## Marble Roller Coaster Create Start of Loop (Part 6 of many) [VIDEO]

Create Loop Start

Many people believe that the shape of the loop should be circular, the problem with a circular loop is that it has an abrupt change in curvature and in the case of a loop causes a significant loss of speed at the top of the loop.  The shape that we should use for this loop is a clothoid.

This shape starts with 0 curvature and then spirals, which is the perfect shape for a loop because the marble will not hop, and it will not lose a significant amount of speed.  However this shape is very complex to model in SolidWorks, we can generate coordinates and create a curve.  But even getting the coordinates is a fairly complex task.  As a simple workaround I will demonstrate sketching by tracing a sketch picture.  This topic is covered in the surface modeling course.

## Alin’s SW2013 Pick of the Day – Bounding Boxes (1)

This functionality has been long time requested by SolidWorks users like you, as a quick way to determine the smallest box you can package your model in.

Watch this video and tell the good news SolidWorks 2013 brings to your colleagues from the estimating and shipping departments.

They will love you for that!

Update: After I finished creating this video I realized that this new functionality will be priceless for users involved with 3D Printing by minimizing the support material and the printing times.

I am pretty sure you have spotted the same opportunity, but, just in case you are in doubt, I will try to prove this point next week with a second video on how to use the new bounding boxes enhancement for saving time and money while 3D Printing.

## Routing: How the “Flip Relation” Option Can Speed Up Routing Sketch Edits

Occasionally when modifying a routing sketch (or other 3D sketch) you may run into a scenario where a spline tangent needs to be flipped or reversed.  See the image below.

Spline before flip

Well, thankfully there is a way to quickly flip it.  Read More »

## 3D Sketching Techniques – Insert points and Connect the Dots

This method assumes that you have a list of points that you wish to sketch to.  Start a 3D sketch as usual.  Using the “point” tool on the sketch toolbar, drop in the needed number of points.  Click on each point in turn in the model window and set the point location in the PropertyManager, once the point coordinates are set, add a fix relation to each point.  Once all the coordinates are set, you can now start the line or spline tool and click on each point to achieve the desired sketch path.

Connect the Dots method

## 3D Sketching Techniques – Create a Curve From a Text File or Table of Values

Use the command: Insert -> Curve, Curve through XYZ points.  Either enter the values into the table manually or open a text file that you have created earlier.  Once all of the coordinates are entered into the dialog, Click OK to insert the curve.  The created curve is a separate entity in the Feature Tree, however it can be copied into a 3D sketch through the use of the “convert entities” sketch tool.

Start the tool

## 3D Sketching Techniques – Multiple Viewports

Although a 3D sketch in SolidWorks does allow us to draw in 3D, we are more or less limited to sketching in 2D planar directions (XY, YZ, ZX) at any one time.  Here’s what I mean: If you have attempted to sketch in 3D in your model using any sort of Isometric view orientation, you’ll know that it can occasionally be a challenge to accurately place your sketch points in space.  A simple solution is to sketch normal to a plane contained within the model.  When you are done sketching in one plane, switch to another as needed.  The sketch is then only created in two directions at a time in this scenario.  This is a much more predictable method.  Splitting the model window into 4 viewports accomplishes the same thing and allows you to click in a viewport that is at the orientation desired for the sketch.  Three of the four viewports can be linked as orthogonal projections to make it simpler.

Viewports Tool

## SolidWorks Routing: 3D Sketching Techniques – Helix for Route

When using SolidWorks Routing, a simple way to have a coil of tubing for strain relief or packaging reasons, is to create the helix outside of the 3D Route sketch and then use convert entities to copy the helix into the Route sketch.

The basic steps are:

1. Insert a dummy part to create the helix in
2. Create the 2D sketch to control the diameter of the helix
3. Create the helix
4. Edit the 3D sketch and use the ‘Convert Entities’ sketch tool to transfer the helix into the 3D sketch
5. Lastly, tie in the transferred helix into the route sketch.

Coil Needed

## Let’s get picky and use the Selection Manager

Dan Johnson asks this question in the SolidWorks Forum:

I am trying to create a handle that is part of a scanner body and I made my curves using a 3D sketch. When I try and make either a loft or boundary surface, I try to grab just one curve in my 3DSketch, but it wants to grab the entire 3DSketch. How do I select just 1 curve for my profile? I tried the right mouse click, selection filter, but it grabs the entire 3d sketch too. Can anyone help?