CNC Machining
Nowhere in manufacturing has the technology moved faster than in the world of CNC Machining. As computing power has increased so has the machines ability to produce more complex geometries. Advances in metallurgy have spawned new technology in the world of cutting tools, allowing feeds and speeds to be increased. Very much like computers and plasma televisions, the technology available in machine tools has increased and the prices have decreased.
Nowhere does the old term “time is money” ring more true than in a CNC shop. Maybe we should change that to time and tolerance is money. The following tips are all about saving you money.
Design Considerations
Specify the surface finish you are looking for. If a fine finish is required in a specific area, label it. Some shops may tumble parts as a matter of course. This may not be the appearance you are looking for. Geometry issues are usually easily corrected appearance criteria not always so.
Never underestimate the importance of a 2-D dimensioned drawing. Even if you have a state of the art CAD system, and the shop has the latest in CAM which is fully integrated into their inspection system, a clean concise 2-D print in the shop floor traveler answers questions quickly and easily.
Tight tolerance is money. Specify it only where you need it. Avoid default tolerance settings on CAD programs. They can cost time and therefore money. On turned parts unless the ends of the part are functional, allow the shop some flexibility on the end geometry so they may cut off the part in the most effective manner.
Avoid square corners on inside pockets. The more generous radii, the larger end mill can be used allowing for metal to be removed faster. Again, time is money.
Deep tapped holes and deep pockets add cost. Deep pockets often have to be “pecked” requiring multiple plunges of the cutting tool. Deep tapped holes always run the risk of a broken tap, requiring extensive rework or scrapping the part altogether.
Economic/Purchasing Considerations
Set ups cost money. Most shops charge a higher hourly rate to set up their machines than they do to run them. A good shop will always strive to reduce set up times; however in many cases buying a higher quantity will outweigh carrying charges.
Birds of a feather flock together. When visiting a shop look at the parts that they currently produce. Do they produce parts of similar size, configuration, level of sophistication, and volume as the ones you are looking to source? If so chances are they will be competitive.
Look for a shop with the resources necessary to support your production. Smaller shops do tend to be very responsive; however CNC machinery is very sophisticated and can be subject to downtime. If you are in a JIT environment, a one machine shop may not be the answer.
How We Can Help
First, we can analyze your part to determine if perhaps an extrusion or casting may save machine time and therefore cost. We have access to…
CNC Milling – Up to 80×40 bed size vertical as well 600mm Horizontal capacity. 5 axis capability.
CNC Turning – Up to 20” diameter swing, 30” work piece length.
Swiss Screw Machining – Perfect for connector pin and precise ordinance components. From .015” to 1.125” diameter. Tolerances routinely held to +/- .00002”
Conventional Screw Machining – Single and Multiple spindle as well as Hydromat equipment.