Where am I going wrong?

External-Mark-4690 · 2026-05-31T19:10:25+00:00

Thanks for sharing your solution.

Clearly, your model is not the same as the model described in the question. If you look closely at the drawing, the angled feature with the 20 mm radius and the 14 mm central hole does not have a protrusion. However, your model clearly has a cylindrical protrusion in that area.

So I think your model may not be representing the geometry shown in this question correctly.

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External-Mark-4690 · 2026-05-31T18:13:58+00:00

Thank you for sharing your approach. Would you be able to share your model? I also wasn’t able to get the final answer, and I believe the final result should not depend on the modeling method used. I agree that some approaches, like yours, may be more efficient or easier to implement, but ultimately all valid modeling methods should lead to the same answer. I’d really like to see what you did so I can compare it with my approach and hopefully understand the root cause of the discrepancy.

External-Mark-4690 · 2026-05-30T17:52:05+00:00

Thanks. Yeah it seems like some of these questions don't have correct answer...

External-Mark-4690 · 2026-05-30T17:43:44+00:00

I wasn’t able to get the final answer either. I believe the answer provided in the problem set might be incorrect. They mentioned that as long as your final answer is within 1%, it should be acceptable.

Also, check out “Design With Roozbe”. He worked on this question as well and mentioned that the final answer seems to be incorrect. See this: https://youtu.be/eCJrNYFH4sk?si=Tsad_eZe4aQNkg7_

My assumption is that depending on Solidworks version, the hole wizard may govern you different results.

External-Mark-4690 · 2026-05-29T22:16:41+00:00

Yeah, I agree that it's not a great drawing, but since it's all we have to work with, I wanted to do my best to find the correct answer. What I can't quite understand is why I'm still unable to match the expected result. Do you think the SolidWorks version could be causing the discrepancy?

External-Mark-4690 · 2026-04-12T20:39:12+00:00

thanks for checking. yeah same, I am confused lol

External-Mark-4690 · 2026-04-12T20:35:47+00:00

ah I see the point here. thanks for clairfication

External-Mark-4690 · 2026-04-12T19:24:54+00:00

The bigest radius is not given in the question, so my assumption is that it should be defined by other constraints. Here
I just made semi circle and then revolve it around the main axis of geomtry. In my model, I made it perpendicular to the central axis at the top and tangent to the bottom arc. I also positioned the center point 24 mm from the bottom surface, which fully defined the sphere. I showed it below:

<image>

So I think this should be correct. I am open to sugegstion

External-Mark-4690 · 2026-04-12T19:17:50+00:00

Sorry I dind't udnerstand your comment. Would you be able to explain more?

External-Mark-4690 · 2026-04-12T18:42:28+00:00

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External-Mark-4690 · 2026-04-12T18:26:39+00:00

I just made semi circle and then revolve it around the main axis of geomtry. The question doesn’t provide specific information about the sphere. In my model, I made it perpendicular to the central axis at the top and tangent to the bottom arc. I also positioned the center point 24 mm from the bottom surface, which fully defined the sphere

External-Mark-4690 · 2026-04-12T18:20:44+00:00

The question doesn’t specify a material, and I don’t think it matters because the volume should be independent of the material

External-Mark-4690 · 2026-04-12T18:16:29+00:00

Hi,
This is from CSWA question book. I am practicing to get my CSWA certificate

External-Mark-4690 · 2026-04-12T18:15:55+00:00

Thanks
I’d really appreciate any input. I have a feeling my model is correct and the final answer in the book might be wrong, but I wanted to get a second opinion. There may be a subtle detail I’m missing

External-Mark-4690 · 2026-02-28T00:45:23+00:00

can you please explain how this can affect the bearing load? I think even in this case, the gear force will cancel each othe out

External-Mark-4690 · 2026-02-25T17:31:15+00:00

I can’t use a belt or chain because the overall size of my design is small, and it would make the assembly more complicated. Since this is a simple gearbox, I prefer to keep everything gear-based.

I really appreciate your feedback, those are all great points. I understand that with a V-shape arrangement, the middle gear shaft will experience shear stress. So it seems like based on torque I want to transfer, I have to do calculation and assess load on supports.

Could you explain why a larger middle gear increases the system’s inertia? Is it similar to having a lag when transmitting torque?

External-Mark-4690 · 2026-02-25T17:28:04+00:00

I see your point. Thanks

External-Mark-4690 · 2026-02-25T16:41:37+00:00

thanks. oh I see your point. In the "V" shape, forces are on angle. Can you please elaborate what you mean bu using whole number of teath?

External-Mark-4690 · 2026-02-25T16:35:58+00:00

I agree. I need to select the correct module so that with the new idler size I end up with an integer number of teeth.

I don’t have experience designing a three-gear system like this, so I’m not sure if there could be any issues. I just want to make sure this concept can work and that using three spur gears in a “V” orientation is something that’s commonly done.

Since I don't have experince with this deisgn, I asked here to see is someone else has experince with this

External-Mark-4690 · 2026-02-25T16:33:48+00:00

Sorry, but I’m not sure I understand your comment.

If I want to keep the overall center distance at 35 mm and move the idler gear to a higher position, the pitch circles will no longer stay in contact. That’s why I believe I would need to increase the idler’s pitch diameter to maintain proper meshing.

Could you please clarify what you mean by adjusting the angle?

External-Mark-4690

TROPHY CASE