Modeling a barbell equipment in Blender 3D

Step 0: Preparation
In this step we do a little research for dimensions and standards for the model to make the model look proportional. Several dimension standards that we’ll use were:
  •  Barbell bar length
  • Barbell bar diameter
  • Barbell disk diameter and thickness
 Barbell bar length standard was 1.2 meter to 2.2 meter. For this tutorial we will use 2.2 meter for the barbell bar length. Barbell bar diameter is between 25-51mm, for this tutorial we’ll use 50mm as the diameter of the bar. Next we’ll write down some standards for the barbell disk. Common diameter for  15Kg of barbell disk is roughly 360mm or 36cm, thickness is roughly 3cm and bore hole diameter is roughly 5cm.
After we get the reference dimension for our model, now we open blender and start modeling, but before we start modeling, we should set our scene to the proper unit. Because the dimension we gather were in metric system, we should adjust our blender scene into metric system. Click the scene panel in blender panels, then under Units subsection click the metric button to make our scene into a metric system.
Image 1.1 Metric system setting

Step 1: Modeling the barbell bar

Step 1.1 Create cylinder object
Make sure the 3D cursor is at the center of the scene. Create a new cylinder by pressing Shift+A, select Mesh > Cylinder. Adjust the vertices to 8, the diameter into 5 cm, and the length into 2 m.
Image 1.2 Add cylinder object

Open the transform panel by pressing N, then rotate the cylinder 90 degree in Y axis by filling 90 to the Y variable in rotation section.
Image 1.3 Rotate cylinder

Freeze the transformation by pressing Ctrl+A then select rotation.
Image 1.4 Freeze / Apply transformation

Step 1.2 Subdivide the cylinder and delete half of it
Change the operation mode from Object Mode into Edit Mode. Change seletion mode from vertex to edge. Select all the non-circular edges by selecting one edge,  pressing ctrl+E then select Edge Ring and press ctrl+E again then select subdivide.  This operation will create new edge loop in the middle of the bar.
Image 1.5 Edge subdivide

Delete the left side of the bar ( the part that’s on the -X side) by changing the selection mode from edge to face, then select the left side of the bar then press del, then choose faces from the dropdown menu.
Image 1.6 Delete left side of the cylinder

Step 1.3 Mirror the barbell bar
After deleting the left side we add the mirror modifier.
Image 1.7 Mirror modifier

Step 1.4 Creating stopper ring for barbell disk
Image 1.8 Stopper ring

Step 1.4.1
Make sure that current operation mode is on edit mode and the editing mode set to Face. Select the cap of the bar, then move it to the -X direction by pressing G then press X then press -0.45(which mean we want to move 45cm into -X direction) to make a precise translation.

Step 1.4.2
Duplicate the cap face by pressing shift+D then click RMB(right mouse button). Move the face 5cm to +X direction by pressing G then press X then press -0.05 to make a precise translation. Then delete the original cap. Somehow blender in our system fail to separate the cap by pressing V button, so we duplicate the cap, move it then delete the original cap.
Image 1.9 Separate cylinder cap
Step 1.4.3
With the cap face still selected, change editing mode to Edge, then press E to extrude the edge. then click RMB to make the result stay at the current location. Then scale the face by pressing S then press 2 to make the current face twice large from the original face. After that, delete both the overlaping caps to make a holed cap. If the holed cap faces look dark, it means that the normal is on the other side, you can flip the normal direction by pressing ctrl+F then select flip normal from the menu.

Step 1.4.4
Change the editing mode to Edge, select the outer loop of the cap by selecting one of the edge then press ctrl+E > 'Edge Loop', then extrude by pressing E then click RMB. Move the selected edges 3cm to -X direction by pressing G then press X then press -0.03 to make a precise translation.
Image 1.10 Extrude Cap
Step 1.4.5
Connect the edges from the bar to the cap. When we connect the first edge to create connecting face, we only select two edges, one edge from the bar and one edge from the cap then press F. For the rest of the edges, we’ll select three edges, the edge from the bar, the edge from previous connecting face, and the edge from the cap. After all connecting edges have been created, change the editing mode to Face then select all the connecting faces then press ctrl+F > Recalculate Normal to make sure the normal facing outside.

