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Plastic Enclosure Designs and Details

At Toolless Plastic Solutions all of our plastic enclosure products adhere to a strict design process to ensure they live up to our high quality standards. We work closely with you on your plastic enclosure design and implementation of any internal that will be placed within the enclosure. All buttons, ports, displays, or switches are all designed with the customer and user in mind, so we're confident the enclosure is easy to use, and fit's your requirements. Below you will find our machining and design tolerances, please contact us with any questions or request a quote today.

Machining:

•All plastic enclosures are designed as flat patterns
•We try to machine only one side – opposite side machining doubles labor per piece
–Tongues & grooves may be added with saw or table router for easy assembly
–“shablone” = “template”; break out part, drop into template for opposite side machining
•+/- .2 mm tolerance for template
•+/- .4 mm tolerance from reverse side features to front side features
•“Single cutter” concept to create smooth, simple, plastic enclosures
–2 mm, single flute, carbide cutters used 95% of the time
–We use 3 mm & 6 mm cutters
–CNC routers very fast – optimized for speed without compromised rigidity or accuracy
–Don’t pretend to be a machining center, plastic enclosures are our main focus!
–1 person runs multiple machines; no tool changes, no cutter resets
–Average product comprised of 8 pieces and 2 thicknesses
–Sheet change plus set up for new part in 30 seconds
–Sheet change plus set up for new project in 45 seconds
•Tongue:  1.8 mm wide x 1 mm deep         Groove:   2 mm wide x 1.2 mm deep
–Design the model/CAD to be solvent bonded by Tool-Less for easy assembly
•Tolerance:  +/- .2 mm (.008”)
•CSK added as post operation or machined by CNC
•Parts untouched until machine process is finished – no handling of individual parts until absolutely necessary
•Flashing is designed to provide rigid holding points during machining and is easily broken out after.

Edge Detailing:

–Vernier adjustable table routers, with fences
–Radii, chamfers, tongues & grooves
–1 mm (.039”), 2 mm (.078”) & 3 mm (.117”) radii standard, 3/16” & 1/4’” non-std
–2mm R on 3mm thick part maximum (must have flat for bearing)
–Up to 6mm chamfers – usually bearing, fence OK
–.5mm chamfer on edge of tongue to create cosmetic seam and hide heat deflection at bend

Bending:

•Maximum 40” long bend
•115° up, maximum standard bend

•45° down, maximum reverse bend

•Inside bend radius square for 90° bend

•Outside bend radius is 1" material thickness

•Long bends in thick (6mm) material tend to warp

•Thicker (6 mm) require longer heating, start to deform at edges  – .5mm chamfer hide’s this

•Strategic use creates structural sections vs. individual parts

•All measurements to inside walls

•Bending cut visible for less than 90° bend (use “caps” or end plates)

•Bends can help in assembly, a “third hand”

•Cold bends

–Tend to create under-bend in adjacent CNC bends
–Can “blow out” groove wall if too much load
–Should be minimum 6” – 7” radius unless less than 1” wide
–Should be relieved either by kerfs or grooves on backside

Assembly:

–Net fit with all tolerances at extreme, nominal .2mm clearance
–Design to hold together without a “third hand”
–Joints allow for elimination of measuring, clamping or fixturing in assembly
–Cold  bends:
•Restrained on both ends (ideally)
•Flatten if wider than 2”-3”
•“oil can” if long (20”-30”) and thin (3mm-4mm material)
•Hard to hold in assembly – require additional assembly time
–Try not to design solvent joints in tension
–“dog bone” feature another “third hand”
–Keyed features for “idiot proof” assembly
•6-32 & 8-32 bosses different diameters
•Inserted bosses and self tap bosses different diameters
•Tabs, ribs, & walls have one-way tab
–Tongue & groove
•prevents solvent from ruining texture, windows, etc.
•Locate features and interfaces