Large format 3D printing in the UK: how to print parts up to 1000 mm

What is the largest part we can print?

The FDM build volume is 1000 × 1000 × 1000 mm. FDM is the process for any part longer than 350 mm, the largest SLA bed dimension. For anything bigger we split the model into sections and bond them, and we confirm at quote whether a larger project is feasible. See the FDM service page for the full specification.

How size changes cost, time and risk

These are general scaling rules, not HenleyPrint3D prices. Doubling every dimension of a part multiplies its volume by 2 x 2 x 2 = 8, and its surface area by 4. A solid part therefore needs about eight times the material and roughly eight times the deposition time. A thin-walled shell is closer to four times, because it scales with surface area. That is why large parts are designed as ribbed shells and not solid blocks.

Risk rises with size too: a failure late in a long build wastes more time, and more of the part is exposed to uneven cooling. Both are reasons to ask an engineer to review the orientation and material before a long build starts.

Materials for large parts

Standard FDM materials include PLA, PETG, ABS, ASA, TPU, nylon and carbon-fibre PETG, with ULTEM and further grades quoted on request. PETG is the default. The choice matters more on large parts, because shrinkage acts over a longer distance.

For the full comparison see the 3D printing materials guide and the FDM materials explorer.

Thermal expansion and shrinkage on large parts

This section is general physics with typical coefficients; check the datasheet for the exact grade. A thermoplastic expands and contracts with temperature. If an ABS-type material has a thermal expansion coefficient of about 90 x 10⁻⁶ per kelvin and a 1,000 mm part cools by 80 K, the free contraction is 1,000 x 90 x 10⁻⁶ x 80 = 7.2 mm. Real parts are held back by the layers below, which is why they warp and curl instead of simply shrinking, and why the effect grows with length.

The same arithmetic matters in service. A 1,000 mm PETG part with a coefficient of about 60 x 10⁻⁶ per kelvin moves 1,000 x 60 x 10⁻⁶ x 30 = 1.8 mm over a 30 K temperature swing. A steel frame (about 12 x 10⁻⁶ per kelvin) moves 0.36 mm over the same swing. If a long plastic part is bolted rigidly to steel at both ends, give it slotted holes or a floating end, or it will bow or crack.

How to control warp on a big part

Warp comes from the part cooling unevenly, so large flat areas and long thin walls move most.

• Add ribs to large flat areas instead of making them thicker.
• Put a 45° chamfer or radius on edges that touch the build plate, to limit elephant foot and warp.
• Choose a material with lower shrinkage for the biggest parts: PETG over ABS or nylon where the duty allows.
• Orient the part so the main load runs along the layers. See layer orientation and part strength.
• Fillet internal corners to spread stress along the layer lines.

Worked example: hollowing and ribbing a panel

Take a flat 1,000 x 500 mm panel that must carry a light load. At 6 mm solid, it has a plate volume of 1,000 x 500 x 6 = 3,000 cm³ of plastic. Print it as a 2 mm skin with ribs, and the skin alone is 1,000 x 500 x 2 = 1,000 cm³, a third of the volume; the ribs add some back, but the panel is much lighter and cools more evenly. Ribs keep stiffness by moving material away from the middle, because bending stiffness grows with the cube of depth. Ask an engineer to propose rib height and spacing for your load; the right answer depends on material and load.

• Corners: round the footprint corners of a flat part. Sharp corners lift first.
• Avoid long, thin, unsupported cantilevers; add a gusset at the root.
• Split a part where the section changes abruptly, so each piece cools evenly.
• Print the largest flat face against the build plate when the part shape allows.

When to split and bond

Split a model when it exceeds 1000 mm in any direction, or when splitting lets each piece print flat, avoid supports or use a different material for a different region. Add alignment features such as tongues, pins or stepped joints so the sections locate without a fixture, and leave a bond line away from the highest-stress area.

Joint design for bonded sections

• Bond area: make the joint overlap long. A common starting rule is a lap length of at least 5 times the wall thickness, so the adhesive carries load in shear.
• Alignment: tongue-and-groove, dowel pins or stepped joints stop the sections shifting while the adhesive cures.
• Keep the bond line away from the highest-stress fillet and from sealing faces.
• Choose the adhesive for the plastic: nylon and PETG bond differently. Tell us the loads and the environment, and an engineer recommends the approach.
• Mechanical fasteners and threaded inserts can join sections that need to be separated again.

What to send for a large-format quote

1. A STEP file, uploaded on the instant quote page. Our STEP export checklist helps avoid review delays.
2. The largest overall dimensions and the datum faces that must stay in tolerance.
3. Load, temperature and environment, so we can choose the material and orientation.
4. Quantity and any finish: sanding, painting, coating or threaded inserts.
5. The deadline. If the date is fixed, say so and an engineer reviews it first.