Image 1.11 Connect the cap with the cylinder

Step 1.5 Creating screw detail

Step 1.5.1
Change the editing mode to Vertex mode. Select the vertex from the top of inner ring of the stopper-ring, extrude it by pressing E, then click RMB. Move it by pressing G then press Z then press -0.003 to move the new vertex 3mm to -Z direction. Then extrude the vertex again by pressing E, then click RMB. Move it 5mm to +X direction by pressing G then press X then press 0.005. Extrude it again then move it 3mm to +Z direction using the same steps, then Extrude, move it again 5mm to +X direction then extrude and move it again 3mm to -Z direction. This step will create a profile path for the screw detail like in the picture below. 
Image 1.12 Screw detail profile path

Step 1.5.2
Change the editing mode to Edge, then delete the edge that connect the profile to the stopper ring.
Image 1.13 Delete connecting edge

Select all the edge of the profile path then separate them from the rest of the barbell bar by pressing P then choose selection.
Image 1.14 Separate profile
Step 1.5.3
Change the operation mode from Editing mode to Object mode then select the profile object. In the object modifier panel delete the mirror modifier and then add screw modifier. Change the axis to X, screw to 1cm, steps to 8, render steps to 8 and iterations to 60.

Image 1.15 Screw modifier
Step 1.5.4
Change operation mode from Object mode to Editing mode. Select all of the vertices then press ctrl+V > Remove doubles. If the surface look darker than the barbell bar, it means that the normals were not facing outside toward the camera. To fix this, change the editing mode to Face, then select all the faces, press ctrl+F > Flip normals.
Step 1.5.6
Next step is to merge the screw object back to the barbell bar object. Make sure the operation mode is back on Object Mode. Select the screw object, then click shift+RMB the barbell bar object.  Press alt+J to merge the screw to the barbell bar object.

Step 1.6 Close the screw cap

Step 1.6.1
Our next step is to close the cap of the screw and connect the gap between the screw with the barbell bar. To create the face for the cap we can duplicate the face from the stopper ring.  First we select one of the edge of the stopper ring by changing the operation mode into Editing mode, then make sure the editing is on edge mode, select one edge from the stopper ring then press ctrl+E > ‘Edge Ring’. Then change the editing mode to vertex then change it again to face.

Image 1.16 Select Faces
Step 1.6.2
Duplicate selected faces by pressing shift+D then click RMB. Move the duplicated faces to the end of the barbell bar screw by pressing G then X then move the mouse to the right until the duplicated faces are at the end of the barbell bar screw. Those faces will become the cap of the screw.

Image 1.17 Duplicate and move face

Step 1.6.3
Now we need to close the hole at the center of the cap. Change the editing mode to edge. select one of the inner edge of the face, then press ctrl+E>’Edge Loop‘. Then press alt+M > ‘center’ to close the inner hole.

Image 1.18 Close hole
Step 1.6.4
Scale the cap faces so it slightly smaller than the screw hole. First change the editing mode into face then select one of the cap face then press ctrl + + (control and plus sign), then press S then move the mouse down until the cap is at the correct size.
Image 1.19 Scale cap to fit the screw
Step 1.6.5
Merge the vertices at the beginning of the screw. First change editing mode into vertex mode, then select the vertices then press alt+M > ‘at last’.
Image 1.20 Merge last two vertices
Step 1.6.7
Connect the cap to the screw by adding faces. Before adding faces, connect the first few vertices into edges by selecting the vertices and then press F to connect them and add edges.
Image 1.21 Add screw cap edges

Step 1.6.8
After we add those edges, we fill them with faces. First change the editing mode to edge mode, then select the edges and start adding faces by pressing F. It’s a good practice to select the edges in counter-clockwise direction to make sure the normal of the face were facing outside.

Image 1.22 Add screw cap faces

Step 1.6.9
Connect the screw with stopper ring using the same step as previous by adding several edges and add faces to connect both section.

Image 1.24 Connect screw with stopper ring

Step 1.7 Adjust edge crease & subdivide barbell bar

Step 1.7.1
Select edges from stopper ring by selecting the one of the edge and then press ctrl-E > Edge loop. After all the outer edge of the stopper ring have been selected, press shift-E then press 0.98 to set the crease of the edge to 0.98
Image 1.25 Crease stopper ring

Step 1.7.2
Do the same thing with the screw outer edge. select one of the edge then press ctrl-E > Edge loop. Then press shift-E to add the crease.
Image 1.26 Crease screw edges

