7075-T5 Aluminum ESC Housing with Thermal Pocket Flatness 0.02mm and Potting Dam Groove for Drone ESC Enclosure

An ESC housing is judged by two surfaces that never appear on a marketing page: the thermal pocket under the MOSFETs and the potting dam that keeps resin off the connectors. This CNC machining parts housing holds the pocket flat to 0.02 mm and its depth to ±0.02 mm, machines the potting dam in the same clamping, and keeps the IP67 gasket land flat to 0.05 mm — so the seal is a seal and not a gap.

A thermal pad only works if it is compressed evenly. If the pocket under the MOSFETs is 0.05 mm deeper at one end, the pad touches there and floats at the other, and the junction temperature climbs while the housing still feels warm and looks fine. The same pocket cut 0.1 mm too deep can leave the pad at half its rated compression.

Here the pocket is machined after a stress relief cycle, flat to 0.02 mm and depth-controlled to ±0.02 mm, and the potting dam and gasket land are cut in the same clamping from the same datum. Anodizing is kept out of the pocket and off the gasket land, because 15 µm of coating on a 1.5 mm pocket is 1% of the compression budget.

• Pocket flat to 0.02 mm — the thermal pad compresses evenly, not just at one end.
• Depth held at ±0.02 mm — compression stays inside the pad supplier's window.
• Dam and land same clamping — potting stays off the connectors, seal stays flat.
• Masked after coating — no anodizing in the thermal path or on the sealing face.

1. Board and thermal review — MOSFET footprint, pad thickness, potting compound and IP rating confirmed before machining.
2. Material verification — 7075-T5 received by heat number with ultrasonic check and 3.1 material certificate.
3. Rough machining — cavity, thermal boss and outer profile roughed with 0.6 mm allowance.
4. First stress relief — low-temperature relief so the 1.8 mm wall does not bow after the cavity is opened.
5. Semi-finish — thermal boss and gasket land semi-finished with light radial engagement.
6. Second stress relief — a second cycle before the final pocket pass keeps the floor flat.
7. Finish machining — thermal pocket faced flat to 0.02 mm, potting dam groove, connector windows and mounting holes cut in the same clamping.
8. Anodizing — 15–20 µm anodizing with the thermal pocket, dam groove and gasket land masked.
9. Verification — pocket depth and flatness, land flatness, window positions on CMM, leak check on request, FAI shipped.

Board outline, connector type, potting compound and IP class all come from your electronics, so the housing is built around the PCB rather than a catalog size. Send the board drawing and connector data sheet and we return a DFM note on pocket depth, dam geometry, gasket squeeze and masking within 24 hours.

• Board interface — standoff bosses, threaded inserts, or a bonded carrier plate.
• Sealing — O-ring groove, moulded gasket land, or full potting with a dam.
• Connectors — XT60/XT90 panel cutouts, MR30, JST windows, or sealed M8 pass-throughs.
• Thermal — flat pocket, finned lid, or a heat pipe land with a clamped interface.
• Sampling — 1 pc assembled with your board for a thermal and leak check.

Motor geometry, stator stack and winding data are competitive information, so access is limited from the drawing stage onward.

• NDA first — mutual NDA and non-circumvention signed before any file is exchanged.
• Isolated area — dedicated machines and authorized staff, no phones or photography inside.
• Codified routing — internal codes on travelers and labels instead of your part numbers.
• Data control — per-project folders on a permission server, destroyed on request with a record.
• No display — no drawings, part photos or logos in samples, catalogs, the website or social media.

Dongguan Changxinda Precision Technology Co., Ltd. — founded in 2008, 90–102 staff, ISO 9001:2015 certified, annual sales USD 10–20 million, export share 50–60%, serving customers in Europe, North America, Japan and Southeast Asia.

Machining, stress relief, anodizing and metrology run in one plant: 5-axis and 4-axis machining centers, turn-mill centers, surface grinders, wire EDM, CMM, 2.5D vision metrology and automated anodizing lines. About 12,000 aluminum parts ship each month, most of them small precision parts where the fixture and the boring sequence decide the result.

• 01 Consumer ElectronicsPhone, tablet and laptop housings · heat sinks · camera brackets · VR/AR headset structural parts · smart wearable housings
• 02 Automation & Industrial EquipmentAutomation jigs · fixtures · module frames · transmission sliders · motor mounts · sensor housings · conveyor line components
• 03 Semiconductor & Vacuum EquipmentVacuum chambers · vacuum fittings · semiconductor equipment precision bases · thermal insulation parts · inspection fixtures
• 04 Medical DevicesSurgical instrument bases · medical device housings · endoscope components · aesthetic equipment structural parts (medical grade aluminum / stainless steel)
• 05 AutomotiveEV motor housings · battery end plates · sensor brackets · lamp structural parts · aftermarket parts · hydraulic valve blocks
• 06 Aerospace & UAVAircraft structural parts · UAV frames · landing gear components · avionics instrument housings (lightweight precision parts)
• 07 Optics & PhotonicsOptical lens barrels · lens mounts · light source heat sinks · camera module brackets · inspection optical stages
• 08 Telecommunications5G heat sink cavities · filter housings · signal adapter brackets · telecom equipment enclosures
• 09 RoboticsRobotic arm joint parts · robot bases · reducer housings · AGV chassis structural parts
• 10 Instruments & MetersInspection equipment housings · precision gauge bases · flow meter parts · laboratory equipment components

Two shifts 07:30–22:00, six days a week, with weekend shifts in peak season. Capacity is locked weekly for volume programs, so a rush order never displaces a scheduled batch.

• Samples — 7–10 days, checked on your stator or bearing set before the batch is released.
• Batch — 15–20 days from deposit and drawing approval.
• Buffer stock — semi-finished stock for repeat models, cutting repeat lead time by about 30%.
• Shipping — DHL/FedEx/UPS in 3–5 days for samples; air or sea for volume; EXW Dongguan, FOB Shenzhen or CIF.
• Documents — FAI, 3.1 material certificate, CMM report and packing list with every shipment.