onshape: nut and bolt tutorial...the chamfer on the bolt head (should be front or right; for this...
TRANSCRIPT
OnShape: Nut and Bolt Tutorial
By: Matthew Jourden
Brighton High School
Brighton, MI
Objective: Design a Commercially Off Shelf (COTs) Nut and Bolt with a detailed thread. COTs Parts are considered to be
standardized parts. Parts like nuts, bolts, screws, washers, cotter pins, woodruff keys, etc. are standardized based on one
measurement. An engineering can gather the necessary resources from a variety of manuals like Machinery Handbook, ANSI or
ISO manuals or Appendix on a Engineering Textbook (see below). The various measurements of fasteners will typically be a
factor of the Major Diameter of the Thread. Utilizing reference charts (see below) will save the engineer time in having to
calculate out the various measurements of a fastener.
Thread Representation
Parts to a Thread
Thread Dimension
Charts: Nut and Bolt Sizes
Major Diameter
1. Navigate to brightonk12.onshape.com > Create a New Document > Rename Tutorial Nut and Bolt
2. Bolt Creation: ½-13UNC-2B
a. Rename Part Studio 1 > Bolt: Detailed
b. Bolt Body
i. Select Sketch > Rename Sketch to Bolt Body > Select Top Workplane (Datum) > Draw the following circle
> Green Check > Select Extrude Icon > Rename Bolt Length > Extrude Length 2 > Green Check to Accept
c. Chamfer: Chamfers are used at the end of a fastener or top of a bolt ahead to make it easier for alignment into
the mating feature (i.e. the bolt shaft into the threaded hole or align the sockets wrench)
i. Select Chamfer Tool > Select the edge of the lower circle (bottom edge of part) > Set Value at
.0625 > Green Check to Accept
d. Bolt Hexagonal Head
To create the bolt head designer will need to first draw a construction circle that will represent the distance
between the corners of a hexagon the then circumscribe a hexagon on the inside of the circle. Using Constraints
the user will then make the hexagon equal length. In the end the designer needs to only set 1 dimension (Circle
Measured Across the Corners).
i. Select Sketch > Rename Sketch to Bolt Head > Select the Top Flat edge of the Bolt Length Extrude
ii. Draw the following Construction Circle (NOTE: Dimension based on Variable G Width Across the
Corners) and Construction Lines
NOTE: There is a Max and Min; this is because the mating feature (socket wrench) has a variance the
size of the bolt head and socket opening can be and the two will still mate. In the end it does not matter
which value we choose as long as it is between these two values.
In this tutorial we will use Dimension Diameter = .866
Construction Lines will be used to help scribe the hexagon and later create the chamfer on top of the
bolt head.
Select Top
Surface
iii. Draw the Following Hexagon. Be sure
1. to make two of the points meet at the intersection of the construction circle and construction
lines.
2. Top and Bottom edge are horizontal
3. All Points touch the Construction Circle
iv. Select Equal Length Constraint Icon > Select Edges to make them Equal Length.
NOTE: Designer should only have to make 3 of 6 lines equal length to make all 6 equal length due to the
design of the hexagon being anchored to the construction circle
NOTE: Hexagonal lines should turn black when lines are fully constrained
v. Green Check to Accept Sketch
vi. Select Extrude Icon > Rename Extrude to Bolt Head > Set Extrude Distance to Variable H (11/32) based
on the Chart above
vii. Green Check to Accept Extrude
viii. Bolt Head Chamfer
In this scenario the chamfer icon cannot be used because the chamfer will not be formed correctly. We will
need to revolve cut the chamfer in order to cut all edges correctly.
1. Select Sketch Icon > Rename Sketch to Bolt Head Chamfer > Select the Workplane that passes
through the two corners of our bolt head that were sketched intersecting the Construction
Circle and the Construction Lines (For tutorial demo that would be the Front workplane (Turn on
the workplanes to see which plane passes through the corners). This is important to have these
two points pass through a workplane in order to get the chamfer to form correctly.
