BILT Speaker

BILT Speaker
RevitCat - Revit Consultant
Showing posts with label winder. Show all posts
Showing posts with label winder. Show all posts

Monday, 6 April 2015

Stairway to Heaven - RevitCat goes to RTC Gold Coast

 
 This year I will be running a Lab Session  titled 'Stairway to Heaven' at RTC Australasia 2015 at the Gold Coast. 

This session will look at ways of making the new Stair & Railing tools in Revit work better for you.  It will start you off on the 'Stairway to Heaven' instead of languishing in the 'Stair & Railing Hell' that most Revit users live in.  *


* Disclaimer:  The aims stated above are of course restricted by the limitations of Revit software.


Stairway to Heaven


In this hands-on lab session I will be teaching new material, not previously shown on this blog, and elaborating on some concepts similar to those already described - including:
  • How to create BCA compliant winder stairs in Revit (Building Code of Australia)
 
  • Using the sketch tools for unusual shaped stairs
 
  • How to make railings do what you want in Revit
 
  • How to eliminate warnings from multistorey stairs and railings
 



So, if you want to learn more about stairs in Revit, and how to bend railings to your will, why not attend the next Revit Technology Conference on the Gold Coast, 14-16th May 2015




Monday, 31 March 2014

U-Shaped Winder Stairs in Revit


In a previous post on Revit winder stairs I suggested that on a U-Shape Single Point winder it is not possible to control the number of parallel treads on the middle section between the two corners of the windersSo you could end up with a stair that has parallel treads on the lower and upper sections but looks more like a balanced winder stair in the middle section, with only one parallel tread.

"Single-Point" U-Shaped Winder
I doubt if anyone would find this acceptable.

Here follows a rather dodgy workaround:

2 x L-Shape = U-Shape

To create a sensible U-Shape winder stair you need to create it in two halves:
  • Start the stair command, and set the overall stair height to be half that you require
  • Go to the L-Shape stair tool
  • Place one as required
 
  • Select the L-Shape stair and make it a Single-Point winder style
  • Set the overall height back to the full stair height required
  • Place another L-Shape winder component - use the space bar to rotate it to suit and snap to the end of the first one
  • It will not create a landing if the two components are aligned (without a gap)
  • You would expect it to automatically start the second run at the correct height
  • But there will be a height mismatch
 
  •  You could try making the lower run not end with a riser and then add another riser to the run - that looks ok but when you finish the stair you get a railing height mismatch
 
  • To solve this you need to keep the lower run ending with a riser
  • Move the second run away by one tread
  • Notice that the riser numbers are different - they need to be the same
  • Drag the blue dot at the top of the lower run to add another riser
  •  Adjust the number of parallel treads on each run (if you can!)

  • When you complete the stair, the railings should now join each other at the same height;  but the balusters will not align to each other without adjusting them - if you can understand the baluster settings in the railing type properties !
  • Note also that the railing heights are not consistent - they are not even close to being the right angle to the run of parallel treads between the winders, nor the right height above them.
 

That is about as good as you can get with the railings, but at least the stair itself has the correct heights - assuming that your building code allows 3 winders on each corner.

If you try to put a one-tread-width gap between the two runs, and then join them with a landing, it might look almost ok . . . . .
Until you complete the stair and look at the railings, which attempt to put in horizontal or vertical sections for the landing
These railings are going to need some serious fixing up!!!  I'll leave you to figure out whether it is possible or even worth attempting it.

And if you want stringers on the stair you get a whole new headache.
So my recommendation is to use this workaround to get the plan working, but if you need a true 3D representation it isn't going to work well enough in most cases.

Thursday, 26 December 2013

Winder Stairs in Revit 2013

Revit Stair By Component


Revit 2013 introduced the concept of stairs by component.  Two of the new stair run component types were for creating "Winder Stairs".  

Winder Stairs

 
When I first tested these new tools I really struggled to get them to work at all, let alone well. I suspect that many people have since tried and failed to use them successfully. Here are a few tips that might help:
  • It is recommended that you only attempt to work with winder stair components if you have plenty of time and patience!
  • It may be more efficient to start a stair as a winder component but convert it to sketch as soon as it starts wasting your time.
Depending on which country you are working in, two different winder styles may work for you:
  • in Continental Europe it is common to use "balanced winders";
  • In Australia they are not suitable, so you need to use "single-point winders".
In Revit it is relatively easy to create a stair with 5 winders; but it is extremely difficult to adjust it down to only 3 to create a legal winder stair for use in Australia ( the maximum in the BCA) - it takes a lot of fiddling around with dimensions.

