Aerobeez 73″ Sbach 300 Step by Step Build Guide

Posted by aerobeez On July - 23 - 2014

Hello Aerobeez Pilots and welcome to our 73″ Sbach 300 Build Guide! Like the previous two articles this build guide will walk you through step by step as you build your new 73″ Sbach 300 ARF Kit. Having experience with putting any ARF together is good, but with our guide even an inexperienced builder should be able to put this kit together in about 10-12 hours. Look for “Pete’s Tip’s” and our notes that will help walk you through this build like a seasoned pro. Now lets get started building!

Step 1.1: First install the main landing gear.  This makes the build much easier by having your fuselage sit up on the wheels. Locate all your main landing gear parts and have them ready to build. Note: Small containers are excellent when you separate the parts for the build.  

Sbach 300 Build Guide

Step 1.2:  Now we will install the wheel axles.

Pete’s Tip:  Tighten the wheel axles with 2 sides of the hexagon axle shape vertical to the landing gear.  This will be the position to install the wheel pants properly.


Wheels axle installed.


Pete’s Tip:  Use a small drop of BLUE loctite on the set screw for the wheel collars. This will prevent the collar from vibrating loose.


Step 1.3: Install your wheel and wheel collars as seen in this photo.

Pete’s Tip:  Do not tighten the wheel collars all the way at this time.  The wheel will need to be adjusted for proper spacing when we install the wheel pants.


Step 1.4: Locate 4 main wheel pant screws and washers.  The screw end utilizes a 2.5mm hex driver.  The blind nuts for the screw have already been pre-installed for you on the inside of the wheel pants.



Wheel pants installed.


Step 1.5: Adjust the spacing of the wheel collars to position the wheel in the center of the wheel pant.


Step 1.6: Once you have installed both wheels and wheel pants, locate the 4 bolts with lock nuts to install the main carbon fiber landing gear to the fuselage.  No loctite is needed.



Pete’s Tip:  For some pilots, it may be difficult to install the lock nuts inside of the fuselage.  The area may be difficult to reach.  Pete uses a piece of blue tape or house hold scotch tape rolled over as pictured.  Stick the nut to the tape.  Now all you need to do is use one finger to locate the bolt end and install the bolt.


All 4 landing gear bolts installed and tightened.


Pete’s Tip:  This step is optional, however Pete always performs this precautionary step.  Use THIN CA (super glue) and basically soak the motor box connections areas.  The CA will “wick” into the wood and make a much stronger motor box.  Pete performs this step to all sides and right angle areas of the motor box including the triangular motor box stocks on the inside.

IMG_0179   IMG_0199

Step 2.1:  Next we will install the rudder with the hinges.

Pete’s Tip:  Use a small drop of oil on the pivoting area of the hinge.  This will prevent the glue from adhering the hinge when we install the rudder.  If you do not have any oil, use a toothpick or small screwdriver and apply a small drop of cooking oil or even motor oil.


Step 2.2:  Use your glue of choice to install the hinges.  Epoxy is the preferred adhesive.

Pete’s Tip:  Install one side at a time.  Do not rush and try to install the hinges and rudder to the fuselage at the same time.  This will not work.  May end up with a mess and non aligned hinges at its pivot point.  Glue the hinges to the rudder FIRST.  Once the glue has cured, move on to install the rudder to the vertical stabilizer.


Step 2.3:  Notice the direction of the hinge.  Be cautious not to install in the wrong pivot orientation.


All hinges are now glued and cured to the rudder.



Step 2.4:  Test fit the rudder to the vertical stabilizer.  When you are ready, glue the rudder to the vertical stabilizer and set your rudder gap.  The preferred gap is as shown here by Pete.


Step 2.5:  Once your rudder installation is complete, locate your tail wheel assembly.

Note:  The assembly may sometimes be split in separate bags.


Step 2.6:  Install the tail gear bolt.


Petes Tip:  Use Blue loctite on all the set screws. Tail gear assembly completed and ready for install.


Step 2.7:  Set the tail wheel assemble on the bottom of the fuselage near the rudder and mark the 3 holes with a sharpie.  Spacing of the tail gear is personal preference.  You can view ahead for Pete’s tail gear sspacing.


Pete’s Tip:  Small drill bit (1/16) is best and drill the 3 marks for the holes.  These are called “pilot” holes.  The screws are self tapping wood screws and this step is not a must.  However pilot holes will prevent the wood from possible splitting and create a stronger self tapping screw to wood hold. Tail wheel assembly installed.


