The eMachineShop CAD software automatically selects the most economical process given your design and settings such as tolerances.
However there are many ways to reduce fabrication costs and delivery time for custom parts. Here are a few:
- Almost all choices you make in each dialogue affect price. Choose the lowest cost options where possible – especially in Job | Material, Job Settings and Job | Finishing.
- Avoid checking Job | Settings | Processes | Secondary Process for Intricate Shapes. See Sharp Inside Corners. Features at edges can sometimes be moved to another view to achieve a sharp corner.
- Generally using line type Auto will be less expensive than special processes like Injection Molding for short runs.
- Click Job | Price | Analyze and view the warnings and advisories to resolve as many machining incompatibilities as practical. This allows the system a better chance of using a lower cost process.
- If you need to apply a finish (powder coat, anodize, plate, etc.) to multiple jobs placed simultaneously, add Comments To Machinist “Apply finishing setup credit for orders placed today.” Your parts will be processed in one batch and the savings passed back to you.
- Do not assume the lowest price combination you tried a month ago is the lowest price today.
- The complex pricing mechanism does occasionally make errors – if you have some experience with the cost of custom parts and feel the price quoted might be an error, please submit your design for review.
- If you imported your design (or part of it) you might find lines made of numerous small line segments. For example, a circle might be comprised of 100 small lines. This can increase price and slow things down substantially. You can determine this by clicking on each line and looking at the status bar. Consider redrawing lines in the eMachineShop CAD so that they are built efficiently.
- Avoid splines. They can occur when you stretch a shape with arcs. Use the Node edit tool to stretch such shapes to avoid conversions to splines.
Very simple parts
If you have a low quantity of a very simple part with loose tolerances, your part might qualify for lower pricing via manual machining as compared to the CNC price computed by the CAD system. Some examples of parts that may be suitable to manual machining: a rectangular block or round bar of a certain size perhaps with a step or simple notch, or one or two holes, etc. If you feel your part might be suitable for manual machining, submit your order with the comment “Please quote for manual machining – do not proceed without approval.”
- If you need a 3D part with it’s mirror image: draw one version; set quantity to total number of both parts; add as Comments to Machinist “Run half quantity using mirror image.”
- If you have a minor variation between two parts, instead of placing two separate orders consider specifying the variation using Comments To Machinist (e.g. “Change diameter to .503 in for half run”)
- Sometimes you can save by using pre-shaped stock such as pipe or square tube.
- For injection molding, minimize use of holes and recesses in the Front, Back, Left and Right views.
- Minimize the number of views used. Slots and other features at edges can sometimes be moved to another view.
- End clamp slots with sharp corners instead of arcs.
- If the design includes a Revolve line with mainly straight line segments along with other features, try rebuilding the shape without using the Revolve line. (Doing so may reduce the number of machining processes from two to one.)
- If the design can be done using the Revolve feature try using that method.
- You can try adding material with positive Z values or removing material with negative Z.
- For simple revolved parts you can compare using circles and grooves instead of the Revolve feature.
- You can compare the cost of creating certain features from another view.
- When possible structure your design to minimize Z values. For example, a rectangular block 1 x 1 x 2″ could be drawn in the Top view with a 1 x 1 square having Z set to 2 or a 1 x 2 rectangle having Z set to 1. The second way will usually result in lower cost. For similar a reason, if you imagine laying down your part on a table, usually you will want to draw the Top view as if looking down on your part.
- Since parts are machined according to the way they are drawn, it is sometimes possible to draw a part a different way, resulting in a different machining sequence and hence a different price. You can experiment to find the lowest price method.
- Make sure your parts are really 2D according to the eMachineShop definition of 2D parts.
- If you have a part that is essentially 2D but needs a few countersinks it may be more economical to specify those 3D features using Comments To Machinist.
- Remove edge rounding and edge wall angles if possible.
- For small parts, if 1/16″ fiberglass can be used, ordering a blank circuit board from our Pad2Pad division may be more economical.
- Try to nest (arrange) parts efficiently to minimize material use.
- Some shapes nest more efficiently by including an extra rotated copy. For example, a part in the shape of the letter C is more efficient with two C’s arranged so that one copy is rotated 180 degrees and shifted down 50% and a bit to the right.
- Sometimes parts can be nested to save material. The CAD does not allow nesting fully enclosed shapes however you can add a link with a comment to remove the link.
- Keep the size of 2D parts under 47.5″ x 23″.
- IMPORTANT: Also see the general cost reduction tips.
Reducing Delivery Time
There are several ways to reduce delivery time for custom parts. Here are just a few:
- In Job | Material, check “Show only recommended materials” – those materials are more often in stock.
- Avoid requesting special materials.
- Reduce the number of finishing steps in Job | Finishing.
- Minimize use of Comments to Machinist.
- Click Job | Price | Tips and resolve as many machine incompatibilities as practical. This can allow you to run the job on machines with shorter delivery times.
- Pay by credit card.
- For high quantities consider splitting the job to two orders – a small run with faster delivery and the main run with slower delivery.