Intersection of two steel channels at an angle

Morning all, I don’t use SU that often, purely hobby so please forgive my simple (for some, not me LOL ) question. I’ve got a 10" channel landing that I’ve also got 10’ channel steel stringers intersecting with the landing at the stair angle. I can’t figure out for the life of me how to trim the top of the channel so it intersects correctly with the vertical side of the channel.
The top landing end of the stringer would be flush to the top of the platform with the vertical edge of the stringer web trimmed to intersect with the vertical web
of the platform.
The bottom landing would be trimmed almost the same but with the top flange landing on top of the channel.
My apologies for such a rudimentary question, I have tried to solve it myself but was getting frustrated :slight_smile:
SU make 2017
Platform.skp (64.1 KB)

@Mrmikey, I’m not sure about the angle of Component#7 in your model and where it is supposed to connect at top and bottom. But it’s great that you used (Solid) groups and (Solid) components.

If you enter a group or component and then select all its geometry then → ‘Intersect Faces → with model’ you’ll end up with new geometry (edges) inside that group or component.
Repeat that sequence of operations for all groups and components involved.

Then enter the groups and components again to clean them from unwanted geometry.

Hi WoDan and thanks for the reply, you’re going to be sorry you replied :slight_smile:
I’m getting extremely frustrated here LOL. If you look at the screen shot, (I’ve hidden the platform frame) you’ll see the two layout lines I’ve marked “cut here” but for the life of me I’m drawing a blank

Platform 4.skp (112.8 KB)

To begin:
Your 10’ channel is not angled right. (see image 1 below)
It should have a face perpendicular to the green axis. (see image 2 below)

I temporarily split the lower landing structure.
Also I lowered the 10’ stringer to “connect” its corners (top and bottom) to the upper landing resp. lower landing.

This should be the start for modeling and trimming the stringer.
Do yo agree?

I would probably use Follow Me for this. Way easier than intersecting diverse parts. If needed, the result is easy to split to parts.


Thanks yet again Wo for the reply.
OK, understood, that was a definite mistake on my part. I did intend to draw it perpendicular to the axis.

I> temporarily split the lower landing structure.

Also I lowered the 10’ stringer to “connect” its corners (top and bottom) to the upper landing resp. lower landing.
Yup, understood what you did. My reasoning for doing it the way I did was the upper and lower landing were a fixed height and had to remain where they were. Not a real life scenario, just trying to demonstrate stair structure for someone.
The stringer channel I drew connecting the upper and lower landing, was drawn an arbitrary length longer than what I wanted with the intent of trimming and coping them to fit the upper and lower landing. The thinking was it would be the easiest way to do it. Shows you what I know right LOL.
The reason the upper end was drawn above the top height of the upper landing was to give the stringer a ‘horizontal nose’ for attaching a vertical pipe for a railing once the top end of the stringer was cut off and capped horizontally the same level as the upper landing.
The lower end was drawn where it was in relation to the landing so the first step would overhang the lower landing deck so there’d be no vertical opening for a foot to go thru.

Thanks Anssi.
That’s an option also, one that I never considered. You have an upper and lower horizontal crank on the stairs. Would follow me be an option where the stringer immediately starts to angle downward from the face of the landing without the cranks?.
Appreciate the help guys, thanks again

Depends on whether it needs to be a bolted construction:

As an architect I would line the end caps and bolts along the dividing line. An engineer might disagree but it is neater…

I agree that it would look better from this side (shown). But there’s the landing profile and the other side of the stairs that might not look so nice.
Meaning that I would go for neither one if the dividing line is “inside” the landing area.

Either a welded solution (according to ‘Follow Me’ and a weld seam at the dividing line) or a bolted one with flanges but with a more elegant choice of profiles.

My “solution” here was more from the SketchUp perspective. Not quite how I used to work together with architects and contracters. I’ve always tried to go along with their presented designes as long as they were feasible.

Didn’t really have to be either, I was trying to show a friend of mine an idea for landings and stringers and how to connect them.

That’s what I was after and I definitely appreciate the ideas from all.

I agree, sometimes it’s a lesson in futility trying to understand what an architect expects you to make and what the reasoning is (speaking from a builders perspective :slight_smile: ). I’m sure they think the same thing about builders as well. Someone always has a "better’ idea LOL.

A fella I used to work with was death on engineers, had no use for them. His favorite saying was: " Engineers, they can give you the square root of a pickle but can’t tell you how to get it out of a jar". 90% of the engineers would take it like it was meant, in good humor, others would go off the deep end.

Again all, thanks for the help


That made me snort hot coffee out my nose! :rofl:

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LOL, that was your morning wake up call. BTW, coffee makes keyboard keys stick :slight_smile:

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Fortunately I was reading your post on my phone. :smiley:

ha !
I could write books about builders and architects, one “fat” volume each, don’t get me started.
We all are different species, Darwin figured that out some years ago.

Something along these lines?


Yes. #4 resembles #6 the most. A swing set and an ordinary tire hanging from a tree branch.

What is #3 about? And #5? Oh my g.d!

You can make each channel a group then use a tool like Medeek Tools which has a trim feature. That is how I do it. It is quick and easy. Otherwise you can draw a rectangular face and use the intersect with selection command (right click) then erase the geometry you don’t need.

Thanks Tony but for a limited one time use it’s not worth it to me. If I was going to make a career from Sketchup I would consider it.

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As an alternative you can use a Life Component like this one and or create your own based on same principle.


This Life component created by simjoubert is available HERE or on 3DWH HERE

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Have you tried the native solid tools?