That page is broken
Slashdot Effect probs
Nope, I just have no idea what I'm doing.
Show HN: Physics-based CAD
11–20 of 28 posts
Re: Show HN: Physics-based CAD
#12It's called parametric modelling, and many CAD software use a parametric kernel (solver). https://en.wikipedia.org/wiki/Computer-aided_design Is this somehow different? Please explain
The difference is that there is a simple physics model that's driving the dimensions. So the arms are getting resized according to beam bending, the battery is a certain size for the energy requirement, motors are sized by kw/kg and kw/m^3 and so on. There's definitely ways to make this sort of model in something like Solidworks through the use of a variables interface that interacts with the drawing dimensions. Thou…
This sounds interesting but I can't react the site. Could you please explain how you get a guaranteed optimum? What if you have conflicting objectives?
Re: Show HN: Physics-based CAD
#13Re: Show HN: Physics-based CAD
#14Re: Show HN: Physics-based CAD
#15Re: Show HN: Physics-based CAD
#16Earlier quoted context omitted.
The difference is that there is a simple physics model that's driving the dimensions. So the arms are getting resized according to beam bending, the battery is a certain size for the energy requirement, motors are sized by kw/kg and kw/m^3 and so on. There's definitely ways to make this sort of model in something like Solidworks through the use of a variables interface that interacts with the drawing dimensions. Thou…
This sounds interesting but I can't react the site. Could you please explain how you get a guaranteed optimum? What if you have conflicting objectives?
I think by react you meant react to, which was fair enough, it was dodgy as. Now running well.
The property of getting a guaranteed optimum is something that arises from setting the design problem up as a geometric program. You won't always get a solution (for example, a certain size quad has a minimum prop diameter). Though if you do, it is guaranteed to be optimum because the problem is convex as outlined here: https://gpkit.readthedocs.io/en/latest/gp101.html
Also, conflicting objectives are naturally traded off until you find a Pareto optimal solution. Using geometric programs lets you balance conflicts in a design quickly. This is why they are super useful for aerospace applications, where you are always looking at a tradeoff between weight and at least one other variable.
Re: Show HN: Physics-based CAD
#17Earlier quoted context omitted.
The difference is that there is a simple physics model that's driving the dimensions. So the arms are getting resized according to beam bending, the battery is a certain size for the energy requirement, motors are sized by kw/kg and kw/m^3 and so on. There's definitely ways to make this sort of model in something like Solidworks through the use of a variables interface that interacts with the drawing dimensions. Thou…
This sounds interesting but I can't react the site. Could you please explain how you get a guaranteed optimum? What if you have conflicting objectives?
It forces you to assign a weight to each objective, converting from a multi-objective to a single-objective optimization problem (the weighted sum method).
By varying the weights and re-running, you could identify a set a solutions on [convex regions of] the Pareto front.
Re: Show HN: Physics-based CAD
#18Interesting, do you have some more info about how it works? When I make the battery larger, is it considering the weight of the battery? Weight of motors, props, etc?
Re: Show HN: Physics-based CAD
#19Interesting, do you have some more info about how it works? When I make the battery larger, is it considering the weight of the battery? Weight of motors, props, etc?
Yes it's considering the weight of the battery, as well as the weight of the motors. It doesn't factor in the props, I didn't get around to that. The props have inaccurate geometry of course, which I'm looking to fix with a mesher.
Have a look at the console for how the geometric program is assembled.
Re: Show HN: Physics-based CAD
#20Interesting, do you have some more info about how it works? When I make the battery larger, is it considering the weight of the battery? Weight of motors, props, etc?
Yes it's considering the weight of the battery, as well as the weight of the motors. It doesn't factor in the props, I didn't get around to that. The props have inaccurate geometry of course, which I'm looking to fix with a mesher. Have a look at the console for how the geometric program is assembled.
Cool. I think this tool has a lot of potential users, especially if you can make it pick between commonly available props, esc, motors and so on. Imagine how cool this would be if it could make a list of those things and export a 3d-printable frame :)