The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: Piston on June 18, 2013, 02:41:43 PM

Title: Sketchup help needed
Post by: Piston on June 18, 2013, 02:41:43 PM
I'm pretty experienced with Sketchup, but I am having a hard time figuring something out, that I've never done before. 

A friend of mine asked me to show him how to "trim" a cylindrical shape.  I told him sure, no problem.  Well, I can't do what he wants! 

He is a welder, and wants to start using sketchup to design some of his projects.  He uses a lot of round bar steel, so needs to use the circle function a lot.  Since the only thing I really use sketchup for is timber frame models, I almost never use the circle function, aside from pegs. 

So I made a 2x10x8' component in sketchup, then I made a 4" circle and extended it, about 6' long or so.  I then moved it so it protruded through the 2x10 (perpendicular) about 2'.  Then using the push/pull tool I simply shortened the cylinder to "trim" the end, and make it flush with the 10" face of the 2x10.  Easy. 

However, he wanted me to show him how to trim it as if it were a brace, so I rotated it 45° and moved it so it protruded through the 2x10 again, but at a 45° angle, just like a brace.  This is where I ran into problems.

Normally if it were a brace, I would just edit the component, draw a line on it, and use the push/pull tool to erase the section I didn't want.  But, with a cylinder, I couldn't do this. 

So how do you "trim" a cylinder when it's at an angle, protruding through a rectangular piece? 
Title: Re: Sketchup help needed
Post by: bmike on June 18, 2013, 07:59:09 PM
Pro? Use the solids tools and trim one from the other.

Free? There might be some plugins to help, but here is the long hand way to do it:

I'll try a post a video later, but you learned the basics in my SketchUp class.

Edit the cylinder component.  Once you are inside the component, triple click to select everything. Now right click while hovering over the geometry you just selected and select 'Intersect Faces...' choose 'with Model'.

This will draw lines where the surface of the cylinder meets the other shape. You'll have to manually clean up the geometry.

Note that SketchUp is a surface modeler, so curves and cylinders (without any plugins) are approximations. You can change how smooth they are by editing the number of sides prior to drawing the geometry. Watch the lower right dimensions box after you select the tool, but before you start drawing.
Title: Re: Sketchup help needed
Post by: isaacpopp on June 18, 2013, 09:44:01 PM
I haven't run into this before but couldn't you just draw two arcs (to match the ellipse) on the plane of the rectangular face where the intersection is and then delete the protrusion from the cylinder component?
Title: Re: Sketchup help needed
Post by: bmike on June 19, 2013, 07:44:19 AM
Quote from: isaacpopp on June 18, 2013, 09:44:01 PM
I haven't run into this before but couldn't you just draw two arcs (to match the ellipse) on the plane of the rectangular face where the intersection is and then delete the protrusion from the cylinder component?

This is essentially what I outline above, but the computer does the drawing for you. You need to delete the geometry that you do not want.
Title: Re: Sketchup help needed
Post by: bmike on June 19, 2013, 11:00:20 AM
http://youtu.be/Gyq3pdHLkFs

Video will take a few minutes to process... but I show the Pro way and the long hand way to intersect a curved object with a flat sided object.

-Mike
Title: Re: Sketchup help needed
Post by: Piston on June 19, 2013, 06:19:00 PM
Mike,
Excellent!  Thank you very much, I got it now  8)

I was trying to figure out how to do it with "intersect face", but I wasn't selecting all the geometry inside the model (while editing component).  I was simply right clicking and trying to intersect. 

Thanks again! 

Also,
I don't have the pro version, but have been thinking of upgrading.  I believe Layout comes with the pro version?  If so, I may purchase it and try messing around with Layout so I can make some nice shop drawings of the model I sent you. 

I don't use cylinders much, and you mentioned plugins, are there any other plugins you suggest for timber framing?  Aside from the TF Rubies? 
Title: Re: Sketchup help needed
Post by: bmike on June 19, 2013, 09:02:36 PM
You can download the pro version of 2013 and try it out for 8 hours free. It resets to the free version after that.