What the heck's up with the steering

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jvandyke

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So we're building a cart, fitted and engine, working stuff out. Got it running a bit took a little spin around the lot, not bad. Then went to move the thing and the front wheels were pointed in different directions. I don't see anything bent. It just looks like the tie rods are too long (adjusting them in all the way doesn't make a difference). It must have gotten tweaked somehow? It sure doesn't look like it. I swear they were straight before, well, I know they were as we pushed the thing around a lot, I guess I'd better look for a tweak, eh?
Here's a shot after I pulled the tie rods. Very strange. I can trim them down on each end and should be able to close them up again, that's just nuts.
I'll go look more closely.
Looking at the picture, maybe the left got tweaked after all.
 

OzFab

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The left arm (right of pic) looks a bit bent but, the right one (left of pic) appears to be severely bent, they should both be square... (well, they shouldn't but, for the purpose of this exercise...)
 

itsid

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Ja, right.
Tony's got a point...

I missed that, even if you get the tierods in you'll basically have "Anti-Ackermann" steering afterwards.
so, bend they are indeed (probably both).

'sid
 

jvandyke

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They sure don't look bent, pretty heavy stuff and good welds, something must have bent obviously but it sure doesn't "look" like it. The two spindles don't match exactly, slightly different look to them. I will try to snap some pictures. Aren't spindles side specific? Can't swap 'em?. Well, that aborted our hugely anticipated pavement run, the run around the bumpy yard probably was ill advised (but man was it fun!!).
Having the tie rods in front of the wheels/kingpins and linkage all forward is "normal"/acceptable? Very ignorant here, sorry.
 

itsid

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Aren't spindles side specific? Can't swap 'em?.

correct, they are (they should be ;)) that's why swapping them causes some odd steering geometry.

So if -for no obvious reason- you have a odd steering geometry (caster, camber ackermann...) chances are you have the spindles swapped.

'sid
 

OzFab

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Normal & acceptable ar not the same thing; if you buy standard go kart spindles (ie: NOT racing or shifter kart style) they are square, meaning all the angles are 90°; king pin to stub axle, kingpin to steering arm, stub axle to steering arm; that is normal but, for a half decent steering setup on a live axle kart, it's not acceptable...

Have a look at this thread & you'll see what I mean...

correct, they are (they should be ;)) that's why swapping them causes some odd steering geometry.

So if -for no obvious reason- you have a odd steering geometry (caster, camber ackermann...) chances are you have the spindles swapped.

'sid

So, how do you explain the pitman arm facing up?
 

jvandyke

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thanks for the thread link, I'm learning more and more, yikes.
So to "fix" this, I'll have to somewhat reengineer the front end. I sorta thought this was an old commercial cart of some sort but now I'm not so sure, it seems well built but not well designed. I guess I'd like the quickest route to a "decent" drivable kart. I was "driveable" yesterday though the steering sure felt odd, but it was very bouncy and a very short little few laps around a tiny lot. Forward facing, upward pitman, wrong angled steering arms, both inner tie rods meet in line quite a lot "wrong".
 

jvandyke

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I guess I can find straighten what I can, get the linkage back to what it was and run it, maybe redo the whole thing down the road, I want my kid to ride around a bit, but I don't the kart to kill him!
 

jvandyke

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maybe I can redo to the pitman arm to "spread the holes out" don't know if that would get me any benefit to the geometry. I can't really see moving the steering arm/linkage behind the axle, pedals and all that right in the way, not that those can't be redone too I guess, maybe new king pins with square or outward pointing steering arms and a more thoughtful pitman arm?
 

itsid

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Looking at the before" pics, it looks like the spindles were already out of shape back then, one wheel almost straight and one in an 15° angle? that isn't right.

The spindle link has to be in an identical angle on both sides of the kart.
At least for this type of steering that is;
So that is the very first task anyways.
And while you're at it you can also include an ackermann angle to it (or at least as good as possible)

If your kart doesn't handle well afterwards, you can still mess with the pitman arm;
but I'd say not at this point.

'sid
 

jvandyke

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Thanks guys. A quick couple taps with a hammer put the right side arm back to where it was, reassembled and did a couple test runs. Good news is the kart runs great. Bad news is I've never tried to drive something so twitchy and scary. I had the alignment pretty decent, just a tad of toe-in, though it was eyeball only at this point but the geometry is so bad it's terrible. PO claimed the kart ran great, well, one man's "great" is another man's "holy #$% I'm gunna die!"
Sounds like I should redo the spindles, get the arms as far outboard as I can (staying with forward setup I guess) or at the very least straight ahead. Go from there?
 
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