Interior Packaging for a Flat-Floor Skateboard EV

The problem

A skateboard platform puts the battery under a flat floor, which frees the tunnel and engine bay but raises the floor and the occupants. Designers must decide seat heights, head clearance, ground clearance and storage early, often before styling exists. Packaging studies that quantify these trade-offs are central to EV concept work.

Objectives

• Build a parametric package layout with battery, floor, occupants and key components.
• Position front and rear occupants and measure headroom, legroom and vision.
• Develop interior surfaces for the floor, console and storage in Alias.
• Quantify interior gains and losses against a conventional baseline layout.

What you need

Key concepts

Skateboard platform

A chassis with the battery spread under a flat floor and motors at the axles, leaving the cabin above largely free of mechanical parts.

H-point and heel point

Reference points for the hip and heel of an occupant. Their vertical distance, often called seat height above the heel, sets the seating posture.

Package envelope

The space each component or occupant needs, including clearances, used to check fit before detailed design.

Floor height trade-off

A thicker battery gives more energy but raises the floor, which either raises the roof, reduces headroom or forces a more upright posture.

Step-by-step guide

1. 1

   Set targets and baseline

   Define an example five-seat compact EV with a stated wheelbase, track and overall height. Measure or take from published data a conventional baseline car's headroom, legroom, seat heights and ground clearance. Set targets for your skateboard version, such as equal front headroom with a flat floor. List battery options as examples, for instance 110 mm and 140 mm module heights including the tray, labelled as assumptions.

   Checkpoint: A target table with baseline values, sources and battery height options.

2. 2

   Build the package layout

   Create a SOLIDWORKS layout with side and plan sketches showing the ground line, wheels, battery pack, floor panel, front and rear motor units, crash zones and roof line. Use blocks for each component and drive key dimensions with global variables: battery height, floor thickness, ground clearance and wheelbase. Add a design table so each battery option becomes a configuration. Save the layout as the master that every later part references, so a change in battery height flows through the whole model.

   Checkpoint: Switching configuration moves the floor and occupants correctly and the layout stays fully defined.

3. 3

   Place occupants

   Insert 2D occupant blocks sized from your anthropometric source for a large male in front and rear positions. Set H-point, heel point and back angle, and constrain the head to clear the roof line. Measure headroom, front legroom, rear knee clearance and the H-point height above ground, which affects ease of entry. Record all values in the design table for each configuration.

   Checkpoint: Occupant measurements for each battery option recorded in a table, with headroom and legroom compared with the targets.

4. 4

   Build the 3D package assembly

   Turn the layout into an assembly with simple solid envelopes for the battery, motors, seats, occupants, steering column and HVAC module. Run Interference Detection for each configuration and fix any clashes. Use Mass Properties with assigned or overridden masses to find the centre-of-mass height for each battery option, which matters for handling. Record the masses you assign and their sources, because the centre-of-mass comparison is only as good as those inputs. Save one image per configuration with envelopes in translucent colours.

   Checkpoint: Interference Detection passes for every configuration and a table gives the centre-of-mass height for each.

5. 5

   Check vision and entry

   Draw sight lines from an example eye point over the bonnet and under the windscreen header, and check the down-vision angle to the road. Check entry by measuring the sill height, step-over width and the door opening relative to the H-point. A higher floor usually raises the sill; measure the effect rather than assume it. Add a simple door-opening envelope to the assembly.

   Checkpoint: Vision angles and entry measurements recorded for each configuration, with the highest-floor option clearly compared with the baseline.

6. 6

   Develop interior surfaces in Alias

   Export the chosen configuration's package as STEP and import it into Alias on a locked layer. Build the flat floor, a floating console and under-seat storage surfaces with Skin and Rail surfaces, and blend them with Surface Fillet. Use Align to reach G2 on visible boundaries and check with Zebra and Continuity. Keep surfaces within the package envelopes. Export the surfaces regularly so you can check them in SOLIDWORKS before the model grows too complex.

   Checkpoint: Interior surfaces stay inside the envelopes and pass the Continuity check at the stated level on visible boundaries.

7. 7

   Quantify storage and space gains

   Bring the Alias surfaces back into SOLIDWORKS as STEP, knit them and build filler bodies for storage spaces. Measure their volume with Mass Properties. Compare cabin length available for occupants, storage volume and floor flatness against the baseline car. Present the gains, such as a flat rear floor, and the losses, such as reduced headroom, side by side. Use the same filler-body method on the baseline car model so both sides of the comparison are measured the same way.

   Checkpoint: A comparison table of storage volume, cabin length, headroom and sill height against the baseline.

8. 8

   Run a parameter sweep

   Use the design table to sweep battery height and floor thickness across a range and record headroom, sill height and centre-of-mass height for each. Plot these against usable battery energy, using an example energy density per unit floor area. Identify a battery height beyond which the posture must change or the roof must rise to keep headroom. Run the sweep from the design table so every point is reproducible, and keep the occupant posture fixed unless you state otherwise.

   Checkpoint: Plots of headroom, sill height and centre-of-mass height against battery height, with the break point marked.

9. 9

   Render and report

   Render the baseline and skateboard interiors in Visualize or VRED from the same camera positions. Write a report with targets, layout method, occupant data, clash and vision checks, Alias surfaces, comparison tables and the sweep. Discuss the limits: 2D occupants, simplified envelopes and no crash structure detail. Recommend next steps such as a physical seating buck. Add an appendix with the design table values for every configuration and the sources of baseline data, so the comparison can be checked.

   Checkpoint: A report with renders, tables and plots that answers how much battery height the interior can accept.

Testing & validation

• Occupant positions use a stated anthropometric source.
• Interference Detection passes for every package variant.
• Storage volumes measured from filler bodies.
• Baseline comparison uses measured or sourced values.

Expected results

A parametric skateboard EV interior package with occupant, vision and entry measurements, Alias interior surfaces, measured storage volumes and a quantified comparison with a conventional layout.

Take it further

• Add a seating buck built from the final layout and check with volunteers.
• Study a cell-to-body pack that removes the separate floor panel.
• Add a third seating row and check the rear occupants.

Viva and review questions

Learn it at DIYguru

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