HABU RC rocket glider kit
The Habu is a limited run kit. First run is sold out. I’m taking names for the next run, use the contact form to get on the list, when I have 10 I’ll order parts for the kits and then invoice you when everything is ready to start kitting.
The Habu RC Rocket glider kit comes with white BMS tubing for the body and engine nacelles and Model Plane Foam (MPF) wing and tail surfaces. You will need two 8-11 gram type servos, a receiver, and a small 500mah single cell lipo battery and an 18″-20″ servo extension. You will need a transmitter with delta or elevon mixing. You will need foam safe CA+ and 3m-77 spray contact adhesive for assembly. Please refer to the General instructions for all kits tab above, then read these instructions completely before starting assembly. This kit is approximately 15% larger than the old hobbylab kit and has about 32% more wing area. Wingspan 21.5″, length 39″(about 1/32 scale) weight 13.5-14 oz rtf.
CG location for rocket flight: 1/4″ behind the the front of the nacelle tubes.
Welcome to the world of rocket boosted radio control gliders. This is not a model for a novice RC pilot, but anyone who is comfortable with RC flying of an aileron controlled medium speed model should be fine. Read through the instructions, look at the photos and be sure you understand the step before commiting to cutting or glue.
Identify all pieces, the kit should contain:
1 wing taped together
1 wing foward section
2 wing doublers taped together
2 vertical stabilizers
2 body tubes
1 nacelle tube(will be split and used for the right and left nacelles.
2 control horns
Velcro(for battery and rx/bec attachment)
3M blenderm tape
Upper and lower nose section
2 intake cones
Ply plate and screw
motor tube with clip
long and short carbon spars.
Wood block and screw for attaching the upper nose.
2 landing skids.
Spare foam (for testing paint, glue, and sanding the edges to see how it behaves)
- Look at all parts and understand what pieces go where. There are a few pieces that are laminated together before assembly. Those are laminated with 3m-77 spray. You apply this lightly to both sides let dry for 1-2 minutes till tacky then press together. Be sure not to spray too close to the foam or it can cause some melting. The model was designed to use foam safe CA+ glue and accellerator(I use bob smith brand with the black cap) and 3m-77 spray adhesive only. If the instructions say “glue” that assumes using foam safe CA+ the 3m-77 will only be used for specific steps.
- The 3-d printed parts will need to be cleaned up a bit. The intake spikes should be cleaned of flashing and the flowthrough holes in the outer ring can be opened up with an exacto knife. The top and bottom cones will need to be separated with a razor saw and the bottom sprues sanded flush. The 3-d printed parts have a texture, you can use 220 grit sandpaper to smooth this and then you can apply acetone to a paper towel folded into about 1/4″ thick and saturated, just wipe the surface a bit and let dry. The foam has texture, and the sanded foam will have texture and the model will be panted flat black, it will never be a shiny model, so do as much as you feel is needed. I like a bit of the texture. Don’t over sand the surface as the surface is thin and the part is hollow with reinforcing inbetween the inner and outer skins, you can sand through these and leave holes if you are too agressive.
- Unfold the main wing and glue the taped joints. the forward joint is taped only on half of the cut so that it can fold to fit into the box, you can add a second piece of tape to support the cut before you glue the front fuse joint.
- Glue in the two spars into the premade slots on the bottom of the wing and then tape over with blenderm tape.
- Unfold the two wing doublers and glue them at the taped joint.
- You may use 220-320 grit sandpaper and a sanding block to round the edges of the foam before further assembly. Sand the two doubler pieces before gluing to the wing, note there is a top and bottom to the doublers and it makes a difference! The top of the doublers is the side without the tape! The bottom has X’s marked with pen. Just round or taper sand the top edge of each piece the full length. Round the wing leading and trailing edges and the strake up till the point where it starts to curve toward the tip. Sand the curved portion and tip after laminating the doublers in place. Round the leading and trailing edges of the vertical stabilizers at this time as well. NOTE***The foam has a smoother side and a rougher side. I’ve created the wing and doublers so that the smoother side is more visible so you will wind up with a more consistent finish when you paint
- The wing and wing top/bottom doublers are laminated together with 3m-77 spray. You apply this lightly to both sides let dry for 1-2 minutes till tacky then press together. Be sure not to spray too close to the foam or it can cause some melting. If you get any overspray on foam you don’t want glued CA accelerator typically will soften the adhesive and you can wipe it off with a paper towel. Be careful taping to the foam, there is a slight skin on the foam sheet and when you remove tape it will remove the skin and it will show when painted. Minimize the amount of masking you do on the bare foam.
- Mask off the area outside the marked lines on the bottom of the wing using wax paper or paper towels. Spray the 3m-77 on the exposed area and the bottom of the wing doubler that has the cutouts toward the front. Make sure you are spraying the side with the X’s marked in Pen. let dry for 2 minutes or until lightly tacky. Remove the masking and apply the doubler onto the wing, using the lines as a guide. Make sure the rear is even with the end and the motor cutout is centered. Note the motor cutout on the doubler is cut at an angle so that the motor will insert and be captured. Repeat for the top of the wing using the other doubler without the forward cuts.
