Heymow - Lawnmower Racing Forum

Mower Building / Setup Help => Chassis => Topic started by: George Herrin on March 04, 2006, 07:55:02 pm

Title: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on March 04, 2006, 07:55:02 pm
Adjusting & Understanding the New E.C. Distributing Mower Front-end Geometry and why it works so well on your mower.
Front-end geometry correctly and accurately set is the key to get the most out of any mower as is with all racing vehicles. Tire wear handling, drivability, and even engine performance can be seriously affected by poor settings whether it's caused by neglect and or damaged or worn components. A mower chassis is totally different than a car chassis, and so are the setups required to make the mower work properly. While they share the same steering geometries as a racecar, a mower's setup is lets say for a lack of better words exaggerated. A mower is combining a solid rear axle (no differential) with a much shorter wheelbase as compared to the very wide track of a racecar, which presents very odd problems for front-end geometry. Now lets say we set up a mower like we would a racecar set up for a road course. You would experience severe under steer at the moment of turn in. Now some of you may have heard me explain that if you blow the initial turn in, you are playing catch up to the next turn. Now back to the subject, this under steer you would experience is because the combined grip of the rear tires would simply push the front wheels straight. Now to overcome this problem, a mower needs to have the steering geometry set up so that it will lower the inside front wheel and raise the outside front wheel in relation to the chassis at corner turn-in. This is very important. Now this changing of the front wheel heights will cause a weight transfer from the inside rear wheel to the outside rear wheel and the inside front wheel. And this will mechanically lift the inside rear wheel off, or nearly off the racing surface at the moment of turn-in. Now once your mower is turned into the corner, this mechanical weight transfer now is no longer important and is superseded by weight being transferred due to forces of cornering. I cannot begin to tell you how important the transferring weight from the inside rear tire of the mower at corner turn-in is. It is so important that almost every steering geometry angle and setting is designed around this. And another thing is a mower that does not do this enough, or does it too much, will not handle well. If it don't lift the inside rear wheel enough, then the front wheels of the mower will tend to slide at turn-in, then all of a sudden gain front grip and throw the rear end into a slide. Now this can be one of the hardest and most difficult ill handling issues to drive with and 9 times out of 10 is mistook as a rear grip issue because the rear end slide is such a strong feeling. Now the opposite if it lifts the inside rear too much, it could cause the mower to feel twitchy and hard to drive it smoothly. Now again this initial turn-in weight transfer is one of the most important factors in making the chassis turn and is mostly all a function of the correct front-end set-up. So getting this correct without a doubt very important. And although it is very important to drive mowers smoothly, would you believe it's possible to be too smooth when turning into a corner. Yes that's right it is possible. Let me explain that one, if when you turn the wheel too gently at the initial turn-in, the mower can act just as though it won't transfer weight from the inside rear wheel. Think about it but this article is not about how to drive it is all about the front end. With that being said lets look at the individual settings and how they work.
1.   Toe is how much the front tires point toward or away from one another. If they are point towards each other this is called toe in. This can make a mower more directionally stable but at the same time make for poor turn in into the corners. If they are pointing away from themselves this is called toe out and is the opposite of toe in. it will make a mower directionally unstable but yet help the mower to initially turn in better. With it toed out, the inner front tire will move down relative to the chassis more so than it would with toe in or no toe in. Toe in any direction causes friction at the point the tire touches the racing surface. This heats the tires that in some cases could result in over heating and also leads to excessive tire wear. This is all generated from the engine power that is not used to accelerate the mower down the straight. Lengthening or shortening the tie-rods adjusts toe.
2.   Camber is the amount the front tires lean in or out from each other. With the tops leaning in this is negative camber. With them leaning out this is positive camber. In order to gain the most grip from your tires you want the largest amount of the tire patch as possible on the ground while cornering. This is obtained mostly with camber adjustments. Camber is adjusted using the camber adjusters at the stub axle mounting (screwing the ½ rod ends in or out) But if the king-pin bearings are housed in the stub axle, caster and king-pin inclination will also change when you adjust camber settings (mowers with the king-pin bearings housed in the chassis (not using ½ rod ends) have no adjustment for caster or king-pin inclination). Not all mower front ends have adjustable camber, caster or kingpin inclination.
3.   Caster angle is the leaning of the tops of the king pins (the bolts that the stub-axles pivot around) rear ward. Caster is responsible for the self-centering action of the steering and is also an important factor in lowering the inside front wheel and raising the outside front wheel of the mower at corner turn-in. The greater the angle, the greater the changes of the front wheels heights. Caster also causes change of camber when the steering is turned, which results in more negative camber on the outside front wheel and more positive camber on the inside front wheel. Caster is adjusted using the 'camber' adjustable plate ends on the axle by loosening the jam nuts on the ½ rod ends.
4.   King-pin inclination is the inward lean of the king-pin (up, towards the centerline of the mower). It causes some of the self-centering of the steering also. It also modifies the amount of camber change caused by the caster angle when the steering is turned, lessening negative camber gain on the outside front wheel and increasing positive camber gain on the inside front wheel. It would be unusual to deliberately alter KPI, but it can be adjusted.
5.   Scrub radius is the distance from the center of the tire at ground level to the point where a line drawn through the kingpin axis intersects the ground. Scrub radius works with the caster angle to alter front wheel heights in relation to the chassis. The greater the scrub radius, the greater the front wheel height changes. Increasing scrub radius will also widen the front track. This track increase effectively softens the front end of the chassis, possibly increasing grip. Scrub radius is adjusted using the track spacers on the stub axles.
6.   Ackerman effect is caused by the relationship between the position of the kingpins and the position of the outer tie-rod ends (the inward angle of the steering arms) and by the use of two separate inner tie-rod end mounting positions. Ackerman effect causes the inside front wheel to turn substantially more than the outside front wheel. Mowers employ far more Ackerman effect than almost any other type of vehicle except karts and it is used for somewhat different purposes than on a car.
A car uses Ackerman to minimize the effects of tire scrub when the vehicle is turning a corner. A mower (mostly) uses Ackerman effect (in conjunction with caster angle and scrub radius), to make the inside front wheel move downwards as much as possible how!! (By making it turn more), in order to raise the inside rear wheel at turn-in. Some mowers have adjustable Ackerman, involving the use of different length tie-rods, and mounting them in different holes on the steering arms and/or steering column.

