A wild day

[Willowbilly3]

I got my rpu inspected this morning and got the VIN tag.[cl[cl I got home put the tags on and went for a ride. I drove around town all afternoon, weighed the car, took and old friend for a ride, ran some errands. Everything seemed fine other than a little shake from my junk front tires, at around 60 or so. Then I was coming back into town, 35 mph speed limit and it went into a violent death wobble that wouldn't stop. I was on the brakes and only going maybe 15 or so, still violent wobble. And then lost the steering. It was on a 4 lane and I was in the left lane, came across and hopped it up on the curb on the right hand side. I got it towed home and found that the center had broken out of one of the sprockets on the chain drop I designed for the cowl steering. The chain is #60 and I thought would be plenty strong. Bad idea and bad design. I haven't liked it since I had the car driving. Now I will re-engineer the whole thing. In order to run a standard type of steering box, I would have to make new pipes. I am considering a cross steer so I can snake the steering shaft inside my pipes. I'm done with the cowl steering. Most of them I've seen don't seem to have much room for big feet like mine.

 

[Flipper_1938]

I'm glad you are alive to take a second swing at it.

 

[Snake Farm]

Holy crap! That sucks.......but I'm glad you are here telling us about it instead of us wondering what ever happened to that 'Willowbilly' guy

What did it weigh? I'm guessing it was lighter after you crapped your pants [ddd
Hope you get it worked out soon so you can get back to enjoying it.

 

[sgtpontiac]

That is one scary story!!!

Glad that it took the curb side and not into oncoming traffic.... Sounds like you have a good plan....let us know how it's going...hey, take some pics of the old set up before you dismantle it....might be a good learning tool for some of us to remember...Please....

 

[Willowbilly3]

Here is a picture of the basic setup. The steering box is upper right.

The bottom sprocket is on the shaft that has the pitman arm.

The lower gear is for a farm implement, the kind that is 2 piece and you weld them together. The weld is on the opposite side, can't believe it failed. Temporarily, I am going to drill a set screw on the parting line to hold it together, and the also weld it. But it isn't going back on the road that way. It's just so I can move it around.

 

[GJunktionMike]

That will get the blood pumping

 

[Sam_Fear]

I never thought about it until now, but I now understand why some guys have redundant chains on their steering. Glad yer alright WB.

 

[sgtpontiac]

Now that I see the pic....

Here is a picture of the basic setup. The steering box is upper right.

The bottom sprocket is on the shaft that has the pitman arm.

The lower gear is for a farm implement, the kind that is 2 piece and you weld them together. The weld is on the opposite side, can't believe it failed. Temporarily, I am going to drill a set screw on the parting line to hold it together, and the also weld it. But it isn't going back on the road that way. It's just so I can move it around.

I can remember you posting pics of the set up...looks pretty darn strong to me....hard to believe it failed...Wow....

 

[YBeNormal]

What caused the death wobble? Do you know? Was it the steering setup? or did the death wobble break the steering?

Glad you're ok man.

 

[Willowbilly3]

On top of everything else, it's a little embarrassing to have one of my welds fail. Part of what I do for a living is welding. Right now I'm in the middle of building buffalo handling systems that I helped design.
Which brings me to another point. It is my contention and the opinion of a few old timers that there are things you shouldn't trust a wire feed weld for as the weld is too brittle and doesn't penetrate as well as some stick rod. The center hub that failed was welded in with a wire feed.

 

[donsrods]

Wow, just think how lucky you are.........that could have happened at 60 mph!

A friend of mine through some forums built a similar system for his 32 Ford, and he did it with a double roller chain setup and an idler sprocket in between on each side, putting tension inward on the chains to keep them tight against their sprockets. He also put an outside cover over the sprockets and chain to keep stuff from getting into the chains and to provide a strong setup so the two sprockets can't pull toward each other under stress.

He tried one idler sprocket at first then went to two because he felt it would keep better tension on the chains when turning either direction. He owns a motorcycle aftermarket company and adapted chains and sprockets from that industry.

Don

 

[Willowbilly3]

After building this, I realized implement roller chain was never designed to be free of any slop. It generally pulls in one direction, often without a tensioner, the slack just drops on the off the side opposite from the pull. In hindsight, I should have designed it around silent chain, like timing chain is made of, with tensioners.
As Don and some of you others well know, this kind of stuff is part of the engineering process. I started with an idea to use a power steering box tucked up under the cowl. From the time I first built the cowl hoop and mount for the box until it finally got finished was several years and it became evident that there was no way the original design would work out as far as the steering geometry. Not wanting to give up on something I had so much thought and labor into, I decided on the chain drop. That in itself was a butt load more development and at one point I almost threw it all away and started over. I probably should have.

 

[CR55]

Wow! At least you're still with us to design another system!!! good deal with finally getting DMV to issue your tags...

 

[Dirtyrat]

Wow, glad you are ok!!!!

I'd like to see how that 2 piece setup looks... is it the hub center that is welded to the outer with teeth? I imagine a proper bevel would have helped immensely for strength...

And it makes total sense about the chain, just like a timing chain needs a tensioner...

 

[Sam_Fear]

We will need pics of the carnage too. So any idea what caused the death wobble?

 

[bruno]

That sucks, glad you're ok. Think i'll go with corvair steering now!

 

[bob w]

It's possible the high speed death wobble broke the sprocket. If the chain set up was on the steering wheel side of the box it is doubtful it would break. But that wouldn't accomplish what you needed.
Sure glad you are okay.

 

[Magnum]

1st off, glad you are ok, & didn't hurt anyone else either... I was thinking the same thing

It's possible the high speed death wobble broke the sprocket.

& as for weld penitration, I'm a newbie at building hot rods, but have been using a stick welder & being very concious of penitration, & being a veteran stick welder, & newbie with the wire feed, I opted for the more time consuming stick method when doing my frame mods...

so do you think with a #60 sprocket, you likely only got 25% penitration with the wire feed ??? I'd suspect that was enough for normal use, but strong arming a death wobble, I'm sure put addition stress on it

 

[CORPO]

Scary man.. glad you are ok...

I have a chain in my system as well mine is still not road tested... but I put it on the steering wheel to the steering box... so that the steering box carries the load rather than the chain and sprockets... its double chained, tig welded and drilled with a set screw just in case.. its also designed so that the shafts are double shear so that there is no deflection.. to but i have been told I over design things..

good luck sorting out your new set up

 

[Willowbilly3]

We will need pics of the carnage too. So any idea what caused the death wobble?

Not really. All of my front end parts are new including the king pins. When I took it out on the highway, I had a little tire shake at about 60, not bad but I could see it. The tires are junk and the dufus at the tire shop must not have balanced them. New tires before it goes back out (and the Fenton Hawks).
corpo, your system will be under a lot less pressure, due to the 16:1 or so ratio that most boxes have. It's no doubt stout enough but that kind of chain just isn't made to be or stay tight, as soon as you drive it, it will develop slack. Not much but it doesn't take much to equate to steering wheel play.

I thought mine would be plenty strong for the task but just didn't anticipate the sheer forces of a violent wobble.

Dirtyrat, these are common machinery sprockets found in farm stores. They have different teeth counts and different shaft size hubs, that way you can make up the sprocket you need. The come with a slight bevel and are made to be welded together. I have no idea why I didn't weld both sides.