Found a Cat trailer that looks pretty good, is there anything I’m missing?

[Jimmy N.]

That is the ideal tie-down method, I think.

Have that setup in the toy hauler, but not on the flatbeds.

 

[DGatzby]

"If you decel at 1g with a 4500# car and the 4 straps shift to 15deg to hold it back, the load in each strap is 4500/(sin15* 4 )=4346# per strap, higher if the load is not shared equally (it never is)."

But thanks for checking, I do make lot of mistakes, but I did divide by 4. Adding a pair of longitudinal straps on the rear will add a lot of safety and comfort. But again, I have zero experience transporting a vehicle, which is why I really appreciate the help!

Okay. You guys should quit when you are ahead. We will need to continue to debate until you have valid info for the public from our Forum.

Where is the force of 1g added to the vehicle weight?

Your equation will result in multiplying the sin 15 degrees which is 0.2588 by four which results in dividing just the vehicle weight and not the vehicle weight multiplied by an appropriate factor to represent 1g in your analysis by 1.03. I’ll explain later that mistake is large.

Your fundamental assumption also has all four straps holding the vehicle and tied to the rear of the trailer.

I really don’t understand all the 15 degree shit. 15 degrees off of your force line? That is not crap, don‘t worry about it. Without your precious multiplication by four, the sin of 15 degrees divides the weight of the car by .2588. Did you check your work? Results in nearly 18,000 lbs.

Engineering major and math minor. I still remember a little of it. Sometimes for a living I do have to be the final approval for lifting and moving shit that would make your blood curl. Just trying to help.

Just get a set of pre-engineered straps, and don’t worry about it, you and I don’t design transport systems for a living. And damn I never want to try to achieve -1g with a trailer attached, that would also be quite a feat.

 

[Jimmy N.]

I think that what 2ndAmend is looking at are those unplanned and abrupt stops.

If just towing at a stead pace, tie downs wouldn't even be needed. Well, for me they still would because of how I go trough curves.

I tend to "over-tie" the rear because it'd be bad enough to have the front of the 3500 crunched. Don't want the front of the car on the trailer to hit the gooseneck, too.

Although, that would still be better than with a bumper pull, which could allow the towed car to also cream the back of the tow vehicle.

 

[DGatzby]

Lightning could strike.

 

[2ndAmend]

Okay. You guys should quit when you are ahead. We will need to continue to debate until you have valid info for the public from our Forum.

Where is the force of 1g added to the vehicle weight?

Your equation will result in multiplying the sin 15 degrees which is 0.2588 by four which results in dividing just the vehicle weight and not the vehicle weight multiplied by an appropriate factor to represent 1g in your analysis by 1.03. I’ll explain later that mistake is large.

Your fundamental assumption also has all four straps holding the vehicle and tied to the rear of the trailer.

I really don’t understand all the 15 degree shit. 15 degrees off of your force line? That is not crap, don‘t worry about it. Without your precious multiplication by four, the sin of 15 degrees divides the weight of the car by .2588. Did you check your work? Results in nearly 18,000 lbs.

Engineering major and math minor. I still remember a little of it. Sometimes for a living I do have to be the final approval for lifting and moving shit that would make your blood curl. Just trying to help.

Just get a set of pre-engineered straps, and don’t worry about it, you and I don’t design transport systems for a living. And damn I never want to try to achieve -1g with a trailer attached, that would also be quite a feat.

Hey D,

Very simple. As you know, a vertical/lateral strap cannot apply any longitudinal force. Only once the load has shifted allowing a longitudinal component will the strap resist a longitudinal load. (This does not consider tire friction, but as you know as an engineer, relying on friction can be problematic.) If the load shifts forcing the strap to 15deg, the longitudinal component will be sin15. This means the 15deg diagonal (strap) sees a load equal to 1/sin15 times the longitudinal load.

At 1g, the longitudinal load for a 4500# car will be 4500#. If equally shared by 4 straps would be 1125# (longitudinal). At a 15deg angle, the load on each diagonal strap would be 1125#/sin15=4346#. (This does not include any lateral/vertical pretension).

If you lock up all wheels, I'm not sure what the g will be but it will approach 1g. Even a minor collision (if some pulls in front of you and stops suddenly) will easily exceed 1g. (A person walking normally on a floor is imposing about 3g.)

I prefer not to post my cv, but I am not wrong (based on the stated assumptions). We are just apparently not communicating well. Peace.

 

[2ndAmend]

Spring FINALLY has arrived and I was able to set up the trailer. First was testing the custom race ramps I made, they work perfectly!

Next was figuring tongue weight, I set up a beam with pieces of steel angle to act as knife edges to put 1:3 on a bathroom scale. Then calculated tongue weight % based on car location and marked it. Now I have a reference so if anything funny happens at speed, I can adjust and know where from and where to.

Tomorrow I'm making brackets to anchor the wheel loops on the front as I don't have the nice rails like DGatzby has.


You guys have all been a great help! Thanks!!!

 

[Jimmy N.]

Nice!

Go a bit heavy on the tongue if you want...it's a whole lot better than not enough.

 

[DavidKFla]

Nice!

Go a bit heavy on the tongue if you want...it's a whole lot better than not enough.

I like mine more balanced over the axles. Gives me a more stable and comfortable ride.

It's sitting on the jack.

 

[2ndAmend]

Nice!

Go a bit heavy on the tongue if you want...it's a whole lot better than not enough.

I want to find the minimum, the 1/2t really sags a lot. I'm hoping it'll be ok with 10-12%, but I'll do what is necessary. Hey it's only a Ford, and it's under warranty!

 

[2ndAmend]

I like mine more balanced over the axles. Gives me a more stable and comfortable ride.

It's sitting on the jack.

Not sure I understand. I'm old, simple is best!

 

[DavidKFla]

Not sure I understand. I'm old, simple is best!

Balance without it sitting on the front jack. You can then tell how it's really balanced.

You don't want the ass end dragging.

 

[Jimmy N.]

I want to find the minimum, the 1/2t really sags a lot. I'm hoping it'll be ok with 10-12%, but I'll do what is necessary. Hey it's only a Ford, and it's under warranty!

A sagging butt goes with the territory when towing with a 1/2-ton. I wouldn't worry about the appearance as much as the stability...or lack thereof.

Adjusting the headlights is lot less work than undoing a tangled mess in a ditch.

 

[DavidKFla]

Crank it up. Let the weight on the truck.

 

[2ndAmend]

Crank it up. Let the weight on the truck.
View attachment 134135

Sorry, still confused. The jack was not involved in my measurements.

 

[DavidKFla]

Sorry, still confused. The jack was not involved in my measurements.

F150, 24ft. Look at position of car.

 

[DavidKFla]

Same trailer. Different car and truck. Look where the rear wheels are.

 

[Jimmy N.]

That's also a heavier trailer, putting more weight on the tongue even when empty.

 

[DavidKFla]

That's also a heavier trailer, putting more weight on the tongue even when empty.

I agree.

Did he balance with the jack down or up?

If down he might need to move it back some since it's moved up on the axles.

 

[Unholy707]

How much did that trailer weigh?

Same trailer. Different car and truck. Look where the rear wheels are.
View attachment 134137

 

[Unholy707]

Why the thumbs down

How much did that trailer weigh?