iLogic Tutorial – Introduction – Modeling the Drawer Box
In iLogic tutorial I will create a half-blind dovetailed drawer box as a single, multi-solid body Inventor part. The resulting SmartPart is designed to be used as a smart element in a larger SmartAssembly.
I envision each SmartPart in this SmartAssembly (in this case, the iCabinet) having the ability to describe all possible configurations (for a given shop) for whatever it is that it represents —–in this case, a drawer box and it’s related hardware.
There also needs to be others that describe doors, carcass types, etc, and possibly sub classes such as a SmartPart specifically for file drawers or specialty drawers, etc, but those decisions will depend on the capabilities of Inventor to handle large part files and how the iLogic is coded, and will be covered as they come up. I would have preferred to have been able to have a single part that describes the entire line of cabinets, but that will not be possible with the current software.
Some Best Practices
Define and rig the skeleton
I generally start my models by figuring out what the rigging will look like. The rigging is a sketch or group of sketches that describe the overall dimensions of the object visually. They can be the plan and elevation sketches themselves, but if there is the possibility of multiple versions of the feature they describe, it is better to just use construction geometry for the rigging. Once the rigging is in place, geometry is projected from it to position feature sketches as well as more localized rigging. The rigging and sketches combine to form the skeleton, and it is best to have most or all of the skeleton complete before beginning the modeling.
Do not reference potentially transient geometry
Wherever possible you do not want to extrude to or project from existing solid geometry. Use a dimension, an existing parameter, create a parameter on the fly, or extrude to points or planes on the rigging. To be absolutely sure you are not selecting solid model geometry, turn off the visibility of previously created solid features so you do not accidentally use them.
The reason for this is that A) the face (edge, etc) may be cut away at a later time creating an error, or B) what you are projecting or extruding to will be toggled between suppression states via iLogic, causing an error at a later time. I am seeing people getting a lot of these errors with iLogic and multi solid body parts, and they can be hard to track down. Don’t create the problem in the first place and you’ll be better off.
Wherever possible, you want to reduce the amount of complex features modeled by taking advantage of various forms of patterning. It makes for a much more robust model. In this model there is only one dovetail each for the positive and negative forms, the rest are patterned.
Modeling the Drawer Box
I’ll point out instances of where errors can crop up as we go, so lets get started. I have a base file that includes all of the parameters shown below except the Reference parameters which you need to create yourself later. You can download it here if you like, or practice your typing and create the following parameters…
Now that the starting parameters are done, we can get on with the Base sketch and the creation of the rigging therein. To begin with, activate the ‘Base’ sketch, or create a sketch called ‘Base’ on the XY plane if you didn’t take advantage of the free file above.
The lines need to be horizontally and vertically constrained. The best way to achieve this is to set your preferences to Horizontal and vertical and watch for the constraint glyph.
I’ve seen huge, problems associated with the Inventor’s default Parallel and perpendicular setting being used, and would recommend changing it if you haven’t already. You do need the P&P setting for block creation, but for the majority of the modeling you will do, it can cause big problems –the bigger your sketch, the bigger the problems.
Once you have the lines constrained horizontally and vertically, grab the Coincident constraint tool from the Constrain panel, and constrain the center of each line to the center point of the sketch, which in this case is 0, 0, 0 in the model.
– iLogic Tutorial for the iDrawer Navigation –