CG Location Calculation
#14
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Cat,
If you plan to relocate the positions of the axles, you still have to be aware of the potential impact on the tongue weight. Is your goal equal weight on each axle with maybe 8-10 % tongue weight?
What if you just position the boat on the trailer at the targeted tongue weight. Now jack up the trailer and loosen and re-position the axles using scales. When you are done with this, you can post the easy way for the rest of us
Ben
If you plan to relocate the positions of the axles, you still have to be aware of the potential impact on the tongue weight. Is your goal equal weight on each axle with maybe 8-10 % tongue weight?
What if you just position the boat on the trailer at the targeted tongue weight. Now jack up the trailer and loosen and re-position the axles using scales. When you are done with this, you can post the easy way for the rest of us
Ben
#15
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Ben, I'm curious to know if there is concern for loaded trailer tongue weight and also, boat CG.
We know the trailer pulls better and the boat runs better if weight is properly located.
Considerations for finding trailer CG (loaded or unloaded ) start with a level trailer. Level can be found with a carpenters level or laser. Then, using a single bathroom scale, three sections of round stock (fulcrums) and lever arm (angle stock for rigidity) 4ft.+/- long,we start. Place the lever arm on one fulcrum located 8-10" from another fulcrum centered under the ball coupler, then the long end of the lever arm on the last fulcrum, centered on the bathroom scale.
Using the trailer jack, raise the tongue to fit all components under the coupler ball. (Blocking may be required on each end of the lever arm). The lever arm assembly should be relatively level from end to end. Note the scale weight (lever arm and fulcrum weight) , measure distance from coupler ball centerline to each end of lever arm. Divide the short end into long end of lever arm to find ratio.
Lower trailer jack until it is off the ground. Read scale weight and subtract assembly weight. Divide net weight by lever arm ratio===Trailer ball weight.
Notes: Respect wt. stated on receiver hitch, hitch insert, ball and trailer coupler. A "sharpy" may look at those items in the event of an accident.
Notes: Personally, 500 to 700# is a good coupler ball wt. Subject to, proper components including 2 5/16" trailer coupler and other components rated for that load.
This has been one leg of finding boat and/or trailer CG.
Ben, did we ever tell you about the boat going out on the town for a week ?
We know the trailer pulls better and the boat runs better if weight is properly located.
Considerations for finding trailer CG (loaded or unloaded ) start with a level trailer. Level can be found with a carpenters level or laser. Then, using a single bathroom scale, three sections of round stock (fulcrums) and lever arm (angle stock for rigidity) 4ft.+/- long,we start. Place the lever arm on one fulcrum located 8-10" from another fulcrum centered under the ball coupler, then the long end of the lever arm on the last fulcrum, centered on the bathroom scale.
Using the trailer jack, raise the tongue to fit all components under the coupler ball. (Blocking may be required on each end of the lever arm). The lever arm assembly should be relatively level from end to end. Note the scale weight (lever arm and fulcrum weight) , measure distance from coupler ball centerline to each end of lever arm. Divide the short end into long end of lever arm to find ratio.
Lower trailer jack until it is off the ground. Read scale weight and subtract assembly weight. Divide net weight by lever arm ratio===Trailer ball weight.
Notes: Respect wt. stated on receiver hitch, hitch insert, ball and trailer coupler. A "sharpy" may look at those items in the event of an accident.
Notes: Personally, 500 to 700# is a good coupler ball wt. Subject to, proper components including 2 5/16" trailer coupler and other components rated for that load.
This has been one leg of finding boat and/or trailer CG.
Ben, did we ever tell you about the boat going out on the town for a week ?
#16
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Is the boat over 21 years old I believe our tongue weight is in the 900-1000 lbs range....we never thought about repositioning the axles but it doesn't surprise me that you have! Are you still planning on a trip to FL?
#19
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The CG thing has evolved from a sequence of events ...it seems to be a topic with limitations. However, from time to time a person might wonder if that extra weight is in the stringers, transom or somewhere else. Or, perhaps it's a new rigging, problem or just fine tuning the set up. Were there to be a need we might consider setting up shop.
My wife and I are going to Key West for the races. I may well be in FL before that ! Want to go the races ?
West Texas is found to be nothing special.