Math formula

[BIGNASTY]

Please watch the video and the question is about the counter balance weight amount?? I built one of these on a small scale and used a GM altenator that has been modified to a PMA type alternator to power some RV water heater probes that I installed in the water buckets of our animals in the barn so that they can have water ANYTIME without waiting for me to come out a bust the ice for them to get a drink. The question is the counter balance weight amount. On mine I used COWBOY CALCULUS and added more and more and more weight until I got it to what was needed. Many times up and down a ladder and up and down the roof of the barn is not what I want to do on a tower as tall as the one we are going to make. I need the mathematical formula to find the weight of the counter balance weight. Thanks for any help



BIG









http://www.youtube.com/watch?v=WwhEI9Wc46g

 

[Wayne M.]

I love the project, and idea. I saw your PMA alternator, but slept through it. Now I know the scope of it, I'll have to tune in. This setup reminds me of the lightpacks we have on the job. Similar winch, cable and a spring loaded lock to lock the mast upright. I'm no mathematician, but I can see that the counterweight cant be too heavy, or it'll never fold on it's own. Also, in my mind, I think the axis has to be offset, or some other principle at work to start the fold when it's time to bring it down. He didn't show that.

 

[BIGNASTY]

He uses a 2x4 to kick it past center and gravity will do the rest to get it down but if its to heavy past center could be a fun way to break a wrist with spinning winch handles :-laf

 

[B.G. Smith]

Just a thought Big, there are worm gear winches available that won't free wheel and beat you to death. bg

 

[BIGNASTY]

Thanks im sure that its NOT going to be up and down very often. In the 3 + years we have been in MT I have had to pull ours down 1 or 2 times because of the weather,they can withstand allot but I just felt better with bringing it down when our Canadian BUDDIES leave both the front and back doors open and the Chinook winds blow http://en.wikipedia.org/wiki/Chinook_wind we dont even get the brunt of them we have seen winds at 75 MPH for long periods. I just didnt want to take a chance on a $$$$$ repair bill. I will look into your suggestion and appreciate the thoughts.



BIG

 

[Bob4x4]

Lol we had an idiot break his wrist at work using a standard winch to close a security chain gate. I installed a worm drive to save more idiots. Now the question remains should we continue to save idiots or help natural selection????

 

[BIGNASTY]

Son has already said that he wants nothing to do with a NON worm drive winch. He was a fireman/paramedic in CA and has seen the the hazards FIRST HAND of NATURAL SLECTION putting them into an ambulance to take them to the hospital.

Best one I thought was the guy that wanted to nail a pipe with a hole in it, to a wall using a pneumatic nail gun
shot the nail gun and the nail ricochet and went back into the bridge of his nose and angled into his eye. Son seen him months later at the hospital the guy said he can see its just everything in that eye is black and white :-laf Ex rays were NASTY to look at.

I WAS LOOKING AT A MOTORIZED WINCH LIKE ON AN ATV WITH A LOOOOOOOOOONG ON OFF SWITCH CORD

 

[CBari]

Big give this page a once over see if it helps you. If not draw out what yours looks like and the weights and I will do the math for you on the counter balance.

http://www.engineeringtoolbox.com/levers-d_1304.html

 

[BIGNASTY]

Looking at this the triangle is the point to where it is attached to the upright poles cemented into the ground the (the pivot point)



The Effort force would be the wind generator including the weight of the pole from the pivot point to the end 450lbs the distance for pivot point to end of wind gen side of lever would be 20 ft (dont know if you need that)



The land force would be the attachment point for the winch cable to pull down and that would in turn raise the wind gen. The distance of the lever from the pivot point to the land force end where the counter balance weight will be is 12ft.



How much weight would be needed on the LAND FORCE to make it easy to let down the wind gen without being out of control.



Hope this made sense.



I built one much smaller and the gen was 100 lbs and the counter weight I dont know because of the trial and error method I used.





Thanks



BIG

 

[CBari]

Big for it to be completely balanced, i. e. no work or effort needed the counter balance would need to be 450. 6lbs. What you need to ask yourself is how much do you feel comfortable lifting or controlling. You can basicly subtract that amount from the 450. 6lbs to make the countrer balance less. The math was 450lbs Fe=F1-12d1/20d2. I would think using a worm gear winch or an electric atv winch would be the way to go. Use a pulley to Multiply the force, but also to slow the movement speed ie for every 10ft of cable let out of the winch you would only get 5ft of movement should give you more control.

 

[BIGNASTY]

I sure appreciate the info im pushing for a atv winch they are not that much and the safety is well worth it not to say the cost of the equipment. Ill give it a try and see what happens. It will need some resistance to make the cable wind better and tighter on the winch.



BIG

 

[CBari]

I bet you could go without any counterbalance using an atv winch.

 

[Wayne M.]

I definetly agree with the electric winch. I know some of them have wireless remote kits. Back when I had my enclosed car trailer, I had a superwinch with the cabled remote. It was top notch.

 

[BIGNASTY]

When you take these things down you have to go slow to get the blades to stop on some they have an automatic FURLING feature it basically takes the wind away from turning them and it has to have time to slow down. The blades on mine are carbon fiber and are not cheap if you should nick one you buy the set. I think the atv winch would be the best in that respect. Having a little more weight might be a good idea.

 

[Wayne M.]

As I think about it. There may be some hurkey jerky with the on off of the winch whereas the armbuster might be smoother.

 

[chipster]

Big for it to be completely balanced, i. e. no work or effort needed the counter balance would need to be 450. 6lbs. What you need to ask yourself is how much do you feel comfortable lifting or controlling. You can basicly subtract that amount from the 450. 6lbs to make the countrer balance less. The math was 450lbs Fe=F1-12d1/20d2. I would think using a worm gear winch or an electric atv winch would be the way to go. Use a pulley to Multiply the force, but also to slow the movement speed ie for every 10ft of cable let out of the winch you would only get 5ft of movement should give you more control.

I think the math is off. if you have 450lb on the end of the 20ft lever and 450. 6lb on the end of the 12ft lever they will NOT be balanced. I think the short lever should have a weight closer to 720lb. or am I missing something in the math formula ??

 

[B.G. Smith]

Not an engineer or mathimatician but my head does hurt sometimes. What am i missing? If you hang 450lbs. on the long end of the pole and 450. 6lbs on the short end how can it be balanced? Not trying to start trouble, would just like to see how it can work. bg

 

[CBari]

Chip I would tend to agree with you logicaly but I don't see it Mathmaticaly unless I am in one of those moods where I cant see the forest for the trees. Please show me my error. Fe=F1- d1/d2. 12/20 yeild . 6 add that to both sides of exquation and you get 450. 6=F1. I agree that I must be missing something because logical you should need more weight.

 

[chipster]

Chip I would tend to agree with you logicaly but I don't see it Mathmaticaly unless I am in one of those moods where I cant see the forest for the trees. Please show me my error. Fe=F1- d1/d2. 12/20 yeild . 6 add that to both sides of exquation and you get 450. 6=F1. I agree that I must be missing something because logical you should need more weight.

when you divide 12 by 20 you get . 6 then you multiply 450 by . 6 and get 270 lbs you add the 270 to the 450 and get 720 lbs. I think the formula in the example was not all there, or a typo. :-laf I think the formula should be 450 + . 6 ( of 450) on the short side. and only 450 on the long side, we are solving for the weight on the short side only.

 

[CBari]

Chip that makes more sense thanks for the correction. No feelings hurt here, I am sure it isn't the first mistake I have ever made nor will it be my last.