Drag Chains

[maker9876]

Does anyone have a good source of drag chain models?

I inserted one from McMaster and enabled Contact Sets but the whole thing just froze up.

Seems that the radius of the holes in the links of their model is identical to the radius of the axles that fit into them such that F360 perceives the links of the chain to be fused together. Guess I could fix that link by link but maybe there's a super drag chain resource on the internet?

[innovatenate]

Contact Sets are computationally expensive. Plus, they really like it when the bodies only intersect in one place. If they touch in multiple places or there are multiple bodies (more than 2) involved, I wouldn't be shocked that it would start slowing things down.

Can I ask what you are hoping to accomplish by modeling the drag chain? Is this something that you would manufacture? There may be a better solution available, but it would help to know exactly what you're aiming to accomplish.

Thanks,

[maker9876]

Certainly this doesn't fit into the food and water category of being essential for life.

And quite happy to accept if it's not readily possible. 

But reasons why being able to model a drag chain in motion would be nice include:

- a drag chain is an item whose shape changes with the relative position of two other elements (its ends). In order to assess the space that that changing shape takes up (whether to look for potential collisions or in order to choose the right shape and size of drag chain in the first place) you want to look at it in a range of different positions;

- inserting different drag chains and testing them out is quicker, cheaper and much more flexible than ordering different sizes and doing the same AFTER you have already built (and therefore designed) the rest of the prototype;

- one of the roles of CAD in prototyping is to avoid errors before building the next iteration; my basic experiences is that anything that I haven't modelled first is going to have a larger number of errors and "unexpecteds" in each iteration;

- much of the design process occurs entirely virtually: which is to say that one takes ones real world experience of holding or working with metal, wood, motion components and so forth and then, develop an emerging idea in CAD long before actually building the thing. If you can't model a drag chain then you sort of leave it out, you just hold onto a vague sense that it's going to be "in there somewhere" and sort of attached here and there. And that means that the CAD model doesn't develop around the drag chain - and the drag chain selection and the details of its attachment don't develop around the model either. It's a setback.

With respect to my project, yes I'm prototyping something that one day I'd love people to find useful and therefore eventually to end up in manufacture. But right now it's lots of prototyping with a view to getting something that can be tested in the real world. Tools include a paper sketchbook, a couple of makerspaces (CNC, 3d printing, lasercutting, welding, metalwork, PCB protos....), my undivided attention and, yes, F360. A single unit will contain two types of dragchain and four in total. They're not yet in CAD. 😉