How to create cuts based upon tube intersections
-
I'm designing a car chassis using tubes. In many places, two or more tubes intersect in 2 or 3 dimensions, with the intersecting surfaces having goofy shapes and angles. It would be GREAT to draw these tubes as lines, convert them to tubes, and let SU figure out where the tube surfaces intersect. This much I can do using the various line-to-tube tools and plugins.
The problem is that after I create these junctions, I want to show the cut lines on each tube. The trouble is that when I back a tube away from the junction, it returns to its original cylindrical shape. I need to apply some tool or techinque so that the intersecting end stays in place so I can dimension it. The goal is to produce drawings for each tube, showing each end and how it must be cut.
How can I do this? Is there a plugin available? The trouble is that I don't even know what to search for in order to see what's out there. Any ideas are greatly appreciated!
-
That's exactly what I want to do. Thank you very much and I will try your suggestion!
-
I use SketchUp to make pipe cutting template for welders when they need to make coping cuts to match pipe angles.
In the example, I show how you use intersect with model to get the cut lines, than you remove the excess. Now, the fun part, using the unfold tool, you can layout the pipe flat. Now if you turn on show hidden lines, you will get a line at each of the circle’s segments.
Not sure, but I believe with small tubbing, you may be able to print this out in scale and just using scissors, cut out the template and warp around the tubing to mark the tubing where and how to cut.
Most of my work is with piping from 4” to 50”. So my templates are big, so I just use the measurements.
Hope this helps.
-
Very cool! A few questions. What tool did you use to create the tubing? Did you make a circle, remove the ID, the use the extrusion tool, or the "follow line" tool, or a plugin? I finally found the Intersect with Model - nice. But how do I remove the one tube from the other after removing the overlaping portion? And finally, where's the unwrap tool?
A annoying problem I will have is creating 3D pipes (tubes) that have true round cross-sections to their lines. I've already run into problems with that, ending up with elipses instead of true circles. I suspect there's an elegant way to do it but don't know how. I hate to do it all the hard way, thenfind there's a simple way! I "think" the Make Pipe plugin takes care of that.
What would be awesome is if there's a tool or plugin that allows me to highlight a line drawing and change the lines to tubes, then do as you show. The trouble is that the only plugins I've found group (I think) the lines so I can't delete the intersecting parts... or maybe I can, I just need to work on it more.
Thank you very much, what you've done is what I'm trying to do. The unwrap feature, once I find it, is very cool - as long as the two ends of the tube are properly indexed!
FWIW, here's the last car I designed, http://www.kimini.com/ and here's the car I'm designing now, http://www.midlana.com/
-
Okay, to show I'm not lazy, I figured out everything except the unwrap, which seems to be a add-on. True?
It would be very nice to have! I'm very interested what you used.
-
Very nice, thanks. If the unwrap tool had a mode to just one-click on a component and have it unwrap the whole thing, that would be awesome. It's funny how we always say, "that's nice, but it would be great if it also did...", then someone writes a plugin to do that, then we say, "that's nice, but if it did just this..." It never ends, lol.
-
I thought I had it figured out. After creating the pipes and applying Intersect with Model, what's the right way to separate the tubes. I've tried Explode but when I try moving one tube away from the other, it drags along the intersection.
-
midlana42
I first draw all my center lines, adding all the lines to a layer called CL. Then I make each line a pipe with 0” ID using “PipeAlongPath”. Then I add all the piping groups to a layer that make sense in my work, “100’Elevation”, “A Row”. To you maybe a layer called “cockpit” or “engine” would make more sense.
After getting all my center lines turned into the proper tubing, I then copy the whole model and paste next to the original. This new model is the model I make all the intersect with model operations. I have found more than once I needed to move or modify a pipe or centerline it is a lot easier to start with member/tubing that has not had the intersect with model operation.
To remove the unused portion, I usually copy the pipe/tube and then remove the unused portion, than after getting the results I want, I then replace the old pipe/tube with this copy. I do this because sometimes intersect with model does not make a complete cut line. Not sure why, but if I make a copy, and work away from the model, it is a lot easier to see the problem.
