Flat Plane Spiral (I think)

[Tentimes]

Hi All,

Newbie to the forum, so please accept my apologies in advance for asking what will probably be some rather basic questions.

My current project is somewhat like a 'swash plate' pump, in that a rotating shaft imparts linear motion to objects situated parallel to the shaft axis.
Below is a rough example I managed to create by lofting. For some reason, I was only able to loft through 180 degrees, so it's constructed from two mirrored halves. This has caused a few issues that have so far gotten the better of me.

Can anyone suggest a superior method of creation that will produce the drawing in one 'piece'?

 

[bigseb]

1) Draw the larger diameter plate first at the angle you want using midline extrude then the shaft following the rotation axis through that or
2) midline extrude a cylinder with the diameter of the plate along the rotation axis then extrude cut through that to create the plate thickness, then create the shaft through the plate.

No. 2 will give you a circle when looking along the rotation axis so that's probably what you want.

 

[HaroldL]

Here's a sample part. Use the Equation Editor (EE) from the Tools menu to change the parameter values. The part will update when the EE is closed. Edit only those parameters with the AA_ prefix.


The swash plate is extruded along the Y axis. But since that will give an elliptical feature that will be difficult to size I put in the last trimming feature that can be sized concentric to the shaft diameter.

 

[Tentimes]

Thanks for the prompt responses. Feeling rather foolish right now, because my original question does not adequately express what I am trying to do.
With reference to my drawing, you will note that the bearing surface of the plate always remains perpendicular to the shaft itself.
This is what I'm trying to achieve, but in a single face, rather than the multi face item I currently have.

Sorry if I wasted anyone's time with my poor explanation.

 

[HaroldL]

With reference to my drawing, you will note that the bearing surface of the plate always remains perpendicular to the shaft itself.
This is what I'm trying to achieve, but in a single face, rather than the multi face item I currently have.

In the screen shot of your model the orientation of the plate outer bearing surface is not clear, However, I think it is normal for the plate to have a circular outer surface that is parallel to the shafts axis. That is how I modeled the sample that I uploaded. Have you downloaded the sample model to have a look at?

On second look I see what you mean by "bearing surface". That is achieved by some secondary operations, whether extrude bosses or extrude cuts. Here is a screen shot of a drawing of the model I uploaded. Is this what you are trying to achieve?



BTW, to clarify terminology, your image is of a model not a drawing. A drawing is the 2D representation of a 3D model.

Do you have a picture of something similar to what you are trying to model or is this a new design?

 

[idslk]

imparts linear motion to objects situated parallel to the shaft axis.

bearing surface of the plate always remains perpendicular to the shaft itself.

Please point out details to your "bearing surface", your "objects situated parallel to the shaft" and "perpendicular" please.

Regards
Stefan

 

[Tentimes]

In the screen shot of your model the orientation of the plate outer bearing surface is not clear, However, I think it is normal for the plate to have a circular outer surface that is parallel to the shafts axis. That is how I modeled the sample that I uploaded. Have you downloaded the sample model to have a look at?

On second look I see what you mean by "bearing surface". That is achieved by some secondary operations, whether extrude bosses or extrude cuts. Here is a screen shot of a drawing of the model I uploaded. Is this what you are trying to achieve?

View attachment 33438

BTW, to clarify terminology, your image is of a model not a drawing. A drawing is the 2D representation of a 3D model.

Do you have a picture of something similar to what you are trying to model or is this a new design?

Hi Harold,

1. I've tried twice to download and open the sample model, but each time, I get one of the famous Alibre Error Messages.
2. Please refer to my pre-emptive apology regarding my mangling of correct terminology (drawing / model). Maybe i should model my dunce hat and rivets )
3. Following a late nite session, I have now managed to loft a better version of the swash plate, but I'm still struggling with some behind the scenes calculations to achieve the desired geometry.

In this version, I now have a single 'bearing' surface (the flat upper and lower surfaces of the plate that are perpendicular to the shaft),
however the angular changes are still not correct.
To make this model, I resorted to creating planes every 45 degrees, then positioning identical drawings at appropriate heights.



Is there some way I can script this procedure, so that I can create drawings that changes Y value for every degree of rotation?

 

[idslk]

 

[HaroldL]

If you want to use Loft to create the swash plate, search the forum for "wave washer" for previous discussions and examples of creating one.

Here are a few more questions for clarification:

1. Which version of Alibre are you using?
   
2. When viewed along the Y axis, is the swash plate round or oval? (In the screen shots it appears to be oval shaped.)
3. What is the offset angle of the swash plate?
4. Is the swash plate flat on the inclined angle, Flat across the surface, or is it offset from side to side?

Here are a couple of screen shots of the model created using extrude bosses. Note that I deselected the Along Normal option and chose the Y axis for extrude direction. That is for all extrudes on the angled swash plate. The plate is round in this example, it could just as well have been an oval shape.