SOME MORE FOOD FOR THOUGHT
The next time you are at the races look around the pits and you will probably see quite a few mowers using noticeably negative camber settings. Some of these mowers will be this way through neglect, but many will have been deliberately set-up this way. Some mower racers see many full sized racing cars using pronounced negative camber settings and conclude that if it works for them, it should work for me too. Unfortunately the only problem with this theory is that most racing car tires use radial construction and have very soft sidewalls, while most mower tires we use are as low a profile as possible and mounted on wider than normal rims which help provide stiffer sidewalls, and doesn't work as well with the large camber settings for this reason.
Many racers will spend large sums of money having their engines blueprinted and getting the latest new pipe for their mower, in the belief that the only way to go any faster is to get more out of the motor. Yet many of these racers are simply wasting some of the engine power they already have, and every little bit counts! Engine power can be unnecessarily wasted in two ways, friction in the wheel bearings, and incorrect wheel alignment. Both of these problems cause an increase in the rolling resistance of the mower, which means more power is required to allow the mower to maximize it's speed and acceleration. Since the engine doesn't magically gain power because the mower has more rolling resistance, it goes just that bit slower, and will probably handle poorly. Try thinking about it this way, if you're losing only ½% per lap to the mower in front due to poor alignment (or any other reason) then in ten laps, on a 256-foot track you will lose 12.8 feet. Think about it. It doesn't even take a mower length to lose a race!
So what is good alignment? A well aligned mower will have the toe and camber settings at, or close to zero toe and camber. This will ensure that the tires are being used as they were designed, not slowing the mower on the straights and also maintaining a wide patch of rubber on the track in corners. It will also have enough scrub radius and caster to adequately lose grip from the inside rear tire (a mower should effectively be almost a three wheeled vehicle in corners). Most mowers, most of the time, will handle and accelerate better with toe set to absolute zero. Sometimes slight toe-out will help turn-in to corners, but rarely more than 1/8" except in wet conditions, when larger toe-out settings can be helpful). Setting camber to zero will nearly always be the best starting point, and can be fine tuned using tire wear as a guide, or tire temperatures across the tread which on the loose dirt or grass tracks we run isn't that noticeable.
A general rule of thumb is the less available grip; the more scrub radius, caster and tire pressure should be used.

