "master" around the tube to draw three consistent rectangles.

Here I used the top of the wrap to check the top and bottom of the ports to be sure all lines were level with each other.

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.

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