A Question for Experts/Mathmatical genius needed?

[devoluter]

Hey guys i will try to explain as best i can.

will att some images aswell.

It will help if you know how staircase stringers are built.
I have modelled a staircase for the high street company "New Look".

Alright so far i have done the treads, plate, nosings, SHS posts and straight stringers.

The inside stringer is as follows: Curved (arc) upwards 4 treads, straight along a short platform, then continuing up another 11 treads.

Plan view:
http://img165.imageshack.us/img165/992/stringertopza9.png (http://imageshack.us)

Side Elevation:
http://img505.imageshack.us/img505/3207/stringersidezd3.png (http://imageshack.us)

3D View:
http://img505.imageshack.us/img505/2639/stringer3dai0.png (http://imageshack.us)



I have tried many methods to get this stringer right but cannot seem to do it. Does any1 know the proper method to make a "solid 3D object rising on the x axis while curving on another axis?

Any help will be much appreciated.

[kduck63]

Looking at the bottom picture:

It looks like the blue line 2D stringer lies in the XZ plane... you want to extrude along the X axis?

[kduck63]

Does any1 know the proper method to make a "solid 3D object rising on the x axis while curving on another axis?

Oh... rising from the X axis, or extrude along the Y axis.

Can you just extrude a uniform distance and slice it along different planes.

[devoluter]

Oh... rising from the X axis, or extrude along the Y axis.

Can you just extrude a uniform distance and slice it along different planes.


This is the straight stringer, going up opposite side.



http://img515.imageshack.us/img515/2295/stringer3d2pi1.png (http://imageshack.us)



I need a stringer like this, same thickness, to follow the curved path on our curved side , again while rising.

any ideas?

[devoluter]

Ah yea i messed up axis a little there. in 3d view Z should be facing up as usual. (not y like i have)

[kduck63]

This is the way I would approach it:

Extrude the 2d profile you have. Slice the 3D to suit.

[devoluter]

I get ya. but there is some complications when that happens.

This is what im trying to achieve (drawn in paint)

http://img512.imageshack.us/img512/8706/stringer3dvl1.png (http://imageshack.us)

i can extrude the section (blue) fine. but dont know how to slice the stringer so that the stringer is 20mm above each step and landing, while keeping the stringer a flat 12mm width.

[kduck63]

Draw a 3dpoly line from the nose of the bottom step to the nose of the top step, move that line up 20mm along the y axis. The end points of this line will establish 2 points of your slicing plane and the third point will be along the x axis.

[kduck63]

I guess i am assuming the x axis is aligned with the first step.

[devoluter]

Draw a 3dpoly line from the nose of the bottom step to the nose of the top step, move that line up 20mm along the y axis. The end points of this line will establish 2 points of your slicing plane and the third point will be along the x axis.


Draw a 3dpoly line from nose of bottom step then each other nose untill the top? or just bottom + top?


I guess i am assuming the x axis is aligned with the first step.

you mean the first step is aligned with stringer? no stringer comes 100mm past step, then straight down into floor.

[kduck63]

The nose of the first step to the nose of the top step. These end points will be two of the points that describe the slicing plane. The third point is any point along a line parallel to the nose of the bottom step but 20mm up.

[devoluter]

Ok so what your saying is i should:

extrude the stringer up from bottom level into shape.

Draw a 3Dpoly from bottom to top (nosing or where i want cut of).

now slice the stringer using normal or 3point slice? and select bottom nosing, then top nosing, then a point which is on the same level as the bottom nose?

Doesnt seem to be working correct.
-When i do this the stringer is cut on the best correct, and the top, but in the middle its way of , pic:

http://img125.imageshack.us/img125/9223/tread1ow5.png (http://imageshack.us)


Argh im missing something?

[Pocket]

A single slice wont fix that

Id draw lines along the path you want it to take (green) and use those as reference points for your slice

Slice gives you the option of either keep one side of the cutting plane or keep both. I reccommend you keep both until you have everything cut up

[kduck63]

I'm sorry I was not more clear. Pocket is correct a single slice will not do it. You will need to repeat the process for each set of stairs and the landing. You will then need to union the parts.

[Strix]

you seem to be making good use of paint in conveying your problems to us....

does this mean you've 'eyed in' some of the lines you used to lay out your original map of your staircase?

if you have produced any of your lines by the 'that looks about right' method, you'll get 'compound errors' which just get bigger and bigger as you progress through your drawing

if you've got something that screwy going on in your drawing it's usually quicker and easier to go back to square one and start form scratch than it is to troubleshoot the error

I don't work in 3d - so can you tell us if your lines in your first pic are supposed to look so non-parallel?

[devoluter]

Yes strix, the staircase is "tapered" to look at plan view. its just the design requested.


I have figured it out, what i did was: extruded the stringer up. got my points from each step and put all of these points on the same line (x axis) and drew a 3d poly up thew them, then extruded this poly across slicing through the stringer.

hooray 1 curved, elevated stringer, thanks guys. pic:

http://img406.imageshack.us/img406/5016/newbitmapimageal8.jpg (http://imageshack.us)



now to add glass balustrade + handrail. i will post a pic when its finished.