NOW the rest is up to you!!!
Title: Understanding E.C. Distributing Mower Front axle geometry
Post by: Mowindown on March 04, 2006, 08:37:02 pm
Great info George you are the KING.  When I grow up I want to be just like you  :D .  Thanks
Title: Understanding E.C. Distributing Mower Front axle geometry
Post by: mowcephus on March 04, 2006, 08:41:03 pm
Very good info for sure.  Now if I can put all that info to use!  :roll:
Title: Understanding E.C. Distributing Mower Front axle geometry
Post by: mightymowe on March 04, 2006, 10:38:01 pm
well said,thanks, read and learn
Title: Understanding E.C. Distributing Mower Front axle geometry
Post by: SilentNoise on March 05, 2006, 04:22:46 am
Wow. That's one heck of a write-up with some well laid out info.
Title: Understanding E.C. Distributing Mower Front axle geometry
Post by: Goosinthamower on August 01, 2006, 03:50:34 pm
I enjoy reading the old post now more than ever after Squidd made me realize i was a dumbass!! But anyways this really helps anyone who is trying to build a competitve mower. Unlike other sports where you have to figure out things like this on your on.
so thank everyone for previous posts !
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: IBuiltmine-o1oo on December 08, 2006, 12:54:01 am
Wow.. If every mower racer doesnt read and read and re-read this, then they are missing out.
this is a freebe, and every mower racer should take advantage of it!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: dang107 on January 20, 2007, 10:01:58 am
nice job putting that together well spoken!!! one thing I questioned was with the KPI besides the E.C. front end Theres alot of guys running fixed caster and camber setups on this site If thats the case you could use KPI to your advantage for turn in and corner exit. I realize this was about a specific front end but alot of other people are going to read this just one more thing to think about when building.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: hiflyer727 on July 15, 2007, 06:34:58 pm
George, this pertains to adjusting negative camber on the EC front axle:

To set 3 degrees negative camber on the right front how many turns of the small 1/2 rod ends should be made? Also, should only the top rod be turned in, or should the bottom rod be turned out also?
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on July 15, 2007, 09:40:09 pm
Sorry I never measured amount of nut turns to achieve x amount of camber. I run mine at 0 on both sides. As to which to adjust or whether to adjust on both. I always adjusted the top.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: cycloneracer on July 20, 2007, 04:06:38 pm
George,
How strong are the heim joints you put on the axle?  Mine seem to keep coming loose and I'm afraid if I go much tighter I'll strip the threads.  Should I have a couple of spares in the tool box?
Do they ever bend?

Thanks
Paul
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Squidd on July 20, 2007, 05:39:49 pm
I bent one... but that was on the third of forth flip ...:lol:
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on July 20, 2007, 06:55:45 pm
Well Jeannie hit a block wall at 40 mph pretty much head on and didn't bend one!!! Bent alot of other stuff but not a heim. I have put enough ump on the nut the back slotted nut actually bent into the grove a little. I don't know of anyone's coming loose. Don't be afraid of putting some muscle on it though. They are rated at 18,000 lbs per square inch. And drilling the cotter pin holes they eat up drill bits so they are not soft.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: cycloneracer on July 21, 2007, 03:19:05 pm
That is what I figured, but wanted to make sure.
Paul
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: KartMan250 on August 15, 2007, 05:38:47 pm
Hi,
Im considering buying the front axle setup, and was wondering if I could use the stock drag link setup (could make a different length rod, but same basic idea) and if it would fit in a craftsman frame just like TOM FOX's (would lower U channel).
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on August 15, 2007, 05:51:18 pm
Yes it works in a craftsman chassis whether you can use the stock rod link not sure.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: cycloneracer on August 15, 2007, 09:33:36 pm
It works awesome in a craftsman chassis.

No the current steering set up will not work, at all.  You will reuse nothing, it all is crap.  Get a kart steering shaft and make direct steering just like George has in his build pics.

Or look do a search for my build stuff, not a lot of pics, but it is a craftsman.  Search for 150.

