Precision CNC machined led heat sink for outdoor spotlight
This is a precision CNC machined led heat sink for spotlight. It actually consists of 2 parts, the aluminum profile is press into a tight fit with the core. The fit is quite tight, so after we have machined the part, you can not see the gaps between the 2 pieces, so it looks like an integral piece.
|Size (inch)||OD 2.25″ x Length 4.3″|
|Tolerance for key dimension (inch)||+/-0.005″|
|Coating:||Primer coating: electrophoresis coating|
Top coating: glossy enamel paint
|Test||Salt spray test, 720 hours, ASTM B117.|
|Processes||CNC turning, milling, polishing|
Burrs removed by polishing
There are slight burrs formed on the fins in the turning process, a polishing process is then followed to remove the burrs. The polishing is done manually and should be controlled carefully not to change the shape of the contour.
Very slight burrs are still allowed.
A perfect fit that makes the 2 pieces look like 1 integral piece
The aluminum extrusion and the core piece need to be machined to tight tolerances, so when they are press-fit together, there will be no visible gaps. This is not only to ensure an appealing look, but the gaps will cause major coating issues, so they are not allowed.
The coating needs to pass 720 salt spray test
The coatings (electrophoresis coating and spray painting) are the most critical processes among all because some of the quality problems are not recoverable and may lead to bulk rejections. The keys to a smooth operation are: 1. a reliable and eligible vendor, 2. on-site monitoring of the processes.
The coating needs to pass different tests, the most harsh test is the 720 hours salt spray test. This means the test lasts for one month and there should be no significant peeling off of the paint.