@@DougBugBuilder yeah this is great. I've been trying to figure out Ackerman on my go-kart for 3 days and couldn't find anything that explains it this simply. Unfortunately my go-kart has the tie rod ends attached in front of the wheel so looks like I can't even do it unless you can modify where the tie rods attach to the end of the steering column that would make it work. It seems like that should be possible but I haven't found anything explaining it yet. Any idea?
@@rhull3939 You can dial in Ackerman with forward steer spindles but it gets tricky. Usually you need to push the tie rod connection points outward as much as possible and move the rack back some. Not always room to do this. So like me with forward steer there is a lot more compromise to Ackerman.
@@DougBugBuilder thanks man. Yeah, I don't have room. The point is right smack I'm the middle of the tire. I read something last night that you can get it to work by not having the tie rods in a straight line to the ends from the steering rack but I can't figure it out. It says to stagger them but I have no clue.
Weight transfer during cornering increases the load on the outside wheel. More heavily loaded tyres need to run at higher slip angles so having less than "optimum" or even anti-Ackerman angles is not necessarily a problem from a performance point of view on tarmac / asphalt surfaces. Conversly, the inner tyre can not develop adequate grip levels and will scrub if the slip angle is too great. Ackerman steering is something that was developed in the days of solid tyres and low speeds, as a means of allowing independent steering systems to more closely simulate the effect of a pivoted, solid axle. It probably helped to reduce 'chatter' in corners. Tyre longevity is another matter, which is one of the reasons it is retained, to some degree on standard road cars. Running on loose surfaces is a whole new kettle of fish where steering force is dependent on more than just friction.
HI Graham can u refer a book or something other form where i can learn and understand vehicle dynamics calculation. i am watching a lot of videos and using other online sources but they mostly tell what will happen and not the calculation part.
@@nc-pf3qm A good place to start, if you can find a copy, would be Racing & Sports Car Chassis Design. It's an old book and may need some adaption of 'units' today but good stuff. It was wrttien by Mike Costin & David Phipps in the early '60s but there are copies available on-line. Mike Costin was the Cos in Cosworth alongside Keith Duckworth. I hope you've heard of them. 😃
Thank you, thank you, thank you... After hours on google and UA-cam, this one video... Within the first 5 minutes... Enlightened me! So simple, concise and yet lucid... Never thought building a weekend buggy for my daughter would bring me here... And boy, am I glad for it!
If the steering box was back in line with the straight line between the two outer ball joints,it would help your ackerman immensely. Also,you may want to put one inner tie rod above the pitman arm and in a hole farther to the opposite side of the center line of the pitman arm,and have the other inner tie rod on the underside of the pitman arm and they will overlap and in effect 'lengthen'as they turn to push either wheel more in it's needed direction. The easiest cure for yours is bring your box back closer to the rear,then shorten the tie rods.By far the easiest 'cure'.
It would be interesting to measure one of your daily driver cars to see just how close the factory gets the angles. Maybe that would get you in the ballpark of what would be acceptable. Not sure what you do for a living but you do a good job teaching this stuff in your videos.
Yeah, I'd be most curious to see how they do on the solid axle of the Wrangler. Then I could compare it to the Volvo S40. I'd think that would be pretty good.
I’m a little confused about how you are measuring your angles for measuring your Ackermann. I believe you are measuring the acute angle between the rotor and the front axel. Please correct me if I’m wrong. I think that the inside tire should have the smaller (sharper) angle and the outside tire should have the larger angle. It’s really hard for me to see in this video, but I’m thinking that your steering ball joints are actually outside of the tire pivot points (which makes it Ackermann steering, and not the reverse). It might be a compromise to the actual approximation of Ackermann but I believe if you drew a line from your steering ball joint through the axis of steering rotation, then it would be pointed towards the middle of the car. If you have reverse Ackermann steering, that line would point outside the car. Please correct me if I’m wrong but from what I see in the video I think your car is approximating Ackermann steering better than you think. (Not talking about the new one you are building)
You are correct about the angles, but my steering ball joints are inside the tire pivot points. Really hard to tell when the wheels are turned. But when they are straight if you imagine a line to the rear axle center you can see they are inside that line. The Ackerman wasn't horrible. But the outside tire was turning sharper than the inside tire. At least what I could tell with how I was measuring. It wasn't to technical.
On dirt you should be OK. You also have the scrub angle of the tires that differs from side to side. As your speed increases on the dirt a little anti ackerman is a good thing
Great video, I love this series so much. Your first bug has a Anti Ackerman setup. That works well with Toe in. I’d be interested to see if you could sweep the old chassis with 1/8 toe in VS 1/8 toe out. Also when your using the cardboard templates I’m wondering how far it’s throwing you off because you don’t have inner tie rods or the rack in the template? Possibly retest that? Great videos none the less, I really enjoy them. ~WesD
More or less check it on the old chassis while you sweep it left to right. Check your ackerman while toe in VS toe out. For me I run a lot of on road Road race cars. We’re normally 1/8- 5/8 toe out to help turn in on a small short course aka Autocross. On a big Road Course we’re finding a very small amount of toe out 1/16 helps calm the twitchyness at high speeds. We also have 8-deg caster and lots of Camber gain for 3-inches or less. Thank you for sharing your thoughts on all this. I thinks it’s time for me to build something like this. Check out my Instagram Wes_D
I'm going to do what I can to keep the Ackerman as good as I can get it but still being forward steer. I'm not interested in adding any more weight in the front. I like keeping most over the rear axle. Your point is valid that more centralized weight would really help with the steering. But I don't mind (or kinda like) that it will understeer or oversteer depending on throttle. Your idea is good though! Thanks for the comment.
