Using a locomotive wheel style coupling rod to offset the steering column?

Has it been done before / Can it be done?

If you have too wide an engine so you must offset the steering column quite a lot
Instead of using gearboxes or chains
Can you actually use a coupling-rod like the ones on locomotive wheels?
http://en.wikipedia.org/wiki/Coupling_rod

IMO this might be safer and more confidence inspiring than chains.
Also it might have less free play than gears.

Any downsides, challenges, comments or advice?

 

What's it in??? Lets see some pics so we can properly assess the situation.
My first thought would be HELL NO, but then I couldn't offer any solution because of no pics.

Scotty

 

wouldnt be able to turn the wheel a full rotation though, the arm would hit it

 

Won't work.
What's going to happen when the rod pushes the wheel all the way to the left or right. It will stop. If it doesn't, there is a 50/50 chance that it will reverse and you'd be turning right and going left or vice versa. Locomotives, I'm sure, have the rods on either side phased so when one is at the front of the driver, the other is at the rear. Sort of like a pedal car'
What's wrong with u joints?

 

There is a company that builds boxes that offset the steering, never seen one except in advertising. I think it uses double roller chain similar to timing chain.

 

I don't understand why people are so paranoid of a roller chain and sprockets. I've seen dual steer garbage trucks that use roller chain to transfer motion from the slave wheel to the master. If roller chain survived on motorcycle final drives with 50 or more HP it sure as fuck will withstand the 1/7 HP a human can exert with his body! all you need to make it work is an adjustable dogbone between the 2 shafts to keep the chain tight. The dogbone can be 2 grease-able heims joints, if you want it enclosed build a sheetmetal box around it.

 

A rural mailman that delivered my mail had a conversion on his Dodge truck that had a pully and v-belt arraingment to move the wheel. That truck had power steering.

 

Motorcycles are driven with chains. The timing in your engine is a chain. Sure, they break once in a while. But how often are they going to break in the relatively low stress protected environment of your dash and steering?

A rod won't work because you'd only have about 300' of total lock to lock turning radius before the rod hits your steering shaft.

 

Think it thru -

You'll find your answer

 

It would work with the right geometry. There are several advantages to the chain and gear though. One is ratio changes.

 

As long as both shafts ended at the "crankpins", and the connecting rod was the only thing in between them, it should work fine.

I do agree that the enclosed chain setup is proven technology. I guess the locomotive rod thing would be perfect for a "steampunk" style rod, though...

 

Something along those lines was used on early 1960's dragsters, a bell crank not a Loco rod. Bob

 

Bellcranks can be used to offset steering as long as the bellcrank is inserted after the steering box. There is a car in a relatively recent issue of the Roddders Journal that uses this exact setup. You can not use a bellcrank before the steering box because they are in my eyes, only good for 180 deg. of operation without reversing direction. I've done a few where we used bellcranks in the sidepanel to lower the pivot point of the cowl steer to put geometry in place, never to offset a motor. The trick is getting the bellcrank solidly mounted enough to not induce slop of it's own.

I'd like to see some pics of what your up to. This is the stuff hot rodding is all about!

 

Problem with the loco rod set up is that it worked on locos because there was two sides and the rods were "quartered" or a 1/4 turn different on each side. So that they wouldn't "get stuck".
With just one, if the shafts were both at either 3 or 9 o'clock and you went to turn the wheel the oposite shaft could go the wrong way. and then they'd be out of sinc.
When the locos had a broken rod they had to watch how/where they stopped the engine in relation to the rod position or they wouldn't go again without a push.
(hope thats clear)
-Pat

 

And the OP could do the same thing, two rods phased 90 degrees apart. Complicated yes....

 

I once had a wheel, it was a good wheel but I thought that I could come up with a better idea. Turned out that what I invented was not a wheel at all but it was damned good at catching mice.

I used a double row timing chain on the engine, it spins 3K plus for hours on end, it currently has about 150K on it. I may change it when I freshen the engine unless it isn't worn out yet.

