DFM · 3-axis CNC machining
CNC machining DFM check for STEP files
Pick a stock and PartCheck checks your part the way a machinist looks at it before quoting: what a cutter can reach, which corners it cannot make, which walls will chatter, how many setups the shape forces, and how much of the billet becomes chips. Free, in your browser, nothing uploaded.
What it does for you
- Lower quotes. Every extra setup, special cutter or slow pass is in the price. Find them while they are a design change.
- Fewer surprises. Corners that cannot be cut and pockets that cannot be reached come back from the shop as questions — or as parts that differ from the drawing.
- Answers before the shop asks. Check the part yourself before you send it out, instead of waiting for the questions to come back.
How to use it
- 1
Open your part
Drop a STEP file on the page and choose DFM.
- 2
Pick CNC and a stock
Aluminium, stainless steel, titanium, brass or plastic — or Generic to check against all five before the stock is chosen.
- 3
Run the checks
PartCheck measures the part and runs every check against your stock.
- 4
Read the verdict
The answer first, then the findings under Will cause defects, Will add cost and Worth knowing, each painted on the part. Click one to zoom to it and step through every place it was found.
- 5
Match your shop
Change the smallest cutter, the number of setups you allow, or any other limit, and run again.
- 6
Send the report
The Manufacturability Report: a PDF to attach to a quote request.
The 8 checks
- Tool access
Closed cavities no cutter can get into at all.
- Undercuts
Faces no straight cutter can reach from any setup — a special cutter, a fixture or EDM.
- Sharp internal corners
Inside corners with no radius, which a rotating cutter cannot make — with what to do instead.
- Internal corner radii
Fillets tighter than your smallest cutter, which mean a smaller tool and a slower job.
- Thin walls
Walls too thin for the material, or thin and tall enough to chatter and bend away from the cutter.
- Pocket depth
Pockets too deep for the cutter that fits them, needing a long, slender tool.
- Setups
A shape that forces the part to be turned over and clamped again more times than you allow.
- Material removed
Parts where most of the billet you pay for ends up as chips.
They are judged for a 3-axis mill, with a smallest cutter of 3.00 mm and up to 2 setups by default.
Thinnest wall by stock
| Stock | Thinnest wall | Recommended |
|---|---|---|
| Aluminium | 0.50 mm | 0.80 mm |
| Stainless steel | 0.50 mm | 0.80 mm |
| Titanium | 0.50 mm | 0.80 mm |
| Brass | 0.50 mm | 0.80 mm |
| Plastic | 1.00 mm | 1.50 mm |
See what a cutter can reach
For a picture of which side reaches each face, and how many setups the part needs, open the Tool access map on the same part. The part's weight, billet size and the share of it cut away are on the part sheet beside the findings.
Good to know
These are geometric checks for a 3-axis mill: they say nothing of cycle time, tooling, fixturing, tolerances, surface finish or price. They are in beta — treat a finding as something to look at, and a clean result as not proof. Confirm with your machinist.
Questions
What is the thinnest wall I can machine in aluminium?
PartCheck flags aluminium walls under 0.50 mm anywhere, and walls under 0.80 mm that run tall and unsupported. The table above has every stock.
What size cutter does it assume?
A smallest cutter of 3.00 mm by default. Set it to your shop's.
Does it handle 4- or 5-axis machining?
No — it judges for a 3-axis mill. A part that needs many setups is often one that wants more axes.
Is my part uploaded?
No. The checks and the report run in your browser. It is free, with no account.
Try it on a real part
The demo is a moulded enclosure lid in two revisions, drawn in CAD. It opens in the tool with no files needed — or open your own STEP files. Nothing is uploaded: the analysis runs in your browser.