Since I'm still building my sandrail. I'm barely gonna start my spindles. This video came at the perfect time cause I had absolutely no clue this was a thing. I was the guy that was gonna use a complete fwd into my rear engine sandrail. I ended up doing a Porsche 911 transaxle with a truck 5.3 (Lm7). Your videos really help me with my suspension questions cause I really doubt myself when I'm doing this cause it's important. Chassis is built though and have everything ready to go pretty much. Just need seats and stuff too
BTW you can correct your steering radius variance dynamics (ackermans principle) with the pitman arm length, position and direction, it’s the left to right full width center-link and tie rod set up that creates the consistent relationship. If you break this up like ford does on their IFS differentials Dana 35 45 55 etc. the pitman arm is on the left forward of the axle with a rearward sweep, connects to the inner tie rod end, and the outer rod end point forward on right spindle the left tie rod attaches to a midway point on the right tie rod and the opposite side forward point on the left spindle. This creates steering input differential. On the Dana60 straight axle front ends, an independent center link in a separate but supporting position reinforces similar geometry, and bump steer not present in the ifs system is countered by a the use of a track link mounted I. A position parallel to the tie rod or drag link.
In my opinion, the biggest reason your baja doesn’t steer well in the dirt has more to do with the non-Ackerman steering than being light on the front. Though a light front makes the effect worse
Ackerman was good enough for horses and carts but the future does not have much more room for this old bollocks.Ackerman is the past there is much simpler and safer way to sort this out. It is called evolutionary design and will be presented soon. Remember,Ackerman is for carts 250 years old crap. There must be other way but maybe it is just easy to copy for many of you guys 250 years old in F1? Can't be right.
@@rickrack78 And the knives are working more less without need for change or the spoon so I don't have no suggestion also on improvements of those. I'm not here to argue or proving you anything what I'm saying is that Ackerman is out dated and not suitable anymore for safe modern design. Ackerman is the reason why car design haven't changed since Ford T. Square box, engine on the front,4-5 seats,boot even the electric Marvell the Tesla washing machine on wheels is the old Ford T you guys polishing the turd here Ackerman is the handbrake of progress and not the solution. Horses and carts pal not 200MPH flying riders.
Hey Mike, little update I ordered a Mig welder for the panel I plan on butt welding I am not sure if I will Tig or Mig, but I think in the future for building up an edge or a seam the Mig will probably be the best bet, what do you think, thanks
Good call, I think once you get used to the Mig you'll use it a lot. I use Mig when I can, but I still use the Tig if I need to be clean, or I really need to control the heat, or if it's aluminum.
Fun fact: Formula 1 cars can have negative (or anti-)Ackerman set-ups like you did show in your model with the short front steering. This is because at the really really high speed turns, it turns out beneficial since there is already inherent slippage of the outside front wheel that requires MORE steering on the outside instead of less to make it go in the corner direction. So there is an actual real world benefit for such geometry in very specific cases.
its not 2 degrees wrong. it is actually 4 degrees. Theese readings need to be vice versa, when correct. I can explain if you need. And I had similar feeling, when I had car wich had really wrong toe in(previous owner had welded one rod). Steering was so soft and when turning it was just empty. like I could rotate 90 degrees left or right and it still went forward on dirt road. To get any turning I did need a lot of turning.
Doug isn't it true if you raise the one inner tie end up higher at mountain ng point you schould get it perfect 0 try it or maybe outer mounting point on one side if you look at vw steering the center mount for tie end is ofsite
I know I am late to the party, but when you are measuring the angle of the buggy you showed 29 degrees for the inside wheel and 31.6 degrees for the outside wheel. By that method doesn't that mean the inside wheel is following a tighter arc? So it has slight amounts of ackerman? And is not actually anti ackerman?
Why can’t you just have rear steer? Are there any advantages or disadvantages to having rear or forward steer? Maybe I missed it in the video if you talked about it. Also, what engine is going the new chassis? Do you have any plans to step up to an LS engine?
I would rather have rear steer. But with this setup I need the rack really far forward so I can have a safe steering link from the rack to the steering wheel. If I pull it back I have to add U Joints and the angles are pretty tight. This chassis will have an Ecotec. My goal (dream) is to get a LS in one of these chassis. But I won't do that until I have a transaxle that can really stand up to the abuse of it.
