Bob Myers Posted June 10, 2009 #26 Posted June 10, 2009 Setup; We have a weight of 100 pounds centered on a frame that is 7 foot long. For this application each end is supporting app 50 pounds, presuming the load is centered correctly. And not accounting for the weight of beam holding load. For simplicity, given that we’re interested in load per support, we’ll assume this to be a point load. If you moved the center of gravity (load point) 3.5ft to right side, then you’d have 100% of the load on one leg and zero on the other (theoretically, and neglecting weight of beam). What if we move this 100 pound, 1 foot to the right. We now have 4½ foot of frame sticking out the left side and only 2½ foot on the right If you move load 1 ft to the right of center, you’d have 100lb acting at a distance of 2.5ft from the right end that produces a moment (torque) of 250ft*lb. The reaction force on the Left end has to produce an equal/opposite moment. So 250ft*lb / 7ft = 35.7lb. Because the two reaction forces have to equal the applied force, 100lb load – 35.7lb on the Left = 64.3 on the Right.
Condor Posted June 10, 2009 #27 Posted June 10, 2009 Setup; We have a weight of 100 pounds centered on a frame that is 7 foot long. For this application each end is supporting app 50 pounds, presuming the load is centered correctly. And not accounting for the weight of beam holding load. For simplicity, given that we’re interested in load per support, we’ll assume this to be a point load. If you moved the center of gravity (load point) 3.5ft to right side, then you’d have 100% of the load on one leg and zero on the other (theoretically, and neglecting weight of beam). What if we move this 100 pound, 1 foot to the right. We now have 4½ foot of frame sticking out the left side and only 2½ foot on the right If you move load 1 ft to the right of center, you’d have 100lb acting at a distance of 2.5ft from the right end that produces a moment (torque) of 250ft*lb. The reaction force on the Left end has to produce an equal/opposite moment. So 250ft*lb / 7ft = 35.7lb. Because the two reaction forces have to equal the applied force, 100lb load – 35.7lb on the Left = 64.3 on the Right. I understand what you're saying, and very well I might add, but now lets talk about a trailer box, not a theoritical beam. You're not going to load 100% of the weight at the wheel end of the box and let the remainder of the box space stand empty. You're going to utilize the entire volumn of the box. Even if you load the heavy items to the 'back of the bus'... sorry had to say that..:rotf:it will not all pack into a small confined area. In practice it will spread over 2 to 3 feet with the remainder of the lighter items distributed forward. In practice everything stowed will increase the weight on the hitch end. Perhaps not on a 50/50 basis, but enough that it will make tongue weight significantly greater than a trailer with the wheel/axle in the center of the load. I guess we'll have to wait and see what the results will be after the trailer is finally built.
ctraylor Posted June 19, 2009 #28 Posted June 19, 2009 I built a similiar trailer and have pulled it more than 3000 miles now and it pulls like a dream. I load the heavier stuff to the back and usually put my ice chest up front when we are traveling. I can't hardly tell it is back there unless there is alot of wind then I can sometimes feel it wiggle a little. All in all I am well pleased and on the bright side I don't have to worry about someone stealing it because the hitch is one of a kind. http://s665.photobucket.com/albums/vv14/ctraylor_photo/
Bob Myers Posted June 19, 2009 #29 Posted June 19, 2009 Wonder if the wind you feel is because the mount is so far above the center of gravity of your bike?? That is same color scheme as the 86 I have. When it shines it is a pretty color, wish mine was blue though
Sylvester Posted June 19, 2009 #30 Posted June 19, 2009 Ok been a bit but i know have most of the parts for my trailer just waiting for a few more small parts that are being made at the machine shop so here is a parts photo of some of the stuff i have done You all lost me on the physics of load bearing, but I am really confused about the universal joints in the picture. WHAT the...? I know you are not putting a motor on this thing.
ctraylor Posted June 19, 2009 #31 Posted June 19, 2009 The universal will let if pivot up and down and left/right but not side ways, if that makes since. I used a total different set up on mine. It works kind of like a fifth wheel set up with a pin securing the trailer.
Bob Myers Posted June 19, 2009 #32 Posted June 19, 2009 You all lost me on the physics of load bearing, but I am really confused about the universal joints in the picture. WHAT the...? I know you are not putting a motor on this thing. Actually it is more simple than you could imagine. The joint is place on the trailer tongue with the cross going straight up and down/ left and right. This part parallel top the ground gives it the up and down float need to go over bumps and suspension to work up and down, and the part of the cross perpedicular to the ground allows the left/right turning. So it is used only as a pivot and not as for rotational alignment
dray Posted June 19, 2009 Author #33 Posted June 19, 2009 this may help see what im doing a bit better http://i66.photobucket.com/albums/h269/drayco58/P1040121-1.jpg?t=1245449611 the hitch!
Sylvester Posted June 19, 2009 #34 Posted June 19, 2009 Aaahaahhh! Now I understand. It takes pictures for my retired brain to absorb the true meaning of words. Thank you. This is very ingenious.
Guest tx2sturgis Posted June 21, 2009 #35 Posted June 21, 2009 Looks a lot like the Eaglemate trailer made in Canada, other than the hitch mounting angle is of course, different. http://www.eaglematetrailers.com/images/gallery/equipment0024.jpg http://www.eaglematetrailers.com/gallery.htm And like the N-Line trailer, some of the weight is carried on the bikes hitch. http://www.n-line.com/photos.htm
dray Posted June 22, 2009 Author #36 Posted June 22, 2009 the eaglemate is nice but i dont like the way the axle bolts solid to the frame and no give to it http://i66.photobucket.com/albums/h269/drayco58/equipment0006.jpg?t=1245629493 im going to have a nice shock with a good swingarm
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