Guides / Cost
Where the money actually goes in a machined UAV part
July 19, 2026
Machining quotes look opaque from the outside. They are not, once you know which four numbers the shop is adding up.
The four components of a quote
1. Setup and programming. Writing and proving the toolpath, building or setting the work holding, dialling in the first part. This is a fixed cost per release, so it hurts small quantities and disappears into large ones.
2. Cycle time. The minutes the machine spends cutting each part, multiplied by the machine rate. This is where geometry lives. Deep pockets, small radii, thin walls and many separate features all push it up.
3. Material. The bar or plate, plus what is cut away. Usually the smallest number on a small aluminium part, and a significant one on titanium or on a part machined from a large billet.
4. Finishing, inspection and documents. Anodising, passivation, heat treatment, the first article, the CMM report, the certificates. These are often quoted as a package and can easily be a quarter of the price on a small part.
Everything you can do to cut cost acts on one of these four, and the biggest levers are the first two.
Design changes that cut cost without changing function
- Open internal corner radii. 1 mm corners need a 2 mm cutter running slowly. 5 mm corners let a 10 mm cutter do the job in a fraction of the passes.
- Reduce the pocket depth to width ratio. A cutter can go three to four times its diameter deep before it starts to ring. Beyond that everything gets slower.
- Cut the number of setups. A feature on the fifth face of a part can double the price. Move it, or accept a 5 axis part, which is often cheaper overall than three setups on a 3 axis machine.
- Loosen the tolerances that do not matter. Two or three critical features, general tolerance everywhere else.
- Standardise hole sizes and threads. Fewer tool changes, fewer tools.
- Avoid unnecessary finishes. A bead blast plus anodise on an internal part nobody sees is pure cost.
- Do not specify a surface finish everywhere. See surface finish on UAV parts.
What almost never saves money
- Switching 7075 to 6061 on a small part. The material difference is small and you may lose the strength you needed. Decide on function, see 6061 or 7075.
- Removing a few grams of material from a shape that still needs the same passes to cut.
- Asking for a cheaper finish when the aircraft needs the better one. The warranty replacements cost more.
- Splitting an order across two shops to play them off. You pay two setups and get two slightly different parts.
Quantity, and why the curve bends where it does
| Quantity | What dominates |
|---|---|
| 1 to 5 | Setup and programming, almost entirely |
| 5 to 50 | Setup amortised, cycle time appears |
| 50 to 200 | Cycle time dominates, a fixture starts to pay |
| 200 plus | Cycle time, material batching and finishing batching |
This is why asking for a price at three quantities is the most useful thing on an RFQ. If the price per piece barely moves between 10 and 100, the part is cycle time dominated and the design is where the savings are. If it drops sharply, the part was setup dominated and ordering in fewer, larger releases is the saving.
Lead time is a cost too
An expedited part is more expensive because it displaces other work. Meanwhile a part that arrives two weeks late can hold a whole aircraft build.
Two practical habits:
- Ask for the standard lead time and the expedited lead time at quote stage, so the option exists before you need it.
- Put the finishing time in your own plan. Anodising is several days and it is on the critical path, not a detail.
What a quote should show you
- Unit price at the quantities you asked for.
- Tooling or fixture cost, separately, or stated as none.
- Lead time for the first article and for the lot.
- What is included in the finish and the documents.
- The Incoterm and the currency. Ours are EXW and USD.
- Any drawing question that would change the price.
If a quote is a single number with no breakdown, you cannot tell which of the four components to attack, and neither can the shop.
Send a model and three quantities through the RFQ page. The reply comes back within 24 business hours, and where we think a feature is making your part expensive for no functional reason we say which feature and what we would change.
Frequently asked questions
Is material a big part of the price of a small aluminium part?
Rarely. On a small milled bracket the material is often under a fifth of the price, sometimes far less. Machining time and setup dominate, which is why redesigning for faster cutting saves more than switching to a cheaper alloy.
Does a smaller part always cost less?
No. A tiny part with deep narrow pockets can cost more than a larger part with open geometry, because the cutter has to be small, slow and fragile. Cost follows machining time, not size.
What is the single cheapest change I can make to reduce cost?
Open the internal corner radii. It lets the shop use a bigger cutter at a higher feed, it removes a stress concentration and it usually saves weight too. It costs nothing and it changes the cycle time noticeably.
Need this part quoted?
Send the model and the quantity. Price and lead time come back within 24 business hours.