Solving difficult problems with SOLIDWORKS Premium
The team at Coalesce Product Development have worked hard to take the best elements of large technology companies and mix them with the benefits of working with independent designers to provide an optimised product development service. The company is run by engineers, allowing the business to stay lean and pass on low operating costs as savings to clients . These days, even large multi-national blue chip clients appreciate getting good value for money.
The engineer-lead structure also means there is a culture of striving for the best technical solution and making investments in the right tools, including software such as SOLIDWORKS 3D CAD Premium, which has proved to be vital to the business.
Director Robin Cocker explains “We were tasked by one of our medical device clients to solve a tough mechanical problem inside one of their device concepts; with extremely tight spatial constraints, the space that was left for us to work in was shallow (which meant we couldn’t stack up components, as you might in a gearbox) and the swept area was restricted so things like cranks and racks & pinions would not fit.
An input lever rotated through an angle of around 90°. It had to move a linear slider a relatively long way but only during certain periods. During the other periods it needed to hold the slider in place. The requirement for these dwells made the problem much, much harder. We had an abstract idea that we might be able to combine a crank and a cam to increase the output displacement beyond what a simple crank alone could achieve and at the same time allow us to create the dwells which would constrain the slider but not move it when required Could we turn this abstract idea into something that delivered the required motion? Thankfully it was a more or less “2D” design problem so we were able to apply traditional technical drawing skills within our SOLIDWORKS models to work out the geometry.
After a bit of head scratching, it looked like we had a solution, at least in theory. Just a chassis, the lever and the carriage with no other parts but it relied on three separate pairs of pegs and cam slots co-operating with each other to achieve the motion and the dwells. Without digital tools to analyse the design, we had to machine a prototype to see if it would work. Despite our trepidation, it worked perfectly first time with no tuning. Smooth. Precise. Brilliant!
When the client was shown our design, he couldn’t put the prototype down. “Mesmerising” was the word he used. We had tested our prototype and characterised its performance but we wanted to know how SOLIDWORKS Premium could help us to analyse such a mechanism before prototyping and testing, which is when we were introduced to the Trace path functionality. This allows you to generate loci, or trace paths within a mechanism effortlessly.
We use SOLIDWORKS Motion Simulation to program the motion we need (direction, velocity, acceleration etc.) and then SOLIDWORKS automatically generates trace paths which help us to create the most effective cam profiles to achieve the motion. Doing it this way around means the cam profile is driven by the analysis rather than us having to design the cam by traditional methods and then analyse it with SOLIDWORKS. It kind of flips the process the right way around and this results in fewer iterative loops. SOLIDWORKS Premium saves us days if not weeks compared to manual methods and we can be much more confident that prototypes will work. We have also gone on to design similar systems with much more complexity in the motions. Imagine the carriage in this example being split in two, driven along an irregular path, rotating at the same time and then sliding apart). Typically, such motions would require several cooperating mechanisms. To do it with only 4 components would have been impossible for us to contemplate commercially had we been relying on manual methods.
Ideas like these tend to be eliminated early because you cannot quickly determine whether they stand a chance of working, let alone assess how long they might take to develop. With SOLIDWORKS Motion, we can quickly gain confidence in seemingly crazy concepts, ultimately allowing us to solve very difficult, complex motion problems with unexpected simplicity, precision, economy and robustness where others may fail altogether.”
Director Dave Ahern said “The Simulation tools within SOLIDWORKS Premium have helped us to be more innovative in the way we approach difficult mechanism design challenges. Not only have we removed iterative loops and streamlined the design process, but ultimately our clients end up with better products. My advice for any design company would be – empower your engineers by investing in your SOLIDWORKS tools and get properly trained. It will pay for itself quickly and in ways that are often hard to predict.”
Mark Bradford, Managing Director at Innova Systems commented “This is a great example of how SOLIDWORKS can be used to solve very difficult design challenges. Coalesce uses the Simulation tools within SOLIDWORKS Premium as an integral part of the product development process. Coalesce recognised the importance of using our expertise for training and guidance on how to get the most out of SOLIDWORKS, and the results are evident. We are delighted to be a partner with the team at Coalesce”.