Straight Ramp with Start/End Ascent - Object Problem?

[Anonymous]

Hi everyone

In ArchiCAD 11, I am trying to create a straight ramp with start and end ascent (ie. variable slope angle). The ramp is 31,200mm long and 4550mm wide, and the ramp connecting the upper and lower floor is 3300mm high in total.

The ramp object allows me to define the length of the start/end ascents, which is 3,00mm long. I intend to have a 1:6 slope for the ascents. However, the ramp object does not allow me to imput the exact slope, and calculates it as 5.85. The value is greyed out in the settings, and does not allow me to change it.

I am not sure if this is a bug, or simply how the ramp object behaves. Does anyone have any idea about this? Thanks!

[Anonymous]

Shingo: AFAIK the ramp slopes are generated by the length of the breaks and the height of the ramp total. The part then calculates the various slopes. By setting the length segments, you get the value of the elements that are greyed out.

Lew Bishop
MBP 2.16 17"
OS X 10.5, AC 12

[Anonymous]

LewBishop wrote:
Shingo: AFAIK the ramp slopes are generated by the length of the breaks and the height of the ramp total. The part then calculates the various slopes. By setting the length segments, you get the value of the elements that are greyed out.

Lew Bishop
MBP 2.16 17"
OS X 10.5, AC 12

Hi Lew thanks for your info.

That said, this means that the object will automatically calculate the slope angle, based on the ratio in the length of the segments vs the total height.

However, when we design ramps, often the slope angle (or slope ratio) is kept in check by the local building codes, where a minimum/maximum slope ratio is stipulated.

With the ramp that I am trying to create using the ramp object, I have calculated exact slope ratios based on design guidelines given. I need an exact slope ratio of 1:12 for the 3m long ascents, and the in-between portion between the ascents to have a 1:9 slope ratio.

Unfortunately, I was unable to achieve this with the ramp object, which has decided to calculate the values for me. The object gave a 1:5.85 slope ratios for the 2 ascents, and a slope ratio of 1:11.7 for the in-between.

This is quite sad because I like how the ramp object creates the upstand and parapet wall for me, which is quite troublesome to model.

[Anonymous]

Looks like we need to have other parameters to make your ramp correct. There are several ways to get it to happen: you can learn a little GDL and program the ramp to allow for user input, you could, since you calculated the segments already, make the sections from roof tool segments and, provided you use the same materials, the segments will join as if they are one. This is the way we had to build ramps in the past as a ramp tool was unavailable.

Good luck!

Lew Bishop
MBP 2.16 17"
OS X 10.5, AC 12

[Anonymous]

Shingo,
If the ramp object does not work for you maybe you could
make the ramp with complex profiles or Trussmaker. Both
give you the control you need to model the ramp correctly
and both can have smooth transitions unlike the roof tool method.
Peter Devlin

[Anonymous]

Hi Peter

Thanks for your suggestion. Anyway I guess I would have to use the roofs or profiler to do it, as we had been doing.

However, seeing the object come so close to achieving what I need, it really feels like a kick in the stomach when I was using it.

I thought that Graphisoft should take note of this, and modify the GDL script to add this feature.

[Ralph Wessel]

Shingo wrote:
Anyway I guess I would have to use the roofs or profiler to do it, as we had been doing.

Take a look at OBJECTiVE too. It will enable you to draw the cross-section through your ramp and dynamically rotate/bend/cut the ramp to the exact shape you require. You can find out more at: http://www.encina.co.uk/objective.html

The first example clip demonstrates modelling a ramp: http://www.encina.co.uk/obj_bend_movie.html

[Anonymous]

Hello Shingo,
After I looking at the ramp object you were trying to get to work,
I became intrigued with the object and decided to rewrite the scripts
so that the object was controllable by the user without the automatic
reseting of the parameters. I started with some assumptions about
how ramps had to be designed and concluded that they are just
like stairs where one must know the floor to floor height and the
code requirements for rise and run at a minimum and the total
length is determined by these factors. The person who wrote
the ramp object had this all backwards.

I re-wrote the code for this object and wondered if you would be
willing to evaluate it and see if it is more useful than the old one.
I should point out that I edited the AC 10 version of this object
which does not have a "Straight Ramp Settings" pane
Thank you,
Peter Devlin