Paul
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nic_hayes on October 08, 2007, 09:24:51 pm
hey george, i see everyone is changing their axles from the straight 90 style to the angled style, i was just wondering how much of an angle you guys are changing them to, thanks
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on October 08, 2007, 10:29:56 pm
Which angle are you referring to.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nic_hayes on October 08, 2007, 10:44:49 pm
the angle of the end of the axle where the spindle bolts to, which also affects the spindle angle, instead of the spindles being straight up and down they are tilted in, thanks
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on October 08, 2007, 10:48:18 pm
App. 10 degrees.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: greenmachine on October 08, 2007, 10:51:05 pm
That's called kingpin inclination.

It's 10* that I measured when I had to narrow the axle 1" if I remember correctly on the axle I bought from E.C. Distributing. There are also spindles available in 11*, 12* and 15* that I know of and probably others too.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on October 08, 2007, 10:52:57 pm
We only sell spindles for our axles in the 10*
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nic_hayes on October 08, 2007, 11:07:52 pm
thanks guys, george how much are your spindles?
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on October 09, 2007, 06:47:10 am
100.00 a set
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: greenmachine on October 09, 2007, 10:47:35 am
100.00 a set

And they are schweeeeet spindles. Really nice machine work.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nic_hayes on October 09, 2007, 11:03:59 am
i might have to get some of those george, i'm going to take some measuments off my old ones so i can make sure they will fit my hubs and i'll get back to ya
forgot to ask, does that price include the heim joints or is that just the spindles, thanks
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on October 09, 2007, 12:51:44 pm
Just spindles and spindle bearings
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nor66 on November 21, 2007, 11:44:13 am
George I was reading this again for the hundredth time, Got a question, I noticed  Sat at the race my front end seemed to bounce a lot usually just on the exit, I have noticed this at most of the races I have run in. I watched several other mowers including yours and they seem to have little or no bounce at all, I am running somewhere around 5 to 7 pounds in the tires. What can I do to minimize this bounce?

 I know it slows me down because I have to lift on throttle to not loose control!!!!!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 21, 2007, 03:01:29 pm
Geometry is a big part. Also driving thru it or should I say powering thru it. Bounce is a a result of good rear bite and sometimes a loose front end IE king pin or something or geometry is off a bit. With more motor you tend to have less because you are generall spinning more than biting. Go up to 10 lbs of air in the fronts it will help a lot. With your front end there is no adjustments so you cannot help it there.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: briggsracer1892 on November 21, 2007, 03:19:15 pm
I agree i had a race in Illinois and coming out of the corner i had alot of bounce (i inflated the tires from 13 to 22 psi in the right frontand from 9 to 15 psi in the left front and in the back i inflated both tires from 17 to 26 psi.

After I did this i had minimal wheel hop and i could "power" through the corners alot better.

Keep in mind i used to use an opposed the "torque monster" in my local organization.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 21, 2007, 03:48:58 pm
Quote
and in the back i inflated both tires from 17 to 26 psi.

Both tires the same HOW did you make it turn.  :omg:
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Tom Fox on November 21, 2007, 05:18:20 pm
Go up to 10 lbs of air in the fronts it will help a lot.

I also had the sme issue my first race this year. Would exit a corner and got a SEE-SAW effect happening. With a "SOFT" front tire it just wanted to be like a rubber band....I incresed the PSI and reduced the bounce quite a bit.

Another thing you should look at as well is your seat location. Get it FORWARD!!! Not sure how much power you have in your engine but my V-TWIN was carrying the front wheels off the ground exiting turn 2 and 4 halfway down stretch! It gets kinda scary when your steering does nothing!!

After looking at a few photo's of me racing I relized that my seat was pretty far back as compared to a few other racers. I moved that seat forward, dropped it down, and now it handles like a slot car!!!

