Cute Character-Based 3D STL Pen Holders

STL MODELLING BRIEF — 3 CHARACTER PEN HOLDERS

I need three separate STL pen-holder designs based on the reference images provided.

I have detailed 2d designs of the models ready to share.

All three characters should use the same core/base body shape and proportions. The only major differences between the three models should be the character-specific features attached to the body:

1. Dragon — dragon wings
2. Dinosaur — dinosaur fins/spikes along the back
3. Dinosaur/Dragon — raised dinosaur-style spine/fins

The overall style should remain cute, rounded and simple, matching the supplied reference images.

CORE BODY — IMPORTANT

The three models should share the same basic body geometry.

The body needs to function as a pen holder, with an internal open cylindrical cavity running vertically down through the model from the opening at the top of the head.

* Opening diameter: exactly 16 mm
* The cylinder must be open at the top
* The internal cylinder should run vertically through the head/body to create the pen-holding cavity.
* The 16 mm diameter must be maintained throughout the usable internal cavity.
* The opening should have a clean, smooth circular rim.
* Do not accidentally close the bottom of the cylinder if the intention is for it to be a through/open cavity.

The outside of the body should remain rounded and organic — do not make the body simply look like a cylinder. The internal cylinder should be hidden within the character’s body.

DESIGN AS SEPARATE STL PARTS

To make manufacturing and printing easier, the model should be designed as multiple separate STL components that can be glued together.

The main body should be one STL.

The character-specific features should be separate STL files/components:

Dragon

* Main body
* Left wing
* Right wing
* Any additional separate decorative features required

Dinosaur

* Main body
* Individual back/spine fins or a single spine assembly
* Any additional separate decorative features required

Third design

* Main body
* Character-specific fins/spine/features as separate pieces

NO PEGS / CONNECTORS REQUIRED

Do NOT add locating pegs, pins, slots or complicated mechanical connectors.

The parts will be glued together permanently, so I want the simplest possible attachment system.

The attachment surfaces should therefore be:

* Flat or appropriately curved to match the body
* Easy to glue
* Large enough to provide a strong bond
* Designed so the separate pieces sit naturally against the body

This should make the STL considerably simpler and easier to print.

PRINTABILITY

Please keep the designs suitable for FDM 3D printing.

Avoid unnecessarily thin features that are likely to break during printing.

The character should retain the cute, chunky appearance of the reference images rather than having delicate, fragile details.

Where possible, use rounded edges and smooth transitions.

CONSISTENCY

The most important requirement is that the three characters look like part of the same product range.

They should have:

* Identical/similar base body proportions
* Identical 16 mm pen opening
* Similar overall height and width
* Consistent facial style
* Consistent rounded aesthetic
* Different character features to distinguish each design

The final result should essentially look like one pen-holder design with three different character variants.

Deliverables: Separate STL files for each body and each detachable character feature, ready to assemble with glue. Final design just not be resold or reproduced in any way.