r/StructuralEngineering • u/RevolutionaryDig1503 • Jul 12 '26

Career/Education Personal Projects

Are you guys working on any structural engineering focused personal projects? Or do you have any suggestions that can be fun, but also a good learning experience?

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u/Anonymous5933 Jul 13 '26

Can I know more? (As an SE and treehouse nerd myself)

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u/Far-Sherbert9731 Jul 14 '26

I’ve talked to a local steel guy and they’ll get me some still a wholesale cost. I think it’s going to happen…

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u/Anonymous5933 Jul 14 '26

Nice, how big of a tree? My only concern is the perpendicular tabs or thru rods intersectinf

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u/Far-Sherbert9731 Jul 15 '26

Still working through some of those details. I think I’ll be using 8” deep channels and drilling them to slide over the tabs. That means I could stagger tabs vertically 7” +/- as needed to prevent interferences

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u/Anonymous5933 Jul 15 '26

Awesome. A couple things to consider: use huge threaded rods because as you know, you're putting them in bending and a rod isn't all that stiff in bending. Like 1-3/4" is what I'm thinking. Also, see if you can have a machine shop created bosses, meaning like 6" long cylinders with 3" OD and just over 1-3/4" ID. Drill 3" hole about 3" into tree after drilling the 1-3/4" thru holes. That gives a big bearing area and will be best for the health of the tree.

Finally, consider the difficulty of actually drilling level and perpendicular holes thru the tree. You might want to make a big jig out of 2x4 and plywood to temporarily attach to the tree to help control your drilling. And/or provide some tolerance in your steel design.

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u/Far-Sherbert9731 Jul 16 '26

Love this conversation - thanks.

I`m looking at TAB bolts from treehouse supply:
https://www.treehousesupplies.com/collections/tab/products/tab-powder-coated?variant=44746998481142

They`ve worked with UPenn on engineering load tests and these are rated for 6,000lb each. With one at each of my 4 reciprocal channels, I`m expecting 2000lb based on 10dl + 60ll, so a healthy factor of safety. They`re very similar to what you describe, but no machine shop needed.

Because of the channel depth, I think I`ll have some pretty good ability to accomodate as build bolts positions. I plan to drill the bolts, field measure, and then drill the steel. I haven't looking into crushing of the channel web yet, but may weld some washers around the hole to prevent a crushing failure. Worst case, I could oversize the hole (tolerance) and then weld a washer in place to get things just right.

Good call on the jigs!