BTW George....you ever get to finish up any spindles yet??? You can ship me a pair keyed for brakes when they are ready!!!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nor66 on November 21, 2007, 06:45:44 pm
I will definitely try the increase in pressure, that seems like it would cause more bounce! I was thinking I was running to much air! Imagine that, sometimes less is more. George I agree with the front end setup, after seeing yours the one I got is definitely entry level, but for the money it got me racing!!!! I am already trying to put some $$$$ aside to get one of yours!! I was thinking it was bouncing maybe because it was too stiff!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 21, 2007, 07:40:48 pm
Generally the softer the track (mudy or thick powder) the less air you run in the fronts. Here is what I ran at the race.... L/F 5psi  R/F 7PSI  L/R 3psi  Right rear heat 15psi feature 23psi. IIn the OUTLAW Race and 1 on 1 I had 28 in the right rear. But that didn't help with the wheel offset in an inch...
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nor66 on November 21, 2007, 08:14:40 pm
Thats kinda close to what I was running, I was running 7psi RF and 5psi LF and the same in the rear, the mower was handling fairly well to me but had a terrible bounce on exit ! Now I not talking about the hole coming out of turn 2 good grief that hole would just about make a bull dozer bounce :woo:
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 21, 2007, 08:21:58 pm
Right I agree but with your front end more air should stop or alow the bounce down. The geometery is off and you cannot adjust it so you have to compensate with air.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nor66 on November 21, 2007, 08:42:18 pm
Thank you for your help I will definitely try the increase in air pressure!!!!!!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: briggsracer1892 on November 21, 2007, 08:45:35 pm
L/R 3psi

Really?  :lol: if this is true disregard the laughing smilie

Oh and i ment to say 17 inner rear and 26 right rear


No problem
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 21, 2007, 09:34:44 pm
Do you think I would lie about my pressure's!!!! You apparently do not know me very well... I never ever touch the left rear. Never Ever except to make sure it is at 3 psi.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nor66 on November 21, 2007, 10:04:05 pm
Trust me I have seen the back of George's mower :mad2: And from the looks of his left rear tire, it might as well be flat!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 21, 2007, 10:27:26 pm
Think Stagger and how to get it legally when you must run the same size tire and rim on both sides!!!!!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: greenmachine on November 22, 2007, 09:51:31 am
Trust me I have seen the back of George's mower :mad2:

 :lol2: How many laps did you get to study his setup :lol:

 :leaving:
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on November 22, 2007, 10:50:18 am
Its not what he saw when he was behind me its what he heard in the pits. Seems he knows how to ask the right questions and I was feeling very gerous with knowledge that day!!!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: nor66 on November 22, 2007, 11:58:51 am
:lol2: How many laps did you get to study his setup :lol:

 :leaving:


EVERY STINKING LAP!!!!!!

Its not what he saw when he was behind me its what he heard in the pits. Seems he knows how to ask the right questions and I was feeling very gerous with knowledge that day!!!

You will never know unless you ask! The only stupid question is the one you don't ask!!!
And you never know when your going to get small tidbits that mean a lot!!!!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: shimmy16 on February 24, 2008, 10:52:04 pm
i'm an old racecar guy  , but ; when it comes down to caster & camber it's all about how much tire tread is on the track(camber) said easily,when going through a corner you want as much tire surface on the track as possible; so for a road coarse you probably want 50/50.(caster) is usually driver preference,especially with power steering by armstong.lol.
I DONT KNOW IF ANYBODY EVER TRIED TIRE TEMPS ,BUT IT'S THE BEST WAY TO KNOW WHAT YOUR CHASISSE/MOWCHINE IS DOING.BY CHECKING TIRE TEMPS ,YOU CAN GET AN AVERGE TEMP;BY CHECKING OUTSIDE ,MIDDLE ,AND INSIDE OF A TIRE AND YOU WILL KNOW IF IT'S ON THE GROUND/TRACK .THE CLOSER YOU GET YOUR TIRE TEMPS THE BETTER,TIRE TEMPS ARE TAKEN WITH A PYROMETER.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: wayne shaffer on June 30, 2008, 09:30:22 pm
I have a question if you want the chassis to lift the inside rear tire when your in the turn, then why would you want the inside tire
air pressure so low? I know running the low pressure will make it want to turn left but when you go into the turn your tire is going to
lift up in the air, or is it to help with the start of your turn before that tranfer happens? I hope I worded it right and sorry to ask
this question I'm just thinking if your inside tire pressure is low you'll fight it down the straight and in the coner it won't really be in use.
Again sorry if I'm sounding really stupid right now but I'm just trying to learn.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on June 30, 2008, 10:50:04 pm
helps going in and coming off. Straights are so short you don't feel the effect. Just like sprint car we want stagger but it is illeagal so we get it with tire pressure. Also less pressure means there is less weight on that corner.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: BrewMeister on March 02, 2009, 05:37:33 pm
ok, so I finished my front axle only to find out that the spindles I was going to use off an atv werent going to work with any hubs. So I bought a set from APS and without checking I welded them on and after mounting the front tires it turns out that there is a lot of neg camber. So I ask this before I cut everything off and reweld it: is there such thing as too much neg camber on a dirt track? I understand that if the tires sat at a 45* angle that would be rediculous, but, what about 20*? I'm not sure what * im at right now but I really dont want to cut em off.