TLDR: crossing the desert is hilly rocky bumpy sandy your cars steering supposed to be locked to near straight and very super heavy. you cross the desert, straight across. no turns ever. no aircon no civilization no bathrooms those can wait you wont have enough water its a death trap. Even if you have to be a boy band go full one direction. Or you could just go the middle of the desert do donuts n burnouts whatever. you cant put your foot into the pedal hard enough ever to get out of the desert fast enough, is why they invented racing engines. You misunderstood why its a front bar and less of an angle. In a toyota AE86 or other vehicles drifting downhill and on smooth road surfaces, the weight of the car shifts to the one side when cornering and powering through a turn at high speed and powering out! because a buggy/ baja type vehicle is for offroad, it drives on sand and loose surfaces, and the weight shift and turns cannot be as fast/sharp because theres not an even surface and no grip, your wheels turning sharper for a tighter turn circle if going fast means your baja car continues in a straight line with the two front wheels at near right angle vector drawing gooves and lines in the sand... the angles and the math of the tighter turning circle work, but the bumps and different suspension mean you dont want your car to turn or swerve as sharply on loose rockey offroad surfaces. it was tightened and closed off for this reason. If you drive it on a track with sealed proper road surfaces then tighter turns and your adjustment might be an okay idea if its steering is heavy and needs a few rotations of the wheel to make some tight inner city parking manuevers. But if you're going down steep sand dunes turning doesnt actually work as it normally would and is less effective and turning sharply means you may roll or veer off vector its a bit like skiing how the skis tend to go forwards or you angle them but when the bumps and rocks come your snow ski at high speed cant keep stable so you hop side to side bouncing and do so on jetskis in surf waves too... though ski's you can lean and sort of snowboard like edging to a halt, your car doesnt jump or lean and it relies on suspension to sorta bounce a little but reduce the bumps to smooth. if your longskis in the snow go fast as a car you will understand what i mean high speed on bumpy roads and loose sand down hill sand dunes. if you plan to only drive it in town then try out your change. In places like australian nullabor plains 11 days of drive of nothing but dirt road rural australians drive their ars at plus infinity miles per hour because nobody has enough lives to spend days to go to the store. your car at a speed high enough should steer or turn with a tight enough circle, maybe consider changing to a smaller easier to grip and spin around rally like steering wheel.
Man, you got me thinking about the steering setup on my toyota pickup. Its forward steer and im sure its just as bad as the demo on paper lol. I think im gonna try to make it rear steer and get better geometry. This might be the reason why my tires need rotation more often than i think they should is because they are scrubbing the heck out of the roads every turn i take lol... Thanks for the great explanation man 👍👌
It looks like Forward steer would cause oversteer. In the case of a go kart you would then want a wider front track (wheel base) because wider front tires lead to understeer due to the rear axle being solid.
ackerman wasnt even born yet when charles darwins grandaddy first devised this setup while making house calls as a doctor in mid 1760's england. he got tired of his carriage crashing on turns, as it was the whole axle turning and a tight turn would turn it from a 4 point support towards a 3 point structure, if that is imagined in ones mind. so he had the local carriage maker craft his design up, leaving the front wheels in place and the control arm to turn them. since he didnt want to be thought of as a mad inventor which could have hurt his doctoral practice he never patented any of his schemes. the royal society of england was aware of the design, thru a friend and admirer of the aforementioned erasmus darwin, yet those old blokes must have had plenty to look at in those days of invention, because it would be 50 plus years before it was patented by ackerman after a german carriage builder named lankensperger developed the mechanism. ackerman was the germans agent and spent years defending the design to reluctant adopters of the technology. or something like that. was a fun rabbit hole to fall in reading about steering.
so does varying the toe of the rear wheels help things? Is it another way of adjusting for an "incorrect" ackerman? Toe changes on swing axle bugs anyway as they are on trailing arms so would changing the ride height affect the way it turns within the concept of the ackerman angles? what about lengthening or shortening the wheelbase?
A lot of what you mention there will help with stability. But none of it will help with the ackerman. But the good news is if your ackerman isn't the best it really only affects you on tighter turns.
So, if your concerned about front track controll rod and steering pivots, why not move to rear pivots etc? Don’t see the need to make life difficult when you already know it’s better with rear steering pick ups
You got me thinking Doug I need to check my baja king link pin. Longer wider . woods chrome Allie stuff . thanks for the kick in the brain bucket . mine is rear steer tie rod to the same rack and pinion box as yours . what front breaks are you running? Mine are to small and the rear locks up first . $ ? .
Mine are Jamar combo spindles. But I'm in the same situation. Although they brake pretty hard, the rear lock up and the front does not. Glad I got ya thinking. lol
what if you flip a arms and spindles from left to right side and move suspension forward accordingly. then you should have room for rear steering. would be cool to see the diffence and for you to give a hands on verdict on the effect. steering rack would need to be upside down too or be 2 axles with a gear on each to change direction of rotation.
FWIW, zero ackerman is a thing for drift cars that are intended to be doing a lot of high speed drifts, but it's a personal preference thing. I guess my point is that it appears to me that you might be able to modify that current spindle to where you can move it out to real close to zero ackerman, and that should be fine. Definitely it looks like that spindle on the old bug could be moved out to zero if you wanted. Also, I think you need to draw a virtual line between your upper and lower balljoints, and see where your outer tie rod pivot lies in relation to that line. Might be a little different than just looking at where your upper ball joint is, and in the case of that current setup, I suppose it might actually be a little less good.. I do agree that it will be fine however you leave it though. Thanks for another fantastic video!!
If you measure the center point at rear axle and put it in front of your vehicle you will have correct Ackerman angle and location in front.for front tie rod locTion
I don't, I just build what I think would be appropriate. I think if you were going to get that technical it would be best to draw it in software like Solidworks or something similar that can do stress analysis.
No entiendo nada, algún día voy a buscar a alguien que me traduzca todos tus videos, y voy a tratar de hacer un juguete para mi, es un reto personal que tengo, gracias por compartir toda tu sabiduría, saludos desde san luis rio colorado sonora, sin llorar..
Lo siento por eso. Si puedo encontrar algo en UA-cam que permita traducciones, lo haré. ¡Me encantaría que pudieras obtener el audio! Gracias por mirar de todos modos. jajaja
I'm a little confused. Inner turn wheel was 29 degrees and outer turn wheel was 31 ? That means that the inner turn wheel turns more compared to the outer turn wheel and thats what you do want, right? -that is, "forward" or "proper" ackerman steering. But shouldnt it be the opposite for your front type steering rack setup ?