If you run a double row chain on the steering in your car it is not going to make nearly as man revolutions or have the same amount of torque applied to it as the chain inmy engine @ 150K. I seriously doubt that the average person on this board will put that many miles on their rod before they die or sell it.

 

While it did not prove or disprove the use of a locomotive connecting rod, this thread made a great case for chain steering!

 

A locomotive style cuppling will never work as smoothly as a chain if it works at all.

If you have ever watched one they have a lot of slop in them and it is designed in to them. You are using an excentric to transfer rotational torque. Think of your steering working in a herky jerky fasion.

 

I've seen chain driven steering at Bonneville, if it's good enough for 200+ it should be good enough for the street.

 

The reason that the crank pin application works on locomotives is because the secondary wheel is touching the track, same as the drive wheel. When the pin gets to its forward-most position, the secondary wheel continues to rotate through this "deadband" area due to its contact with the track. You don't have that situation in your car and when you reach the forward-most position, the secondary wheel could easily rotate either direction, depending upon the forces being fed into it by the steering geometry. Use a roller chain, even a dual roller chain if you get queazy thinking about a single chain breaking.

 

DOH! I guess there really is nothing to "push" the driven shaft uphill when it's in the 3 or 9 o'clock position...

 

Oh oh, is this the next hot trend??

 

Stude while it has been many years ago I worked on several short track cars that had the steering column relocated with a chain and sprockets. They obviously seldom reached speeds of 100 MPH but the steering really took a beating on them when they were riding over berms or banging into each other.

I think that the locomotive idea is something to ponder and maybe with enough money and engineering prowess one could figure out a way to make it work but I see no reason to waste time on it when that time could be well spent on something else.

Someone mentioned single row and double row chain in a different post. About a month or so back I rode a motor cycle that would roast the tire @ 80 MPH. It has a double row chain for its primary drive and a single row for its secondary drive, the guy that owns the bike rides it every day as his primary form of transportation and he does not seem to concerned that eiher chain is going to break.

Granted both chains are probably 50 or 60 pitch which is not what most people use in ther cars when they move the steering column, I am just using it for an example.

 

If you really can't live with a chain, use gears, you will need 3, and the slack adjustment is a little more complicated.

 

I have one. If I remember correctly it's called a steer clear and uses a chain. I installed one in my 31 coupe after I had a construction accident which amputated my right leg. The steer clear got the column out of the way,and up higher so it would interfere . It could be off set to the side to get you past the motor also.

 

Still waiting to see photos of the application here, so we can make an actual call on this one.
What about a good old cowl steer set-up? Gets around the wide engine and it's traditional as anything.

Scotty

 

Chrysler used to offset their wide engines to the passenger side, some as much as 1.25".

I've never seen an OEM factory production vehicle with chain steering...

But, as Benno pointed out, there were some roundy-rounds (jalopies, 'hard tops', and Sportsmen) that, while lacking in the 'engineering dep't', could still steer the course.
Some chain/bracket breakage occured, such as intersection accidents in 'Figure 8' races.

But on something 'pristine', like Bart Root's '29 Highboy...the Niekamp roadster...Naaaah...

 

I still want to see how the railroad wheel connection would steer a car even in conceptual form?

I can't see a well engineered chain steering unit ever giving cause for concern.
If it does, a standard rag joint ought to keep you up nights too.

 

Something like this. Takes to arms to get over the "TDC" problem of one arm.

 

It would be possible to construct a drive rod mechanism to do this. You would need at least 2 drivers, and don't put them at 180 degrees or they will lock or bind. Offset one of them, or use 3 rods at 120 degrees to each other. It would resemble a crankshaft and connecting rods in miniature.

I wouldn't want to pay the machine shop bill.

Some Bentley OHC engines from the thirties used drive rods to drive the OHC. So did a German 250cc motorcycle.

It would be way easier, and cheaper to use chain and sprocket or better yet design a proper steering mechanism.