Problem assembling parabolic shape

[samfisher]

I am trying to assemble support frame for a parabolic trough. The main support frames are of the required parabolic shape and so is the sheet (note that in pro/e the sheet is modeled as a standard part, not a sheet).

The problem is I can't get any constraints to fix the sheet on to the frames. The sheet has to be bolted on to the frames and I have provided the required holes. I moved the sheet and placed it on the frame and then applied the fix constraint. This is not a satisfying method of constraining.

Please help me in this regard. Hopefully the image attached will make my question clear.


View attachment 5673

 

[samfisher]

Anybody please help me in this regard

 

[telecomguy]

"I can't get any constraints to fix the sheet on to the frames"


What all constraints have you tried? Seems like an edge on surface should work. But if I was modeling it, I would have a plane tangent to the apex of the parabola and similarly on the frame members. This would be my mating constraint.


<tg>

 

[dr_gallup]

Align the bolt hole axis.

 

[samfisher]

I've tried aligning the axis of holes. If the top 6 holes are aligned, then somehow the bottom 6 gives constraint invalid message. If I try the vice versa I get the same message.

The sheet is modeled using the sweep feature. The problem with sweep is that Pro/e doesn't recognize a swept feature as a surface. Whenever I try to select the parabolic shape for any purpose (hole, datum planes, edge on surface constraint etc.) I can't select the sheet.

 

[dr_gallup]

Only use enough constraints to satisfy Pro/E. Don't use all 6 top holes, 2 should be enough to orient, then you just need one more mating constraint.

You probably have some misalignment of the axis due to the curvature. Try putting points at the intersections of the axis and the curve.

 

[samfisher]

Thank you for your kind help. However, I am unable to understand your last sentence, "Try putting points at the intersections of the axis and the curve."

Secondly, I can't select the mate constraint as I mentioned earlier that Pro/E doesn't take a swept feature as a surface.

 

[dr_gallup]

Mate only applies to flat surfaces or datum planes so obviously you can not use mate. You had to draw the parabola, you have to have a sketch or datum curve or you could use an edge. You have plenty of references, you need to learn how to use them. Post a model and I'm sure someone can do it in 5 minutes.

 

[anwyl]

Make your life easy and mate coordinate systems on the
part and assembly.

dr_gallup is mistaken when he says mate only applies to
flat surfaces. We routinely mate the conical face of
flat head screws to the conical countersink they go into.

In WF5 I was able to fully constrain two parts with faces
which are extruded parabolas, they look similar to your
model, with a tangent constraint between the parabolic
faces and normal alignment constraints on two orthogonal
datum planes

View attachment 5679
Edited by: anwyl

 

[samfisher]

Thank you anwyl. Please tell me how to create the parabolic sheet with extrusion. Presently, I have plotted the datum plane with the required equation and then used the swept feature.

 

[anwyl]

I used a conic arc with rho=0.5 created in sketcher to make
the parabolic extrusions.

Search the web for "proe conic arc parabola" for more
information.