The way I was measuring it 0 degrees was straight ahead. So 29 degrees was not as sharp as 31 degrees. So it was a little backwards to what it should have been for proper Ackerman.
If I can leave a suggestion, I would try to move the steering rack to the back. Your shock looks like it is in the exact middle of the lower arm so it will not interfere, you may just have to get a different rack (that has the shaft coming from above) to help with steering shaft routing/angles. If not an option, while you move the steering arms on the spindles may as well make some new ones that sit as close as possible to the rotor so that the ackerman will be "less worse" 😂 rotors don't flex and your spindles look beefy so I'd say a few mm clearance between them would be enough
Great ideas! I originally was trying to mount the rack back like where you are describing. But the steering shaft was impossible. At least with this rack. So I went with the front steer. I really like your idea on hugging the rotor though. I'll consider that. Thanks for the idea.
Moving the steering rack rearward should resolve the ackerman issue. 1st and 2nd gen miatas are front wheel steer and the steering rack sits behind the attachement points for the tie rods. Its all about the triangles. Take the triangle that you make with the centerline of the rear axle and the pivot point of the spindle and youll get an angle. Its probably going to be around 20 to 30 degrees depending on track width and wheel base. Thats the angle youre shooting to make between your steering arm and your tie rod connection arm. So lets say you need your tie rod connection arm to be offset at 25° angle for your Ackerman to be right but you have to make it at 20° to keep bumpsteer in check. you can move the steering rack rearwards (in your case) to increase the angle between the steering arm and the tie rod arm by and additional 5° to get your magic number of 25°. Hopefully that makes sense. Unfortunately i cannot upload pictures for you.
I know I'm 4 years too late.. but you have ignored the pitman arm in your model. The ackerman adjustments don't have to happen at the spindle. they can be made at the pitman by overlapping the tie rods. Hopefully you've already figured that out.
Great video mate very informative 👍keep it up! I have never tackled a steering or suspension build it looks pretty intimidating if im honest. Just wondering if your first bug is actually 5.2 ish degrees out of this acra...thingy 2.6 to get it equal then another 2.6 to get it to zero scrub? Im not being critical or trying to be smart , just seeing if im undstanding the concept correctly. Anyway cheers mate, love your vids and thanks the work you put into sharing with us. 🤙
Keep in mind I'm going a little OCD with this. Building a front end doesn't have to be this neurotic. If I could remove the 2.6 degrees then I'd be at neutral steering. I don't know how much it would need to be true Ackerman. I'd need to lay it out like I did on the board. But it would probably be a couple degrees. But pretty much what you described.
@@DougBugBuilder thanks mate, I think it's all above my pay grade but I might give it a go one day. I agree physical models are the way to go with things like this. Rock on brother 🤙
Your cardboard demo is for a single point of attachment. The buggy has two points of attachment. Cross the attachments and you will be fine. Passenger side steering rod to drivers side bolt hole (rear). Drivers side rod to passenger side bolt hole (front). This is still Ackerman's theory. If two attachment points they need to cross.
I can't argue with you. But the point of the cardboard was really just to visualize for people how the Ackerman works. Pretend this buggy is solid axle. 😂
Would you provide a link to your next video that explains your outcome of your changes to the Ackerman angles. I cannot find it in your list of videos. Thanks
I never did a second video on the Ackerman. But I can tell you with the changes the steering is pretty good. Straight line running no issues obviously, tight turns you can hear it scrub some on asphalt, but it's not bad. And this vehicle is really only used at dirt tracks and trails, so really a non issue here. I hope that helps.
@@DougBugBuilder Thanks for the reply. This video was very helpful because I had a major anti-ackerman on my 1991 Dodge XPlorer motor home. With that much weight it didn't take long to eat my tire treads. I moved my steering center link closer to the axle and it worked. I guess it is the same as if you moved your steering rack closer to the front axle.
@@DougBugBuilder hahaha... thats funny! im actually watching a bunch of your videos right now, getting caught up on them. and contemplating on buying a bug, im wanting to start where i left-off 35yrs ago, oh, i had a baja buggy and i loved it very muchly, but one day it was gone, someone stole it from me, i hope i can come up with the money for this one ive been looking at, before someone else gets it, ha its ever the same color i painted mine and with the same kit too... yay! :D my videos suck but i just might make a few if and when i get my lil buggy back home!
I think you may have made a mistake when you were measuring the steering angle on the car, at least as shown. You are supposed to measure the angle away from straight/neutral (whatever you like to call it), so either choose parallel or perpendicular lines. 10:20 shows that you were measuring the angle between the line that is perpendicular to when steering is centre, and the line that is parallel to the wheel. If this meathod is used, then the inside wheel should have a lower number.
Those calipers and rotors came in the Combo kit from Jamar. www.kartek.com/parts/jamar-performance-combo-link-front-disc-brake-kit-with-2-piston-calipers-and-10-rotors.html
Can’t you simply add more of a cantilever device where the tie rods come together. So when turning to the left, the left tie rod would travel further distance than the right tie rod utilizing the angle of the pitmann arm thus adjusting you ackerman angle to a more favorable ackerman? In your schematic, you use a straight tie rod from one spindle to the other, but in reality, the tie rod on the left and right could have a different rate when turning left vs right? Couldn’t it?