- Glue the two pushrods/control horns in the bottom of the wing in each control surface in the pre-punched holes using CA+. Apply CA+ to the top of the control surface on the prongs from the control horns to capture them in place. Set with accelerator. Note in the picture how the control horns face, the flat part of the control horns faces forward so that the holes that the pushrod go in are even with the hinge line.
- Your radio needs to be configured for Delta mixing, this means that the servo arms will move the same direction during elevator stick movement and opposite for aileron stick movement. Connect your servos to the receiver one in the aileron connection and one on the elevator connection and apply power. Use a servo arm at least 9/16” long and with holes small enough that there won’t be slop with the pushrod wire when installed. I use the hole furthest out on the servo arm, to maximize movement. On some servos there are a long two-ended servo arm, you can use this arm and trim off one end. Zero out any trim settings on the transmitter.
- Connect a servo to each pushrod. If the pushrod is too tight, you can use twist an X-Acto knife in the servo arm hole to make it larger, but be careful and do not make it too large. Note that the servo arm will be facing the center of the model so that the pushrod comes to the servo at a 90 degree angle from the hinge line. Once connected check control surface direction. Flip the model right side up and look at it from the rear. Moving the transmitter stick back(up elevator) should move both elevons up. Moving the transmitter stick to the right should move the right elevon up and the left elevon down. If you can’t get the servo reversing to give you the right polarity try swapping aileron/elevator inputs to the receiver or turning the servos over and swapping the servo arms to the other side of the output shaft. If that is correct insert the screw to hold the servo arm in place.
- Flip the model upside down. The servos may be attached to the model using double back servo mounting tape(not included) or by directly gluing the servo to the wing with foam safe CA+. Double back servo tape can loosen over time and with exposure to heat, I prefer to glue the servo in place. With the radio still on, put a moderate amount of glue on the servo, being careful not to get any near the output shaft, and set it in place on the model keeping the control surface centered. Do the same to the other side. Make sure the glue is set before continuing. Note** The servo electrical wire should point toward the front of the model, you want the pushrod to be perpendicular to the hinge line, the servo will be near the edge of the wing doubler. See the photo for an idea of how it should look. Tape the servo wires down toward the center of the model.
- I mounted my receiver on it’s side in the center of the model. I had to cut a hole in the center of the model so that the long antenna from the AR-400 receiver goes through the model and tapes to the top of the top doubler so that the body tube would clear the receiver when glued in place. I inserted an 18″ to 20″ servo extension into the throttle output and connected the battery wire to the other end and taped it down in the center of the model. The wire needs to be long enough so that the battery connector sticks out the front of the body tube for access. I taped down the antenna on the top of the wing down the middle as well. If your servo wires are longer you can place the receiver further forward, or you could use servo extensions to move the receiver further forward as well. You do not want the receiver all the way out of the front of the body tube because you need room under the cone for the nose weight and battery.
- Glue the two body tubes together with the foam safe CA+. The body tube is marked, make sure you align the two tubes so that the arrows are aligned so that the marking guides are correct.
- Once the glue is set, using an exacto knife, carefully using multiple light cuts slowly cut the body tube into two pieces. I found that trying to use a piece of angle aluminum as a guide to cut the line caused deformation of the tube and make the knife go crooked. I found doing it slowly freehand took a little bit of time but if you go slow and make multiple passes a little at a time will yield the best result. you can sand the edge slightly if desired but the glue fillet will hide small gaps.
- On one of the tube halves there are marks for the rail buttons. This will be the bottom of the model. Cut holes as marked and install the rail buttons from the inside. If the rail button T nut flanges deform the tube, bend the flanges slightly with a pliers to allow them to contour to the inside of the tube.
- Place the bottom tube on the bottom of the model with the rail buttons toward the rear and with the rear of the tube even with the rear of the model. Make a mark where the tube goes over the servo wires and cut small notches so that the body tube clears the wires.
- Carefully glue the bottom tube in place using foam safe CA+ and accelerator. Take your time and do a bit at a time, you may need to squeeze the tube slightly as you go to keep it round since it tends to flatten out once cut in half. This is especially important as you get to the front where the cone shoulder needs to fit inside. Use the cone as a guide at the front but be sure not to glue the cone to the foam.
- Make holes and glue in the two skids on the bottom of the model on the marks. Make sure the skids are vertical and in line with the rail buttons. The skids help protect the rail buttons when landing on a runway and keep the nose off the ground.
- Find the short 2″ diameter pre-marked body tube with the slots pre-cut. Carefully cut the tube on both sides to make two halves using an exacto making multiple light small cuts, take your time. Using an exacto or scissors cut the rear angles as marked, these are needed to clear the elevon. Note the angles are not symmetric because the elevon is angled and the two sides need different angles.
- Flip the model over and lay one side of the wing on a table edge and supported so that it is flat.