2. Draw the following profile and construction line > Green Check to Accept Sketch
Plane Passes
through the corners
of hexagon
Construction Line
located at the center of
the bolt
3. Select Revolve Icon > Rename Extrude to Bolt Head Chamfer > Select Remove Tab >
Profile/Faces: Select Bolt Head Chamfer Sketch > Axis Line: Select Construction Line > Select
Merge with All > Green Check to Accept
e. Detailed Threads
i. Select Helix Icon (Either located on the Tool Bar or in the drop down menu below the Plane Icon)
> Rename Helix to Detailed Thread > Switch Setup from Turns to Height and Pitch > Select the Top Circle
of the Chamfer (.50) > Set Height at 1.5 > Set Helical Pitch little larger than the actual pitch (pitch is the
distance between peaks on the thread) a of the thread (Actual Pitch 1/13 (13 threads per inch) set to
.085 > Green Check to Accpet
Axis Line
Change to Height and Pitch
Select Top Edge of Chamfer. This
will make it so the helix wraps
around the outside edge of the
cylinder (Major Diameter)
ii. Select Sketch Tool > Rename Sketch to Thread Profile > Select the Workplane that was used to create
the chamfer on the bolt head (should be Front or Right; for this tutorial the right plane was selected) >
Draw the following profile > Green Check to Accept
NOTE: The triangle is
1. Set outside of the part and material side (For this tutorial Quadrant 4 of a grid)
2. Equilateral
3. 1 Dimension is set to the actual Pitch of the thread 1/13 (13 threads per inch)
NOTE: May use the Use, Construction Tool to help located the triangle
Use Tool and Construction Tool to find
edges not on the same plane as sketch >
Line Tool and Construction tool to find
corner point of part
iii. Select Sweep Tool > Rename Sweep to Detailed Threads > Select Remove Tab > Faces/Sketch:
Select Triangle Sketch or Thread Profile from Model Tree > Sweep Path: Select Helix Line on the Solid
Model > Check Merge with All
Select Helix on the
part NOT from the
Model Tree
NOTE: The Detailed Thread Helix is still visible. To
Hide Select Eyeball next to Curves from the Model
Tree (Located at the bottom of the model Tree) this
will hide the Helix Sketch
3. Nut Creation: ½-13UNC-2B
a. Create new Part Studio Tab in the Tutorial Nut and Bolt Document > Rename Tab Nut Creation
b. Nut Body
i. Select Sketch Tool > Rename Sketch Nut Profile > Select Top Workplane > Draw a Construction Circle
equal to Variable G Width Across the Corners (.866) and Construction Lines that provide 2 of the 6
corner points to help with revolving the chamfer
ii. Scribe a Hexagon on the interior of the circle with
1. to make two of the points meet at the intersection of the construction circle and construction
lines.
2. Top and Bottom edge are horizontal
3. All Points touch the Construction Circle
4. All lines are equal (Use the Equal Constraint to set lines equal to each other)
And
Draw a circle in the center that represents the major diameter of the threaded hole
5. Green Check to Accept Sketch
iii. Select Extrude Tool > Rename Extrude to Nut Body > Extrude Distance from the Chart use Variable H
Thickness of Hex Nuts: 7/16 > Select from the work area the area between the hexagon and the inner
hole; this will create a hole in the center of the hex nut > Green Check to Accept
iv. Hex Chamfer
1. Select Sketch Icon > Rename Sketch Hex Chamfer > Select Workplane that pass through the two
points of the hexagon > Sketch the following sketch > Green Check to Accept
2. Select Revolve Tool > Rename Revolve to Hex Chamfer > Select Remove Tab > Faces/Sketch:
Select Triangle > Axis Line: Select Construction Line > Check Merge with All > Green Check to
Accept
Select Area between hexagon
and inner circle
c. Thread Body
i. Turn on Sketch Nut Profile by placing cursor on the model tree name > Select the Eyeball next to the
name unhide
ii. Select Extrude Tool > Rename Thread Surface > Select New Tab > Select Circle Edge of the Hole from the
