Re: Will a 3000lb electric wench
[Re: RATTRAP]
#1048215
08/06/11 04:53 PM
08/06/11 04:53 PM
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69CHARGERMD
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Found this,,,,the link gives a table for ground effect percentages,,,and effort required,,,,, Calculating Winch Loads Total Weight = Vehicle Weight + Load weight Winch Pull = ( <Slope degrees> * Total Weight /60) Ground Factor Weight = Winch Pull * Ground Effect Percentage Winch Load = Winch Pull + Ground Factor Weight Example. Given: * Vehicle weight = 4,400 pounds * 300 pounds of total load weight * winch up a 50 degree slope consisting of shallow mud Total Weight - 4400 + 300 = 4700 Winch Pull - (50*4700/60) = 3917 Ground Factor Weight - 4,700 * 35% = 1645 Winch Load - 3917 + 1645 = 5562 http://www.4wd4all.com/forums/attachment...012&thumb=1
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Re: Will a 3000lb electric wench
[Re: 69CHARGERMD]
#1048216
08/06/11 04:58 PM
08/06/11 04:58 PM
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69CHARGERMD
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not sure what the "slope" is your pulling your car up,,,,but,,, eg,,if you use the 50* as below,, and your on pavement,,i think you would be ok...or close.....
Total weight = 3400
Winch pull = 50*3400/60 = 2833
Ground factor = (pavement) 3400 * 4% = 136
Winch load = 2833 + 136 = 2969
hope this helps....
Doug
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Re: Will a 3000lb electric wench
[Re: RATTRAP]
#1048219
08/06/11 05:10 PM
08/06/11 05:10 PM
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Posts: 52,972 Romeo MI
MR_P_BODY
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Most winches are rated to pull a vertical load... as in your case 3000 lbs it should lift 3000 lbs vertically... so when you induce a drag weight it will pull MUCH more than the rated lift weight... I use a 1500 lbs winch to pull my car up a pretty good angle on my ramps.............. but I guarantee your 3000 lbs winch will pull your 3400 lbs car up a set of ramps all day long
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Re: Will a 3000lb electric wench
[Re: MR_P_BODY]
#1048220
08/06/11 05:17 PM
08/06/11 05:17 PM
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Posts: 3,031 Erda, UT
67Charger
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You're calculating it backwards. The slope is the angle of the ramp to level ground, and is usually about 10° to 20° for trailer ramps. The 50° was just an example for winching a truck up a steep, muddy slope.
Total weight = 3400
Winch pull = 10*3400/60 = 567
Ground factor = (pavement) 3400 * 4% = 136
Winch load = 567 + 136 = 703
Total weight = 3400
Winch pull = 20*3400/60 = 1134
Ground factor = (pavement) 3400 * 4% = 136
Winch load = 1134 + 136 = 1270
Last edited by 67Charger; 08/06/11 05:24 PM.
11.33 @ 118.46 on motor 10.75 @ 125.35 w/ a little spray Now, high Speed Open Road Racing - Silver State Classic Challenge, Nevada Open Road Challenge, Big Bend Open Road Race Rocky Mountain Race Week 2020, 2022 2.0, Sick Week 2023
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Re: Will a 3000lb electric wench
[Re: 67Charger]
#1048221
08/06/11 05:19 PM
08/06/11 05:19 PM
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MR_P_BODY
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Quote:
You're calculating it backwards. The slope is the angle of the ramp to the ground, and is usually about 10° to 20° for trailer ramps. The 50° was just an example for winching a truck up a steep, muddy slope.
I dont think your talking to me on that
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Re: Will a 3000lb electric wench
[Re: MR_P_BODY]
#1048222
08/06/11 05:23 PM
08/06/11 05:23 PM
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Posts: 3,031 Erda, UT
67Charger
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Quote:
Quote:
I think you're calculating it backwards. The slope is the angle of the ramp off level, and is usually about 10° to 20° for trailer ramps. The 50° was just an example for winching a truck up a steep, muddy slope.
I dont think your talking to me on that
nope, 69CHARGERMD
11.33 @ 118.46 on motor 10.75 @ 125.35 w/ a little spray Now, high Speed Open Road Racing - Silver State Classic Challenge, Nevada Open Road Challenge, Big Bend Open Road Race Rocky Mountain Race Week 2020, 2022 2.0, Sick Week 2023
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Re: Will a 3000lb electric wench
[Re: RATTRAP]
#1048224
08/06/11 05:30 PM
08/06/11 05:30 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
Now i just need the rain to quit so i can go out and install my new toy,
Just starting here(rain).... if you have a 3000 lb winch it will pull 4500 lbs up a 45* slope(add 1/2 the rated weight... then if you want to figure the rest of the angles.... go for it)
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Re: Will a 3000lb electric wench
[Re: MR_P_BODY]
#1048225
08/06/11 05:42 PM
08/06/11 05:42 PM
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69CHARGERMD
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Quote:
You're calculating it backwards. The slope is the angle of the ramp to level ground, and is usually about 10° to 20° for trailer ramps. The 50° was just an example for winching a truck up a steep, muddy slope.
I just left 50* as a example...i assumed his angle was less than that... thanks.
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Re: Will a 3000lb electric wench
[Re: 67Charger]
#1048226
08/06/11 05:54 PM
08/06/11 05:54 PM
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Joined: Oct 2007
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polyspheric
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Total weight = 3400 Winch pull = 20° × 3400 ÷ 60 = 1134 Ground factor = (pavement) 3400 × 4% = 136 Winch load = 1134 + 136 = 1270
That looks better, but please note that the angle input is not proportionate to the actual forces. The usual test with a formula is to exaggerate a variable in both directions and see if the results make sense. Here, a vertical pull would mean multiplying by 90, but 90 ÷ 60 isn't the vertical pull, it's much more. I have a feeling that the variable you want is a trig function of the ramp angle, rather than the angle ÷ 60. Example: with a 20° ramp, the variable should be .333 (20 ÷ 60). The sine of 20° is .342, pretty close (2.6% error). Use 10°, should get .1666667 (10° ÷ 60). The sine is .174 (4.2% off) Really steep ramps, like 45° and up, are where the angle/60 method begins to fail: 45 ÷ 60 = .75. The sine of 45° is .707, a lower figure. Using 60°: the above method says the load is 1.00 (same as vertical), but of course it isn't, it's probably the sine, .866. Go to 90°: the sine of 90° is 1.0, so the calculation exactly equals a vertical pull (whereas the above method predicts 1.5).
If the winch is too small but has a long cable, just use a pulley (or more than 1). Running the line to a pulley at the load, then back to the winch almost doubles capacity (some minor loss through friction and cable bending). The cable length must be doubled, but of course if splicing it the added cable can safely be as small as 50% of the original rated load.
Last edited by polyspheric; 08/06/11 06:03 PM.
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