does anyone know the length of the chain on the stage in CRESENDO? as far as i am aware it is not given in the manual.
You can find it on page 27
“3 chains, designated STAGE Left, STAGE Right, and Center STAGE, as shown in Figure 5-9, span the space between each STAGE truss leg. Chains attach to each leg via a carabiner, eye bolt, and mounting gusset 4 ft. (~122 cm) above the carpet. Chains droop such that their lowest points are 2 ft. 4¼ in. (~72 cm) from the carpet, and the chain rests 1 ft. 4⅝ in. (~42 cm) from the face of the STAGE core. The chain is ¼-in. Grade 43 zinc plated chain.”
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The exact length is not mentioned.
It probably will not be set, as the critical measurements are the distance between the truss legs and the height from the carpet. There will be some variability as the distances will not always work out to an exact chain link length.
That being said, ~5.05’/60.6"/1.5m (not including the length of the carabiners and eye bolts, is my best calculation. Thanks ChatGPT
"In this case, you can use the Pythagorean theorem again to calculate the length of the chain. The formula is:
[ c = \sqrt{a^2 + b^2} ]
where:
- ( c ) is the length of the chain.
- ( a ) is the vertical distance from the attachment point of the chain to the lowest point of the chain.
- ( b ) is the horizontal distance from the attachment point to the wall or support.
Given the information provided:
- ( a = 4 , \text{ft} - 28.25 , \text{in.} ), which is equivalent to ( 4 - \frac{28.25}{12} ) feet.
- ( b = 4 , \text{ft} ).
Now, plug these values into the formula:
[ c = \sqrt{\left(4 - \frac{28.25}{12}\right)^2 + 4^2} ]
Calculate this expression to find the length of the chain:
[ c = \sqrt{\left(3.08\right)^2 + 16} ]
[ c \approx \sqrt{9.48 + 16} ]
[ c \approx \sqrt{25.48} ]
[ c \approx 5.05 ]
So, the length of the chain is approximately (5.05) feet.
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chain is going to be a catenary curve.
Chat GPT has a long way to go.
from the stage at home game element document:
Carabiner (McMaster 3216T41 or similar) – 2 Pieces
Stage Chain (Grade 43 Zinc Plated Chain, 1/4" Trade Size) – Approximately 108”
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I was curious about the length of the chain between the trusses. Obviously with it being slacked its not an exact length, but we can’t find a distance without doing unnecessary math!
Does such a thing exist?
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For me, there is LOL
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Side question, is this is same chain and links we got in 2021 for game design. If so teams might already have a small section in house.
It isn’t in the manual, but it is given in the official game drawings. On page 93 of the full package, we get this:
So the length of the chain is 108 inches.
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IIRC, there is a carabiner on the end, so closer to 110" I think when installed. The catenary math says ~110.1 or so.
If you look at the field CAD you’ll see that it’s not attached at the last link. I imagine the effective length will be adjusted so that the dimensions given in the manual are met. So there could be a few links unused at both ends.
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This thread does bring up the interesting point about how the consistent the height of the chain will be. The FRC manual gives an exact spec, but no indication of what range around 2’4.25" will be considered acceptable.
I ran some rough calculations based on a catenary curve. What I got was:
When placed under tension at the center of the chain at a single point (so chain forms a shallow V), the droop is ~22" (vs ~19.75" when slack).
When placed under tension at the center of the chain by two points 26" wide (such as the back of a robot, or two robots), the droop is ~19".
Your mileage may vary. Exact numbers may depend on your local value of G.
Stage Chain (Grade 43 Zinc Plated Chain, 1/4" Trade Size) – Approximately 108” per the read me in the Team version drawing document for the stage
This reminds me of a classic interview question reportedly used by Amazon…
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Answer… No
Checked tonight after I found our 2021 KOP leftovers
Traditionally plus or minus an inch for something like that. Aim to be able to deal with plus or minus two inches at least.
hahaha. nice. 