Drawing around other 3d objects to create another object

[fastfox]

I am trying to draw a boom for a sprayer and I have the 3 main tubes extruded. I need to draw plates every 48 inches in between the main tubes. I wanted to draw each plate to make sure it would fit and then use the drawings to cut the plates on my CNC plasma cutter. However, I can not figure out how to draw on the same plane right around the main tubes. What am I missing? I have a screen shot blow showing the tubes and I have a small 2D sketch similar to the plates I need to draw in every 48 inches to the right. The plates will be perpendicular to the top tube.

I am still new to auto cad so I apologize if this easier than I think. I use autocad enough to be dangerous. Just trying to learn as I go, but this project needs to be completed as soon I as possible so hopefully someone can help me out. Thanks in advance!!

[ReMark]

So as you work your way down those three tubes the plates get higher and wider?

[fastfox]

Yes, that is correct. The plates get wider/taller as you move along the tubes.

[ReMark]

Do you have a 2D elevation of each plate for every location?

 

2009 does not have the parametric constraints feature right?

[fastfox]

No, I don't know the dimensions for each plate.

[ReMark]

The holes in the plate stay in the same position though don't they? They don't get larger or get spaced differently do they? As plates are added do the number of holes change?

 

I suggest you attach a copy of the drawing to your next post.

[fastfox]

I'm sorry, I misunderstood. Yes, the holes are the same position all the way through and they stay the same size and position all the way though as well.

boom2.dwg

[fastfox]

ReMark, after rereading your last post I see that I missed the question about the holes. The 7 holes shown go all the way through the boom to the end, which will transfer to another 15' boom that gets attached to this boom. The first plate will have a total of 15 holes to hold air tubing. The tubes stop every 30" so the second plate in from the tall end will have 13 total holes. (I know this is getting confusing!) I can take care of adding the holes to the plates on each one, but I need to learn how to get the plates in the correct position first.

 

Hope this makes some sense. I really appreciate your time and effort!!

[ReMark]

I suppose you could cut a section every 48 inches along the tubes to assist you in getting the size/shape of each plate correct.

 

The plates will be notched to fit around the three tubes right?

[fastfox]

That is correct, the plates will be notched to fit around the three tubes.

[ReMark]

Another possible way of doing it would be to create a 2D profile of both end plates, loft them, create sectional slices using extruded rectangles passing through the 3D solid you created then use the Interfere command to visualize and isolate the individual sections. Depending on the overall length of your boom you might need to add a 2D profile of the middle or use "guides" to keep the lofted object true to form as it tapers.

 

BTW...why are you using surfaces and not solids? And how thick are the plates supposed to be?

 

After looking at your drawing a little closer I think that your geometry may be slightly off.

Edited August 7, 2013 by ReMark

[JD Mather]

That is correct, the plates will be notched to fit around the three tubes.

 

Also keep in mind that perfect parts cannot be manufactured out on the shop floor.

Allow clearance on the notches for the manufacturing tolerance.

[fastfox]

Thank you for the suggestions. I have tried the sections but I haven't been able to get a section across the tubes in the correct orientation yet. I will play with lofting and see how it goes. It doesn't sound like there is an easy way to do this in auto cad, so I may be in over my head.

 

My geometry may be off, I am very new at this. I just extruded squares and then rotated them in this model to get them close to the right dimensions to see if I could figure out how to draw the plates.

 

Thanks for the comment on the leaving some tolerance, I always watch that as I am also the guy that runs the cnc and then assembles.

[ReMark]

Lofting the end profiles will work better if use using Guides option.

 

After using the Interfere command you'll end up with a graduated set of plates that you can punch your holes through as required.

 

The above image was done using a 2Dwireframe visual style.

[ReMark]

The graduated plates. I moved them closer together just for comparison purposes. Each plate is a 3D solid not an extruded surface.

 

The above image was created using a realistic visual style.

[ReMark]

The four green lines you see are what I used as my guides for the Loft command.

[ReMark]

fastfox: How did your boom drawing turn out?

[fastfox]

Remark,

Thank you for all of your help. I was busy in the shop yesturday afternoon...but I am going to try to tackle the boom today again. I'll keep you posted.

 

Thanks again!

[Dadgad]

[ATTACH=CONFIG]43345[/ATTACH]

Lofting the end profiles will work better if use using Guides option.

 

After using the Interfere command you'll end up with a graduated set of plates that you can punch your holes through as required.

 

The above image was done using a 2Dwireframe visual style.

 

Nicely done ReMark, very accessible solution, good problem solving!

[JD Mather]

Nicely done ReMark, very accessible solution, good problem solving!

 

I would look closely at the plates.

Go to a view parallel to a plate.

Are the cut edges perpendicular to the flat? (might be easiest to check in wireframe shademode - there should be only one boundary)

That is the way sheet metal is generally cut.