2073 800+ Lb winch

[billbo911]

Originally Posted by CalTran

The 814 number, is it calculated or tested?

Calculated with the JVN Mechanical Design Calculator.

[JimC]

If that is #35 chain that you are using (I can't quite tell) then be careful because it only has a load rating of 480lbs.

Of course you're not really going to lift 800 lbs, I'm just pointing out that the load calculator doesn't take everything into consideration.

Be careful, have fun!
Jim

[dodar]

I have a very strong feeling that your chain is gonna catch whatever you are using as your "cord" for the winch and it will either snap or cook the motor.

[billbo911]

Originally Posted by JimC

If that is #35 chain that you are using (I can't quite tell) then be careful because it only has a load rating of 480lbs.

Of course you're not really going to lift 800 lbs, I'm just pointing out that the load calculator doesn't take everything into consideration.

Be careful, have fun!
Jim

Understood! We have no intent of carrying others up the Pyramid. Our 150Lb. is all it will ever see.

Originally Posted by dodar

I have a very strong feeling that your chain is gonna catch whatever you are using as your "cord" for the winch and it will either snap or cook the motor.

Guard(s) and guides will be in place to prevent this issue. Alternatively, we might swap out the 36 tooth sprocket for a 22 tooth. This will bring the chain inside the OD of the spool. It will also increase our climb rate by 1/3 without over stressing the CIM.

With the current design, the calculated current draw is 39.75A for a 150 Lb. load. With the 22 tooth sprocket, that value goes to 63.33A. Additionally, it would reduce the lift time for a 30 in. pull to 2.32 sec. Not enough to trip the breaker. It would also reduce the controllability for the drivers. So, we will start out with the 36 tooth and see if there is even a need to go to 22.

BTW, from Wikipedia:

ANSI B29.1 roller chain standard sizes
Size Pitch Roller diameter Tensile strength Working load
25 0.250 in (6.35 mm) 0.130 in (3.30 mm) 781 lb (354 kg) 140 lb (64 kg)
35 0.375 in (9.53 mm) 0.200 in (5.08 mm) 1,758 lb (797 kg) 480 lb (220 kg)

[EricPalmatier]

First, congrats on the awesome winch! Looks similar to something I have been working on! Just two quick questions. The first is what is you final calculated gear ratio before the winch drum? And second, you stayed that the close to 60 amps would not trip the breaker? I would think that's true of the main 120 amp breaker, but what about the 40 amp breaker feeding your motor controller from the PDB?? Just curious, and good luck!

[billbo911]

Here are the reduction stages we are using:

Toughbox Mini: 50:14 and 48:16

Next stage spur gears: 48:17

Final stage chain: 36:12

Total reduction is 90.67:1

The 40A snap action breakers can handle a heavier load for a short period of time. 60A for 5 seconds is fairly safe.