I thought that neg camber was good especially when your wanting your inside tires to lift. My understanding was always that with negative camber as you proceed thru the turn the weight transfer sets the tire upright to a zero* camber level; thus putting the whole footprint of the tire on the ground. Ill post pics later if that will help, I just have to go read the thread on how to do it.

Thanks!

Joe
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Rooster on March 25, 2009, 11:51:49 pm
That is correct...assumng you have suspension.
With a solid axle your tires aren't going to get much flatter than they are sitting still.
If you set up right and get the left rear lifting, you'll get a little out of right fron, but very little!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Dawg on May 15, 2009, 12:03:05 pm
Do you take a payment plan on your front ends LOL.. About broke  :( trying to build one of these mowers..
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Allstar9031 on August 03, 2009, 10:14:52 am
George, When you say
" A mower needs to have the steering geometry set up so that it will lower the inside front wheel and raise the outside front wheel in relation to the chassis at corner turn-in."  I'm getting a little confused with the " wheel raise, wheel lower "  Are you saying that what needs to happen is that the chassis needs to get closer to the ground on the front right , and further from the ground on the front left ? of vise versa ?
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: DanW on August 03, 2009, 11:04:05 am
Push the inside front down, pull the outside front up.  Going through a turn this will raise the inside rear tire off the ground (if the chassis is stiff enough) because your momentum will rock the mower forward putting pressure on the outside front, allowing you to turn effortlessly with a posi traction setup.  This is how kart guys get a "suspension" without actually having one. 
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Allstar9031 on August 03, 2009, 11:22:16 am
So Dan, are you saying that the chassis needs to get closer to the ground on the right front, creating a pivot point between the left front and right rear, lightening the load on the left rear and allowing slippage of that wheel?
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: tjbryner on August 03, 2009, 11:40:43 am
I wouldn't say the chassis gets closer. When you turn left and every thing is set right and built correctly the tires make some what of an sweeping arc. This makes the tire push down on the ground. The chassis should tilt (but not twist). I hope this helps
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: DanW on August 03, 2009, 11:55:12 am
So Dan, are you saying that the chassis needs to get closer to the ground on the right front, creating a pivot point between the left front and right rear, lightening the load on the left rear and allowing slippage of that wheel?
Yup!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Allstar9031 on August 03, 2009, 01:39:50 pm
Thank you Dan and TJ for the info. This post and you guys clarification is going to help out so much.
 
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: taters on December 12, 2009, 06:00:03 pm
"Excellent Read" thanks "George" !
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on May 12, 2010, 09:16:43 pm
I mounted my EC front end on my A/P. It's a Huffy with a mid mount engine. The problem I'm having is that it doesn't bite well when I'm cornering with the engine not sitting over the front wheels. I just push to the outside of the turn until I let off on the gas. Do I need to add weight?, or adjust the settings? Currently all the settings are in a neutral position. Suggestions??

Lambo
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on May 12, 2010, 09:25:30 pm
How much caster and how much tow out are you running. HOW much do you weigh. How far back have you moved the motor.
OH and what tires are you running.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on May 16, 2010, 02:26:09 pm
10* caster, 0* toe-out. Engine is in stock location, approx. 17 " from front axle. I weigh 185lbs.

Tires:
Front = Trac-Gard 13-5.00-6 @12p.s.i  (both)           

Rear =                13-6.5-6   @15p.s.i  L    18p.s.i  R





And by the way that 17" is measured from front axle to point at which crank goes through hole in engine plate...

