Help understanding constraints.

[cvriv.charles]

Damn I didnt install the content center. Maybe I'll go ahead and install it.

[cvriv.charles]

Hey eribiste, I installed the content libraries and tried to fit an o-riong without any luck.

 

I selected a surface and a reference in the placement square of the o-ring window. I then click in the o-ring box to select one and nothing showed up.

 

So then I tried it again with using the placement selections and thats when I saw a hole list of o-rings. I am thinking that the shaft diameter i have didnt match any of the o-rings and thats why nothing showed up after i made my selections.

 

Do you know if my shaft diameter has to be the exact same as one of the o-rings!?!? Does INV allow stretching of the o-rings a bit?!?!

[cvriv.charles]

Nevermind I found this:

http://askthecadgeek.blogspot.com/2008/05/take-design-work-out-of-using-o-rings.html

 

Good tutorial video of how to use the o-ring generator. The only thing I dont like about it is that your shaft diameter has to be one of the diameters within the o-ring generator.

[cvriv.charles]

Ok I this doesnt make any sense. i used the o-ring generator and the only o-ring for the diameter I need was way to thick. Way to thick. Apparently, the larger the diameter the thicker the o-ring has to be according to INV. Absolutely useless.

[eribiste]

I can't say that I've tried the O ring generator myself. As we know, in the real world one can make an O ring from a kit to suit a particular installation. When I had a go, using the Content Center, the first thing I did was model a shaft with a completely arbitrary choice of diameter, just as long as it was a 'popular' size. I chose to make the diameter 22mm. Then I opened an assembly file and placed the shaft in it. Next job was to use Place from Content Center to select an O ring, choosing one of the ISO standards (ISO 3601-1) because I was modelling in metric units. When the O ring appears, it is as a preview in a window. There are three tabs, Select, Table View and Family Info. If you LMB Table View the whole pantheon of sizes, ring cross section and so on appears. I scrolled down to the one that gave me as near 22mm as possible, which turns out to be 22.6mm OD and placed an instance of that in my assembly pane. The ring cross section is 1.8 mm, so I cut a 1.8mm wide square groove around the shaft with a 1.5mm depth and assembled the O ring to the shaft gland as per my previous email. This might be more cumbersome than using the generator, but it sounds as though you get more choice of O ring.

 

Hope this helps

 

John

[cvriv.charles]

Well,... I kind fo figured it out but I noticed that there are alot of o-rings missing from the library that are standards. So I think im stuck modeling my own o-rings. Only thing is that I dont know how to model a flattened o-ring to spec. Basically how to calc the bulge on the sides.