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Old 10-18-07, 06:12 AM   #1
dubstylee
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Engineering optimization project, need ideas

I am completing my final semester as a Mechanical Engineering student, and need a few ideas.

One of my final projects is the optimization of a mechanical system of my choice. I will be using CAD and finite element analysis software to complete stress analysis of a system.

Basically I am looking for cycling-related topics that I could investigate. I had a couple thoughts, but am looking for other ideas.

-Shaving weight off an existing crankset with machining processes (from an end mill for example), yet still retaining adequate strength and stiffness. Make your Sora cranks as light as 105 or Ultegra.

-Different style cantilever brakes. Something like an old-school canti with more stopping power.

Anyone have suggestions? It's a real open ended project; I just need to find some area of a component that needs improvement, then provide suggestions based on my computer simulations.
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Old 10-18-07, 06:31 AM   #2
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I am a mechanical design engineer with a love of bicycles and their properties.
Consider exploring a low profile behind the fork braking system.
Belt drive drivetrain system.
Optimized hydraulic shifting with electronic signaling.
Composite/Ti exotic material disc brakes. Ceramic disk.

I have designed unique frame designs, wheels, suspension systems which utilize an arched cylindrical elastomer system. Way Cool!
Designs which replaces the "triangle" frame approach usually seen in today's bikes.

Keep in mind bike usage. i.e. Road bikes need weight savings. MTB's need ruggedness, etc.

Good Luck!

SolidWorks Rocks
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Old 10-18-07, 06:32 AM   #3
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I'm a mechanical engineer. Congratulations on your last year in college!

You picked a tough one dubstylee...bikes have a loooong history of optimization!

I did work for a while on redsigning the cranks based on shear center. As you recall, this is where you can load a non-symmetrical beam off axis, but incurr only bending stresses, and no torsion. This is perfect for the loading of a crank.

But in the end, you have a crash or something, and all your optimization goes out the window.

I kind of have to laugh at some fo the "aero" components too. Compared to my fat @$$, there's not much I can do to get any aero advantage by changing components!

Except for very specialized applications, you have to design the bike so it will stand up to all stresses it could possibly see. That includes touring loads, off-road shock loads, crashes, vibration, you get the picture.

For example, in my work, I have to design valves that may see very high shock loads (read: explosions). The shock requirements drive the whole design. If it will not fail in shock, then I'm not too concerned about pressure, fatigue, etc.

I do enjoy my folding bike, but I'm actually beyond the upper recommended weight limit. How about a smaller fold, and higher weight capacity?

Besides cycling, engineering design and stress analysis is my life. I've been doing it for about 26 years now. If you have any questions, ask me and I'm sure it's something I have forgotten !

Seriously, feel free to PM me and I'll help if I can.
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Old 10-18-07, 08:23 AM   #4
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Thanks for the replies guys. Good to have some experienced engineers on here!

I will keep you posted on what I decide to do.
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Old 10-18-07, 08:44 AM   #5
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If you want something simple, try a front fork-crown lamp mount that doesnt crack-n-fail.
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Old 10-18-07, 07:52 PM   #6
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Im an engineering manager
All you engineers posting, GET BACK TO WORK SLACKERS !
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Old 10-18-07, 09:27 PM   #7
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I'm an Engineering Technologist.

Which CAD system?
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Old 10-18-07, 10:28 PM   #8
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There are different arrangements of spokes in wheels. So which is best? That should be a nice little optimization problem for you.
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Old 10-18-07, 10:30 PM   #9
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Another idea. An observation on my now-gone $100 mountain bike- the brakes can be set up where you have lots of force but little movement or lots of movement (and therefore clearance) but little force. How bout a non-linear system where say, the first 1/4 of lever travel does 3/4 of the motion to pull the brake up against the wheel and leverage then shifts for maximum braking power?
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Old 10-18-07, 11:01 PM   #10
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I'm an Engineering Technologist.

Which CAD system?
If anyone knows solidworks, and needs a new job.....pm me
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Old 10-18-07, 11:04 PM   #11
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Another idea. An observation on my now-gone $100 mountain bike- the brakes can be set up where you have lots of force but little movement or lots of movement (and therefore clearance) but little force. How bout a non-linear system where say, the first 1/4 of lever travel does 3/4 of the motion to pull the brake up against the wheel and leverage then shifts for maximum braking power?
I think this is a great idea!, and I bet it can be done with geometric considerations/design inside the brake lever. It would make it much easier for people to keep brakes with strong stopping power on wheels that aren't true and therefore need extra clearance. Bravo to StephenH!

I could have used something like this on my Raleigh Record's 30-year-old steel wheels.

Oh, and I suppose I should admit, I'm an engineer, too.
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Old 10-18-07, 11:17 PM   #12
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If anyone knows solidworks, and needs a new job.....pm me
I worked with AutoCad way back when ... it's probably a completely different program now.

Then I moved into Unigraphics and Intergraph on a UNIX (?) system.

Then I moved into Solid Edge, which is also a Unigraphics product, I believe, but is much more user friendly. I have several certificates for the Solid Edge training I've had, but unfortunately I haven't used it in a few years ... my life has kind of taken a different turn. However, I've still got all the manuals etc.

