Hi Paul,

This is quite a complex project and will need some thinking to get all the details sorted out.

Firstly I would suggest that you make 2 separate stairs.

Combining both stairs will make it too difficult to work on the manufacturings details.

In general it will be better to work each stair individually and for client presentation  export the 3D dxf file to SketchUp.

If possible, I would also try to avoid modelling the first floor  attached to the stair.

I’m actually away from my office so can’t give you a detailed review just now.

Can I suggest that you repost you project as separate stairs and I’ll look at it again ASP

cheers,

Ness

Hi Paul,

Nice to hear from you again.

Your stair looks good.

StairDesigner will draw the string developments so you can use them to mark out the laminates for the curved section.

For some gentler curves, cutting the handrail from the top of the stringer makes perfect sense and can save a lot of time.

However, in your case things are a little different and there are 3 major points you have to beware of.

StairDesigner will draw the inner face development so you’ll have to draw yourself the outer face that will of course have the same rise but will be longer and therefore be at a different angle.

On a tight curve like this the variations can be significant and make gluing up quite tricky so it’s always necessary to add plenty of extra material width.

The second point is that StairDesigner calculates the handrail at a vertical height of 900mm from the step nosings.

Although this is hypothetically right you’ll find that moving down a quickly descending curve the handrail will seem to be very low.

This is a sort of compression effect that gets more accentuated as the curved section gets tighter.

For this reason I would suggest that the handrail be raised around the curve. The exact height is not very important but it might  be necessary to add easings either within the curve or, usually better, on the straight sections leading into the curve.

And this leads to the third point. Because of the varying height and the handrail not strictly following the string, that is already tightly curved with a steep slope creating long and wide laminates, it might be easier to make the handrail separately. Making a separate laminated handrail using the same form, allows you to build in plenty of lee way for cutting an elegant shape, as well as eventually incorporating easings.

I’ve written a couple of articles on a similar stair I built here:

https://wooddesigner.org/farm-…..-building/

https://wooddesigner.org/quick…..tallation/

https://wooddesigner.org/insta…..-handrail/

Otherwise your model looks OK. I’ve just one remark, Your step and riser penetration is actually 30mm, isn’t this a lot?

Personally I would only use 15mm.

Hope this is helpful.

Ness