Guides / Design and Fit

What to Send a Shop Before It Can Quote Your Case

September 21, 2026

Shops quote fast and keenly when a package is complete, and slowly and defensively when it is not. A defensive quote has padding in it, because a shop that does not know your cosmetic standard has to assume the worst one.

Here is what complete looks like.

One STEP file per machined part

Not one assembly export that somebody has to take apart. Each part as its own file, named for what it is: top case, bottom case, plate, weight.

Send the assembly as well, as a separate file. The shop uses the parts for programming and the assembly for understanding, and occasionally for spotting an interference you have not noticed.

Native files are welcome if the shop can open them, but STEP is the universal format and it should always be in the package.

A 2D drawing per part

This is the document that turns a shape into a job. A model is geometry. A drawing is intent, and intent is what a quote is priced against.

Each drawing should carry:

  • Material: alloy and temper, for example 6063-T5, with a no substitution note.
  • General tolerance in the title block, and specific callouts on the handful of dimensions that matter. See which tolerances actually matter.
  • Cosmetic faces identified. Which surfaces will a buyer look at, and which are hidden inside. This changes the price more than most designers expect.
  • Surface finish: blast media and grit, then the coating and its colour reference.
  • Threads called out properly, with depth.
  • A note on whether dimensions apply before or after finishing.

The PCB outline

Send it. Nobody is machining it, and it is still one of the most useful files in the package.

The case exists to fit the PCB. The mounting holes have to agree with it, the connector cutout has to align with a socket soldered to it, and the internal clearance has to accommodate whatever is standing up on its surface. A shop that can see the PCB will catch an interference you missed; a shop that cannot see it will machine exactly what you drew.

Quantity, at more than one number

Ask for a price at three quantities rather than one. Fifty, a hundred and fifty and three hundred is a reasonable spread for most keyboard projects. It costs the shop very little extra effort and it shows you the shape of the curve so you can set your buy target sensibly. The reasoning is in the real minimum order quantity.

While you are at it, ask for a prototype price separately. You want that number visible rather than buried.

The finish, properly specified

“Anodised black” is not a specification. It is a hope.

Give the process, the blast grit, the colour reference and the batching instruction:

Bead blast, 120 grit glass. Type II anodise to RAL 7016 approximate, physical sample supplied. Top case and bottom case to be processed in the same anodising load.

That paragraph prevents more problems than any other four lines in the package. More on why in how anodised colour is really decided.

The date, said out loud

If your run has a public ship date, put it in the RFQ. A shop that knows the date up front will tell you honestly whether it can hold it, and an honest no in week one is worth far more than a cheerful yes that becomes a six week slip in month three.

Ask specifically for the finishing lead time as a separate number. It is the step most likely to move and the one your machine shop controls least.

What else to say

Three lines that cost nothing and change how a shop reads your project:

Whether you need a prototype first. Almost always yes.

How far you want the shop to go. Machining only, machining and finishing, or machining, finishing and packing. This changes which shops fit as much as it changes the price.

Whether an NDA is needed. Unreleased keyboard designs leak, and a leaked case is worth nothing. Ask for the NDA before the files move rather than after.

The package, in one list

  • STEP per machined part, plus the assembly
  • Drawing per machined part
  • PCB outline
  • Quantity at three levels, plus a prototype price
  • Finish specification including blast grit and colour reference
  • Ship date and whether it is public
  • Service level and NDA requirement

That is perhaps an hour of work. It is the hour that decides whether you get three comparable quotes or three numbers you cannot compare. When it is assembled, send it.

Frequently asked questions

Is a STEP file enough on its own?

No. A model carries geometry but not intent. It cannot tell a shop which faces are cosmetic, which tolerances matter, what the alloy is or what the finish should be. The drawing carries all of that, and without it the shop is guessing.

Should I send the whole assembly or individual parts?

Both. Send each machined part as its own STEP so it can go straight to programming, and send the assembly so the shop can see how the parts relate and spot an interference you missed.

Do I need to send the PCB file?

Send the PCB outline with mounting hole positions and connector locations, even though nobody is machining it. The case exists to fit that board and most fitment problems start with a case designed around a PCB nobody measured.

Need a quote for your case?

Send the files. We match you with up to 3 shops that machine keyboard cases and reply within 24 business hours.

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