GDRM Instructions

The GDRM(Gliding Der Red Max) RC Rocket glider kit is a gliding version of the classic Estes Der Red Max rocket.   It comes with a plastic nose cone, 2.6″ white tubing for the body,  6mm depron wing and tail surface. Spars are pre-installed, elevons pre-hinged, body tube pre-slotted for the tail.  Construction is very simple and takes about an hour and a half.   Please refer to the General information for all kits tab above, then  read these instructions completely before starting assembly.   Length 34″, wingspan 23″, weight 10.75 oz rtf.  High quality cut vinyl decals available from stickershock23: HERE

CG location for rocket flight:  13” forward of the rear end of the body tube.   

Unpacking your kit:

The kits are packed to protect them in shipping, but the contents are fragile so unpack carefully.  Carefully cut the tape holding the tubes in the box, then unwrap/lightly cut the plastic wrap to free the tubes, the spar may be packed in the tubes and the baggie with the little parts and nose cone will be in the tubes as well.  Carefully cut the tape holding the cardboard wing protector in the box and carefully remove it, don’t pull hard or bend it.  Then carefully cut the tape holding the cardboard top piece to the bottom.  There may be some sticky tape holding the cardboard to the bottom cardboard piece, carefully peel it being sure not to bend anything.  Once the top cardboard is free you can see the foam wing/tail parts, there are little fragile pieces in here, so unwrap carefully.  It may be best to use an exacto to lightly cut the plastic wrap and carefully remove it without cutting into the foam.  Make sure everything is free before you remove the pieces to avoid breaking anything.  Kits contain one or two scrap pieces for repairs if you damage anything in construction or flight, just cut and patch in a spare piece of the foam if needed using foam safe CA+.

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 a medium speed model should be fine.  Read through the instructions, look at the photos and be sure you understand the step before committing to cutting or glue.

Identify all pieces, the kit should contain:

1  wing  taped together

1 Nose Cone

1 vertical stabilizer

2 wing reinforcing strips

2 control horn​s/Pushrods

2 Body Tubes

1 coupler

Motor mount

3  13/16″ x 2.5″ wide strips to center the motor tube

Velcro(for battery and rx/bec attachment)

Lead weight

Notes before starting:

Foam safe CA+(Bob smith super gold + is good) is the only glue recommended for construction.  You will also need foam safe accellerator to set the glue.

I prefer to use an exacto and a straight edge to cut a 1/16″ bevel into the edges of the foam before assembly, it’s less messy and faster than trying to sand the edges round.


  1. Glue three 2.5″ long foam strips on  the motor tube using foam safe CA+.  These help center the motor tube in the body tube once you insert it into the body tube.   Note the tabs will be on the sides and bottom of the tube, the fin tab will make contact on the top of the tube. Refer to the picture. Glue the motor block in the front of the motor tube at this time.   Motor hooks never stayed taped in place so I don’t use them any more, simply put a small piece of tape on the motor to keep it from falling out after burnout.
  2. Install the rail buttons in the rear body tube at this time.
  3. Join the two body tubes using the coupler, make sure you keep the arrow marks aligned on the two tubes so that the wing alignment mark is straight.
  4. Apply CA+ to the taped  wing joint, and apply CA in a squiggle pattern about 1/2″ on either side of the wing joint and on either side of the pencil mark on the body tube.
  5. Lay the wing over the body tube upside down, and make sure the rear of the wing at the center is even with the rear mark on the body tube.  Make sure the line drawn lengthwise down the tube is aligned with the center of the wing joint.   The wing tips should touch the table top that the body tube is resting on to set the dihedral angle.  Hold the wing in place till it sets completely, use accelerator to help set the glue.
  6. Once set flip the model over.  Apply glue to the reinforcing strip on the flat bottom edge and slide it into the joint between the  body tube and the wing.  This adds extra glue surface to help reinforce the wing joint.  The foam strip should be centered front and back on the wing.  Don’t press the strip in too hard as it can rotate the body tube wrt the wing and make the vertical fin offset.  Apply a fillet on the top and bottom of the strip/wing and strip/body tube joint.  Repeat on the other side.
  7. Glue the vertical fin into place.  Make sure the vertical fin is straight up and down.  Apply a light filet to both sides of the vertical stab on the inside and outside of the body tube.
  8. Test fit the motor mount into the body tube and under the fin tab.  Make sure it fits, or sand the foam tabs lightly.  Glue the motor tube in place, it will inset about 3/4-1″ from the end of the body tube.   Put a fillet on each side of the motor mount tabs and fuselage.
  9.  Apply CA+ to one of the control horns and press it in place on the BOTTOM of the control surface in the pre-made holes. Note The control horn holes face forward and the pushrod should be closest to center of the wing.  Repeat for the other side.  Apply a fillet around the control horn on the the prongs on the top of the wing to lock them in place.​  See photos.