L-Shaped Winders


This requires just one mouse-click to place the start of the run, in the orientation shown in the tool icon.   
  • You can mirror the run before placing it, by ticking the “Mirror Preview” box on the options toolbar ;   
  • You can also rotate the stair by pressing the spacebar before placing it.  
  • It places the run with the number of risers you have set, depending on the full remaining stair height required; alternatively you can override the number of risers in the overall stair instance properties before you place it, then set the number back to the full number afterwards.   
  • There are two styles of winder stair available – “Balanced” or “Single-Point”
Balanced Winder Stair
Single-Point Winder Stair
  • Balanced winder stairs generally have angled risers spread over most of the stair – the change in angle of each riser is incremental.  These are commonly used only in continental Europe.
  • Single Point winders generally have parallel risers for most of the stair, while the angled risers are concentrated around the change in direction, with only a few winders.  These are more commonly used in the rest of the world, outside Europe.  This implementation of single-point winders has many limitations, and is very difficult to work with – it is impossible to create a stair with only 2 winder treads;  it is difficult to achieve only 3 or 4 winders.  The main reason for this is that the number of angled risers is controlled by setting the number of parallel treads.
 

  • This system works ok for balanced stairs, but for single-point stairs you actually want to define how many winders there are, but you are forced to do the reverse and calculate how many parallel ones you need in order to achieve it.

To place a single-point winder:

  • First set the desired height and run width properties;
  • Place a winder run, accepting the default layout;
  • Change the overall run lengths using the arrow shape handles;
  • Change its properties to a single-point winder;
  • Increase the number of parallel treads for each leg, but do it incrementally so that you can tell at which number it fails;
  • Fine tune the overall run lengths – place reference planes so that the shape handle arrows can snap to them (the only way to control it - important step).
 


  • It is almost impossible to control the location of the setout point for the winders – it seems that it has to be outside the run, not on the edge of the run as is normal in Australia.  The closest it will go is 26.35mm from the inside corner (in each direction), or 0.8mm in one direction, and 51.7mm the other. 
  • NB. when placing a winder stair, if you have just ticked the Mirror Preview  box, you may need to get the focus back on the main canvas before pressing the spacebar (use the middle mouse button to do it).

 U-Shaped Winder


These work in a similar fashion to L-shape winders.   If you use a balanced winder, Revit will balance the entire stair layout around the three legs of the run - this may work for you?


Single Point U-shaped winder stairs do not have any way to control the number of parallel treads in the middle section of the stair – thus rendering it completely useless unless you only require one parallel tread!
 
There is a rather dodgy workaround for U-Shaped Winder Stairs although the railings never really work properly

 

Modifying L-Shaped Winder Stairs


Single-point winder stairs are very difficult to work with and modify in Revit - so you may need help!  Balanced Winders are not discussed here as modification is somewhat simpler.


Once you have created a Single-Point winder stair, most likely you will have set the number of parallel treads on each leg to as high as Revit will let you (to keep the number of winder treads down to just 3).
 



Almost any subsequent change that you try to make to the winder run will result in an error message saying that it cannot be done. 
For example, if you try to adjust the number of treads on each leg of the winder by dragging an arrow shape handle at the top of the run, you will get an error message:
 


Most likely this is because it cannot deal with the adjusted number of parallel treads – it is trying to add a riser to the top, and remove one from the bottom of the run;  but the number of parallel treads at the start is set in the properties so it just fits into the run before the winders start.  When you try to change the run, it can no longer fit that number of parallel treads before the winders start. 
Solution:
The solution to this is to reset the number of parallel treads back to 1 or 2; 
 
Then make the change to the run (by dragging the top shape-handlle arrow for example - this will shorten the lower part of the run, and reduce the number of parallel treads again)
 
After that you need to reset the number of parallel treads to what will fit – it may not be the same as before, so you may need to recalculate how many are required.
 

This technique will probably be required for almost any change that you need to make to a single-point winder stair, including changes to stair width, height or dragging any shape-handles.

Shape-handles
The arrow shape-handles at the top and bottom of a winder stair behave like other stairs.  However,  it seems different because a winder stair does not usually have landings.  On a stair with a landing, dragging the arrow handles will move the stair ends by increments of one tread;  on a stair with no landings the shape handles allow free movement (no increment snapping) - hence the need for reference planes to snap to.

The square shape-handle in the middle of a winder will adjust the location of the selected leg of the winder - it moves the leg sideways, and as a result will adjust the length and end point of that leg while the other leg does not move (its end point stays fixed).  If you have a single-point winder, you will almost certainly get an error message if you try to drag it (refer to solution above).

Temporary Dimensions
Winder run lengths cannot be changed using the temporary dimensions - therefore it is wise to create reference planes so that you can snap to them when dragging shape handles.