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General rules to follow and to verify for the

construction of a sketch / part / assembly

1. Sketch / Part create 3D model considering symmetries (even partial) and reference planes of the part; place the reference frame (origin and axis) and the reference planes from which the

model is created properly, then use the reference system for model creation;

try to minimize the number of features (extrusion, revolution, cut, etc) adding rounds,fillets and chamfers (collected by dimensional groups) at the end of the features tree;

every sketch must be totally defined. This means that all the borders must be black,neither blue (underdefined, floating) nor red (overdefined) with respect to the reference

frame.

change the orientation in space of the reference frame (e.g. in isometric view, zpositive directed upwards) through View, Modify, View Orientation ... (you have to

choose the front view of the model, then select Front, then updates the standard views, and

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the new orientations are then stored), then check the correct orientation by placing the

model in isometric view.

2. Assembly / Mates define the origin of the assembly (in a significant point of the system), the axis and the

reference planes (the observance of this rule facilitates the subsequent definition of the

mates, since the planes and the part location will be uniquely defined);

the first part inserted in the assembly is assigned as fixed (the symbol (f) in the FeatureTree; to make it floating right click on it and set Float) and then it can be constrained to

origin and/or planes;

mates should not be set with respect to the assembly properties (assembly origin andreference planes), but with respect to the other parts (or their reference planes); it is goodto try constraining the parts with adjacent ones (exploiting actual contact surfaces),

avoiding if possible mates between distant parts;

you must enter a correct number of mates:o for each part in order to eliminate all the exceeding degrees of freedom (e.g., screws

must be completely defined);

o to leave only the desired ones (a part with labilities, not completely defined, willhave a minus (-) sign in the Feature Tree, while a fully defined part will have no such

sign);

o enter only the necessary mates, avoiding unnecessary, and sort them following thesame criteria ((+) sign means too many constraints have been defined and they have

to be removed); placing last (and possibly rename) those that define any alternative

configurations;

o Suspendmates that belong to different configurations, use appropriate sub-assemblies to minimize the length of elements in the Feature history

(consider that a sub-assembly does not allow any internal kinematic with respect of higher

superior assembly; in case to allow their degrees of freedom, right click and set Dissolve

subassembly);

if the assembly consists of several constructed sub-assemblies, you can group them into asingle one the fixed parts, while the floating ones should be levelled to the main assembly,

otherwise kinematics could not be allowed;

order the parts in the assembly in order to comply, where possible, the assemblingsequence.

NO !

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3. Verify and Save the model must be placed with the whole Feature history collapsed as much as possible; the model must be oriented with respect to the appropriately defined reference frame,

placed in isometric view and optimal zoom (f key);

all necessary mates must be activated, in order to have isostatic assembly or with properfree dof to demonstrate the goodness of the model;

parts, assemblies and drawings must all be contained in the same folder, even any othersobtained from libraries must be saved in the same directory and not be linked to the

library;

recommended verifying criteria:o constraints (constraint checks for unnecessary/redundant: parallel and coincident,

parallel and distance);

o explosion test (makes mobile the fixed part and translates/rotate assembly) and pinstest and unnecessary dof need to be removed;

o penetration test (Tools, Interference Detection ...) to save the whole model, use File, Pack and go:

o allows to recover all parts used in the model, also from libraries;o save in a single directory (flattens) the model completed with parts, drawings and

sub-assemblies,