Step 3.1:  At this time we will install the control surface arms.  Use a bright flashlight or simply press to locate the horn slots.  Use a sharp hobby knife to cut the covering away for the arms.  It will be your build preference if you wish to at one sitting, cut out the covering slots for all your control surfaces (Elevators and Ailerons) at one time.


Note: the rudder Pull/Pull arms will need to be cut shorter on each side.  Remove 2 tab count of the fiberglass control surface arm.


Step 3.2:  With the control surface horns cut and ready for glue,  now please use Epoxy for the adhesive and install the control surface arms.

Pete’s Tip.  Use a Dremel or rotary tool to “scuff” the area the glue will be applied.  Using sandpaper will work just as well.  800 Grit or lower.  Before you glue, make sure to clean off the area with a paper towel.  If you have any rubbing alcohol around, a small amount will assist in the cleaning.  At this time, scuff all your control surface arms for the other surfaces.



Step 3.3:  Once your control surface arms are cured from gluing, we will install the rudder Pull/Pull cables and servo.

Petes Tip:  Use a small piece of blue tape to keep the rudder centered as seen here.   This will assist in centering the cables properly. IMG_0197

Step 3.4:  Test fit your rudder servo and drill the servo pilot holes.  Note:  this is best for all the servo installations.

Pete’s Tip:  Use one drop of thin CA per hole to give the wood a stronger screw hold ratio.  DO NOT install the servo until the CA has fully cured.  This is preventative step.


Step 3.5:  Install your rudder servo.


Step 3.6:  Center your rudder servo and install your rudder Pull/Pull arm of choice.   We opted for the Miracle Pull/Pull arm available from Aerobeez.



Step 3.7:  Layout your rudder Pull/Pull parts as shown.

Note:  Crimp pliers are an option and are not needed.  A pair of strong pliers will work just as well.  The Miracle crimp pliers shown are available from Aerobeez.




Step 3.8:  Install the Pull/Pull rod to the ball end.

Pete’s Tip:  You can use the aileron push rod inserted through the ball side to assist in the tighten process.  Do not over tighten at this time.  Leave enough threads for fine adjusting the cables later.


Step 3.9:  Install all 4 Pull/Pull ball pushrod ends.



Pete’s Tip:  Use a long stick and tape one side of the Pull/Pull cable as seen here.  Do NOT cut the cable at this time.  Insert the cable through the inside of the fuselage to the rear exit area of cable slot on the tail section of the fuselage.


Steps 3.10: Insert the cable and loop crimp as seen here.


Step 3.11:  Pull the cable taught and prepare to install to the servo arm.



Step 3.12:  Rudder Pull/Pull cables installed.

Pete’s Tip:  When the cables have been installed, turn on your radio to set the cable tension.


Cables crossed and installed.


Step 4.1:  Now locate the servo bays for the elevator servos.


Note:  You can also at the same sitting, cut the servo bays for the ailerons.  

Pete’s Tip:  Use a bright flash light from the opposite side of the fuselage or the inside of the fuselage to assist in locating the area to cut the covering away. Step

4.2: Cut the covering away.

Note:  There are 2 methods to cut the covering away.  You can choose to cut the servo bay area exactly to the size of the servo cut out bay.  Petes method is to cut and leave about 1/8″ of the covering and using a covering iron, press the covering to the inside of the servo bay.  This will help in the securing the covering.  This step is not a must.




Step 4.3:  Now install the elevator control surface arms.

Note:  The Elevator and Aileron control surface arms will need to be “shaved” cut one notch step.


Step 4.4:  Once the control surface arms are cured, install the ball ends to the elevator push rods.

Note:  The elevator and aileron push rod screw threads are REVERSE direction on ONE SIDE.


Step 4.5:  Test fit your elevator servo and install.

Pete’s Tip:  Use 1/16 pilot holes and a drop of CA per hole.  Install the servo once the CA has completely cured .


Step 4.6:  Install the horizontal stabilizers using the screws as seen here.

Pete’s Tip:  Use Blue loctite on these screws.  2 per side.


Step 4.7:  Elevator push rod installed.  Turn on your radio system and adjust the pushrod length to your desired settings.


Tail section is now complete.



Step 5.1:  The firewall engine template is outlined for a DLE30.  We will now mount our engine.

