Tuesday, July 29, 2014


Recently I had a project where the kitchen specialist showed some "turnstiles by others".  Whenever you see that little phrase, you know someone has dumped a problem in your lap.  So I hopped onto the internet and searched for a local installer.  These days I make a point of using Bing for most of my searches.  Why should Google have all the fun  ( = information = power )  There is a delicious irony in choosing Microsoft in order to resist a monopoly but that seems to be the situation in certain areas these days.  I digress.

I found a product that looked something like this.

As usual there were questions to be asked.  One day there will be a proper BIM way to do this.  In this case there wasn't even a family to download, but one day it will go much further than that.  I imagine dropping the family into your project, creating a section box around the area concerned and uploading the result (in IFC format perhaps) to a web portal.  Here you can add some comments and questions, bookmark a couple of views and press submit.

This would initiate a 3 way conversation between yourself, the manufacturer and the local installer.  Comments would be tracked and tagged of course, and all parties would be able to create options and new views within the 3d model.  You would be able to synchronise any of these proposals with your project at the click of a button.  But there wasn't even a family.  Has anyone ever come across a turnstile family ?  I decided to make one.

Start with the tripod.  Generic Model, plan view.  Add 2 reference planes at 60 degrees to the vertical.  Go to a left elevation.  Create sweep.  Draw a path on the "centre L/R" workplane.  Guess the length or use information from the product website.  It's around 450mm, maybe a bit more.

Finish path, set the workplane to the "profile plane".  Select profile, edit profile, draw a circle.  I used a radius of 20mm.  Now you have a cylindrical arm.  Go to the plan view and mirror this using one of the angled work planes.

Select the second arm and mirror again using the "centre L/R"

Hey presto, three arms.  I guess we could have used a radial array.  Probably would make the file a little heavier.  I opted for mirror.  I also decided to represent the hub by a hemisphere.  Keep it simple stupid.

That's going to be  a revolve.  I drew my sketch in a front elevation view.Now we are going to load this component into another family, but first we need to make a couple of adjustments.

Uncheck "Always vertical" and check "Work Plane-Based".  Then start a new Generic Model family and load in your tripod component.  I'm starting with Generic Model out of habit really.  We can change the category later.  If you think this should be "Specialist Equipment" then you can start from that template instead.

Set up some reference planes based on dimensions from the catalogue and create an extrusion.  I didn't bother to lock it to any of the planes because I don't intend to make the size parametric.  There is only one size for this product.

Now sketch a void extrusion, flip over to a side view and stretch out the start and end points.  I will probably cut itself out of the solid as soon as you finish the sketch, but if not use the "Cut" tool.  To place the tripod you need to set the workplane, either using pick face, or by naming the angled reference plane to something appropriate (tripod slope?) Once you give a ref plane a name you can set it to be the active work plane by selecting that name. Basic stuff.

You probably need to slide the tripod around a little to get it centred.  You might want to rotate it as well.  Do this in the 3d view, making sure you set the work plane to the one the tripod resides on first.
So that took maybe half an hour.  I loaded it into my project, and tried out 2 different arrangements.  One of them required a centre division.  I won't explain how to make that.  It's just a box. Set up a plan and a camera view on a sheet, added some comments/queries and emailed it to the local installer.

A couple of days later I got a response.  Try another product which has a purpose made end post.  So I made a second version.  This time I have a pdf with orthographic views.  Use the windows snipping tool to make a jpeg of the part I want.  Drag and drop this into the front elevation of the turnstile in family editor.  Scale it up with Revit's wonderful three click resize command.

Edit the extrusion using the front elevation as a guide.  You can delete the void.  Notice that the arms of the tripod appear to he horizontal and vertical in front elevation.
Edit the tripod, left elevation.  Rotate the arm a bit.  Delete the other 2 and restore them by mirroring the first one as before.  Check the side elevation again.  Is that close to a right angle ?  If not rotate a bit more and repeat the mirror routine.  Maybe there is something to be said for a radial array after all, but it only takes a few seconds to do the mirror thing so I stick with that.

I also remade the revolve for the hub.  You could go even further in the search for authenticity, rounding off the edges of the pillar with a void sweep.  I decide to keep it simple.  Then I weakened a little and rounded off the ends of the tripod arms.  Void sweep.  Pick 3d edges.  Pick the circle at the end of the arm.  You will have to pick twice to create to semi-circles.  Finish path.  Draw the profile in side elevation. 

Load it back into the turnstile family.  You may need to adjust the angle of the inclined plane and the rotation of the tripod to get it to read properly in plan and elevation.  Even so it probably won't be perfect.  You might decide to use symbolic lines for the tripod in orthographic views, just to get a cleaner line.

Now for the end post.  Create extrusion.  Draw a circle in plan.  Guess the size.  I made mine from the box I had before, so the height was already set to 990.  The next bit is fun.

Create another extrusion in plan.  Sort of a butterfly shape.  Pure guesswork for the dimensions.  Go into a side elevation.  Create a void extrusion to round off the ends.  This needs to be accurate.  True semi-circles that match the size of the solid extrusion.  Stretch out the ends so that it cuts all the way.

You've made a shape that will act as a rig for a sweep.  Select this shape and uncheck "Visible"  Now the rig will not show up in your project.  You can change it to glass material if that makes you more comfortable, but it really doesn't matter.

Create sweep.  In a 3d view, pick 3d edges.  Go all the way around one "side".  Now you have a path that mimics a 3d polyline.  You can sketch a circle for the profile, or load a circular profile.  I used a sketch.

Repeat for the other side.  Actually I'm not sure that a two-sided product exists, but that's what I needed and I used this family to ask the question.
Shortly after that I decided that 2 turnstiles oriented the same way made more sense, and the pdf I had was showing a recommended spacing for this configuration so why not go for that ? 

Now I'm going to send the manufacturers a link to this post and encourage them to join the global Virtual Design & Construction movement (VDC) call it BIM if you prefer, I usually do.  We are working with a contractor at present who prefers to use the term "Digital Engineering".  Nothing wrong with any of these terms, but I think BIM just slips off the tongue more easily.  That's usually the deciding factor when it comes to language.  Forget the pedantry.  BIM model is easy to say and it gets the idea across.  Get a life.

Sorry about that. 

Dear manufacturer, 
Here is a link to some Revit Families.  At least one of them represents a product that you make.  You are free to take ownership of this family and make it available on your website and via your global network of suppliers.  But make it free.  And even better, consider setting up a web portal that will enhance the flow of intelligent 3d information and ideas between people who are using your products.

Imagine a world where contractors bidding for a job can link to this portal and see the virtual mock-up that you and the architect developed (see above)  Imagine the contractor that wins the job being able to communicate with you and your local trained installer via this same 3d portal.  That world is coming so why not take the initiative and help to create it.  Be a leader and a winner.  Make the world a better place.


by the way, here's a snippet from the actual documentation for the project.  We don't usually describe the product in text right on the sheet like that, but for various reasons we didn't want to reissue the specification ... it's just a workaround to get the job out of the door on time.

P.S.  I have no particular reason to prefer one make of Turnstile over the other, the second version just happened to work on this project and I didn't have time for too much back & forth, so I went with it.  Maybe next time I will use the first one.  Or maybe I will go with whoever puts a Revit family on line.


I've been getting a lot of spam so had to tighten up comments permissions. Sorry for any inconvenience. I do like to hear from real people