I have another family download to help out with hydraulics services documentation. This time around, I have an ACO H100K Slab Drain.
This family has a little more smarts than the Steibel Eltron that I posted earlier and shows that with a little bit of extra thinking you can produce quite powerful Revit families. This time around you can adjust then length and grade of the drain. The grade can be controlled by entering the grade i.e. 200 for 1:200 and then the family will calculate the angle that it needs to tilt. You can also override the grade if you require the trench to be flat.
So how do you convert grade to an angle in Revit? Do you remember sitting in your high school maths class telling everyone “What am I going to ever use this trigonometry stuff for?” well, this is one of those times. If you check the Revit Forum post Revit formulas for “everyday” usage there is a handy reference about halfway down the page showing formulas for trigonometry.
In the instance of this diagram, we know that 1:200 is 1mm of fall to 200mm of run or “rise over run”, in the case of our diagram above a = 1 and b = 200, and from that we can calculate angle A.
To perform this in our Revit family, I have created a parameter named GRADE_RATIO_1_IN which allows us to enter our grade and the parameter CALCULATED_ANGLE which is the result of our calculation, or the angle of tilt required.
So what we end up with is:
GRADE_RATIO_1_IN = 200
CALCULATED_ANGLE = atan(1 mm / GRADE_RATIO_1_IN)
Which gives us the result of 0.286°
To add the flat grade, I have included a check box associated with the parameter IS_FLAT to then allow that to override the angle, I have changed the formula of CALCULATED_ANGLE to
if(IS_FLAT, 0°, atan(1 mm / GRADE_RATIO_1_IN))
which sets simply sets the angle to 0° if the checkbox is ticked.
To allow the family to tilt, I have used reference lines and an angle parameter associated with a circular reference line as outlined in great detail at The Revit Complex in the fantastic article Rotation Rigs That Do Not Use the Angluar Dimension. In this particular instance, I nested the 3D face based family and hosted it to my reference lines.
Finally to round the family out, there is the obvious adjustable trench grating length with grips and the option for HDPE (110 dia) or PVC (100 dia) pipework connections.