E-ticket ride

[HarveyMushman]

Originally Posted by bugpac\";p=\&quot

interesting, you have ackerman but no king pin inclination, still looks good but seems you may have concentrated on the wrong geomtry, any way my car is a dual sport as well, i actually have negative ackerman, if you think about it, when your ass end is sliding around you, you have the outside tire facing right to turnleft, so your outside tire is turning farther away from the corner or something like that, i just researched the opinions here about ackerman, and decided to go away from it....

I have had king pin inclination in other vehicles and it would be an improvement to what I have in my current buggy. *When I get around to making new spindles from scratch I will definitely add inclination.

I have used reverse Ackerman in another buggy and it worked well driving around soft berms but I didn't like the steering feel as much when driving fast around wider turns on hard pack so changed to Ackerman and liked it better. *It was an easy mod to get Ackerman in the stock Sandbullet spindles so I went ahead. *One of the many things I like about buggies is that we can research what others have done (especially helpful on this website), try different setups on our buggies and then set them up to what works best for our application.

[Bugpac]

did the othe have inclination in it, i think not having inclination will give a false result on ackerman as well....

and i agree, i just went from the most popular, i may switch mine to have ackerman later on as well...

[Rorty]

I hope this doesn't start another war of words, but I'm afraid I have to stick my hand up here.

Any on-road car (that's driven in the manner it was intended for) has two front wheels that describe two entirely separate radii as the car turns a corner – hence the necessity for true Ackerman.
There are many cases for on-road cars not to have modified or even reverse Ackerman too, but I'll try and stay focussed for this debate! *

With any car that sees lots of sideways action (like our off-road buggies), then in a corner slide, the front wheels are basically acting as one and are more or less perpendicular to the axis of the turn and track the same circle – therefore no need for Ackerman. *

On the few occasions when we do turn without applying any opposite lock, there still isn't the necessity for true Ackerman because there is invariably insufficient surface grip for it to be effective.

I'll go one step further and say that (true) Ackermann in an off-road buggy can actually slow the buggy.

When applying full opposite lock, the Ackermann effect increases exponentially the more lock is applied. This translates to drastic toe change which in effect turns the front wheels into a snowplough which will slow the buggy's progress.

To avoid this snowplough effect, an off-road buggy should run somewhere between zero and reverse Ackerman (depending on other aspects of the set-up).

[HarveyMushman]

Originally Posted by bugpac\";p=\&quot

did the othe have inclination in it, i think not having inclination will give a false result on ackerman as well....

and i agree, i just went from the most popular, i may switch mine to have ackerman later on as well...

The other buggy did not have inclination. *But I used it mostly in sand and the reverse Ackerman was fine. *It was when driving on hard surfaces that I noticed the difference.

[Bugpac]

thats cool, when is number 3 getting built, myself i will be starting number 2 next fall, got a 32 coupe to build first, will start that in april, that will be quick tho, as most parts will be bought and bolted, hopefully the profit margin will cover #2 and 3.....well i may have hard time convincing wife of that but.....

[Gene]

Thanks for the pics that helps.

SandBullet did put some inclination in the spindles and it is in the right direction. When you decide to add more inclination the front suspension will change.

Sandbullet, SSC and Sick Sand Travel front suspension geometry is similar but so far the edge is to bullet, at least there is some inclination. The unequal length A-arms you made is key.

A car that cost north of 20k should have suspension geometry that works. It seems that you have your car figured out.

[HarveyMushman]

Originally Posted by Rorty\";p=\&quot

I hope this doesn't start another war of words, but I'm afraid I have to stick my hand up here.

Any on-road car (that's driven in the manner it was intended for) has two front wheels that describe two entirely separate radii as the car turns a corner – hence the necessity for true Ackerman.
There are many cases for on-road cars not to have modified or even reverse Ackerman too, but I'll try and stay focussed for this debate! *

With any car that sees lots of sideways action (like our off-road buggies), then in a corner slide, the front wheels are basically acting as one and are more or less perpendicular to the axis of the turn and track the same circle – therefore no need for Ackerman. *

On the few occasions when we do turn without applying any opposite lock, there still isn't the necessity for true Ackerman because there is invariably insufficient surface grip for it to be effective.

I'll go one step further and say that (true) Ackermann in an off-road buggy can actually slow the buggy.

When applying opposite lock, the Ackermann effect increases exponentially the more lock is applied. This translates to drastic toe-in which in effect turns the outside front wheel into a snowplough which will slow the buggy's progress.

To avoid this snowplough effect, an off-road buggy should run somewhere between zero and reverse Ackerman (depending on other aspects of the set-up).

No problem Rorty, no war of words. *I am new guy to these threads and not trying to convince anybody of anything. *I am just describing what I did with my setup based on personal experience, surface conditions and driving style and answering questions. *I do find the various opinions interesting and usually educational. *In fact there are a few things on my buggy that can be improved.

I agree with bugpac about inclination. *Based on your experience what thoughts and suggestions do you guys have on how much inclination (degrees the top spindle pivot leans inward from the bottom) is appropriate for hard dirt surfaces? *I am sure this depends on type of Ackerman as inclination, like caster, effects height jacking of front wheels when turning. *In my case during counter-steer the inside front wheel is barely touching the ground and I like the increasing exponential Ackerman effect on the outside wheel which is doing the steering. *Rorty, did you mean 'drastic toe-out'?

[Rorty]

Originally Posted by HarveyMushman\";p=\&quot

No problem Rorty, no war of words.

Actually I didn't mean to imply that you and I might have a war of words; there are a few members here who regularly argue black is white just for their own amusement.

Originally Posted by HarveyMushman\";p=\&quot

Based on your experience what thoughts and suggestions do you guys have on how much inclination (degrees the top spindle pivot leans inward from the bottom) is appropriate for hard dirt surfaces?

KPI in a buggy can be quite a bit more than you're used to on a bitumen track - up to 15°. Castor will usually fall between 6° and 10°.

Originally Posted by HarveyMushman\";p=\&quot

I like the increasing exponential Ackerman effect on the outside wheel which is doing the steering.

It can be useful for keeping up corner entry speed and then scrubbing off some of the speed mid corner. It all depends on ones driving experience, style and track surface/condition.

Originally Posted by HarveyMushman\";p=\&quot

Rorty, did you mean 'drastic toe-out'?

Sorry, yes I should have just said toe change, as it affects both wheels differently.

[HarveyMushman]

Originally Posted by bugpac\";p=\&quot

thats cool, when is number 3 getting built, myself i will be starting number 2 next fall, got a 32 coupe to build first, will start that in april, that will be quick tho, as most parts will be bought and bolted, hopefully the profit margin will cover #2 and 3.....well i may have hard time convincing wife of that but.....

No number 3 for a while, still have some things I can change on existing buggy to improve it and I have limited free time and money. *Sounds like you have some nice projects lined up.

[HarveyMushman]

Originally Posted by Gene\";p=\&quot

Thanks for the pics that helps.

SandBullet did put some inclination in the spindles and it is in the right direction. When you decide to add more inclination the front suspension will change.

Sandbullet, SSC and Sick Sand Travel front suspension geometry is similar but so far the edge is to bullet, at least there is some inclination. The unequal length A-arms you made is key.

A car that cost north of 20k should have suspension geometry that works. It seems that you have your car figured out.

Well it's not totally figured out, but thank you though. *I do enjoy working on it and look forward to free time when I can implement something new to make improvements.

Sandbullet must have updated their spindles as on mine the upper and lower pivot line (where kingpin would be if there was one) is 90 degrees to the axle. *I wonder if they changed the tie rod end mount location.