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

 

[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?

 

[Gary_in_Indiana]

Harv, my very first thought on this was very similar to your U-bolt idea. I was going to use a single piece of 1/2"-5/8" plate slightly wider than the frame rails to accomodate two U-bolts on either rail. The length of the sides under the rails would be such as to accomodate one U-bolt at the rear on the angles section of the frame rail and another forward enough to be on the flat. The front side of the plate would be cut 90 degrees from the sides. The back, however, would come to a point so the plate took on the appearance of home plate. At the back point would go my trailer ball (or receiver). In the middle of the (home) plate would be a loop, hook or eye-bolt.

The driver could toss this on the ground, place a bar with an attached ratchet across the frame rails, run the ratchet strap to the center of the plate and crank it up. Then the U-bolts could be attached without having to hold and balance the plate. When that's done just unhook the ratchet strap and toss it and the pipe in the trunk, put the dolly on the ball, load your car and go.

Why didn't I go with this plan? Well, to get the U-bolts far enough forward to get the front U-bolts on the flat part of the frame rail moved it dangerously close to the tandem air bags and, even without that problem, I wasn't sure if the tension on the two U-bolts on the flat of the frame rails would be sufficient to keep the assembly from sliding back.

I know U-bolts are all that hold cargo boxes, etc., on straight trucks but also know they have the downforce of the box working for them, too.

 

[shade2u2]

Gary,
This beyond what you're looking for, but a guy has picked up trucks from us before with a "hydraulic-trailer/hitch/connector contraption" that he had custom made in Indiana - I think... Basically, he pulled in with his pick up towing this heavy-duty "trailer" full of hydraulic thingies.
He hooked up one end of the trailer to the 5th wheel of one truck. Then he tilted the trailer & drove his pick up on the trailer. He then jacked up the other end and hooked it up to the other trucks 5th wheel. He then jacked up the trailer further against the trailer axle so that the 2nd truck's drive tires were off the ground -> ready to be towed...
It was all pretty slick.
My detailed, sophisticated, diagram /w3tcompact/icons/laugh.gif /w3tcompact/icons/laugh.gif may (or may not) help to visualize...

 

[hazmat]

Gary,

If you go for the swinging tongue, you would only have to pull one pin, and then rotate the tongue. No need to assemble/disassemble the fifth wheel tongue.

If you go with a car trailer instead of the dolley, you can beef up the tongue as much as you see fit, IE build it more like a frame, than a single tube.

 

[hazmat]

Here is the beginning of a the "framed tongue"

You could add diagonal bracing and additional members as needed.

I would put a flat plate on the bottom of the rotating post to give it a bearing surface you could grease to make the rotating easy.

I think the trailer would give you better "tongue weight" on the fifth wheel, I don't know how much it takes to keep the things together. You won't have to worry about overloading the big truck.

 

[Gary_in_Indiana]

Shade,

I actually have a car trailer that works very much like that. It has an electric hydraulic tilt bed. I tilt it down, load one on the bed. So far it's the same deal.

Whereas you describe the second semi being lifted by it's fifthe wheel, I then drive one axle of my second vehicle being transported onto a platform on the rear of the trailer and secure the wheels on that axle to that platform. I then lower the bed which lifts the one end of the second vehicle and off I go with one carried on the trailer and another towed (dolly'ed?) behind it.

That concept would be slick even for the semis IF I were typically buying more than one at a time at the same place (or even reasonably on the same route). /w3tcompact/icons/smile.gif

 

[hazmat]

Gary,

Option 3. Custom built "car trailer" that attaches to semi truck fifth wheel. Custom semi truck fifth wheel in bed of pickup truck chase vehicle.

Unhitch from pickup, back the semi under, load and go!

 

[Gary_in_Indiana]

I definitely like the idea of the swinging (or at least reversable) fifth wheel tongue extension. I assume I should still be using tubing and not pipe for each of those pieces for strength, right?

The only other thing I'd want to add would be a similar connection in the horizontal piece so the length of it could be adjusted for varying distances between the fifth wheel and the rear of the frame rails and so that when the dolly isn't being used as a fifth wheel option the tongue extension could be removed in smaller, lighter sections.

Would it be reasonable to attach a tube sleeve atop the vertical piece (making it something between a 'T' and an 'inverted L') through which the horizontal piece could be moved then pinned?

 

[Gary_in_Indiana]

Stephen,

Option three (already suggested by one of the guys here who's been campaigning for a company four door dually 4x4) changes the concerns from "fabricating and framing" to "funding" this plan. /w3tcompact/icons/smile.gif

 

[Anonymous Poster]

Gary, since yer havin so much fun with the CAD program, here's option Q.1.2
Tubular member from 5th wheel to double channel (similar to meat rail hanger) across frame rails at tail end of truck. {may have to sit foreward to accomodate beavertail rails, so this cross member would slide on tube like Reese}.
Drop leg from tubular assembly to 18" ball height for dolly.
Cross member could be U bolted to frame rails.
Make in 3 pieces, and pin together so it could ride in chase car trunk, and easily assemble by driver.
Blue piece (5th-rear could be telescopic to accomodate different 5th locations) Red piece (teletoung assembly to ball dropleg, inserts into teletoung) Green piece Cross member with sleeve for teletoung)
[censored], this is almost as much fun as Christmas assembly directions.

 

[Gary_in_Indiana]

Was there an attachment that was supposed to go with this showing all the colors you described?

Actually, it sounds like kind of a hybrid of the two styles. the fifth wheel connection provides the actual connection point to the truck and the cross member eliminates lateral movement and the pivot at the fifth wheel. It sounds like a workable plan. /w3tcompact/icons/smile.gif