bottom (opposite of the chamfer end) > Extrude Distance (Distance needs to be a minimum 1 thread
length longer than the nut in order to have the threads exit the hole in the thread correctly) Set at 1” >
Green Check to Accept > Hide Sketch Nut Profile by clicking on the eyeball next to the sketch in the
model tree
NOTE: There should be two parts listed in the model Tree. Change the Names to the following
iii. Hide Hex Nut (Part 1) from the model tree
iv. Select Helix Tool > Rename Helix to Thread Helix > Change type to Pitch (this will create the helix along
the entire cylinder) > Select Cylindrical Face of Thread Surface (Part 2) > Pitch .085 (Same as bolt; so
when assembled user can match the threads up) > Green Check to Accept
v. UnHide Part Hex Nut (Part 1) and Change View Display to Hidden Edges Visible
vi. Select Sketch Tool > Rename Sketch to Thread Profile > Select same workplane as the Revolved Chamfer
that goes through 2 of 6 points > Draw the Following (To gain references use the Use Tool) > Green
Check to Accept Sketch
vii. NOTE: The triangle is
1. Set Inside of the part and material side of Thread Surface (Part 2) (For this tutorial Quadrant 4 of
a grid)
2. Equilateral
3. 1 Dimension is set to the actual Pitch of the thread 1/13 (13 threads per inch)
Use Tool and Construction
Tool > Select Circle to Show
Location of edge of circle
Pitch of Thread
viii. Select Sweep Tool > Rename Sketch to Thread Body > Select Add Tab > Face/Sketch: Select Triangle >
Path: Select Helix from the Workspace > Body Scope: Select Hex Nut (Part 1) from the Model Tree >
Green Check to Accept
NOTE: DO NOT select Merge with All
ix. Hide Curves from the Model Tree.
NOTE: Cleanup Work will still need to be cleaned up
Select Merge Scope = Hex Nut (Part 1)
NOTE: Extrude Cut to
show interior details
x. Select Thread Surface > Press Delete Key on the Keyboard or Right Click on Thread Surface Name and
Select Delete > Green Check the Delete Feature > On the Model Tree Delete Thread Surface will appear
xi. Select Sketch Tool > Rename Sketch to Thread Cleanup > Select Front or Right Workplane > Draw two
rectangles from the edge of the hex nut extending to include all of the excess thread material > Select
Green Check to Accept
NOTE: Use Tool and Construction Tool to find location off the edge of the hex nut
xii. Select Extrude Tool > Rename Extrude to Thread Cleanup > Select Remove Tab > Select Thread Cleanup
Sketch from Model Tree > Change Extrude type to Symmetric > Extrude Distance set to 1.5 (larger than
the diameter of the hole to cut away all material)
4. Assembly Nut and Bolt
Goal: Match up Threads
a. Select Assembly Tab
b. Insert Bolt > Fix in Default Location
c. Insert Nut > Place away from the Bolt > Select Fastened Constraint > Select center points from both objects
NOTE: Chamfer from the nut should be facing the end of the threads on the bolt (Flip constraint direction as
needed.
d. Set Offset Distance Z to the height of the nut 7/16 (this will make the chamfer end of the nut flush with the end
of the bolt (NOTE: technically the nut could be anywhere along the thread; we are just trying to match up the
threads.)
NOTE: Notice how the threads do not match up. This is do to how the helix start point is created in OnShape.
To Correct this we will create a layout with a full section and find the difference between the two threads and
adjust the Z Offset
e. Create a Drawing Tab > Place Hexagonal View of the Assembly (Top View) > Create a Full Section Thru the Center
of the Hex Head creating an assembly section view
f. Measure Between Threads > Modify Z Offset on the Assembly by this Value > Update Drawing to check if
threads match up (If not check with a new dimension and repeat steps)
Distance between Bolt Thread and Nut
Thread
Adjust Fastened Constraint on Assembly with Measured Value
Update Drawing to see if Threads Matchup
Submission: Show Teacher upon Completion