Starting with exercise 3, the instruction slides will only provide part-by-part instructions and key details.
For exact feature details, you should refer to the exercise solutions document.
This is to prepare you for later exercises that are gradually less guided.
In this exercise, you will be modeling a very simple 2.5" ball shooter.
This mechanism features 3D-printed pulleys, a 3D-printed ramp, and nut strips. Be sure to pay attention to layout sketches when modeling.
3D-printed Pulleys
Thus far, you've only utilized COTS pulleys in your assemblies.
However, 3D-printed pulleys are a fantastic alternative since they are cheaper, readily available (assuming you have a 3D printer), and highly customizable.
3D-printed pulleys can easily be generated using pulley generators, such as the one included in MKCad.
Close attention must be paid to the shaft interface however. 3D-printed hex profiles can easily strip out, so a metal insert (Available from vendors like WCP or Thrifty Bot) should be used to better transfer torque.
Take a look below at some examples of 3D-printed pulleys with different types of inserts.
3D-printed Pulley Inserts
Warning
Since 3D-printed pulley bores are easily worn out, you should try to always use a metal insert or a pinion gear insert.
A cheap alternative to buying COTS inserts is to order them from a laser cutting service like Fabworks. In large quantities (~20 pieces), they only cost around $1 each.
Nut Strips
Nut strips are a very versatile structural component often used to connect perpendicular plates or a plate to a tube.
Vendors like WCP, REV, and Last Anvil carry nut strips in 6" long segments with either #10-32 or #8-32 tapped holes.
These nut strips are very robust and can be easily cut to any length.
In the exercise you just completed, the nut strips would allow you to easily mount the shooter onto any surface.
Nut Strips
Part Studio Instructions
Navigate to the "Exercise #3 Part Studio" tab in your copied document and follow the instructions in the slides to complete the part studio for this exercise.
Assembly Instructions
Next, navigate to the "Exercise #3 Assembly" tab in your copied document and follow the instructions in the slides to complete this exercise.
Verification
Make sure to have you and/or a more experienced member/mentor of your team review your CAD! Your assembly should have 44 instances.
Isolate, Hide, and Make Transparent
The Isolate tool hides all other parts except the selected ones, helping focus on specific components.
The Hide tool removes the selected parts from view, while Make transparent allows you to see through the selected parts without removing it, useful for accessing obscured components.
Rather than deleting or moving parts, you should use these tools to access the parts you need for your task. If you hide parts, don't forget to un-hide them for the next person!
Isolate, Hide, and Make Transparent
Keyboard Shortcuts
Just like most other tools and constraints in Onshape, hide/show has a nice keyboard shorctut combination. Hover over a part with your cursor or select it and press y to hide it. Hover over the same space and press shift+y to unhide the part.