Home |
Search |
Today's Posts |
#11
|
|||
|
|||
Trailer Axel / Physics Puzzler
"Gary Warner" wrote in message ... PUZZLER: Does the axel "balance" the weight over the axel or over the wheels? . Over the wheels. To be precise, over the point at which the wheel contacts the ground, which had better be directly under the axel. A thought just crossed my mind: You should also check the tongue weight when the trailer is empty. From your description it sounds like you won't have a problem, but I have seen trailers built for a center engine boat that had negative tongue weight when the boat was NOT on the trailer. Rod |
#12
|
|||
|
|||
Trailer Axel / Physics Puzzler
A clarification on my previous answer:
"Gary Warner" wrote in message ... The thing is, it's not just a straight across axel. Well, the axel goes straight across, but coming from the center of the axel is a 6" arm that goes back to the spindle. In other words, the tires are off-set 6" behind where the axel is. By definition, an axle (vs axel, which is a figure skating jump) is the shaft on which the wheels rotate about. In other words, axle = spindle. The tube that goes across the trailer that contains the torsion bar would be called something else. So, the pivot point is at the wheel, where the spindle/axle is. Sorry for the confusion. Rod |
#13
|
|||
|
|||
Trailer Axel / Physics Puzzler
"Gary Warner" wrote in message ... Thanks all for the replys. I will call the company and ask them too, but I always like the comments and thought processes I get here. Since the axle is fixed to the frame, it is part of the frame. The spindles go where the axle would go if it were straight across. Consider the vector through the center of mass of the boat and trailer. It should be just forward of the center of the spindles which is where the upward vector from the ground passes up. The remainder of the torque is supplied by the force upwards on the tongue. Just remember that the sum of the torques about any point must be zero. So pick a convenient point and draw the force vectors. del cecchi |
#14
|
|||
|
|||
Trailer Axel / Physics Puzzler
"basskisser" wrote in message om... Your current thinking is correct, if all things equal, AND if you didn't consider the torsion of the spring. What????? The torsional forces can not have any effect on the trailer balace as long as the wheels are round or allowed to rotate. Again, if you put the wheel at the center of gravity of the boat, it will be balanced. No, it would need to be at the center of gravity of the boat + trailer. Trouble is, when this is done, will the boat's C.G. be at the C.G. of the trailer? Probably not. Which is why you would want to use the C.G. of boat + trailer for any calculations. See, you could load the boat on the trailer, and the CG of the boat could be far enough behind that the tongue has a negative load. A universally true statement. Take any boat and trailer, load the boat far enough back and the tongue weight will go negative. What's your point? Rod |
#15
|
|||
|
|||
Trailer Axel / Physics Puzzler
Gary,
When using tandem axles some method of equalizing the weight must be used to keep one set of axles from being over loaded. The trailer will rarely be setting perfectly level and without an equalizer the tires will be unequally loaded as well. In the case of leaf springs, it's done using a common, rotating equalizer. In your case, I'm not sure. I'd ask the manufacturer of the axles. This catalog shows the normal axle setup and may show your's as well. http://www.championtrailers.com/catalog_pdf.htm "Gary Warner" wrote in message ... "Harry Krause" wrote: Out of curiosity, how does one place the axle? Is it at the centerpoint? I think you'd want it a bit forward of the centerline. I built a box trailer some years ago, and was advised to have the axle forward of center under the box. I knew why at the time, but I've since forgotten. I'm not an expert (obviously) but our thinking is: We experimented with the trailer WITH the boat on it to find a point that is just BACK of the true center of gravity. A single axel placed right AT the center of gravity would give essentiall no tongue weight. Moving the single axel back just a little gives some tongue weight. In our case we are putting tandem axels. So one axel will go forward of the point we found and the other back of that point by the same distance. |
#16
|
|||
|
|||
Trailer Axel / Physics Puzzler
"Rod McInnis" wrote in message ... A thought just crossed my mind: You should also check the tongue weight when the trailer is empty. From your description it sounds like you won't have a problem, but I have seen trailers built for a center engine boat that had negative tongue weight when the boat was NOT on the trailer. That's a great point and one I hadn't thought of. Will do it. Rod |
#17
|
|||
|
|||
Trailer Axel / Physics Puzzler
"Rod McInnis" wrote in message ... A clarification on my previous answer: By definition, an axle (vs axel, which is a figure skating jump) is the shaft on which the wheels rotate about. In other words, axle = spindle. The tube that goes across the trailer that contains the torsion bar would be called something else. Makes sense and well said. Thanks. |
#18
|
|||
|
|||
Trailer Axel / Physics Puzzler
"QLW" wrote: Gary, When using tandem axles some method of equalizing the weight must be used to keep one set of axles from being over loaded. The trailer will rarely be setting perfectly level and without an equalizer the tires will be unequally loaded as well. In the case of leaf springs, it's done using a common, rotating equalizer. In your case, I'm not sure. I'd ask the manufacturer of the axles. This catalog shows the normal axle setup and may show your's as well. http://www.championtrailers.com/catalog_pdf.htm Question: On this axle each wheel has independent suspension. Would this take care of the situation you mentioned? Seems to me it might. For example, say the trailer was on totall level gound except for one wheel which was on a rock sticking up 3" above level. Hmmm, maybe not. I just don't know. |
#19
|
|||
|
|||
Trailer Axel / Physics Puzzler
On Mon, 26 Jan 2004 13:33:17 +0000, Gary Warner wrote:
Thanks all for the replys. I will call the company and ask them too, but I always like the comments and thought processes I get here. ...then you are one sick and twisted individual! Lloyd |
#20
|
|||
|
|||
Trailer Axel / Physics Puzzler
Lloyd Sumpter wrote:
On Mon, 26 Jan 2004 13:33:17 +0000, Gary Warner wrote: Thanks all for the replys. I will call the company and ask them too, but I always like the comments and thought processes I get here. ...then you are one sick and twisted individual! Lloyd This from a man who used to have a relationship with a woman known as Vinyl Valerie. -- Email sent to is never read. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Boat fell off trailer | General | |||
Update on Homemade Trailer Building | General | |||
Where to find ramp stories? | General | |||
Trailer Brakes: Electric vs Hydraulic-Surge | General | |||
Correct Trailer set up for towing my speedboat. | General |