ST3 OWL Flying Videos and Pictures

If you would like to have sport flight and long flight then this model may suite your requirement. It has spacious battery space and can take 4000mAh 4s or more to get the CoG correct. Lower battery capacity size is possible but may need to put more weight at the front position to get the CoG in the correct position. You can use the battery protection and balancer that can be found in our library page or one of the sections below in this page. With that size of battery, the model can fly more than 7 minutes easily with aerobatic style flying. 


Try to avoid printing all parts with 0.40mm extrusion width for getting the best experience with the model. If you still want to print with that extrusion width then try to print some parts with LW-PLA, ePLA-LW or PolyLight 1.0 such as stabilizers (at least/recommended). Saving some weight on the stabilizer parts will save significant amount of weight for the battery (nose side) to get the correct CoG.

ST3 OWL videos posted on the youtube were printed with all PLA+ and 0.32mm extrusion width. 

Spar Requirement :

– Primary Wing Spar : 1 x 12mm OD and 1000mm long fiber carbon tube (Required).

– Secondary Wing Spar : 1 x 8mm OD and 300mm long fiber carbon tube (Optional).

– Horizontal Stabilizer Spar : 1 x 5mm OD and 450 long fiber carbon tube (Optional).

Spacious Battery Compartment :

Center of Gravity (CoG) :

Weight and Time Estimation :

Following tables show the weight of printed parts, number of required filament rolls and time required to print. The numbers are taken from S3D slicer calculation. From experience, actual numbers show about -5% less than depicted in the table. But the number may vary from printer to printer due to:

– Stepper Jerk value.

– Stepper Acceleration value.

– Steps per unit (either calibrated or uncalibrated)

– Extruder quality/condition.

– Nozzle quality/condition.

– Filament quality/condition.

– Etc. 

For sure the relative number are useful when deciding to accept the total strengths or weights when printing. Picking higher strength to some parts are necessary to avoid breaking during high impact landing or sharp maneuver for example.  

Here are the summary tables:

Table of Contents

Update History

No Update for this model yet.

Recommended Setup

Battery Protector and/or Weight Balancer Holder for 2200mAh 3s/4s and 3300mAh 4s Battery.

One of challenges in 3D printed plane is where it has a wide range of possible total weight result. For example, the plane printed with 0.40mm comparing to 0.32mm extrusion width may end up the CoG moved about 2cm – 3cm backward with using the same battery. You may need to move the battery forward or add more weight at the nose to get back the CoG to its previous location. To solve this issue at the same time protecting your battery, the following STL files are created for your 2200mAh 3s/4s and 3300mAh 4s. Feel free to download and use the files (G-code files are also provided for Bowden or Direct Drive setup including STEP files).

Tools and Materials

OWLplane Printers (for your ref.)

See figures below some printers used, created, developed and modified by OWLplane. Two group printers are set, the first one is utilized only for printing PLA/PLA+ and the other one is utilized to print with ABS, ASA and HIPS filaments (the one with enclosures). Just hover onto the figures to find more information about them.

Modified all Bowden setup printers into Direct Drive but leave Tevo Tornado and Anycubic Mega as is (still in bowden setup).

Hardware Needed

For Fuselage and Canopy:

For Wings (except the control surfaces):

For Aileron, Flap, Stabilizer, Rudder and Elevator Servos:

*) Illustration only

Setup for Servo Travel/Throw

Suggested setup for medium travel/thrown are depicted below and you may adjust the setup according to your need.

3D Printed Motor Mount, Propeller Spinner, Collet and Spar

Motor Mount Requirement

Motor mount wall should be 3D printed with more heat resistance filaments such as ABS, ASA or HIPS. If your 3D printer does not have enclosure you may want to try with PETG filament (more heat resistance than PLA/PLA+). In case you still would like to use PLA, please do annealing process (not sure can do for standard PLA), some successful with HT-PLA/Hight Temp-PLA. Click here for you to read about annealing article.

Motor Mount
Propeller Spinner and Collet Requirement

OWLplane does not provide STL file for printed propeller spinner due to our concern about strength, shape and uniform weight when spinning at high speed. Not all 3D Printer has really free of skew issues for all their axes. The skew issue generates uneven shape that will lead to problem when spinning. Good spinner should be available in your local hobby store or online store, even that spinner, you still need to balance it before using it.

Spinner and Collet Requirement :

1. 50mm Diameter Size Spinner.

2. 5mm or 4mm Shaft Propeller Collet (check your purchased motor shaft to pick the right size propeller collet).

Please watch the following Videos to balance your Propeller and Spinner:

Assembly Figures

ST3 Fuselage Assembly

ST3 Wing Assembly

ST3 Horizontal Stabilizer Assembly

ST3 Vertical Stabilizer Assembly

ST3 Canopy Assembly Animation

ST3 Main Gear Assembly

Watch ST3 OWL Animation and Assembly Video
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