Here's a bike shock system than can be controlled -- soft or rough.
Jason Brack and his fellow Colorado State engineering students, David Dang and Broc SommerMeyer, created a magnetorheological (MR) bicycle shock absorber that can be adjusted using a touchscreen to affect the bike’s ride. The MR fluid reacts to a magnetic field. In this case, the viscosity can be increased or decreased to change the dampening rate of the shock absorber. Using the touchscreen display, the user can select the ride quality of the bike.
Here is the touchscreen mounted on the bicycle.
The ride selection screen helps you pick your ride quality.
I love the design and concept...I just wonder. Is this not already being done in cars today? Or is this transfering that tech to bikes? Love to have my motorcycle realize I am coming down from a 50 foot launch and readjust the suspension for me!
As this appears tto be an engineering project developed by some college students it may well be that the problems and shortcomings were of greater benefit than the pars that might be termed successful. For them to look back and see what they didn't know and what could have been done better they will become much better engineers.
Because of energy requirements this might not be a practical application of this technology, but it is a much more responsive test bed that a heavy automobile might have provided. and I am sure that there are many more questions that could be asked. Like how will those iron particles affect the small orifices over time and might it be necesary to use carbide or other hard material to limit wear?
And as to why they used an Arduino - Probably because they could afford it... Another one of the constraints on an engineer. Can it be made? And can it be made within the budget? And now can you make it for less?
I am happy to hear that you have done some thinking about possible design improvements. I realize that a perfect product cannot be made in such a short time. Iterative development processes are much better and let you learn and develop a "feel" for the relative importance of the various factors that influence performance. It would be nice if you had time and resources to make version 2.0. Good luck.
Thanks for the information on what iron powder would work better. The professor we talked to about the MR damper conversion said almost any iron would work but the smaller the better.
The draw back to this design and the difference between production MR dampers is the coil placement and the field direction. For optimal results the coil should have been located internally, closer to the valve and around the small ports. The magnetic field needs to be normal to the flow direction to cause a drastic change in the damping being developed, which only occurs at the coil entrance and exit. To get enough damping change we had to run very high current through the coil to make it work and locate the coil exit close to the valve. If we could have done all of that then we could have made it much more compact and run it on little to no power. We didn't have the time in a 3 month project to completely re-engineer the shock and then modify it to work in that manner.
All three of us who worked on this are mechanical engineering majors. None of us had much experience with electronic gadgets, so a lot of the decisions we made were based on very little information.
As far as entirely magnetic damping, we didn't really consider that very much. At first glance I would think that it would be difficult to generate enough field to support the impact forces generated on a mountain bike. I guess I need to do more research now!
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