Like Tree0Likes

CG Location Calculation

Reply
Old 10-10-2009, 09:57 AM
  #11
Gold Member
Gold Member
Thread Starter
 
CcanDo's Avatar
 
Join Date: May 2002
Location: DFW
My Boats: "Udderly Fantastic" Motion / 28 Skater 300x's / Bennington Tri-toon 350 Yam
Posts: 1,126
Default

Has anyone bought a custom trailer and had the manufacture ask for the boat CG to find axle location ?
CcanDo is offline  
Reply With Quote
Old 10-10-2009, 10:05 AM
  #12
Gold Member
Gold Member
Thread Starter
 
CcanDo's Avatar
 
Join Date: May 2002
Location: DFW
My Boats: "Udderly Fantastic" Motion / 28 Skater 300x's / Bennington Tri-toon 350 Yam
Posts: 1,126
Default

Quote:
Originally Posted by Sean H View Post
why not just CG it?
Sean, was the picture taken with the boat rigged or un-rigged ?
CcanDo is offline  
Reply With Quote
Old 10-10-2009, 10:40 AM
  #13
A to Z
Platinum Member
 
Sean H's Avatar
 
Join Date: Apr 2004
Location: KC/LOTO
Posts: 9,156
Default

Quote:
Originally Posted by CcanDo View Post
Sean, was the picture taken with the boat rigged or un-rigged ?
rigged, weight in the seats, race ready.
Sean H is offline  
Reply With Quote
Old 10-10-2009, 10:46 AM
  #14
Platinum Member
Platinum Member
 
Join Date: Dec 2002
Location: Dallas, TX
My Boats: 1987 Scarab Panther
Posts: 2,118
Default

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
BenPerfected is offline  
Reply With Quote
Old 10-10-2009, 02:14 PM
  #15
Gold Member
Gold Member
Thread Starter
 
CcanDo's Avatar
 
Join Date: May 2002
Location: DFW
My Boats: "Udderly Fantastic" Motion / 28 Skater 300x's / Bennington Tri-toon 350 Yam
Posts: 1,126
Default

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 ?
CcanDo is offline  
Reply With Quote
Old 10-10-2009, 05:47 PM
  #16
Platinum Member
Platinum Member
 
Join Date: Dec 2002
Location: Dallas, TX
My Boats: 1987 Scarab Panther
Posts: 2,118
Default

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?
BenPerfected is offline  
Reply With Quote
Old 10-10-2009, 06:19 PM
  #17
Rob
VIP Member
Trade Score: (6)
 
Strip Poker 388's Avatar
 
Join Date: Aug 2001
Location: Madison,Mississippi
My Boats: Hustler 388
Posts: 21,567
Talking

Quote:
Originally Posted by Sean H View Post
why not just CG it?

thats allot of weight in that one small spot.do ya do it with fuel and driver in boat?

When I took my rub rail off for painting it has a black magic marker mark 'arrow',its close to what Chip Fendt told me it was,which was the back of the drivers bolster.
Strip Poker 388 is offline  
Reply With Quote
Old 10-10-2009, 07:23 PM
  #18
Platinum Member
Platinum Member
 
Steve 1's Avatar
 
Join Date: Apr 2001
Location: Beautiful Fort Lauderdale www.cheetahcat.com
My Boats: Slippery when wet!
Posts: 10,833
Default

You can scoot a sling back and forth until the CG is revealed.
Steve 1 is offline  
Reply With Quote
Old 10-10-2009, 08:30 PM
  #19
Gold Member
Gold Member
Thread Starter
 
CcanDo's Avatar
 
Join Date: May 2002
Location: DFW
My Boats: "Udderly Fantastic" Motion / 28 Skater 300x's / Bennington Tri-toon 350 Yam
Posts: 1,126
Default

Quote:
Originally Posted by BenPerfected View Post
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?
No the boat isn't quite legal, someone else probably bought

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.
CcanDo is offline  
Reply With Quote
Old 10-10-2009, 10:24 PM
  #20
Platinum Member
Platinum Member
 
Join Date: Dec 2002
Location: Dallas, TX
My Boats: 1987 Scarab Panther
Posts: 2,118
Default

No on the races, but I am going to the PRI Show for the day on 12/10
BenPerfected is offline  
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 05:27 AM.


Copyright 2011 OffShoreOnly. All rights reserved.