elastic bands for pistons

[4man85]

Hello everyone, I have a small problem in modeling two elastic bundles for a piston.
the first is a metal elastic band, the second in composite material.
the metal one must be inserted inside the piston quarry and serves to expand the second that is in contact with the cylinder.
My problem is quite simple, but the solution is not the same (at least for me who are at first).
I want to bind the length of the arc (or development) and be able to change the diameter of the bands so that we can assemble them inside the cylinder.
I tried with a sweep and with fold part, but the results are not satisfactory.
I hope I'm well explained.
Do you have any advice?

allego paper design and ipt model
I thank in advance those who will help me solve the problem.

 

[4man85]

possible that no one has ever tried to assemble a cylinder-piston with elastic bands?
Please, I am still with the project:

 

[Peppe]

clearly the band should be designed "free" as it happens for the seegers generated by the contained center and at the level of together you can not "adapt" the band to the piston/cylinder for which you will see a little interference.
You could use 2 files, i.e. a "free" band as a particular constructor and a fit for the axieme, but I don't know how worth it.

 

[pagnotz]

However this discussion does not concern inventor (even if you are using this program), but a problem of mechanics, it was better to insert it into the mechanical design forum even to have more answers. Maybe you can think of some moderators moving him. . .

 

[4man85]

thanks for the answers.
I started with the idea of quotating the length of the arc and the diameter so that I could export the parameter and import it into the axieme assigns the value of the cylinder diameter. In this way I would have had only one model.
I understand it's not feasible. - What?
in my case I couldn't quote the length of the arc (development) because inventor does not admit this command in the sketch ipt.
In general, when faced with models that in initial condition have one form and in assembled position have another, what is it used?
cases can be just as you said: seger, sealing rings, springs, elastic and similar segments.

If I'm wrong, I'm sorry, but I thought it was about inventor work.

 

[pagnotz]

If I'm wrong, I'm sorry, but I thought it was about inventor work.

I apologize to you, I didn't read well and it seemed to me that the problem was just design and not even design cad, I said a cabbage, I'm still sorry:

 

[Tarkus]

thanks for the answers.
I started with the idea of quotating the length of the arc and the diameter so that I could export the parameter and import it into the axieme assigns the value of the cylinder diameter. In this way I would have had only one model.
I understand it's not feasible. - What?in my case I couldn't quote the length of the arc (development) because inventor does not admit this command in the sketch ipt.In general, when faced with models that in initial condition have one form and in assembled position have another, what is it used?
cases can be just as you said: seger, sealing rings, springs, elastic and similar segments.

If I'm wrong, I'm sorry, but I thought it was about inventor work.

No, but you can create a parameter where development is the function of the radius and angle of the arc....

 

[4man85]

How could I do that?
I had also done this test but maintained the constant opening angle

 

[Tarkus]

No, but you can create a parameter where development is the function of the radius and angle of the arc....

Maybe I talked too soon, I thought about an equation like this:

development = (2*rage*pi/360)*n° grades arc

But he doesn't take it.
strange, because such an equation,

(L_arco * 180 gr) / (Ray* pi)

that I use to vary the angle depending on the length of the arc,it takes

 

[GiGa]

Maybe I talked too soon, I thought about an equation like this:

development = (2*rage*pi/360)*n° grades arc

But he doesn't take it.

Could it be a problem of angle measuring units?
if I don't remember badly (at least using ilogic) you have to convert the degrees to radiants.. .

if you're told qui

 

[Tarkus]

I don't think, the underlying formula where there are expressions in degrees, it works me and I did it just during that discussion you indicated. . .