I could be mistaken but believe Solid Works is sort of a distance cousin of Solid Edge ... or at least has some similarities to it.
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Old 10-18-07, 11:49 PM   #13
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There are different arrangements of spokes in wheels. So which is best? That should be a nice little optimization problem for you.

I was thinking of going with this. After speaking with my prof, the he emphasized that it should be a relatively simple problem seeing as I only have a few weeks to complete it.

I am thinking of comparing combinations of lacing patterns, rider weight, and spoke material/diameter.
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Old 10-18-07, 11:50 PM   #14
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I will be using Pro/ENGINEER for CAD and Mechanica for any finite element analysis.

Other calculations will be crunched out with some combination of Excel, EES, and Mathcad.
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Old 10-19-07, 06:13 AM   #15
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If anyone knows solidworks, and needs a new job.....pm me
I use Solidworks all the time for part and product design.
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Old 10-19-07, 06:12 PM   #16
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Quote:
Originally Posted by StephenH View Post
Another idea. An observation on my now-gone $100 mountain bike- the brakes can be set up where you have lots of force but little movement or lots of movement (and therefore clearance) but little force. How bout a non-linear system where say, the first 1/4 of lever travel does 3/4 of the motion to pull the brake up against the wheel and leverage then shifts for maximum braking power?
Odyssey used to make a roller-cam/pulley that varied the leverage & pull ratios. That function has now been incorporated into a lot of levers on the market.
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Old 10-19-07, 06:18 PM   #17
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Cycling related right?

How about child carriers or those bolt ons that turn your regular bike into a psuedo tandem with the kid.

I'll bet those have not been quite as fine tuned as a lot of other things.
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Old 10-20-07, 02:38 PM   #18
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I worked with AutoCad way back when ... it's probably a completely different program now.

I could be mistaken but believe Solid Works is sort of a distance cousin of Solid Edge ... or at least has some similarities to it.
Autocad is still a similar program, fancier ui to it now. Still has an extremely large user base.

Solid edge i've seen a few years back but never used. At that time it was lagging behind solidworks. Of course today things could be totally different. We chose solidworks a couple years ago, and im not changing again for a long time

To the OP, let us know what you finally decide on
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Old 10-20-07, 02:51 PM   #19
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To the OP, let us know what you finally decide on
And make sure to post some sweet 3-D figures with highest stresses in bright red...
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Old 10-20-07, 09:31 PM   #20
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Design a step through frame that achieves some rigidity by putting the bottom frame member level with the bottom of the chainring and the top tube level with the top of the chainring. Also allowing enough horizontal distance for the foot to pass over the chainring without being obstructed by the top tube or seat tube.
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Old 10-21-07, 04:36 AM   #21
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Just trying to think outside the box here.... Most/all parts of a bicycle have been analysed to death by the manufacturers. Why not focus your work on perhaps analysing a cargo trailer hitch?

If you're really keen why not analyse the entire trailer chassis, not just the hitch. Maybe try to incorporate suspension (for on road use) to improve handling?
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Old 10-21-07, 09:14 AM   #22
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Originally Posted by dubstylee View Post
I was thinking of going with this. After speaking with my prof, the he emphasized that it should be a relatively simple problem seeing as I only have a few weeks to complete it.

I am thinking of comparing combinations of lacing patterns, rider weight, and spoke material/diameter.
This is better than reinventing the wheel in a few weeks. How doing a comparision on wheel strength, repeating jobst brandts study on spoke tying efficiency.

Wheel strength, stiffness, different spokes, different rims, differing spoke tension ... the effect of a broken spoke given varying rider weight. There's a billion permutations here.
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Old 10-22-07, 09:59 PM   #23
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Quote:
Originally Posted by dubstylee View Post
I am completing my final semester as a Mechanical Engineering student, and need a few ideas.

One of my final projects is the optimization of a mechanical system of my choice. I will be using CAD and finite element analysis software to complete stress analysis of a system.

Basically I am looking for cycling-related topics that I could investigate. I had a couple thoughts, but am looking for other ideas.

-Shaving weight off an existing crankset with machining processes (from an end mill for example), yet still retaining adequate strength and stiffness. Make your Sora cranks as light as 105 or Ultegra.

-Different style cantilever brakes. Something like an old-school canti with more stopping power.

Anyone have suggestions? It's a real open ended project; I just need to find some area of a component that needs improvement, then provide suggestions based on my computer simulations.
Me too. BSME 1972, U of Toledo

How about:
  • 2 passenger Pedal Powered Vehicle with maximum efficiency
  • Seat with user-adjustable contours
  • If you didn't have to use a standard Bottom Bracket Shell, what would an efficient Bottom bracket look like?
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Old 10-22-07, 10:01 PM   #24
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If anyone knows solidworks, and needs a new job.....pm me
Sorry. Too far, too cold...

I finish a training course on SolidWorks in 2 days, after using it on my own for about 6 months. Nice to have some of the blanks filled in by actually being trained!
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Old 10-22-07, 11:04 PM   #25
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Sorry. Too far, too cold...
Too Cold?

I can cycle every day of the year on slicks without studs...dont need a balaklava...and only have a couple days a year a below freezing.......try that in New York
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