Legacy Drawing Conversion

Input formats accepted

• PDF technical drawings and multi-sheet drawing packages
• Scanned paper blueprints (TIFF, JPG, PNG) — any resolution
• DWG / DXF files (all AutoCAD versions including legacy R12, R14)
• Photographs of drawings or physical parts
• Hand sketches with dimensions
• Microfilm scans

How it works

1. Send us the drawings in whatever condition you have them.
2. We read the source material and send a fixed quote within 12 hours.
3. Our engineering team models the part natively, and stops to ask whenever the drawing is unclear.
4. You receive the files and tell us what needs to change.

Steps 2 and 3 are where legacy work goes wrong, and they fail for different reasons.

Step 2 fails when nobody looks closely at the source before pricing it. A scan that reads fine at thumbnail size can turn out to be a third-generation photocopy where the tolerance block has gone to mush. A drawing set described as complete can be missing the section view that defines the internal bore. Neither is visible from a file list, and both change the job. We quote from the actual files at full resolution, after checking that the views present are sufficient to define the part. If they are not, that goes in the quote rather than surfacing halfway through the work.

Step 3 fails when a drawing contradicts itself and somebody resolves it quietly. Old prints accumulate hand corrections, superseded revisions, and dimension chains that no longer close. Anyone modeling at speed will pick the reading that lets him finish, and you will not find out which reading he picked until a part is cut. Our team does not do this. An unreadable dimension, a missing view, or two revisions that disagree stops the job and comes back to you as a specific question identifying exactly what we need.

What we deliver

A native model with a real feature tree — on SolidWorks, Inventor, and Creo. We model in whichever package you run, and on those three the file you receive carries editable history. A hole is a hole feature with a diameter you can change. That is standard on every such project, not an upgrade.

AutoCAD is the exception, for a technical reason. It has no parametric feature manager comparable to the other three, so a 3D solid authored there carries no editable history tree — that is a property of the software, not a lesser tier of service. AutoCAD work is delivered as a 3D solid DWG, with a 2D drawing set on request. If an editable feature tree matters to you, specify SolidWorks, Inventor, or Creo at quote stage.

The distinction matters more than it sounds. A converted STEP file imported into SolidWorks arrives as a dead solid with no history, so changing a bore diameter means surface editing rather than typing a new number. Plenty of conversion work is delivered that way without the difference being mentioned. If you plan to modify the part, or if the model is going into a product that will be revised, imported geometry costs you the time back later.

Geometry also ships as STEP AP242, so the part opens anywhere. Full PMI and MBD data is available on request rather than by default, because most conversion work does not need it and carrying it adds cost to every job that does not.

3D model only, by default. A 2D drawing set is available on request.

Assembly structure is your call, specified at quote stage. Either a mated assembly or individual parts, depending on how you intend to use it.

Dimensioning follows ANSI Y14.5 or ISO 1101, matched to whichever standard your source drawing was drawn to. We do not silently re-standardize a print.

One revision is included with every project, covering change requests. Errors attributable to our team are corrected free within 30 days and do not consume it.

Output formats delivered

• STEP / STP (AP203, AP214, AP242)
• SolidWorks SLDPRT / SLDASM
• Inventor IPT / IAM
• PTC Creo (native)
• IGES / IGS
• Parasolid (X_T)
• DWG / DXF (updated 2D)
• PDF drawing (2D output)

Typical inputs and outputs

A 1970s paper blueprint pulled from an archive drawer

In: one D-size linen or vellum print, hand-dimensioned, with no digital copy anywhere in the building. Often the only surviving definition of a part still in service.

What happens: the print gets scanned at high resolution before anything else, because handling degrades it further and the scan becomes the reference copy from that point on. Our engineering team works from the scan, models to the dimensions as drawn, and checks the finished model against the print view by view.

Out: a native file with editable features, plus STEP AP242, dimensioned to the standard the original followed.

A vendor PDF for a bought-in component with no native file

In: a PDF from a supplier who either will not release the model or no longer has it. Usually a vector PDF exported from CAD, sometimes a scan of a printout.

