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- TL;DR Summary
- Homemade tripod tree stump/root puller design question.

WHAT: I'm designing a simple tree stump puller. It consists of a tripod made of square (or round, if it's easier) steel tubing with a winch at the top. The cable from the winch drops down, attaches to the stump, then pulls the stump upward.

DIMENSIONS: The top of the tripod, where the winch sits, will be 5 feet high. The tripod legs will be evenly spaced from each other (120 degrees apart). Assume each tripod leg will be 30 degrees from a vertical line. I could change the vertical angle if 30 degrees is not optimal. The tripod legs will be tied together at the bottom, bit the tripod feet are not attached to any fixed point on the ground.

SAFETY: While the winch is engaged, no humans will be near. So, I don't think I need a huge safety factor. Once the stump breaks free, they typically weigh less than 100 pounds. So, the tripod is only under significant stress while it is pulling the stump out of the ground (and I'm standing 20 feet away).

QUESTION: If the winch is rated at 12,000 pounds pulling force, what size square steel tubing do I need for the tripod legs? I was thinking of 2-inches square tubing with 0.25 thick steel. Is that enough?

QUESTION: I might also use a "snatch block" with the winch cable. This loops the cable back upwards and doubles the pulling load to 24,000 pounds. What then?

DIMENSIONS: The top of the tripod, where the winch sits, will be 5 feet high. The tripod legs will be evenly spaced from each other (120 degrees apart). Assume each tripod leg will be 30 degrees from a vertical line. I could change the vertical angle if 30 degrees is not optimal. The tripod legs will be tied together at the bottom, bit the tripod feet are not attached to any fixed point on the ground.

SAFETY: While the winch is engaged, no humans will be near. So, I don't think I need a huge safety factor. Once the stump breaks free, they typically weigh less than 100 pounds. So, the tripod is only under significant stress while it is pulling the stump out of the ground (and I'm standing 20 feet away).

QUESTION: If the winch is rated at 12,000 pounds pulling force, what size square steel tubing do I need for the tripod legs? I was thinking of 2-inches square tubing with 0.25 thick steel. Is that enough?

QUESTION: I might also use a "snatch block" with the winch cable. This loops the cable back upwards and doubles the pulling load to 24,000 pounds. What then?