SUMMARY:
This model is a replica AH-1S Super Cobra attack helicopter used by the Army and Marines. The model is designed to print and assemble easily, so there are minor modifications to the overall design in order to do that. The initial upload was the entire project file with multiple plates. I will be leaving this and v2 in the raw model files, but I’ve removed the print profiles as the latest revision supersedes these. If you come across any issues, please leave me some feedback. Assembly instructions are found below.

Printing/Post-Processing:

If you decide not to use the print profiles, these are the settings I used.

• Global Settings:
  • 0.16mm Layer Height
  • Arachne Wall Generator
  • 3 Wall Loops
  • Gyroid Infill
  • Outer Wall Speed: 100 mm/s
  • Overhang Speed:
    • 25,50%: 40 mm/s
    • 50,75%: 20 mm/s
    • 75,100%: 20 mm/s
• Cabin:
  • No object specific settings changed, uses global slicer settings only.
• Tail:
  • Enable Support: Paint them on under the stabilizers only.
    • Normal (Manual)
    • Snug
    • On Build Plate Only
  • Once printed, I use a deburring tool to clean up any rough surfaces on the overhang of the tail as well as the bottom of the stabilizers.
• Wings/Cowl:
  • Brim Type: No-Brim
  • Enable Support: Painted on under the wings only. The remaining overhangs will print as is.
    • Normal (Manual)
    • Snug
  • Once printed, I used a deburring tool to clean up the bottom of the wings.
• Rotors, Landing Gear, Mounted Turret:
  • Layer Height: 0.12mm
  • 8 Wall Loops
  • Primary Rotor Brim: Outer Brim Only and 8mm Width.
  • Turret:
    • Enable Supports: Normal (Auto)
    • Snug
    • On Build Plate Only
  • Once printed, I used a deburring tool to clean up the bottom of the turret barrel. You’ll also need to remove the brim from the rotor and landing gear.
• Windows:
  • The windows were designed to print on the topside so you can use a patterned plate to create visual effects.
  • There are 3 windows which need supports enabled. These are the rear left and right windows as well as the rear top window. The two side pieces may print fine as is, but have a very small angle at the corner. I’ve printed them successfully without supports, but why not? The top rear will definitely need the supports as it wraps slightly around the top.
  • Enable Supports: Normal (Auto)
    • Snug
    • On Build Plate Only

Assembly:

The assembly requires no glue, but I recommend using super glue if this is going to be played with. The fit is fairly snug for most components, so all you need to do is press them into place. The connecting joints have sloped holes, so as you press the pieces into place, they will tighten down. I used a small clamp to make sure they were all pressed in sufficiently.

1. Assemble the tail and cabin by inserting the alignment pin and pressing the pieces firmly together.
2. Insert the wings into the cabin and press firmly into place.
3. Insert the smaller alignment pins into the cabin and press the cowl onto the pins.
4. Press the windows firmly into place.
5. Push the primary rotor into the slot. This will require a little force, so I recommend either using a clamp and slowly tightening until it pops into place, or hold the piece parallel to the slot as much as possible and press directly onto the center of the rotor so you don’t bend the connector. Once it snaps into place, it should spin freely with no slop.
6. Push the tail rotor into place. Try to press slowly and straight so you don’t snap the connector.
7. Push the nose mounted turret into its’ socket. This will be tighter than the other two and once it snaps into place, it will have mild resistance when rotating.
8. Finally, press the landing gear into the slots on the cabin and you’re done.

That's all there is to it. I tried to break it up into pieces that would likely be the same colors, but the raw files are also up. Follow my facebook page, RC3D, for giveaways and entry details as well as my latest models.

CHANGELOG:

UPDATE (11/22/2023):

I revised several pieces to either print in fewer pieces or to assemble easier without glue. The overall project was reduced to 4 plates that print with settings closer to the default profiles.

1. Increased tail rear curve radius to print easier without rough spots on the rear of the tail.
2. Revised the tail rotor to press into place without snapping as easily and to rotate freely without resistance.
3. Decreased tolerance on alignment pin for cabin and body. This ensures a tight fit that doesn’t require glue to remain in place.
4. Tightened tolerances for the wings, landing gear, and nose mounted turret.
5. Increased turret guide shaft diameter to provide mild resistance when turning. Revised the connector to hold in place more firmly.
6. Added connectors to the windows for a press-fit assembly.
7. Added alignment pins for the cowl.

UPDATE (11/13/2023):

The tail piece for the v2 print profile was missing the supports under the stabilizers. v2.1 fixes that.

UPDATE (11/5/2023):

I've made numerous updates to improve printer friendliness, ease of assembly, and functionality. I've uploaded the v2 files into the raw files repository as 3mf files. I've also added print profiles for each plate of v2. The settings used are above, so you may only need to change the filament type. Most of the plates with multiple pieces are auto arranged and printed by object to avoid banding at different layers. See the change log below:

1. Combined the wings and their mounted weapons. There's a small integrated support that prints with this piece. It will leave a slightly rough edge on the wing, but a quick pass with a deburring tool cleans it right up.
2. Added a second alignment pin on the cowl so it's easier to align when assembling.
3. Added a guide on the main rotor so it doesn't wobble. It should feel tight and spin freely now.
4. Adjusted the rear rotor to fit better and prevent snapping the ends off.
5. Added a guide on the nose mounted gun to make it less wobbly as well.
6. Tightened up several connection points. The wings are a more snug fit now, but still require glue. The center alignment pin now fits very snug.
7. Combined the tail and stabilizers. These now require supports painted on underneath the stabilizers. This also leaves a slightly rough surface, but is cleaned up easily with a deburring tool. This eliminates another assembly step, and looks clean so I'm going to accept that it requires support. Any sharper of an angle and they wouldn't look right, so this is the best of both worlds I think.

This version came out just as clean, but more functional and easier to assemble. I hope everyone enjoys it as much as I have!

INITIAL RELEASE (9/19/2023):

The models were designed to print without support. They're arranged on the plate how they should be printed, but the ones that matter most are the cabin and tail of the helicopter. As long as those are printed as shown with adaptive layers, they should come out as intended. The assembly is pretty simple, but I will include the steps below. Detailed instructions to follow in the near future.

1. Super glue the cabin and tail together with the bottoms aligned.
2. Super glue the cowl on the top of the cabin with the indent aligned.
3. Super glue the gun turrets to the wings, and super glue the wings to the cabin.
4. Super glue the tail wings to the tail.
5. Super glue the machine gun barrel to the turret.
6. Slide the tail pin through the hole and super glue the rear prop to the pin.
7. Pop the primary prop into the slot.
8. Pop the machine gun turret into the slot under the cabin.
9. Press the landing gear into the slots on the cabin.

Print Settings:

1. I used 0.16mm layer height on all of them.
2. I set the cabin and tail to adaptive layers and smoothed out a bit.
3. I used 6 walls on the landing gear, props, barrels, etc. The plate with the primary prop.
4. Otherwise default settings including brims. No supports.