Dude, you're making my brain hurt first thing in the morning.😉 You can do that if the center steering is rotating on an axis. Like a Pitman arm setup. But mine is a rack, and that moves linear back and forth. So I don't have that option with this setup. But your logic is sound for sure. 👍
Don't forget that each front tire has a different slip angle going through the turn... You have more slip angle on the laden wheel(outside) than you do on the inside. Thus, the path that your outside tire is taking is actually less severe than the angle that your outside hub/ wheel is taking... thus minimizing the anti ackerman that you have... check out the anti ackerman on an F1 car, might be shocking...
Not really, although I do try to set them up so they are at least 1/2" away from the inside of the wheels. This allows dirt and rocks to pass between the calipers and wheels if possible.
Hello from my understanding for your vehicle you actually should have steering in front of axel. This is called anti ackerman and the reason is because you have soft suspension. With soft suspension when you turn the load/weight easily shifts to the outer tire. Due to physics this means the outer tire needs more angle than the inner tire in order to turn that extra load. This is why your other vehicle also has anti ackerman
Making it rear steer would solve the Ackerman issue for sure. But the reason this is front steer is because there isn't room with the A Arm suspension to have the rack and pinion mounted that far back. So for clearance the rack has to go forward and makes it need to be front steer.
It might good idea to move, the main pivot of tire , inboard, to improve the pivot-set alignment. Instead of move the secondary one. thanks for attention, enjoy.
My rotor ends up being in the way too. The rack position will affect it, but honestly it has to be pretty far forward or back to actually have any negative effects.
Great video! I emailed you some pics of my build, it was all simulated in CAD before I built it. I downloaded your files that you shared for the spindle layout, and also discovered the issue with the backwards Ackerman! The setup I have now is not perfect, but it's pretty close.
Designing a go-kart and realizing I meant to use Ackerman, but I accidentally made it forward steer... oh well :P I guess it doesn't matter that much, though. Anyway, thanks for the video! Nice looking machines, btw
Cool ! If only a dependable Davis mechanism could be devised and built it'd suit your baja just right, both because of its mathematically perfect differential steering (compared to an Ackerman type) as well as its standard assembly being already ahead of the spindles...
thanks for this. Im old and feeble and limited to 1/10 scale rc cars. however, next time I put additional rear drive axles on a home built rc car or build a half track truck, Ill smoke a joint or 6 so I can work out the correct ackerman easily. A great explanation.
I was just hoping you would have a model and then bam, model comes out. The model made all the difference I had experience with the topic but you your explanation was very good. Good video.
My understanding is that Ackerman is for perfect conditions, but with slippage and loss of friction as off-roaders will often encounter, having a toe-in on the wheels helps with stability in most conditions so I wonder if the pro-ackerman linkage was chosen to enhance stability on variable terrain.
Personally I think the design was more "this is what fits". But you're right, Ackerman isn't that important for offroad. But I'll still do what I can to get it as close as possible.
One of the best explanations i’ve seen on Ackerman, Awesome stuff dude!
Thanks Bud!
@@DougBugBuilder yeah this is great. I've been trying to figure out Ackerman on my go-kart for 3 days and couldn't find anything that explains it this simply. Unfortunately my go-kart has the tie rod ends attached in front of the wheel so looks like I can't even do it unless you can modify where the tie rods attach to the end of the steering column that would make it work. It seems like that should be possible but I haven't found anything explaining it yet. Any idea?
@@rhull3939 You can dial in Ackerman with forward steer spindles but it gets tricky. Usually you need to push the tie rod connection points outward as much as possible and move the rack back some. Not always room to do this. So like me with forward steer there is a lot more compromise to Ackerman.
@@DougBugBuilder thanks man. Yeah, I don't have room. The point is right smack I'm the middle of the tire. I read something last night that you can get it to work by not having the tie rods in a straight line to the ends from the steering rack but I can't figure it out. It says to stagger them but I have no clue.
agreed!
Weight transfer during cornering increases the load on the outside wheel. More heavily loaded tyres need to run at higher slip angles so having less than "optimum" or even anti-Ackerman angles is not necessarily a problem from a performance point of view on tarmac / asphalt surfaces. Conversly, the inner tyre can not develop adequate grip levels and will scrub if the slip angle is too great. Ackerman steering is something that was developed in the days of solid tyres and low speeds, as a means of allowing independent steering systems to more closely simulate the effect of a pivoted, solid axle. It probably helped to reduce 'chatter' in corners. Tyre longevity is another matter, which is one of the reasons it is retained, to some degree on standard road cars. Running on loose surfaces is a whole new kettle of fish where steering force is dependent on more than just friction.
HI Graham can u refer a book or something other form where i can learn and understand vehicle dynamics calculation. i am watching a lot of videos and using other online sources but they mostly tell what will happen and not the calculation part.
@@nc-pf3qm A good place to start, if you can find a copy, would be Racing & Sports Car Chassis Design. It's an old book and may need some adaption of 'units' today but good stuff. It was wrttien by Mike Costin & David Phipps in the early '60s but there are copies available on-line. Mike Costin was the Cos in Cosworth alongside Keith Duckworth. I hope you've heard of them. 😃
@@grahambambrook313 🙏 Thank you Graham. Yes got the copy. Will read it. And i have heard about them. ...from you😀.
factssssssssssssssss
I really appreciate the visual aid. Thanks for that.
Glad it was helpful!
Thank you, thank you, thank you... After hours on google and UA-cam, this one video... Within the first 5 minutes... Enlightened me! So simple, concise and yet lucid... Never thought building a weekend buggy for my daughter would bring me here... And boy, am I glad for it!
