4 wheel trailer with front wheel steering questions

[Steve_Cox]

lol thats cute...

As per the geometry of having it follow the tow vehicle properly, how do diff length vehicles get away with it following an RV? A jeep cherokee would have a diff wheel base than say a toyota corolla. Both seem to be favorites for tow behinds. The tow bars are not extremely differant

Then beg's the question, how are they to back into place. Are you sliding the front wheels on the ground?

If its only asthetics, How about sliding axles... they are together at the back when towing, but when ya get there, slide one axle to the front just for the look.

It's all about the aesthetics, wanting to go fast was possibly secondary. Maybe building on an unsprung hay hauling gear is the way to go. Somewhere there is the right trailer gear for this project, however obscure it seems to be at the moment.

[brian_bp]

Outside the Box thinking: I wonder how a small 5th wheel receiver would work mounted on car dolly

Car dollies come in two versions:

the car sits on a turntable, which lets in rotate on top of a non-steering axle
the car sits directly on the dolly frame, but the dolly wheels steer (often only by castering)

In both cases, the 5th wheel hitch would be redundant, since the dolly already has the steering pivot in it, but some way to pivot in pitch would be required; if this were done with a 5th wheel, the steering built into the dolly would be redundant.

A car dolly has one other big problem: it doesn't have suspension. Normally they depend on the towed car's suspension.

By the way, although rigs built up of a dolly and some other hardware could work, I believe that they would almost certainly not be legal for recreational use in many jurisdictions.

[brian_bp]

What about an articulating front wheel setup with some sort of return to center dampening system and the hitch is hard mounted to the trailer frame. It would pull like a small car behind an RV.

Harder on tires yes but no weight on the tow vehicle and proper asthetics.

Yup, they make those, or have in the past. Seems the important thing, high speed operation aside, is to get the tongue length right so the rear wheels of the tow vehicle and the turning wheels of the trailer have the right geometry to cause the tow to follow the track of the tow vehicle.

In this type of setup, you basically have a trailer with its normal axle at the towed car's rear axle, and an extra castered wheel set holding up load at the front. The track taken by the towed car cuts in severely on corners because it is so far back. It works with any length of towed car because even the shortest car is long to the rear axle.

The trailer will not follow the track of the tow vehicle... it cuts inside on turns like any trailer.

I think the difference between how well vehicles work for this is in how well the front suspension and steering caster. It's not how they are supposed to be driven, but it works... it's certainly not what I would want to deliberately produce.

Backing up works as well as castering works in reverse; that is, lousy.

By the way, I've seen full-size truck-based SUVs flat-towed behind motorhomes... when you have a ten-ton rig, what's three more tons?


If you do want to more closely follow the track of the tow vehicle, then you must connect a pivoting drawbar/tongue to the steering of the trailer. Then...

I think the key to coordinating the tracks taken at each axle of a steered trailer has four factors: the tongue length, the distance between the axles of the trailer, the distance from hitch to tug's rear axle, and the "steering ratio" (how much the trailer's steering wheels turn compared to how much the drawbar/tongue is turned).

The trailer's steering wheels could nearly follow in the tracks of the tug's rear wheels, but the trailer's rear wheels will not follow in the tracks of the trailer's front wheels, unless they are countersteered as well... which would not be stable at speed. This is done in low-speed stuff like the baggage trains at airports.

[brian_bp]

why not start with a car/truck frame and axles and build on top of that. Then just flat tow it like a car.

That could work, although the frame is usually not all that well suited to mounting a trailer. All of the parts could be used, although the parts which would fit best in a trailer would include an A-arm front suspension (rather than struts) and non-driven rear axle... and that's a virtually non-existent combination in a single vehicle.

Rather than using a rigid drawbar and castering the front wheels (like a flat tow), I'm sure that this would be more desireable with a drawbar linked to the front wheels' steering, just like the many commercial chassis equipment sets which are sold for exactly this purpose.

Since the highway-speed chassis sets for trailers seem to generally come from Europe, salvaging automotive parts to build your own seems like a reasonable choice for someone in North America. Given the desired look, my guess is that a beam axle from a two-wheel-drive light truck at the front and a regular trailer axle at the rear, both on leaf springs, might be a good fit.

[Steve_Cox]

why not start with a car/truck frame and axles and build on top of that. Then just flat tow it like a car.

That could work, although the frame is usually not all that well suited to mounting a trailer. All of the parts could be used, although the parts which would fit best in a trailer would include an A-arm front suspension (rather than struts) and non-driven rear axle... and that's a virtually non-existent combination in a single vehicle.

Rather than using a rigid drawbar and castering the front wheels (like a flat tow), I'm sure that this would be more desireable with a drawbar linked to the front wheels' steering, just like the many commercial chassis equipment sets which are sold for exactly this purpose.

Since the highway-speed chassis sets for trailers seem to generally come from Europe, salvaging automotive parts to build your own seems like a reasonable choice for someone in North America. Given the desired look, my guess is that a beam axle from a two-wheel-drive light truck at the front and a regular trailer axle at the rear, both on leaf springs, might be a good fit.

My thoughts as well on that type of running gear.

But I still think there is something else out there that would give the traditional look and not be constrained by only traveling 35 mph. I saw a picture of what I'm looking for the other day, just can't remember where

[Ron Dickey]

you might look at this book
freewheeling homes by David Pearson

offers gypsy wagons and a 4 wheel trailer home pulled by a old truck
offers lots of ideas and history
in my gallery there is a trailer that has 2 front wheels only under the tung pull-a-long not made there were plans to restart it but it never happened.
I always wondered about 3 wheel trailers and 4 wheel too.
good luck
Ron D.