What happens: a vector PDF carries lines and arcs, not solids, so there is nothing in the file to convert directly. (Why automated converters fail on this.) The geometry gets rebuilt as a solid from the dimensions the drawing states. Where a dimension is absent and the geometry cannot be derived from the ones present, that becomes a question to you rather than a number scaled off the page.

Out: a solid you can fit-check inside your own assembly. See PDF to CAD.

An AutoCAD R12 DWG from a decommissioned product line

In: 2D DWG in a format three decades old, often with text in a font that no longer resolves and layers named by a convention nobody wrote down.

What happens: the file opens, and opening it is not the hard part. R12 2D geometry is line work, so it defines the part only as well as the original draftsman dimensioned it. We work from the stated dimensions rather than measuring the vectors, because old files accumulate stretched and non-associative geometry that measures wrong while looking correct.

Out: a 3D solid with editable features in your current SolidWorks, Inventor, or Creo version, plus STEP AP242.

A sheet metal enclosure supplied as flat-pattern prints only

In: flat patterns with bend lines marked, no bend allowance table, no material callout, no press brake documented.

What happens: a flat pattern plus a bend line is not enough to produce a folded model. Developed length depends on material thickness, bend radius, and the K-factor of the tooling that made it, and those are frequently absent from old prints. Rather than assume a value, we come back with the specific question: what material and gauge, and is there a sample part we can reference. You supply the value or authorize one, and the model is built to it. See sheet metal CAD.

Out: a folded solid plus flat pattern, with bend parameters set to values you confirmed.

When this gets difficult

Legacy conversion is rarely hard to model. It is hard to interpret. Five situations account for most of it, and one policy resolves all five: when the source material does not say clearly, we stop and ask rather than deciding for you.

Illegible dimensions. The tempting fix is the wrong one. Scanned prints are not to scale, paper shrinks, copiers stretch one axis, and old drawings were frequently annotated NOT TO SCALE precisely because a draftsman changed a number without redrawing the view. A dimension measured off a print is a dimension somebody invented, and in the delivered file it looks identical to a real one. There is one case where an unreadable dimension does not cost you a query: when the surrounding chain of dimensions leaves exactly one arithmetically possible value, we close it and move on, because the drawing has already fixed the number. Everywhere else — including where a value merely looks plausible — you get a specific written question identifying exactly what we need.

Missing views. A part is defined when the views present constrain every feature. A single front view with a circle tells you there is a round feature and nothing about whether it is a through hole, a blind hole, a counterbore, or a boss. We check view sufficiency during quoting rather than during modeling, so a missing sheet is a decision you make before spending money.

Conflicting revisions. Two prints of the same part number with different revision letters and no clear supersession, or a print carrying a hand-marked change that never became a formal revision. This is a records problem, not an engineering one, and it cannot be resolved from the drawings. We identify the specific conflict and ask which document governs. The person with the production history makes that call.

Ambiguous tolerances. Older prints often carry a title-block general tolerance and nothing else, or GD&T on a datum scheme that is incomplete under current ANSI Y14.5 practice. Geometry gets modeled to nominal regardless, so this does not block the model. It does affect whether the file is safe to send straight to a supplier, which is worth knowing before you do.

Units and projection convention. Prints from the transition decades mix inch and metric, sometimes on the same sheet, and first-angle versus third-angle projection is not always marked. Getting projection wrong mirrors the part, and a mirrored part passes visual inspection.

What this costs you

Asking has a price, and it is honest to state it. Every query pauses the clock. A drawing that generates two questions takes longer than a clean one, and if you are slow to answer, delivery moves out by however long the question sat. A vendor who never asks anything will always appear faster.

The alternative is a vendor who resolves the same ambiguity silently, delivers on schedule, and transfers the risk to you without telling you it happened. That cost does not appear until the file reaches a supplier.

One practical consequence: the queries and your answers accumulate as a written record of every judgment call on the job. If a part is questioned later, the reasoning is retrievable.

Who this is for

Your supplier went out of business and you have paper prints only. The part is still in your product, still needs sourcing, and no new supplier will quote from a photocopy.

You are bringing a discontinued product back into production. Tooling is gone, the engineer who drew it retired, and the drawings in the drawer are the entire definition.