Well as much as you enjoyed the video I enjoyed this comment.
Thanks!
Your little model clearly shows the problem and the solution, and without all the daunting formulae and techno speak. Thanks.
You bet! Thanks for the comment.
If the steering box was back in line with the straight line between the two outer ball joints,it would help your ackerman immensely. Also,you may want to put one inner tie rod above the pitman arm and in a hole farther to the opposite side of the center line of the pitman arm,and have the other inner tie rod on the underside of the pitman arm and they will overlap and in effect 'lengthen'as they turn to push either wheel more in it's needed direction. The easiest cure for yours is bring your box back closer to the rear,then shorten the tie rods.By far the easiest 'cure'.
Thank you so much sir!! This is what you call a perfect video! 👏👏
Thanks bud!
You can use steel cables to steer, when you pull on one side the other side is free to find its own angle.
The thing is. I could watch your classes all day!!! I’m into the knowledge. I vote you start getting more in depth. Lol
Lol, thanks Vic.
you are wonderful. Thanks to you, I solved the steering problem in my car.
Awesome! Thanks for the comment. 👍
This is the explanation I was looking for! Excellent work, thank you!
Glad it was helpful!
Thanks for the comment.
It would be interesting to measure one of your daily driver cars to see just how close the factory gets the angles. Maybe that would get you in the ballpark of what would be acceptable.
Not sure what you do for a living but you do a good job teaching this stuff in your videos.
Yeah, I'd be most curious to see how they do on the solid axle of the Wrangler. Then I could compare it to the Volvo S40. I'd think that would be pretty good.
Really nice job explaining a difficult concept. Loved the moving pieces model, that was terrific.
Thanks buddy!
your videos have transformed into advanced classes in... EVERYTHING !
Lol, yeah right!
Lol, yeah right!
Excellent video
Thanks!
Perfect explanation
Thanks!
Love your videos thank you for help.
Glad you like them!
Thanks for the comment.
gracias amigo
I’m a little confused about how you are measuring your angles for measuring your Ackermann. I believe you are measuring the acute angle between the rotor and the front axel. Please correct me if I’m wrong. I think that the inside tire should have the smaller (sharper) angle and the outside tire should have the larger angle.
It’s really hard for me to see in this video, but I’m thinking that your steering ball joints are actually outside of the tire pivot points (which makes it Ackermann steering, and not the reverse).
It might be a compromise to the actual approximation of Ackermann but I believe if you drew a line from your steering ball joint through the axis of steering rotation, then it would be pointed towards the middle of the car. If you have reverse Ackermann steering, that line would point outside the car. Please correct me if I’m wrong but from what I see in the video I think your car is approximating Ackermann steering better than you think.
(Not talking about the new one you are building)
You are correct about the angles, but my steering ball joints are inside the tire pivot points. Really hard to tell when the wheels are turned. But when they are straight if you imagine a line to the rear axle center you can see they are inside that line.
The Ackerman wasn't horrible. But the outside tire was turning sharper than the inside tire. At least what I could tell with how I was measuring. It wasn't to technical.
"I'm not going to explain how Ackerman works"
*Perfectly explains how Ackerman works better than any other video*
Thanks man
Lol, thanks dude.
On dirt you should be OK. You also have the scrub angle of the tires that differs from side to side. As your speed increases on the dirt a little anti ackerman is a good thing
Yeah I don't even notice it on dirt.
Great video, I love this series so much.
Your first bug has a Anti Ackerman setup. That works well with Toe in. I’d be interested to see if you could sweep the old chassis with 1/8 toe in VS 1/8 toe out.
Also when your using the cardboard templates I’m wondering how far it’s throwing you off because you don’t have inner tie rods or the rack in the template?
Possibly retest that? Great videos none the less, I really enjoy them. ~WesD
Thanks Wes, Interesting about the toe in. I can easily experiment with that and see if it feels any more responsive. Thanks for the tip.
More or less check it on the old chassis while you sweep it left to right. Check your ackerman while toe in VS toe out. For me I run a lot of on road Road race cars. We’re normally 1/8- 5/8 toe out to help turn in on a small short course aka Autocross. On a big Road Course we’re finding a very small amount of toe out 1/16 helps calm the twitchyness at high speeds. We also have 8-deg caster and lots of Camber gain for 3-inches or less.
Thank you for sharing your thoughts on all this. I thinks it’s time for me to build something like this. Check out my
Instagram Wes_D
Awesome
Thanks Bud!
wouldn't it be smarter to do proper ackerman on the new chassis and moving the fuel tank up front for better weight distribution. just my opinion
I'm going to do what I can to keep the Ackerman as good as I can get it but still being forward steer.
I'm not interested in adding any more weight in the front. I like keeping most over the rear axle. Your point is valid that more centralized weight would really help with the steering. But I don't mind (or kinda like) that it will understeer or oversteer depending on throttle.
Your idea is good though! Thanks for the comment.
WAY BETTER explanation than all these 3D computer generated engineering videos. Great job, thank you!
Glad it was helpful!
Thanks for the comment.
Since I'm still building my sandrail. I'm barely gonna start my spindles. This video came at the perfect time cause I had absolutely no clue this was a thing. I was the guy that was gonna use a complete fwd into my rear engine sandrail. I ended up doing a Porsche 911 transaxle with a truck 5.3 (Lm7). Your videos really help me with my suspension questions cause I really doubt myself when I'm doing this cause it's important. Chassis is built though and have everything ready to go pretty much. Just need seats and stuff too
That sounds like a great sandrail. Having an LS I think would be sooo much fun. Hope you get to take it for a rip soon.
