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#1
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pic: Twisted Hex Shaft
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#2
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Re: pic: Twisted Hex Shaft
Impressive. A harsh reminder of the kind of force that FRC bots exert.
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#3
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Re: pic: Twisted Hex Shaft
3/8" diameter, 2024 aluminum?
I'm curious to know just how much torque that took... In 2008, our arm was able to rotate the keyway of a piece of hardened 1/2" steel keyshaft almost 90 degrees. It's impressive how an FRC robot can destroy itself! |
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#4
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Re: pic: Twisted Hex Shaft
Quote:
Not sure the alloy, but it was some small diameter (bad idea in hindsight) |
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#5
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Re: pic: Twisted Hex Shaft
gotcha 7075 was the number iw as looking for. Just to be nosey it wasnt 7075 -0 right?
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#6
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Re: pic: Twisted Hex Shaft
I've never seen Al hex in anything other than T6
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#7
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Re: pic: Twisted Hex Shaft
Wow, that is quite a failure for a 1/2" 7075 shaft. Can you explain in a bit more detail the application this was in under failure?
-Brando |
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#8
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Re: pic: Twisted Hex Shaft
never seen dosent mean never exists.
most common types of 7075 is 0, T6, and T631. Although there are MANY different types such as T7362 is also a common one. |
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#9
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Re: pic: Twisted Hex Shaft
Quote:
It was on our arm. Basically we have 2 Banebot's gearboxes with chain running up to the arm. We have approx. 50 lb-ft of torque (don't worry, 1:4 chain reduction, only 6.25 lb-ft on each gearbox). We have chain on either side of the arm, and we decided to change the tensioning method to turnbuckles. Almost immediately as we raised the arm, the turnbuckle one side (the twisted side failed) while the other one held. The torque of the arm in addition to tension being held by the chain all released in one instant twisting the shaft, as the tension still held on the other side (on which the gearbox's rollpins sheared) |
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#10
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Re: pic: Twisted Hex Shaft
thanks for the assist...my brains all scrambled this morning |
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#11
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Re: pic: Twisted Hex Shaft
Whew! thought that was a lead screw
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#12
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Re: pic: Twisted Hex Shaft
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#13
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Re: pic: Twisted Hex Shaft
waht kind of aluminum is the turnbuckle?
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