A vendor sends a PDF for a component you need inside your assembly. You cannot fit-check a PDF, and the vendor either will not release a model or does not have one.

You are migrating to a PLM or ERP system that expects native models and a large share of your part catalog exists only as 2D.

You are re-sourcing an existing part and the shops you want quoting it will not take 2D prints.

If no drawings survive and you have only a physical part, that is reverse engineering rather than drawing conversion. Different process, different inputs.

FAQ

Do we get an editable model or imported dead geometry?

An editable one on SolidWorks, Inventor, and Creo. We model natively in the package you specify, and on those three the delivered file has a real feature tree with history, so changing a hole diameter means editing the hole feature. Converted geometry imported from STEP arrives as a B-rep solid with no features, where the same change means surface editing. Both are legitimately called 3D models, which is why the difference is worth confirming with any vendor.

AutoCAD is the one exception on our side: it has no comparable parametric feature manager, so AutoCAD deliverables are 3D solid DWGs with no history tree. That is a property of the software rather than a lesser service, but specify SolidWorks, Inventor, or Creo if an editable tree matters to you.

What happens when a dimension cannot be read?

You get a question, not a guess — with one precise exception. Where the surrounding chain of dimensions leaves exactly one arithmetically possible value, we close it and carry on without asking. That is not an assumption: the drawing has already fixed the number, it simply does not print it.

Everything genuinely ambiguous stops the job. We do not measure the drawing to fill a gap, because scanned and photocopied prints are not dimensionally reliable and a scaled number is indistinguishable from a real one once it is in the file. A value that merely looks plausible is still a guess, so it gets a question rather than a decision. Open points are batched into a single written list identifying exactly which dimensions we need and where they sit on the drawing, so you answer once instead of fielding a stream of messages. Work resumes when you reply.

Does asking questions slow the job down?

Yes, and the turnaround figures assume a clean drawing set. Each query pauses the clock until you answer. A print with two unreadable dimensions and a missing section view will take longer than the stated range. The tradeoff is deliberate. The alternative is a delivered file containing decisions nobody told you about, which is faster right up until a supplier cuts to it.

Do you carry GD&T and tolerances into the model?

Geometry is modeled to nominal, which is standard, since a solid represents one state and not a tolerance range. STEP AP242 carries the geometry. Full PMI and MBD annotation, meaning tolerances and datum references embedded in the file rather than sitting on a separate drawing, is available on request rather than by default. If your downstream process is model-based, specify PMI when you request the quote, because it affects price and time.

What if the delivered model is wrong?

Errors attributable to our team are corrected free within 30 days. That is separate from the one revision included with each project, which covers changes you want rather than mistakes we made. Sending unclear source material back to you as a question during the job removes the most common cause of delivered errors, which is a silent judgment call nobody recorded. It does not remove every cause, and the 30-day window covers the rest.

What if we need a format you have not listed?

We work in AutoCAD, SolidWorks, Inventor, and PTC Creo, and deliver STEP AP242 alongside any of them. STEP imports into essentially every major CAD package, so a format outside that list is usually a conversion question rather than a modeling one. See CAD format conversion. Ask before ordering rather than after, so nobody finds the mismatch at delivery.

Can you work from a phone photo of a drawing?

Sometimes, and it is the weakest input we accept. A photo adds perspective distortion and uneven focus, and faint dimension text is exactly what fails first. If the print is flat, evenly lit, and shot square, a photo of a legible drawing is workable. If the print is already faded, a photo will not rescue it, and it will generate queries that a scan would not. A flatbed scan at 300 dpi or higher takes minutes and changes the result.

Turnaround

Simple, 24 to 48 hours. A single machined part, roughly under 20 features. One bracket, one shaft, one plate.

Medium, 2 to 3 business days. A multi-feature part, or a small assembly of two to ten parts. A sheet metal enclosure, a small sub-assembly.

Complex, 4 to 6 business days. Assemblies over ten parts, single parts requiring surfacing, or multi-sheet drawing sets.

Rush service returns in 12 to 24 hours when we receive files before 11am, subject to availability. All of these assume source material we can read without coming back to you.

See pricing, or send a drawing for a fixed quote within 12 hours.