BTW you can correct your steering radius variance dynamics (ackermans principle) with the pitman arm length, position and direction, it’s the left to right full width center-link and tie rod set up that creates the consistent relationship. If you break this up like ford does on their IFS differentials Dana 35 45 55 etc. the pitman arm is on the left forward of the axle with a rearward sweep, connects to the inner tie rod end, and the outer rod end point forward on right spindle the left tie rod attaches to a midway point on the right tie rod and the opposite side forward point on the left spindle. This creates steering input differential. On the Dana60 straight axle front ends, an independent center link in a separate but supporting position reinforces similar geometry, and bump steer not present in the ifs system is countered by a the use of a track link mounted I. A position parallel to the tie rod or drag link.
Wasn’t Ackerman the guy who invented tire tread cupping?
I hate that guy!
I hate him too. ;-)
He's a pain in my ass.
In my opinion, the biggest reason your baja doesn’t steer well in the dirt has more to do with the non-Ackerman steering than being light on the front. Though a light front makes the effect worse
Maybe, I'm sure it would be better with proper Ackerman.
@@DougBugBuilder i wish this Ackerman fella would get his crap together already lol :] ]
Ackerman was good enough for horses and carts but the future does not have much more room for this old bollocks.Ackerman is the past there is much simpler and safer way to sort this out. It is called evolutionary design and will be presented soon. Remember,Ackerman is for carts 250 years old crap. There must be other way but maybe it is just easy to copy for many of you guys
250 years old in F1? Can't be right.
@@radnasirhill, it’s worked well for 250+ years… what is your solution for the width of standard railroad rails? They date back to the Roman Empire
@@rickrack78 And the knives are working more less without need for change or the spoon so I don't have no suggestion also on improvements of those. I'm not here to argue or proving you anything what I'm saying is that Ackerman is out dated and not suitable anymore for safe modern design. Ackerman is the reason why car design haven't changed since Ford T. Square box, engine on the front,4-5 seats,boot even the electric Marvell the Tesla washing machine on wheels is the old Ford T you guys polishing the turd here Ackerman is the handbrake of progress and not the solution. Horses and carts pal not 200MPH flying riders.
Hey Mike, little update I ordered a Mig welder for the panel I plan on butt welding I am not sure if I will Tig or Mig, but I think in the future for building up an edge or a seam the Mig will probably be the best bet, what do you think, thanks
Good call, I think once you get used to the Mig you'll use it a lot. I use Mig when I can, but I still use the Tig if I need to be clean, or I really need to control the heat, or if it's aluminum.
Thanks mike, Merry Christmas
@@DesertRatFabrication Merry Christmas buddy!
Thank you sir for your detailed explanation. It helped me understand about ackerman and anti-ackerman very clearly.
You're welcome, thanks for the comment.
Fun fact: Formula 1 cars can have negative (or anti-)Ackerman set-ups like you did show in your model with the short front steering. This is because at the really really high speed turns, it turns out beneficial since there is already inherent slippage of the outside front wheel that requires MORE steering on the outside instead of less to make it go in the corner direction. So there is an actual real world benefit for such geometry in very specific cases.
its not 2 degrees wrong. it is actually 4 degrees. Theese readings need to be vice versa, when correct. I can explain if you need.
And I had similar feeling, when I had car wich had really wrong toe in(previous owner had welded one rod). Steering was so soft and when turning it was just empty. like I could rotate 90 degrees left or right and it still went forward on dirt road. To get any turning I did need a lot of turning.
Don't sell yourself short, that was the best explanation have come across even though am 2years late🤦♂️😂. Definitely subscribing
Welcome to the channel, thanks for the comment. 👍
Doug isn't it true if you raise the one inner tie end up higher at mountain ng point you schould get it perfect 0 try it or maybe outer mounting point on one side if you look at vw steering the center mount for tie end is ofsite
Look at stock vw set up front end incorporate in your bug to make it o Ackerman maybe
I think that works on a VW because it rotates on an arc. But my rack moves back and forth in a straight line. So that point stays constant.
I know I am late to the party, but when you are measuring the angle of the buggy you showed 29 degrees for the inside wheel and 31.6 degrees for the outside wheel. By that method doesn't that mean the inside wheel is following a tighter arc? So it has slight amounts of ackerman? And is not actually anti ackerman?
Why can’t you just have rear steer? Are there any advantages or disadvantages to having rear or forward steer? Maybe I missed it in the video if you talked about it. Also, what engine is going the new chassis? Do you have any plans to step up to an LS engine?
I would rather have rear steer. But with this setup I need the rack really far forward so I can have a safe steering link from the rack to the steering wheel. If I pull it back I have to add U Joints and the angles are pretty tight.
This chassis will have an Ecotec. My goal (dream) is to get a LS in one of these chassis. But I won't do that until I have a transaxle that can really stand up to the abuse of it.
Doug Bug alrighty, that make sense. Never really thought of it that way. An LS would be awesome, but the transaxles are very expensive.
8:20 ever think thats because the arkerman is complete shit?🤣 complete shit steering (under power) AND complete shit akerman? nah cant be related
TLDR: crossing the desert is hilly rocky bumpy sandy your cars steering supposed to be locked to near straight and very super heavy. you cross the desert, straight across. no turns ever. no aircon no civilization no bathrooms those can wait you wont have enough water its a death trap. Even if you have to be a boy band go full one direction. Or you could just go the middle of the desert do donuts n burnouts whatever. you cant put your foot into the pedal hard enough ever to get out of the desert fast enough, is why they invented racing engines.
