Design for Manufacturability
& Error Code Lookup

STEP is a text-based exchange format with a strict header and data section. Cloud exports that fail partway, files renamed from another format, and files zipped by the browser all produce a body the kernel cannot open.

Many drawing tools write non-standard or very old DXF revisions. Binary DXF, DWG renamed to DXF, and files exported from illustration software with clipping groups are the usual causes.

Online pricing needs exact geometry. Mesh and picture formats describe a surface approximation or pixels, not the contours and thickness the engine needs to nest and price a part.

Sheet metal pricing derives thickness, flat pattern, and cut length from a watertight solid. Surface bodies have no volume, so none of those can be computed.

The engine prices each component individually. Anything without volume breaks that loop, so the whole assembly is rejected rather than silently skipped.

A laser follows closed loops. An open contour has no inside and no outside, so the machine cannot decide what to keep and what to drop — and the nest cannot compute part area.

The flat blank is what actually gets cut. If the unfolded outline overlaps itself, the blank is physically impossible — the same piece of steel would have to be in two places. Cut lines crossing bend lines mean the brake would be bending across an open slot.

A 2D fiber laser cuts straight down. Any bevel modelled on the perimeter cannot be produced on the cutting table — the engine flattens it to a perpendicular edge and prices it that way.

Either every body failed recognition, or the file contains only reference geometry and no manufactured component.

Partial recognition usually points at one bad region — a corner that will not unfold, an imported face with bad topology, or a feature that conflicts with the sheet metal model.

A part is cut from one sheet of one gauge. Varying thickness means the model is not a true sheet metal part — or a machined pocket, embossed area, or modelling error has changed the wall locally.

Every edge face must run cleanly between the two sheet surfaces. Isolated edge faces come from bad boolean operations, imported geometry with healing errors, or a chamfer applied to the thickness.

Unfolding fails when bends conflict — flanges that overlap when flattened, bends that run into each other, non-developable curved faces, or bends applied to an already-bent region.

STEP files carry a modelling tolerance. When a body was built or translated at coarse precision, faces can be several thousandths apart while still being reported as joined. Downstream operations then fail unpredictably.

Feasibility is a whole-part test: tooling has to physically reach every bend in sequence without the part colliding with the ram, the backgauge, or itself. Deep boxes, opposing flanges, and closed sections often fail here.

The blank — not the folded part — is what has to fit on the table. A 24″ deep box with 6″ flanges unfolds far larger than its folded footprint.

Very small blanks fall through the slat bed, tip into the scrap, or cannot be picked without damage. There is also a minimum size below which the part cannot be held for any secondary operation.

Every station has a weight ceiling: brake operators handle blanks by hand, coating lines hang parts on hooks, and tumbling barrels have a load rating. The message names the limit that was hit.

Sheet is stocked in discrete gauges. A model built at a rounded metric value (2.0 mm) may sit between two imperial gauges, and not every alloy is stocked across the whole gauge range.

Heavy gauges are often stocked only in smaller formats, and some large formats only come in thin material. A large part in a thick gauge can fall between the two.

The nester tries the blank at every allowed rotation against every stocked format. This message means all of them failed.

Two separate ceilings: physical axis travel on the cutting machine, and a total cut-length threshold above which a job stops being an instant-quote item and needs scheduling.

Even when a blank fits the cutter, every downstream station — brake, finishing, packaging — has its own envelope. This is the ceiling across all of them.

Edge rounding runs on a through-feed belt machine with a fixed working width. Anything wider than the band cannot be fed through.

Small parts are not held by the feed rollers — they tip, jam, or get thrown by the abrasive head. There is a hard minimum footprint below which the machine cannot run them.

In air bending the blank spans the V-die and the punch pushes it down into the opening. If the flange is shorter than roughly half the die opening plus a landing, one side of the material hangs in open air instead of resting on the die shoulder. The punch then cams the part sideways: the angle varies along the bend, the flange curls, and the part twists.