- Look at the two pieces of nacelle tubing. There is a left and a right. They are marked on the tubes and the slot on for the vertical stab will be inward. If you have these swapped the elevon won’t have proper clearance to move.
- Glue the correct nacelle tube in place. The font of the nacelle tube is even with the front of the wing and the rear must allow the elevon to move fully. There is a line on each wing half for gluing the nacelle. IT IS CRITICAL the first edge is glued on the line otherwise the nacelles may not be straight and the vertical stabs will have an undesired rudder angle built into them!! Glue the other edge in place, at the front use an intake cone as a guide for the front of the tube to be sure it is round and will fit the intake cone. You can glue the intake cone at this time, it will butt against the wing and recess into the nacelle tube.
- Repeat for the other side. Use accelerator to set the glue as you go.
- Test fit the motor tube in place, the doublers are angle cut so the motor tube should slide in and be held in place and straight, lightly trim or sand so that it slides in place. Note the motor hook is glued and taped at the front, make sure you slide the motor tube in so that the motor hook is on the top or bottom so that the hook can move to release the motor, apply foam safe CA+ along the top of the tube to keep it from moving. The motor will be pushing on the foam so the motor tube doesn’t need a lot of glue to hold it in place.
- Glue the top body tube in place on the wing doubler keeping it straight and centered and even with the rear of the model as you did the bottom tube. Do a little at a time and make sure the front is centered and round using the top cone shoulder as a guide at the front as you did the bottom tube.
- Glue the top cone in place
- glue the two vertical stabs in place in the slots. There is a smoother side to the foam, have that side outward. The stabs angle inward, it isn’t critical the absolute angle just try to get both sides approximately the same. Reinforce the joint on both sides with a CA fillet on the inside and outside of the tube, use accellerator to set the glue before proceeding.
- Flip the model over.
- Glue the wood block into the front of the recess in the bottom doubler as shown.
- Attach two of the lead weights into the recess just beind the wood block.
- Put some velcro on your battery and on the lead weights. Attach your battery to the velcro and install it into the model.
- Insert the bottom nose cone into the model and center it. Drill through the hole in the bottom cone into the wooden block. Use the provided screw to hold the cone in place. Note do not snug the screw down so tight you break the plastic, it just needs to not fall off.
- Paint the model using ONLY testors Flat black small rattle can paint. This is the only paint I recommend. Mask off the rail buttons and the servo output arms to prevent paint from getting on them. Do not spray too close to the model. Use many light coats and do not spray heavy. I apply a coat to all the edges of the foam first since it tends to soak into the sanded exposed edges and look lighter, then apply light coats till the model is covered. Paint adds weight, use just enough to get a nice even finish.
- Once dry you may apply the markings. Carefully apply the markings and slowly roll the backing paper off as you apply pressure to the marking. Once applied, use a hot hairy dryer to soften the markings and press them down with your finger to set them into the paint and foam. You can use a silver sharpie to add panel lines or accents if you wish. I’ve included some silver strip that is marked in 1/4″ squares you can cut this into squares and apply them for the rear bypass inlets on the nacelle. I also included a piece of silver that can be used for cockpit windows if you don’t like the blue. Simply apply the blue cockpit windows to the back of the silver backing, then cut out from the backside using the decals as a template, then apply by hand.
- Install your loaded motor.
- Support the model at the balance point indicated for boost. Add more weight as required, if the slot in the foam is full attach the weight inside the bottom nose cone as required to balance. If the model is nose heavy you may remove some of the lead weight that was installed. Do not try to fly the model too nose or tail heavy. Remember, a nose heavy model flies poorly, a tail heavy model flies once.
- Set up your throws and trims: The model uses approx 5/8-3/4″ up and down elevator throw and 1/2″ left and right aileron throw. It is quite roll sensitive on boost so you may tone this down as needed. For boost I used zero trim but you may need some depending on how your model is built, and for glide I’m using about 3/16 of up trim or a slight bit more. I put this trim onto my flap switch so that I can go from boost to glide trim with the flip of a switch. Make sure when you launch you are in boost trim or it will be a very short flight.
Flying: Be ready on the first few flights to keep the model straight till you have the trims set perfectly for boost and glide. Try to do initial flights in dead calm conditions. You need to be ready to react quickly to keep it boosting straight up or slightly away from you. Keep the wings level. Count to 7 and start to push the model over level as the motor burns out and it slows down. Then click in the up trim. Once in a glide, if the model wags the wings it is getting too slow so push the nose forward slightly or reduce your up trim. Avoid drastic bank angles which cause you to lose altitude and make it easy to lose orientation. Gently fly around, and set up for landing into the wind when about 100′ high. The model will rock the wings if you start to get too slow, if this happens push forward on the stick slightly. The decent rate is very predictable, note the angle it is coming down at and head into the wind, keep some speed up so you don’t stall, and keep the wings level as it decends and gently flare just before touchdown. Try not to flare early and stall the model.