17 votes
Accepted

Would this TV stand made almost entirely of 3/4 in birch plywood withstand the load?

If you build this right I think you could safely park a motorcycle on top of it. And no, I'm not exaggerating. A (very large apparently!) TV and soundbar should not pose any risk whatsoever. As ...
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  • 59k
16 votes
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How can I determine the load capacity of a simple bench?

The 4x4 posts used for the legs support virtually "infinite" weight longitudinally. Now, of course, given a naive design, each leg would only transmit force onto one 4x2 beam (which are then maybe ...
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  • 3,825
14 votes

How can I determine the load capacity of a simple bench?

When determining the load bearing capacity of any structure, you'll need to take into account several different factors: Acceptable deflection Maximum allowable bending stress Column compressive and ...
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  • 4,328
13 votes

How do I calculate the weight threshold for plywood boxes/cabinet carcasses?

The sagulator will give deflection values for horizontal shelf spans using various materials and thicknesses. Unless you are working with extremely heavy loads (more than the weight of a countertop ...
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  • 18.6k
11 votes

How can I determine the load capacity of a simple bench?

Just to find the load bearing capacity of the horizontal bench top, I'd treat it like a shelf and run the numbers through some sort of load-bearing calculator like the sagulator. The load-bearing ...
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  • 18.6k
8 votes

Would this TV stand made almost entirely of 3/4 in birch plywood withstand the load?

3/4" plywood is VERY strong. I have some on a shelf in my shed holding my turning wood, I used full 4'x8' sheets and I have several hundred pounds on it. no dipping. I also have some 1/2" ...
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6 votes
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Will my table top hold 300 lbs?

You haven't shown the leg arrangements, so a more immediate problem might be racking forces. That is, depending on how the legs are attached and arranged, a ~300lb. weight on the top may cause the ...
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  • 6,194
6 votes

How much could I load on to this cabinet? Should I reinforce it?

TL;DR: Maybe, but I don't think we can tell you. This probably cannot be answered, at least fully. It depends if you want to think like a woodworker acting as an engineer, or an engineer acting as a ...
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  • 6,194
6 votes
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Can I enlarge this wood rack without beefing it up?

Firewood stacks pretty well, so there shouldn't really be any load acting sideways on the upright supports, even with a much wider (longer?) rack. Additionally, you're only making it taller by about 5 ...
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  • 2,612
4 votes
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Weight bearing for a loftbed and wood only joints

I see three inherent weaknesses, two of which critically compromise the strength of the bed. I'd suggest looking at commercially-produced solid wood bed frames for some design ideas (don't look at ...
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  • 18.6k
4 votes

Pull-Up Bar - Wooden dowel - 1.25" actual diameter

TL;DR: Use a metal pole. Commercial dowels are not a good material to use for pull-up bars. The supports for the metal pole can be wood. I'm going to take the unpopular opinion and suggest that random ...
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  • 6,194
3 votes

Pull-Up Bar - Wooden dowel - 1.25" actual diameter

I don't know how to calculate it, but it passes the sniff test when compared to parallel bars used in gymnastics: These are made of (unspecified) wood, are 11.5ft long and 2 inches thick. They are of ...
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  • 3,809
3 votes

How do I calculate the weight capacity of my one side supported bookshelf (Spine Booshelf?)

Your design raises some interesting issues and requires additional consideration for connections. Each shelf is supported at only one location and the actual load on each shelf is not the only ...
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  • 7,854
3 votes

Weight bearing for a loftbed and wood only joints

Rob's concerns are important. When you calculate the load that the main beams will carry you must ignore the depth of the notches and calculate the sag/load based only on the depth of the continuous ...
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  • 7,854
3 votes
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Canopy bed frame design supporting a suspended adult?

What you have described is a swingset with a mattress connected below.To design this hybrid fabrication you must first consider each function separately. For the swing, consider the designs for ...
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  • 7,854
3 votes
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How to increase maximum load capacity of a table?

First of all, the 110 pounds they say for that desk almost certainly is being very conservative, it will probably actually hold at least twice that. That being said, we can look at the ways it can ...
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  • 8,026
3 votes
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How much weight can this stand hold?

I would not recommend using this table for a fish tank. There are too many potential sources for failure. If the tank rests upon the 3/4" top instead of extending to the width and length of the ...
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  • 7,854
3 votes
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For a kid's balance beam, which way should the grain face?

You want the grain/growth lines to be oriented vertically to maximize strength. Most 4x4 posts will have curved annual growth lines. Choose the orientation that is most vertical. As a caution, note ...
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  • 7,854
3 votes

Load Bearing Weight Capacity of a 3/4" x 3/4" Wood Molding?

While your concept can certainly work, there are several considerations that will help it perform well. Wood species. A softwood is not nearly as strong and will be more prone to splitting ...
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  • 7,854
3 votes

What is the minimum thickness of plywood needed to support an adult on a 38" span?

As long as you still plan to use the slats, you can go pretty thin with whatever material you put over them to smooth out the spaces between the slats. 1/4" plywood should would work fine.
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3 votes
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How to use Sagulator for Sofa / Bed?

The weak point is the front, in the middle of the sofa (and correspondingly, the middle of the bed on the seam). You could fix the sofa with lumber on edge underneath the ply, but that doesn’t fix the ...
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2 votes
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What is the minimum thickness of plywood needed to support an adult on a 38" span?

I would suspect that a 3/8" would be enough. If you want to screw your slats to the bottom of the plywood, you could use the 1/4" plywood. 3-4 slats would be enough to stiffen up the 1/4" to handle ...
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  • 15.1k
2 votes

How can I determine the load capacity of a simple bench?

You can always take the Calvin & Hobbes approach!
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2 votes
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Convert a minimalist bench design into a desk

Are any structural concerns with making the table this long? No. Even with a top much thinner than you're going to end up with you can have a >100" span. Would the table need to be reinforced ...
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  • 59k
2 votes
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What Screw Should I Use For Fasten a 3/8th Steel Flat To A 4x4?

I would like them to lay flush against the steel flats This will be the role of countersinks you make in the steel rather than determining what screw to use. Note however that if you decided to use ...
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  • 59k
2 votes
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How do I calculate the weight capacity of my one side supported bookshelf (Spine Booshelf?)

How do I go about figuring out how much weight each shelf can support? Based on what follows this becomes sort of irrelevant, but if you did want actual numbers the only way I can think of ...
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  • 59k
2 votes

Is this desk structurally secure?

It's unclear if this question fits within the purview of "woodworking", and we are only guessing that you are asking "will this walnut stave top split under load or because of fasteners?...
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  • 6,194
1 vote
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Weight limit of IKEA Lagkapten/Alex desk

I think this should be fine, but as mentioned in the Comments you'll want to assess for yourself. While the knockdown fasteners that Ikea use here are not noted for being a super-strong way to put ...
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  • 59k
1 vote

How can I figure out how much weight a piece of wood will be able to handle before breaking?

In evaluating if the members in an assembly will be adequate, it is important to consider both the individual pieces, the connections and geometry of the entire project together to determine if it is ...
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  • 7,854
1 vote

Weight capacity for 3/4" plywood curvy board

You will be making these in batches of some sort, even if it is an evening of 2-3 items. Semi-regularly you pick one at random and test it using a test platform of some kind. Ideally you want to know ...
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