Need some design help

[hazmat]

In chase vehicle configuration.

 

[hazmat]

There are basically two desing approaches.

1. Make the trailer "convertable" so that it can be towed with a fifth wheel or a ball

2. Make a universal hitch to fit the tractor so that the trailer can be towed conventionally.

I think with my rotating tongue idea I am leaning towards option 1.

Comments?

 

[wroughtn_harv]

Man I wish I had your talent with the puter!

I bet it didn't take you near as long to do that with colors as I did just using words.

Thanks for making my idea visible. I needed that./w3tcompact/icons/laugh.gif

 

[hazmat]

<font color=blue>Man I wish I had your talent with the puter!</font color=blue>

I wish I had your talent with the welder, and the plazma cutter, and the bender and the ......etc. etc. etc./w3tcompact/icons/grin.gif

I can cook up grand ideas in my head and on the screen, but when it comes time to fabricate, it never comes out perfect./w3tcompact/icons/blush.gif I think the melon works faster than the hands.

Now that I work for a big company, they don't let any of us engineers near any of the tools.

So Gary, is this a project for your newly learned welding skills, or are you going to let the local trailer shop take care of it?

 

[Gary_in_Indiana]

<font color=blue>"How smart is the driver you're gonna send?"</font color=blue>

Let's just say that, much like the trucks themselves, there can be tremendous variation from driver to driver, too. /w3tcompact/icons/smile.gif

As to the pintle, very, very few semis have those. The tough part of this whole thing is there is such variation in the trucks I'm buying. Some use a true cross member at the very rear and mount the rear lights in it. Others use the cross member further up toward the cab and just have some lightweight metal at the back for the lights.

 

[wroughtn_harv]

<font color=blue>I wish I had your talent with the welder, and the plazma cutter, and the bender and the ......etc. etc. etc.</font color=blue>

Stephen I've got a confession to make. It's all about blind luck when it comes to me having any kind of proficiency making things.

I think blind luck is the key phrase. You see I don't consider failure as a negative, it's just a result that turned out not exactly like we wanted. So blind, as in not seeing the potential failure, and luck, as in odds are with us. I mean you can't have negative results everytime./w3tcompact/icons/laugh.gif

I think what Gary ought to do is take our idea and make a fortune selling them to all his auction hound buds. Then take us, yours and mine, out to dinner, say in Hawaii, twice, maybe three times a year./w3tcompact/icons/laugh.gif

 

[wroughtn_harv]

Gary I think you're trying to make this difficult. Must be the potential air fare for Stephen and my dinners.

We know there is a commonality with the frame rails.

So Stephen, this is working for food, right? Imagine U bolts over frame rails picking up the reciever hitch assembly hanging underneath.

The pieces the U bolts attach are plates with two and half inch square quarter wall females for the horizontal piece with the reciever attachment.

Another option would be two pieces of a C configuration. I'd say made out of three eighths plate with a three inch leg on the bottom side and two inch leg on the top side. The inside measurement of the C would be five eighths inch.

On top of the top leg would be welded two five eighths standard thread nuts over three quarter inch holes. In these nuts would be five eighths grade eight bolts. They would be tightened down to hold the plates in place over the bottom of flange of the frame rail.

The bottom of the C would have the two and a half inch tubing pieces for the catching the horizontal reciever piece.

This configuration means having four pieces in the box to carry. The two flange brackets, horizontal tube and insert for the reciever assembly. With the flanges facing out and firmly attached to the frame rails along with the horizontal piece bolted tight you have a bullet proof hitch assembly that will fit nine point nine nine nine nine nine out of ten truck frames. The one it doesn't fit you figure the good truck gawd didn't have in your future anyway.

 

[Hank]

<font color=blue>I can cook up grand ideas in my head and on the screen</font color=blue>

What software are you using to make the drawings?

 

[hazmat]

ProEngineer

 

[Gary_in_Indiana]

And I just wish I has some talent. /w3tcompact/icons/sad.gif

Anyhow, I think the diagrams are pretty cool, too, and go a long way toward making me see the ideas.

I think I can get on the bandwagon for the 'convertible' dolly set up because it sounds like a more simple attachment when it comes time for the driver to hook the whole thing up to the truck. With that in mind, let me run an idea by you. What do you think about permanently affixing a slightly larger piece of square tube (like one of WHarv's reciever tubes) to the dolly tongue coming upmaybe half a foot at 90 degrees from it (like you show the upright part of the 5th wheel adapter) into which the tube with the 90 degree piece could be inserted?

My thinking there is that I have no reason not to have an upright there as it won't be in the way at all and that the rest of the fifth wheel adapter could be easily removed in two or more pieces. Again, the attaching pins could allow adjustments to the length as well.

My big concern (based on a lack of knowledge of what these tubes can and cannot withstand) is whether or not this tubing is going to be able to take the twisting and torquing I forsee in this application. I'd just hate to get a phone call telling me the chase vehicle and dolly took off on their own. /w3tcompact/icons/shocked.gif

The entire new fifth wheel tongue would probably run six feet from the fifth wheel to the drop, about two feet to the attachment point on the original dolly tongue and that runs about another six feet to the dolly axle. That just seems like a pretty good distance for tubing to run towing a car/truck on a dolly. Am I worried over nothing here?