Lambo
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on May 16, 2010, 03:08:49 pm
First thing I would do is lower left rear air pressure to get more stagger that will help it turn quite a bit. I would run 5lbs left rear. When I run a huffy I litterally had to add some weight to the left front it was simply too light with my big but on it.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on May 16, 2010, 05:25:38 pm
Ok George, thanks. How would you recommend adding the weight? , and made out of...?

Lambo
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on May 16, 2010, 05:39:14 pm
I used a lead weight from old race car weights, bolted it to the frame right behind front corner of chassis. I could move seat any farther forward. I could move motor, battery everything I could mount to the front was. Been several years I think all it took was 20lbs. It made all the difference in the world.
Regardless thouogh I still looked like a ape riding a golf ball.. LOL
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Burwell555 on May 16, 2010, 06:10:20 pm
Lol I would like to see a pic of that!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on July 29, 2010, 12:19:48 am
George, everything went well. I made adjustments to the air pressure and front end. Added 14lbs. of lead by melting a bunch of wheel weights and pouring into a form. When it cooled I bolted it to my E.C. front end. Runs really well. Thanks
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on September 15, 2010, 06:26:55 pm
So, after all of my adjustments, it does corner better. But now the one thing I noticed is that it pulls left down the straight-away. The more caster I give it, the more it does it. I'm not at 10* caster,  I'm at about 7 or so. Is that normal?

Lambo
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on September 15, 2010, 07:34:04 pm
Depending on left front pre-load yes its normal.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Rooster on September 15, 2010, 08:14:29 pm
When my mower is like I like it I don't turn left, I hold right down the straight and let it turn into the corners!
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on September 17, 2010, 02:19:07 pm
Now you're talking!  :thumbup: Thanks guys.

Lambo
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: crmtruck on September 23, 2010, 12:27:11 pm
can any one tell me what size steel to use to make the front axle is it 2x2 square tube quater inch thick and how long is it
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: Lambo on September 24, 2010, 02:08:10 am
Well- I would go a little more rectangular like 1 x 2. The length will be determined based on the finished dimension you want for the overall width with the wheels and tires on. Mine is around 18", so once i got the spindles and wheels/tires on, I'm closer to 36-38". I bought mine from EC. all ready to go-and love it.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: marv on April 07, 2014, 09:48:32 pm
Excel. post from George H.axel geom. To bad there is not a rough setting to start out with. Many people ask for this,myself included.
I found the initial set up post after I commented. thanks George Herrin. marv
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: finn1 on July 22, 2014, 02:17:37 am
hey george on a super mod should the spindles be in the center of the axle? or below the center of the axle? mine are centered with spacers, i was having a major plowing issue this past weekend. i was running 10psi on all tires except right rear which was about 14psi. i am about 260lbs.thanks bob
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: George Herrin on July 22, 2014, 07:35:39 pm
Drop left front or raise right front or do both one spacer. Too much cross will make her push.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: finn1 on September 01, 2014, 03:53:22 pm
thanks George that helped a lot. just some fine tuning now, and learning how to drive through the corners now. thanks bob
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: damon.mosley57 on February 07, 2016, 10:11:37 am
Great info. I was wondering pros and cons of tie rod fwd vs aft of front axle
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: berthyd on February 07, 2016, 10:40:10 am
Forward is a pull. Behind is a push. Pull is more precise. No flex created in the steering hardware.

Bert
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: DeereRacer on February 07, 2016, 06:35:14 pm
I don't know about the push pull thing but if you have the tie rod in front you don't have to notch the frame for clearance and if you hit something it will not bend the tie rod. That being said my next build I am going to try rear center steer with a bell crank for better ackerman.
Title: Re: Understanding E.C. Distributing Mower Front axle geometry
Post by: damon.mosley57 on February 09, 2016, 09:36:07 pm
Mine had a center steer but badly damaged when I bought it. I put a old Mike Cupps front axle on it but don't know where spindle are from. Drag link runs thru between tie rod and front end. I was told going to tie rod in front would cause one side not to turn as much as the other. Talked to EC and they said I wouldn't have that problem with their front end. Going to stay with side steer to stay simple until I know more on set up. Got a bent spindle axle on rt side giving me a lot of neg chamber. Works for me with narrow tires but just ordered wide tires and rims so I'm going to get new from end. Thanks guys.