Half-Cut Hypotube Retention Fixture

Design specification: Half-cut hypotube retention fixture Create a precision fixture channel for retaining a longitudinally split medical hypotube. Hypotube geometry Original hypotube ID: 0.272 in Wall thickness: 0.020 in Calculated OD: 0.312 in Outside radius: 0.156 in Inside radius: 0.136 in Split the hypotube longitudinally exactly through the centerline. The result is a semicircular shell with: Outside radius = 0.156 in Inside radius = 0.136 in Wall thickness = 0.020 in Straight cut-edge-to-cut-edge width = approximately 0.312 in Shell depth = approximately 0.156 in Fixture channel Create a semicircular concave channel to support the outside surface of the half-cut hypotube. Nominal channel radius = 0.156 in. Recommended manufacturing starting radius = 0.157 in. Radial clearance = 0.001 in. Diametral clearance = 0.002 in. Do not create an interference fit. The half-cut hypotube should sit concentrically in the fixture channel without significant deformation. Hypotube retention Add continuous retaining lips along both longitudinal straight edges of the channel. Retaining lips should mechanically capture the two straight cut edges of the half-hypotube. Initial recommended lip overlap over each cut edge = 0.005 to 0.010 in. Lips should be low-profile and should not deform or crush the 0.020 in wall. The hypotube should be removable by sliding or lifting it out without permanent deformation. Add an axial end stop to prevent longitudinal movement of the hypotube. Do not use an interference fit as the primary retention mechanism. Fixture material Fixture material: 3D-printed SLArmor nickel nano-tool composite. Account for the dimensional tolerance and surface finish achievable with this material/process. If manufacturing tolerances are not specified, retain the nominal R0.157 in channel and allow adjustment of the retaining lips during prototype iterations. Desired cross-section The final cross-section should consist of: A semicircular fixture channel with approximately R0.157 in. A 0.020 in wall half-cylinder hypotube seated inside the channel. Two small retaining lips capturing the longitudinal cut edges. An axial stop at one end. No excessive radial compression of the hypotube. Important dimensional relationship Original tube: ID = 0.272 in Wall = 0.020 in OD = 0.312 in Outside radius = 0.156 in Inside radius = 0.136 in Recommended fixture: Channel radius = 0.157 in Radial clearance = 0.001 in Diametral clearance = 0.002 in Retaining lip overlap = 0.005–0.010 in per side Design intent: Precisely locate and retain the longitudinally split half-hypotube while minimizing deformation and allowing the hypotube to be installed and removed from the fixture.

Parameters

This model was generated without adjustable parameters. Open it in the editor to add your own dimensions.

Every value above is a live dimension. Open a model like this in the editor and each one becomes a slider you can drag before exporting.