The basic construction is now complete.

Radio Installation

Note:  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 trim off one end and use that arm to get sufficient length.   Zero out any trim settings on the transmitter.

  1. Flip the model upside down.  Connect each servo to a 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.  Each servo  should be on the bottom of the wing, with the servo electrical wire pointing forward and the servo arm pointing toward the wing tip.  Tape each servo in place so that the control surfaces are centered and the pushrod is perpendicular to the control surface hinge joint, the servo will be in the middle of the wing.  With the model right side up 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, continue.
  2. 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 wing keeping the control surface centered.   Do the same to the other side. Note the servos are in the middle of the wing and the pushrod is pointing straight ahead.  This is to make sure the servos are far enough out on the wing that the dihedral will prevent the servo arm from making contact with the ground first on landing.  Make sure the glue is set before continuing. Note**  The servo wire should point toward the front of the model.  Apply a fillet of glue around the servo/wing to help secure it and let it cure being careful not to get any glue near the output shaft of the servo.
  3. Attach a 16″ servo extension to each servo. You just need to be able to route the wire to the front of the tube to attach it to the receiver.
  4. Make a 1/8″ wide by 1/2″ long slot in the wing centerline and through the body tube.  Route the wires through to the inside and toward the front.  See photo for more clarity. You can use any spare vinyl trim, trim monokote, packing tape etc to tape down the servo wires to the bottom of the wing.
  5. Re-Attach the servo wires to the receiver and make sure they are going the right direction.
  6. Make sure the control surfaces are centered, use trims if needed.  Now measure the control surface movement.  Full elevator movement should be 5/8-3/4″ in each direction, aileron movement should be 3/8-1/2″ in either direction.  Sometimes the foam has a slight curve to it at the wing tips, it won’t affect flight performance.  When setting the control surfaces for neutral use the middle of the wing as your guide for what is level.
  7. If you have a flap/elevator mix you can program up elevator trim for boost and glide.   If you can’t set the up elevator trim to a switch on your radio you’ll have to manually put in boost and glide trim using the trim tabs which is hard to do while flying the model.  My model needed  approximately 1/4-5/16″ of up trim for glide.
  8. Use the included Velcro to attach the receiver insde top of the nose cone. This allows you to be able to remove and replace the receiver if needed for repairs or for removing the servo wires.
  9. I attached the battery inside the nose cone on the bottom of the shoulder with velcro.
  10. If you decide to paint your model, I can only recommend testors/model master enamel spray at this time, others I’ve tried damage the foam surface.   Paint typically adds 1/2 to 3/4 oz. The body was painted with testors flat read and the nose cone and a 3.25″ wide band at the front of the model was painted using gloss black.  The band starts 1/2″ to the rear of the front of the body tube.
  11. If you choose to use the stickershock markings, after application use a hair dryer on hot to warm the markings and them push them down into the foam surface with your finger.  They will really conform and stick down well. Read the general instructions tab above about applying the decals to painted surfaces.
  12. Install your battery.
  13. Insert your heaviest loaded rocket motor into the motor mount
  14. Support the model upside down at the balance point indicated for boost.    Glue supplied lead weight  in the nose or tail as needed to balance it. Do not use all of the lead, just as much as needed.  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.

Flying:  See the General Instruction link at the top for flying instructions.  Be ready on the first few flights to keep the model straight till you have the trims set perfectly for boost and glide.