Constant Velocity Joint Improvements
Greetings!
Our initial prototype is shown below in Figure 1.
Figure 1. Assembly Prototype of the Compact Constant Velocity (CCV) Joint
The joint works well to demonstrate the function of a typical Constant Velocity Joint. We would like to highlight that we appreciate several aspects related to the prototype. It works well and the final product meets its specification. We made several changes throughout the prototype design progression. Each of these changes contributed to the improvement of the model’s design as well as the enhancement of both the performance and appearance of the CCV joint.
Figure 2 shows the assembly of the joint mechanism. This assembly ensures the following assertions:
Figure 2. Assembly of Joint Mechanism
- It functions well and rotates freely.
- The Clearance of 0.5 mm is very adequate.
- It rotates best while in line.
- Its rotation starts to be rough and noisy as the angle exceeds about 30 degrees.
Therefore, we confirm that the joint mechanism meets the project purpose and goals.
Concerning the CCV joint Housing shown in Figure 3, we realized that:
Figure 3. Assembly of Joint Support
- The clearance between the axle shaft and the housing is too high. To deal with this problem, we decided to reduce the clearance to 1mm. (Diameter of the housing – Diameter of the axle shaft = clearance)
- The distance between the right and left housing is too high. So, we decided to make the joint mechanism snug between both support housings.
- The support is not strong. We opted to make it wider and stronger.
- The surface of the vertical section is very rough due to material rippling. We decided to make the vertical structure wider, stronger, and with much better surface finish.
Results
After implementing the changes, the prototype showed great improvements as depicted in Figure 4.
Figure 4. Prototype after Support Modifications
- The CCV joint is functional. In fact, we added a screw to the shaft so we can easily drive the shaft with electric drill.
- Tolerances and gaps of moving parts are optimum.
- Print orientation to obtain best possible surface finish between moving parts are optimized.
- 3D printing ability to manufacture “suspended Parts” inside assemblies has been successfully implemented.
Print Parameter:
The CCV joint support pieces were printed as shown in Figure 5 for several reasons:
- The hole in the part
- The fastest print time
- Least amount of support material
- Best surface finish
- The strength of the vertical part is not optimum with this print direction, but we thickened this section to optimize the strength.
Figure 5. Print Orientation of CCV Joint Support
The CCV assembly of joint mechanism is printed as shown in Figure 6 for several reasons:
- The fastest print time
- Least amount of support material
- Best surface finish
Figure 6. Print Orientation of CCV Joint mechanism assembly
The print Parameters of the CCV joint support (2 Pieces) are listed in Table 1.
Table 1. Print Parameters of the Joint Support
|
Build Material: PLA |
Support Material: PVA |
|||
| Layer Height |
0.2 |
mm |
||
| nozzle temp |
230 |
C |
225 |
C |
| wall width |
2 |
mm |
2 |
mm |
| Top/Bottom thick |
2 |
mm |
2 |
mm |
| print speed |
40 |
mm/s |
35 |
mm/s |
| infill density |
20 |
% |
35 |
% |
| infill speed |
50 |
mm/s |
30 |
mm/s |
| wall speed |
36 |
mm/s |
30 |
mm/s |
| travel speed |
250 |
mm/s |
250 |
mm/s |
| print jerk |
25 |
mm/s |
25 |
mm/s |
| travel jerk |
30 |
mm/s |
30 |
mm/s |
| Cooling |
100 |
% |
50 |
% |
| Length |
8.75 |
m |
4.17 |
m |
| Mass |
69 |
g |
32 |
g |
|
Platform Temperature |
75 C |
|||
|
Print Time |
15 H 53 min |
|||
What a great deal, indeed!
With FDM technology, we can produce multi part functional assemblies with just one print.
Thank you for reading!
Compact Constant Velocity Joint Team.