An MEP wish

[Conrado Dominguez]

MEP Branch Pipe behavior when START ROUTING is attempted from the end of a Wye or a T

CONDITION –A- Main line horizontal, branch out horizontal, Wye or T horizontal

No problems encountered. START ROUTING allowed snap to end of Wye and 90 degrees takeoff was possible as well as a takeoff on an angle using the guide lines
 

CONDITION –B- Main line horizontal, branch out rotated around ‘X’ axis. Wye or T horizontal

START ROUTING from Wye at a selected slope angle is not possible.
After the start, the only possible move is to introduce a small transition piece, which runs horizontal and then select the slope angle on the routing palette. This introduces an error in the elevation at the end of the pipe rise, when measured from the center line of the main branch since the pipe starts rising at a point away from the center line of the main
 
CONDITION –C- Main line horizontal. Wye or T rotated around ‘X’ to match desirable slope to takeoff

Under this condition, it is possible to START ROUTING at the end of the Wye but only after choosing the “bottom” position to start, then run for a short distance and only then we have the ability to select a slope in the routing palette. Also, if the takeoff slope turns to be less than 4 degrees, results are not reliable.
For accurate work with a takeoff branch at a slope from a Main Line, we need the ability to a) rotate the Wye to the desire slope, and b) start routing from the end of the Wye, with the “starting” branch recognizing and adopting the rotation angle of the Wye or c) start routing from the end of the Wye and be able to indicate in the routing palette the slope to follow.
This will result in a continuous slope from the center of the Main without the need to introduce any piece of pipe before start sloping away from the Main line.

CONCLUSION

From a horizontal or slopping Main line, in which a rotated Wye or T (rotated around the ‘X’ axis) has been placed, it will be highly desirable to START ROUTING from the end of the Wye or T, with the same rotation angle.
I spent many hours figuring out this work around and describing a desirable improvement and hope to see a patch with this implemented, very soon.

Yours truly,
Conrado Dominguez, San Mateo, CA

[Anonymous]

Improvements in this area would be fantastic. Drainage lines are very difficult to model accurately. This is in part due to the inherent difficulty of dealing with multiple rotations and small pitches, but there is much that could be done to improve matters.

While it is presently possible to get very precise routing it take all sorts of special tricks to do what comes easily to even an apprentice plumber.

The rotation of TEEs and WYEs as Conrado points out should be much more flexible and automated. Presently to branch at 1% slope off a main I find I have to start by placing the TEE, then rotate it to 0.6° (~1% slope), then add a pipe to it. Then I can finally stretch it or start routing from the end of the pipe and retain the proper slope to the center of the main rather than having the horizontal offset that results from routing straight out of the main (as Conrado describes).

Another great improvement would be to allow snaps to vertical when running a sloping drain. The current snap to perpendicular I find only useful when running supply pipe in which case perpendicular is vertical. Perhaps this could be accomplished with the shift+Q modifier as it is in plan. I suppose it might also be accomplished with the 3D edit plane except that that is hardly working at all with the piping tools.

Speaking of the 3D edit plane. There are serious problems with this and the coordinates palette when running pipes which are new to AC15. I have reported these problems as bugs but am not clear what (if anything) is being done about them. I don't have time for details, but the edit plane is definitely messing up some actions and the coordinates issues represent a significant loss of function compared to 14.

It also seems that the bends used as fillers cannot get closer than about 1° to 180°. I'm guessing that the code is constraining it to a maximum of 179° to avoid a divide by zero or something internally. The problem is that this often prevents fine tuning adjustments to slightly sloping pipes with the elevation snapping to a few inches to either side of what is desired. I know it seems counter intuitive but these "bends" need to be able to be straight (180°) or very slightly off straight. Since 1% or 0.6° slope is quite common and incremental adjustments of tenths of a degree are often necessary this is very important.

The general limitation of routing only at right angles to a pipe (whether horizontal, sloping or vertical) really need to be fixed. Not just for getting the drain pitches right but also to be able to begin routing from a vertical or horizontal pipe in any direction as may be needed. It seems this could simply be like most other things where a shift constrain can snap the fitting to right angles (or other increments) with numeric input to the tracker for odd or precise angles.

For all these complaints though, ArchiCAD MEP is still far better for drainage work than Revit. Even when the automatic routings are wrong at least you get a result that you can fix or figure a way to redo. Revit often just refuses to make the connections leaving you to keep tweaking this and that in hopes of satisfying its obscure requirements, or putting things kinda close to where they should be and calling it good enough. ArchiCAD also doesn't spontaneously decide to "fix" things the way Revit often wants to.