Pete’s Tip:  If you are using a DLE35RA, the top mounting template holes are correct.  The lower holes will need to be marked.


Top holes are drilled.


Step 5.2: This is for DLE-35 RA users only.  You will need to remove a small portion of the lower lip section of the motor box for clearance of the DLE35RA muffler.






Step 5.3:  Lower mounting holes for a DLE35RA marked and drilled.

Pete’s Tip:  When you drill the holes to mount your motor of choice, the holes do not need to be the “perfect” size as the engine stand off bolts.  Drilling the holes with a larger diameter will assist in positioning the engine later for a center prop hub location.  Keep in mind to not Over drill the hole diameter!


Step 5.4:  Mount your engine temporary and mark the fuel line and throttle arm position.  Drill the fuel line and throttle push rod holes.



Step 6.1:  Prep and prepare to install the aileron control surface arms and servo if you have not done so prior.

IMG_0235 IMG_0236


Step 6.2:  Install the aileron servo and push rod.


Step 6.3:  Turn on your radio and adjust the pushrod length.

Pete’s Tip:  The aileron and elevator push rod screw threads are reverse direction on one side to make adjusting easy.  First make sure when your radio is on, the aileron servo arm is as close to 90 degrees to the servo as possible.  Install the push rod length close to center 0 degree control surface.  Once the pushrod is installed and both sides are tightened to the servo and control surface, you fine adjust the push rod length by turning the center of the push rod.  A hexagon center is provided to assist in the adjustment.


Step 7.1:  Test fit the cowling and cut your exhaust holes.

Pete’s Tip:  Use a flashlight to shadow the areas to be cut.  Mark with a sharpie and cut the openings with a Dremel or rotary tool.


Step 7.2:  Cut a opening behind the exhaust for proper cooling for your engine.


Step 7.3:  Test fit your cowling and now adjust your engine position for a centered main engine hub.  When you are content with the position, tighten down your engine stand off bolts.


Step 7.4:  Install your throttle servo.  The throttle servo bay is not pre glued due to different engine manufactures and throttle arm location.  Use Epoxy to adhere the throttle servo bay.


Step 7.5:  Before you install the fuel lines to the included pre-plumbed fuel tank, using a sharpie, note the different sides of the fuel/vent lines. Pete’s Tip:  Hold the tank to a bright light and you will be able to pick out the main fuel line with the clunk, the vent line and overflow line.



Step 7.6:  Install your fuel lines. Pete’s Tip:  Use a zip tie per nozzle.  This will greatly assist in keeping the fuel line in place. IMG_0247

Step 7.7:  Install the top motor box cover when your fuel lines and throttle servo have been installed and adjusted.

Note:  the screws for the covers are not included.  Covers are included and are optional.


Step 8.1:  Now for the finishing touches. Install your propeller and spinner. 19×10 or 19×8 props will work well, but this is personal preference on flying style. For the spinner, you can use any 3.5″, but we have chosen to use a 3.5″ Carbon Fiber Spinner available at


Pete’s Tip: When applying decals.  Use a water or Windex type glass cleaner spray.  Wet the area you would like to apply the decal.  Peel and apply the decal.  You can then slide and move the decal around.  Press out any air bubbles or liquid under the decal.  Dry the excess liquid with a towel and let sit.  The decal will dry and you are ready!


Step 8.5:  Set your control surface throws to your flying preference.  Range test your radio system and test CG. For CG on this ARF measure the CG from the leading edge of wing root rib.  Adjust the battery pack location. For CG proper position should be at 27% MAC. This recommendation balance point is for your first flights. The CG can be moved around later to fit your personal taste. If you are not comfortable with the calculus involved you can use this online CG Calculator. Just plug in the simple measurements and the app does the calculus.

Note: Use Diagram below as a reference for manual calculation. 


And now we are Ready to Fly!



Note: Always perform a pre flight check.  Range test your aircraft and make sure ALL the control surfaces are moving in the correct direction!

Aerobeez would like to thank you once again for reading our build guide and for your purchase!  Control surface deflections are a personal preference in your flying style.  For unlimited 3D, please use the surface throw in MAXIMUM deflection before surface bind.  Your Aerobeez team is available for any technical questions.  Please feel free to email us at any time. Aerobeez appreciates your patronage!  Now go fly, enjoy your air time with your new Sbach 300!


Your Hobby, Our Passion!


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