Jump to content

flexible strap with gravity?


3dCADguy

Recommended Posts

Quick question:

 

I want to create an assembly in which a nylon webbed strap (like the one you tie stuff down with in trucks or the TRX straps) will be flexible. Is this possible in Inventor or Solidworks? I want it so move as the two things its connected to move, and have it be the limiting factor to stop the things from moving when it's fully stretched. I see a lot of stuff with cables online but I would like to accurately simulate the actual part I'm using, which is a webbed strap, if possible with maybe a spline and driving the spline and maybe sweeping a profile over the spline? Would something like that work? I'm a noob so if I butchered that i'm sorry.

Link to comment
Share on other sites

  • 2 weeks later...

 

Made this in four minutes. Create the part you are going to secure. Then create a new part, derive the first part, use it's projected geometry to draw your strap. Create assembly and bring two parts in, ground and root components. Add the parameters to your favorites and drive. There might be simulation software to test things but that is beyond my scope without more info. Thought I would show you this and see if that makes sense or is helpful. The more info provided the better answers you'll get.

Link to comment
Share on other sites

 

Here are two chain videos that might help. Maybe make small sections of strap, link them, and constrain to one side plane to maintain your strap loop.

Link to comment
Share on other sites

Dont forget you posted the same topic in the solidworks forum.

 

Do you need to do this to find the length of strap needed? I would suggest using a spline(I can make an example for you) but actually using a limit mate on the assembly. When you get mechanical linkages or a sketch like you need for this, at their limit they can flip and do funny things. If you have to use a strap rather than mate limits it will be important to make some construction references and variable to control it. You will control the spline length but also you need to control a midpoint and a variable of "weight" on the middle spline handle. In real life you can pinch that nylon webbing flat bit in cad if a solid sweep intersects itself it will fail. There is no "contact" limit you can on a body with itself.

 

The easiest way(in solidworks) to validate this is with sketch blocks. I taught a class at solidworks world on kinematics with blocks and have a course about it on O'Reilly. It's powerful and quick. Reply on the solidworks posts with some dimensions of your mechanism and ill try to make some videos in the next few days.

Link to comment
Share on other sites

This is probably not the right way to do what you want, but made a 1x1x.125 round ended extrusion and imated a ton. Opened simulation an put gravity on, took a video with phone to be super lazy instead of rendering.

Link to comment
Share on other sites

i did a quick sketch block test in Solidworks. I didn't have a mic hooked up but you can see how the spline behaves by default.

 

 

Notice that in reality the strap would actually push itself out of the way. Its going to take a lot to make that work. This spline would fail as a sweep when it crosses itself.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...