After getting everything to my liking, I then lock the original group, move to a safe location and hide. From then on I work on the copy.
If your are working on small tubing, 1” to 4” it may be a benefit to work on a model that is scaled 10x larger, and reduce at the end by scaling to .1x to get back to the correct scale.
I saw the unfold script movie, which is a very good video on how to make templates for coped or rolling offset pipe templates.
Ken
-
@unknownuser said:
To remove the unused portion, I usually copy the pipe/tube and then remove the unused portion, than after getting the results I want, I then replace the old pipe/tube with this copy. I do this because sometimes intersect with model does not make a complete cut line. Not sure why, but if I make a copy, and work away from the model, it is a lot easier to see the problem...
How about this:
- you make the intersection
- copy the wanted part
- undu the intersection
- delete what you wanted to intersect
- paste in place what you have copied
The main advantage is: you don't need to fiddle around with meticulously deleting all little unwanted piece of geometry.
-
I'm experimenting around with all the suggestions. One thing is that when I try to follow the advice to "make the intersection", that works. I copy the wanted part, that works, but when I paste it somewhere, it's the full tube without the intersecting lines. What are you guys doing that when you copy the tube it also copies the intersection? I'm guessing I must select the intersecting line too in addition to the tube I want, true?
Also, if I explode the tube in-place and try and delete the intersecting parts, sometimes when deleting one face, it grabs tube segment down its full length instead of just the overlapping portion.
I'm getting their slowly, but since I have so many tube intersections to deal with I need to have this down.
Thank again guys for all the help
-
@midlana42 said:
...it's the full tube without the intersecting lines ...Also, if I explode the tube in-place and try and delete the intersecting parts, ...
I think this is the problem here. If you have the tube in a group or component and do the intersection while outside its editing context, the intersection line will also be outside (and not part of the mesh inside the group) thus there is no interaction between them.
You either need to explode the tube or edit it while doing the intersection.
-
@unknownuser said:
When you first make the tube with the ruby it becomes a group, thats why I said explode it in my first post...
Here's the procedure:
1.When making a tube with tube along path it will automatically become a group apart from the original line now inside, this can be deleted at any time.
2.Explode the tube you want to trim and intersect with model.
3.Triple click the exploded tube to select all of it and regroup it.
4.Now right click and select edit group, delete unecessary linework in wireframe mode.
Thats it all trimmed and in a group.Ah, Explode the tube thenIntersect with Model thenregroup it! I was was doing it all out of order.
So regrouping causes the unwanted intersecting portion to become it's own "object"? I'm guessing that means that I should be able to delete it by clicking once to select it and deleting it, instead of having to delete every single exploded line segment separately, which was driving me nuts.
Okay <room gets brighter> I'll give that a try tonight, thank you!
-
I don't think I'm doing that, though. I draw two lines, then convert both to pipes with zero ID. I use the Intersect With Model to show where they touch, and that's where I run into trouble, when I try to back away one tube from the other for editing; the intersecting line says on the other tube.
I figured out that I can select the pipe - and must also include the intersecting line - in order to move it for editing. That works better though I was surprised that when I selected the intersecting area and hit Delete, it also deletes the entire tube, but I can deal with that.
Subject change:
Somewhat related, my chassis consists of a mix of square and round tubing. Is there a plugin to produce square tubes the same way that pipes are created? I realize there may be an issues with how to orient the flat sides but having a tool would be much better than placing a square normal to a line and projecting it. I found when I use the Extrude or Follow me tool, it doesn't act the way I want and a plugin would be a great time-saver.Thanks again for the generous help and I hope to pass on the favor to others.
[edit] Found this: http://sketchup.engineeringtoolbox.com/section-steel-to_2.html
Don't know if it'll do what I want but I'll give it a try. Regardless, if anyone has a "Line-to-square-tube" plugin I'd like to try it.
Advertisement