Step 1.7.3
Next we do the same thing to the screw cap. Select the edge then add the crease.
Image 1.27 Crease screw cap
Step 1.7.4
Add subdivision modifier and then apply the mirror modifier, or you can apply the mirror modifier first then add subdivision modifier. Set the render subdivision to 3. If you only want the hi-res version of the barbell bar object, you could also set the view subdivision to 3 then apply the subdivision modifier.
Image 1.27 Add subdivision modifier
Step 1.7.5
Rename the cylinder object to ‘barbell_bar’ to avoid confusion with other models. To rename the cylinder object just double click the cylinder object in the outliner window then rename it to ‘Barbell_bar’.
After we done modeling the barbell bar, we move it to other layer so we can model another object in current layer. To move the barbell_bar to other layer first make sure the 3d view was on object mode. Select the barbell_bar object then press M then choose the bottom right box (the last layer).
Image 1.28 Rename and move object
Step 2: Modeling the barbell disk
Step 2.1 : Create base object
Make sure that the 3d view is on the first layer (top left corner) and the 3d cursor is on the center of the scene. Add a cylinder by pressing shift-A>Mesh>Cylinder. Set vertices to 8, radius to 36cm, depth to 5cm, and cap fill to ‘Triangle Fan’.
Image 2.1 Add cylinder and edit properties

Step 2.2: Create bor hole using boolean modifier
Create another cylinder. This time set the radius to 5cm and depth to 10cm. Then select the previous cylinder and then add the boolean modifier. On the boolean modifier panel, set the operation to difference and set object to the other cylinder(Cylinder.001). Then click apply and delete the other cylinder.
Image 2.2 Add bor hole

Step 2.3: Mirror modeling
Subdivide the barbell disk outer edge and delete the bottom half of disk’s faces so we only have to model the upper half of the model. To do that, first we select the edges of the outer ring of the disk. Select one of the outer edge of the disk then press ctrl-E>'Edge ring’ to select all of the outer edges of the disk. then press ctrl-E>subdivide to create the center line. Change the editing mode to face, then select the bottom half of the disk. Delete the bottom half of the disk then add mirror modifier. Set the axis of the mirror modifier to Z.
Image 2.3 Mirror modeling

Step 2.4 : Add detail for the barbell disk
Select the edge of the cap then subdivide them by pressing ctrl-E>’subdivide‘, then set subdivision to 2. Then change editing mode to face. Select the outer part and the inner part fo the subdivided faces then extrude them by pressing shift-E then press 0.015 to set the extruded face 15cm from the original.
Image 2.4 Extrude detail

Step 2.5 : Crease edges and subdivision modifier
The next step is to make creased edges and add subdivision modifier to make the barbell disk smooth. First select the edge loop of the disk, then shift-E to crease the edges, press 0.98 to set the crease value. Then add subdivision modifier and set the view subdivision to 3 and set object shading from flat to smooth. Optionally you can click apply for subdivision and mirror modifier to make the modifier permanent. Then rename the object to ‘Barbell_disk’.
The barbell disk model is actually done, but if you want to add more detail, you can also add text such as ‘15 Kg barbell’ on the center of barbell disk. The next step is for you who wanted to add text to the barbell disk...
Image 2.5 Crease detail edges

Step 2.6 : Add text
Inside 3d view press 7 keypad to make the viewport to top. Note that it is the keypad  button, regular ‘7‘ button is assign to other function in blender which is to change the current layer to layer 7. From to viewport, create a circle by pressing shift-A > Curve > Circle. Then create the text by pressing shift-A > Text. Move the barbell disk to layer 2 so that it won’t block your view to the text object. To move the barbell disk to layer 2, first select the barbell disk, then press M and select the destination layer. Next step is to change the content of the text object. With the text selected, press tab then change the text to ‘15 KG Barbell’. Set the size of the text to 0.08. Then on Text on Curve option select the curve as path object. On Modification option set the extrude to 1cm and on the bevel option set the depth to 1mm. Next we scale the text to fit the barbell disk. First we move back the barbell disk to layer 1, then we select the bezierCircle object, then press tab to enter edit mode. Scale the curve so the text fit inside the barbell disk.
Image 2.6 Add text

Step 2.7 : Join text with the barbell disk
The final step is to join the text with the barbell disk. To do that, first we need to convert the text into a mesh. To convert text to a mesh press alt-C >’Mesh from curve‘. Then select the barbell disk, then add boolean modifier. On boolean panel set the Object option to text and the operation to union. The model is done. My personal habit is to move my final objects that i modeled to the last layer and only use a copy of them in whatever scene i need. That way if something goes wrong, i still have my original model.

Image 2.7 Merge text with barbell disk