Specrom build manual

3D printed racing wing

Share your builds and questions here:

​Filament

Recommended to use eSun PLA+ or PETG filament

PLA is too brittle, ABS is hard to print.

Bill of Materials

These are parts and materials you should have prior to building the wing.

Slicer settings

All parts are pre-oriented in the right position - no need to rotate or move them.

No supports are required, please follow the instructions below to configure your Slicer.

Nozzle temperature and cooling fan

When printing single wall parts, you should always set the highest possible temperature for your filament without fan cooling to make sure you have a perfect layer adhesion. The temperature should be much higher than during regular printing - your thin wall should sustain high loads without layer debonding.

Ultimaker Cura settings

It is recommended to use Ultimaker Cura slicer with the following important parameters:

• Surface Mode = Normal
• Spiralize Outer Contour = Disabled
• Z Seam options:

• Z Seam Alignment = User Specified
• Z Seam Position = Back Left
  together with the default parts position this will make your seam invisible

• Enable Retraction = true

• Retraction Distance = 6.5 (bowden) and 0.8 (direct drive)
  These are preliminary values that user should adjust as needed for the printer
• Z Hop When Retracted = true
  It is helpful to make sure the nozzle does not touch the thin parts and not causing the detachment

• Union Overlapping Volumes = Disabled
  This is important setting that allows you to
• Combing Mode = Off

Tested Cura versions: 4.12.1

How to Print Thin Wall - Planeprint | Big Bobber

Slicer profiles

Parts Settings

Assembly

I recommend you watching this YouTube video with the detailed assembly procedure

3D printed Spec wing full build video #Specrom

General points

• Always test fit the parts before the glue application. Once glued it cannot be undone!
• Use 5-8 mm filament pieces to help you with the alignment of the wing parts

• Make sure there’s no excessive glue in the reinforcement filament channel - it will be hard to insert reinforcement filament at a later stage
• Insert filament reinforcement to the channel using a smooth stick or pen.

Use glue only in the beginning and at the end of the filament string just to fix it in place

DO NOT spill the glue across the entire filament path - this is not necessary.

• You can use either FWD or AFT bay for battery and Flight Controller. This is up to you to. By design, with insta 360 go 2 camera CG is exactly right when the battery is in the AFT section

First flight

As 3D printed wing are easy to build and easy to destroy, I do not recommend flying 3D printed wings as your first wing.

Before the first flight it is critical to set the CG correctly.

Remember: FWD CG wings fly bad, but AFT CG wings fly only once.

The best CG location is 5 mm to the front of the rear spar:

Wing is flying really well when the CG is at the rear spar, but launch may be a huge problem - eventually it may stall and fall down (I’ve lost few wings already)

Flight controller flight

You can use various flight controller options to fly this wing.

iNav settings

Please refer to the Appendix

Manual flight

Manual flight requires significant experience and 3d printed planes are not the best way to learn how to fly. A severe crash of this wing requires a reprint.

As an experienced line of sight pilot, you know the best way to configure expo and throws. 1 mm reflex is required to fly straight for this wing (watch the video).

Repairs

Sometimes things may go wrong and you crash your wing. Depending on the severity of the crash you may decide - reprint the entire plane or just individual parts.

This example shows where wings are in a the perfect shape (PLA+) with zero damage, but the fuselage part (PETG) was completely destroyed.

In such cases you can try to detach undamaged parts and reuse again. General recommendations - heat your knife and remove

This is why it is important not to use excessive glue - you can easily remove reinforcement filament and attach new one.

Local damage

Cracks

When your plastic wing hits something you make, it has local cracks and damage. Before applying any glue or doublers, make sure you stop the crack from growing (it may eventually grow in the air otherwise).

Just use your soldering iron to make a hole at both sides of the crack.

After this you can either apply glue along the entire damage or add a doubler to make sure you reinforce the damaged airframe.

Reinforcement

Do not throw away your test prints or parts that cannot be used for your wing. Keep it until you need it. One example is - to make a thing 1-wall doublers.

Just cut the patch and glue it to the surface where the damage was found. This will give you enough reinforcement to keep flying.

Appendix I: iNav parameters

# mixer

mmix reset

mmix 0  1.000  0.000  0.000  0.000

# servo mix

smix reset

smix 0 1 0 -50 0 -1

smix 1 1 1 50 0 -1

smix 2 2 0 -50 0 -1

smix 3 2 1 -50 0 -1

# servo

servo 1 1000 2000 1444 100

servo 2 1000 2000 1544 100

# aux

aux 0 0 0 1700 2100

aux 1 1 1 1300 1700

aux 2 12 1 1700 2100

aux 3 53 3 1300 1700

aux 4 11 2 1300 1700

aux 5 10 2 1700 2100

aux 6 21 3 1700 2100

aux 7 54 1 1300 1700

aux 8 13 2 1700 2100

# profile

profile 1

set fw_p_pitch = 15

set fw_i_pitch = 5

set fw_d_pitch = 5

set fw_ff_pitch = 93

set fw_p_roll = 15

set fw_i_roll = 3

set fw_d_roll = 7

set fw_ff_roll = 82

set fw_p_yaw = 20

set fw_i_yaw = 0

set fw_ff_yaw = 100

set max_angle_inclination_rll = 550

set dterm_lpf_hz = 10

set fw_turn_assist_pitch_gain =  0.200

set nav_fw_pos_z_p = 15

set nav_fw_pos_z_d = 5

set nav_fw_pos_xy_p = 60

set d_boost_min =  1.000

set d_boost_max =  1.000

set rc_expo = 30

set rc_yaw_expo = 30

set roll_rate = 19

set pitch_rate = 14

set yaw_rate = 3

Appendix II: common issues

Gaps in walls

Eclipson FAQ

Overheat when printing

Overheat

• Left - Fan 30%
• Right - Fan OFF

Walls misalignment

This usually happens when you apply activator to the CA glue and deformation due to heat starts

Thin parts detach from the build plate

Sometimes your thin vertical parts (servo covers or FWD bay hatch) may detach from the build plate at the middle of the printing.

Solution: make sure you set your Brim Distance to 0.0 mm as per print parameters. This will keep your parts from falling down.