To bend past 90° the punch must penetrate deep into the V-die. The included angle of the punch and die set the floor: an 88° punch cannot make a 30° bend. Thicker material takes up more of the die opening, so the achievable minimum angle opens up as gauge increases.

Every punch and die combination has a working range. Past its limit the material has to be over-bent beyond where the tooling can reach, or the flange collides with the punch body on the way round.

In air bending the inside radius comes from the die opening — roughly 16% of the V width for mild steel. A very large radius needs a very wide die, and past a point it is no longer a bend at all but a rolling operation.

A real bend has concentric inner and outer surfaces separated by exactly the sheet thickness. When they disagree, the model was not built with a sheet metal bend feature — it was drawn with two independent fillets, or edited after the fact. The engine cannot derive a reliable bend allowance from it.

Every bend is a separate setup step and a separate handling. Past a certain count the sequencing, tool changes, and collision checks stop being predictable enough to price without an engineer looking at it.

A press brake bend wraps material around a single punch nose, so both surfaces are arcs about the same center. Non-concentric faces come from stretched or manually edited geometry, or from a "bend" that is really a lofted or swept surface.

The punch has to descend between the existing flanges to reach the bend line. In a deep narrow section the punch body fouls the standing walls before the ram reaches the bottom of its stroke. Gooseneck tooling buys clearance, but it too has a limit.

Engraving happens on the flat blank before forming. Once the part is bent, the head has no access to the interior. If the engraved face is not exposed on the flat sheet, it cannot be marked.

The blank is cut and marked in a single pass with one side up. Marking the reverse means unloading, flipping, re-registering, and running again — the second side cannot be located accurately enough to be an automatic operation.

Tube and profile work runs on a different machine with rotary axis handling, different nesting, and different pricing. It is not part of the flat-sheet flow.

On mill-formed tube the inside corner radius equals the wall thickness and the outside equals twice the wall. Anything else describes a section that is not made.

Tube comes in fixed catalog sizes. A section drawn to arbitrary dimensions has no matching stock.

Powder coating is a hanging line. Parts hang from hooks on a moving conveyor and pass through a cure oven, so both the oven opening and the hook rating are hard limits. Heavy parts also sag on the hook and mark where they contact it.

These are all immersion processes: the part is lowered into a bath. Tank internal dimensions set the maximum size and the crane sets the maximum weight — neither can be stretched.

Blasting happens in an enclosed cabinet with media recovery. The part has to fit inside with room for the operator to reach every surface, and it has to be supported without collapsing the grate.

Wet coating needs a ventilated booth and a drying area. Both are sized around the booth opening and the rack rating.

Pickling and passivation are immersion chemical processes for stainless steel. The tank dimensions and the hoist rating are hard limits, and the part must be fully submerged for the treatment to be uniform.

Grinding runs on a wide-belt through-feed machine. Wide parts do not fit the band; short parts are not gripped by the feed rollers and get thrown; heavy parts overload the table.

Like the other through-feed machines, the trowelizing line has a fixed working width and a minimum part footprint the rollers can grip.

Brushing is a through-feed abrasive process. The part must be wide enough to be gripped by the feed belt, narrow enough to fit the band, and light enough not to slip under the head. Parts outside that window either jam or come out with an inconsistent grain.

Weld pricing depends on joint type, length, position, access, and required inspection — none of which can be read reliably from a CAD model. Some materials also need processes or shielding we do not run.

The engine prices parts it manufactures. Catalog components have to be sourced and are not part of an automatic quote.

Machined parts are priced from stock size, material removal, setups, and tolerances — a completely different model from cut-and-bend sheet work.

Self-clinching hardware is thickness-rated. Each nut, stud, and standoff has a minimum sheet thickness — around 0.040″ for the smallest sizes, up to about 0.093″ for larger threads — and needs an exactly sized mounting hole to clinch properly.

These are catch-all codes returned when an internal step throws before a specific rule fires. The usual triggers are very large files, unusual geometry that breaks an assumption, or a transient service problem.