I need to fabricate a bench as shown in the image attached. I have extracted all the profiles in the attached Rhino file. The material that I have available are planks with a cross section of 275mm x 6000mm that I need to cut my bench sections from. Is there a way to automate this process instead of manually overlaying the plank profile over the bench profile and making the cuts? This could save me a ton of time Bench Profiles (3.3MB)
Check the size of bounding rectangles without clearance if you want. IMO, enough length but too narrow plank for fitting.
BoundingRectangles.gh (682.5 KB)
2 Likes
Hey. Thanks for replying.
The width of the rectangle has to stay fixed. The length can be cut shorter and flown along the shape like I’ve shown in the attached image. Every shape has to be cut in a way that they fit inside the rectangles and the cut pieces don’t overlap with each other.
You think there’s a possible solution to this?
If I were you, I won’t use that method because it will be difficult to ensure the quality of the final results.
And it’s going to cost a lot more labor work.
You’ll have to choose whether to waste materials and get quality or put in more labor and risk uncertain quality.
It would be better to attach the boards with each other in the direction of the length to get the width.
What you’re saying does make sense. I might have to consider using some other material that allows me to cut each of these profiles in a single piece.
But, just for the sake of experimentation, do you reckon it’s possible to automate the cutting of these profiles to fit rectangles of a fixed width and variable lengths in a way that the pieces don’t overlap?
Of course I think it’s possible. Perhaps using only GH can be a difficult task. May be some sort of coding is necessary.
If I were you, I would first nest the section profiles and then try to cut them using a very wide plywood or MDF board. Because it is a rather economical and the result would be decent enough.
Hi there,
Maybe you could try this?
I did try myself but seems to fit your nesting goal.
How closely do you want to match the original photo? Looks like the orientation of the planks is along the length of the bench, not front to back. If you are prepared to consider a different approach that would allow you to consider steam bending or lamination. IMHO that would look better than joints.
But if you are going to have joints then you need to consider the alignment of those joints as part of the aesthetic, and that would affect how you place your rectangles.
I did consider using MDF, but my profiles are 3400mm in length whereas MDF comes in 1200mm x 2400mm units here commercially. Now I could split the profile into 2 pieces and join them, but I don’t know how strong an MDF joint really is. Since this is a bench and would have to carry additional load, I can’t take a chance with strength.
I’m not that great at coding yet, so I might just have to do the cutting manually. 
I use OpenNest quite often actually. After the profiles have been cut up, I’d use OpenNest to place them inside the rectangles and send the drawings for machine cutting. So nesting would be my next step but, before that, I’d still have to cut the profiles into smaller pieces that can fit inside the constraints of the rectangle.
It’s an interesting idea but I think it might be an even more complicated operation to conduct with good quality.
You’re right. I can’t just place the joints just anywhere. There has to be some sense to that as well.
IMO, your image is not real, but a redering maybe, but if the section profile(Rib)that will be that thick, you should think about materials other than wood.
If only the outer finish is possible with printed sheet(which means fake wood), there would be a wide variety of the materials you can choose.(ABS board, HDPE, Plastic foam with honeycomb paper core, etc…)
Yea, I just did a quick render to help you visualize my situation better.
The thickness of each profile is 35mm. I also reduced the width of my profiles from 200mm to 100mm so that I can have longer pieces and fewer joints. That should help with the strength and also save me some time possibly.
That seems reasonable thickness, but your rendering looks almost 150mm thick.
How do you plan to join the pieces? Do you need to allow overlaps in your plank placements to provide material for the joints?
Nah. I would do a biscuit joint instead.
If anyone is sitting on this, biscuits at small butt joints are probably not good enough. To do this in a way that’s structurally sound, you’d need to use some kind of tenoning system between the parts, like a Festool Domino, and probably you’d get better results by tenoning first, which would then make for a fun and tedious process of placing the workpieces before CNC cutting.
If you can double up your planks on top of each other for each curve, you can have the divisions on the first layer offset from the divisions on the second layer, and use dowels on faces between the layers to align the parts. That can be automated much more easily.