Time to practice! Start by make a copy of the Stage 1B Exercises Document through the button below, just like you did with the Stage 1A Exercises Document. Each exercise has a folder, a "reference" tab (a preview of what the final model should look like), and a tab or two for doing your exercise in. Solutions are also provided in the 1B Exercise Solutions Document to check your work afterwards.
In this exercise, you will be CADing and assembling a simple single stage gearbox. The goal of this exercise is to introduce how to model a very simple gear transmission. Additionally, you will learn how to use the the Shaft Featurescript, Replicate tool, MKCad parts library, and part configurations.
Warning
As this is the first exercise where MKCAD is being used, please be sure you have it added by following the tutorial in Stage 0! MKCAD is a parts library for FRC used for inserting COTS components into assemblies.
Note
Exercise 1 adds hardware (bolts and nuts) to the CAD models. You can read more about hardware standards on the Design Handbook page.
Layout Sketches
A layout sketch is a sketch that captures the geometry of a design without specifying the exact details.
They are like the framing of a houseāit defines the overall structure and relationships between key components, but doesn't include the finishing details like walls or paint.
Keeping the key dimensions in a layout sketch makes it easy to adjust when needed. We will utilize layout sketches for almost all designs moving forward.
Part Studio Instructions
Navigate to the "Exercise #1 Part Studio" tab in your copied document and follow the instructions in the slides to complete the part studio.
Assembly Instructions
When putting together the assembly, you may need to use the "Lock Mate Inferences" functionality to properly mate the motor pinon. Watch the following video to learn how:
Locking Mate Inferences when Mating Assemblies
To lock mate inferences when you see the one you want to select, hold the Shift key when mousing. This is particularly useful for mating the motor pinion gear.
Using Shift key to lock mate inferences while mating.
Navigate to the "Exercise #1 Assembly" tab in your copied document and follow the instructions in the slides to complete the exercise.
Verification
Make sure to have you and/or a more experienced member/mentor of your team review your CAD! Your assembly should have 19 Instances and weigh approximately 2.3 lbs.
Configurable Parts
In this exercise you made your first gearbox. In doing so, you also used part configurations - a powerful tool that allows for variations of the same part. The gears that you inserted from MKCad were configurable - you were able to easily change the tooth count of the gear without needing to inserting a new component. Try and use configurable parts when they are available to make your models more parametric.