# wind speed into fcorce conversion

#### Thunderchild

##### New Member
I'm setting up a solar system (ok banter aside) and intend to track the suns course. I'm planning on using a 919D8101 motor and gear box from MFA comodrils:

MFACOMODRILLS.COM

so i know that my motor has a torque of 125 Kg (and a stall torque of 810) so am I firstly to assume that the gear box was made to withstand such forces in reverse, say the motor is stationery but an external force is pushing at the shaft.

Now I will have a 36 X 54 cm solar panel exposed to the wind, how do I calculate the force of say a 70 mph wind on this surface ? the panel will be centrally pivoted and be mouted on a wall with the ability to tilt 45 deg either way

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#### nickelflippr

##### Member
As a rule of thumb, used to use 15lbf per sq. ft. for 70mph wind loads. You could try the UBC, IBC, or some sort of building code for the actual calculation.

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#### Thunderchild

##### New Member
I'm also thinking that as the panels are pivoted at the centre surely as both sides are going to be hit evenly won't that cancel out the "twisting" force as aech half will oppose the other ?

#### Thunderchild

##### New Member
Maybe this will help.
hm thats helpful, a I to asume that the area is in sq foot and the resulting force in pounds ?

#### nickelflippr

##### Member
I'm also thinking that as the panels are pivoted at the centre surely as both sides are going to be hit evenly won't that cancel out the "twisting" force as aech half will oppose the other ?
That might be the case if the wind is normal to the panel at all times, which it won't. If the panel is given a chance to oscillate, it will do so, given the right conditions.

Looking for a description of the solar panel frame to pivot point connection. The larger the diameter of the connection, or support of that connection, the sturdier it will be in a stiff wind. How about a boat seat swivel? They can be had at Wally World for not much.

Another thought was a satellite tracker setup, that was made for the RV industry. There was a surplus company selling one. It had some double helical gear setup, with very low backlash.

#### Thunderchild

##### New Member
well at the panels will be running pretty much paralel to the wall and theres another wall oposite the wind pretty much goes in one direction I think I'll just have to give it a shot and see what happens.