[Steve_Cox]

you might look at this book
freewheeling homes by David Pearson

offers gypsy wagons and a 4 wheel trailer home pulled by a old truck
offers lots of ideas and history
in my gallery there is a trailer that has 2 front wheels only under the tung pull-a-long not made there were plans to restart it but it never happened.
I always wondered about 3 wheel trailers and 4 wheel too.
good luck
Ron D.

Ron,

Thanks, page 76-79 was where I saw the photos I've been looking for. I have a copy of that book in my gypsy caravan. (duh). The trailer that has the running gear I've been searching for was built by Dan Wing in Vermont I've searched the internet for more photos and his e-mail address but can't find them so far. I did find his medical office phone number and will try to make contact with his office tomorrow. He and his wife have traveled the country in this trailer pulled with a vintage pickup truck, so it must pull pretty well. I think he might also spend some time in Petaluma, CA. Maybe he's just an old hippie in disguise. Sure would be nice to get to know him and talk trailers. Any readers here know this talented fellow?

[jhouk2000]

Here is a trailer that represents what I think Larwyn is talking about.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... gory=73934


A friend of the family had one of these trailers a few years back and I have witnessed it being pulled by an S-10 with 2 horses at interstate speed with no problems. (both axles had brakes) The steering on it was different from what is on a "hay" wagon running gear.

(I can draw this up in ACAD when I get to my other computer)

On the horse trailer above the two front wheels are mounted soildly to an axle parralell to each other, much like a Radio Flyer wagon. When you turn the axle pivots on a center point. I am unsure of how the suspension was configured.

A "hay" wagon running gear has each front wheel mounted to a spindle that turns with the tongue much like a car steering.



I hope my minimal knowledge can help out some.

[Steve_Cox]

Here is a trailer that represents what I think Larwyn is talking about.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... gory=73934


A friend of the family had one of these trailers a few years back and I have witnessed it being pulled by an S-10 with 2 horses at interstate speed with no problems. (both axles had brakes) The steering on it was different from what is on a "hay" wagon running gear.

(I can draw this up in ACAD when I get to my other computer)

On the horse trailer above the two front wheels are mounted soildly to an axle parralell to each other, much like a Radio Flyer wagon. When you turn the axle pivots on a center point. I am unsure of how the suspension was configured.

A "hay" wagon running gear has each front wheel mounted to a spindle that turns with the tongue much like a car steering.

I hope my minimal knowledge can help out some.

Thanks for the link and the input. I wonder about the suspension with that type of steering too. By the way that type of steering is called "5th wheel" steering. Here's a link that shows several types of trailer steering http://www.irwincar.com/trailers_steering_options.html i think what would look best under a classic looking shepherd's wagon or vardo would have to be something pretty old with artillery wheels.

[Rigsby]

Steve, there are a lot of what we call drawbar trailers over here in europe. They come in 4,6,or even 8 wheel designs, but are all associated to the commercial haulage or agricultural buisnesses. The haulage ones have each wheel sprung by either leaf springs or airbag suspension, and ALL wheels are braked, by air brakes, The drawbar design is of A frame construction, rather than straight bar. If you do build on this design, make sure that any journey is nearby, as you cant go very fast with this type of trailer
A couple of pics for you


steve

[brian_bp]

...The drawbar design is of A frame construction, rather than straight bar. If you do build on this design, make sure that any journey is nearby, as you cant go very fast with this type of trailer

That drawbar would indicate that they are the "5th wheel" type, or what the BPW chassis page calls "turntable drawbar trailers". On the other hand, BPW (apparently a major Euro trailer chassis component supplier) also sells steering axles (wheels each steer via linkage to a pivoting drawbar) which are used in the front of what they call "twin axle" trailers (see a steering axle on their Axlespage); these follow the automotive steer design in the Irwin list.

A turntable-type car dolly is a "5th wheel steer" configuration; they are routinely pulled at highway speeds, so the basic configuration doesn't seem like a problematic limitation to stability.

[Larwyn]

The trailer I was talking about was used when we got it in the early to mid 60's. It had a steering axle with king pins and tie rods like the front end of most pickup trucks of the time. Best I can remember it may have been built by a company named Dilly.

[Steve_Cox]

Lots of good info, thanks guys.

I found out more about the gypsy trailer I had been seeking information on, it was featured in a book about Craftsman style houses. Funny place for a gypsy wagon. Anyway, the builder of the trailer mentioned he wasn't too happy with the suspension or lack of it, but he didn't mention the steering. Very likely it was an old hay wagon, because he also said something about getting a team of horses to pull it.

Lately, I've watched a few fifthwheel turntable type trailers in tandem do a lot of swaying at highway speeds. Don't think that would be too stable in a light weight rig.

I got behind a trailer load of cabbages yesterday, finally passed the guy, he was doing 55-60, with no problems. When we got to the next small town I got beside them at a stop light. The driver caught me ogling his cabbages and gave me weird look. It was a farm trailer with lots of leaf springs, a pivoting tongue and tie rod steering linkage and brakes on the rear wheels only. The trailer looked pretty old as it had artillery wheels that looked to be at least 16" or more with regular trailer tires. It wasn't very big either probably 7' X 12' with a pental hitch. The truck had the name of the farm on it. Maybe I can get a better look later.

Now I have a new hobby: Farm auctions

[PanelDeland]

There are a lot of variables to the design.I do know that someone conversant in auto suspensions could probably point you more in the right direction but a term called "Ackerman Steering" or "Ackerman Angle" would most likely come into play at hiway speeds.