You misunderstood why its a front bar and less of an angle. In a toyota AE86 or other vehicles drifting downhill and on smooth road surfaces, the weight of the car shifts to the one side when cornering and powering through a turn at high speed and powering out! because a buggy/ baja type vehicle is for offroad, it drives on sand and loose surfaces, and the weight shift and turns cannot be as fast/sharp because theres not an even surface and no grip, your wheels turning sharper for a tighter turn circle if going fast means your baja car continues in a straight line with the two front wheels at near right angle vector drawing gooves and lines in the sand... the angles and the math of the tighter turning circle work, but the bumps and different suspension mean you dont want your car to turn or swerve as sharply on loose rockey offroad surfaces. it was tightened and closed off for this reason. If you drive it on a track with sealed proper road surfaces then tighter turns and your adjustment might be an okay idea if its steering is heavy and needs a few rotations of the wheel to make some tight inner city parking manuevers. But if you're going down steep sand dunes turning doesnt actually work as it normally would and is less effective and turning sharply means you may roll or veer off vector its a bit like skiing how the skis tend to go forwards or you angle them but when the bumps and rocks come your snow ski at high speed cant keep stable so you hop side to side bouncing and do so on jetskis in surf waves too... though ski's you can lean and sort of snowboard like edging to a halt, your car doesnt jump or lean and it relies on suspension to sorta bounce a little but reduce the bumps to smooth. if your longskis in the snow go fast as a car you will understand what i mean high speed on bumpy roads and loose sand down hill sand dunes. if you plan to only drive it in town then try out your change. In places like australian nullabor plains 11 days of drive of nothing but dirt road rural australians drive their ars at plus infinity miles per hour because nobody has enough lives to spend days to go to the store. your car at a speed high enough should steer or turn with a tight enough circle, maybe consider changing to a smaller easier to grip and spin around rally like steering wheel.
Man, you got me thinking about the steering setup on my toyota pickup. Its forward steer and im sure its just as bad as the demo on paper lol. I think im gonna try to make it rear steer and get better geometry. This might be the reason why my tires need rotation more often than i think they should is because they are scrubbing the heck out of the roads every turn i take lol...
Thanks for the great explanation man 👍👌
It looks like Forward steer would cause oversteer. In the case of a go kart you would then want a wider front track (wheel base) because wider front tires lead to understeer due to the rear axle being solid.
ackerman wasnt even born yet when charles darwins grandaddy first devised this setup while making house calls as a doctor in mid 1760's england. he got tired of his carriage crashing on turns, as it was the whole axle turning and a tight turn would turn it from a 4 point support towards a 3 point structure, if that is imagined in ones mind. so he had the local carriage maker craft his design up, leaving the front wheels in place and the control arm to turn them. since he didnt want to be thought of as a mad inventor which could have hurt his doctoral practice he never patented any of his schemes.
the royal society of england was aware of the design, thru a friend and admirer of the aforementioned erasmus darwin, yet those old blokes must have had plenty to look at in those days of invention, because it would be 50 plus years before it was patented by ackerman after a german carriage builder named lankensperger developed the mechanism. ackerman was the germans agent and spent years defending the design to reluctant adopters of the technology. or something like that. was a fun rabbit hole to fall in reading about steering.
so does varying the toe of the rear wheels help things? Is it another way of adjusting for an "incorrect" ackerman? Toe changes on swing axle bugs anyway as they are on trailing arms so would changing the ride height affect the way it turns within the concept of the ackerman angles? what about lengthening or shortening the wheelbase?
A lot of what you mention there will help with stability. But none of it will help with the ackerman. But the good news is if your ackerman isn't the best it really only affects you on tighter turns.
So, if your concerned about front track controll rod and steering pivots, why not move to rear pivots etc? Don’t see the need to make life difficult when you already know it’s better with rear steering pick ups
You got me thinking Doug I need to check my baja king link pin. Longer wider . woods chrome Allie stuff . thanks for the kick in the brain bucket . mine is rear steer tie rod to the same rack and pinion box as yours . what front breaks are you running? Mine are to small and the rear locks up first . $ ?
.
Mine are Jamar combo spindles. But I'm in the same situation. Although they brake pretty hard, the rear lock up and the front does not.
Glad I got ya thinking. lol
what if you flip a arms and spindles from left to right side and move suspension forward accordingly. then you should have room for rear steering. would be cool to see the diffence and for you to give a hands on verdict on the effect. steering rack would need to be upside down too or be 2 axles with a gear on each to change direction of rotation.
Part of your having hardly any steering on the gas is a symptom of poor Ackerman angle. The scrub causes understeer
FWIW, zero ackerman is a thing for drift cars that are intended to be doing a lot of high speed drifts, but it's a personal preference thing. I guess my point is that it appears to me that you might be able to modify that current spindle to where you can move it out to real close to zero ackerman, and that should be fine. Definitely it looks like that spindle on the old bug could be moved out to zero if you wanted.
Also, I think you need to draw a virtual line between your upper and lower balljoints, and see where your outer tie rod pivot lies in relation to that line. Might be a little different than just looking at where your upper ball joint is, and in the case of that current setup, I suppose it might actually be a little less good.. I do agree that it will be fine however you leave it though. Thanks for another fantastic video!!
Thanks for the tips. Like you said, I'm going to try to help the Ackerman. But I won't lose any sleep if I can't get it right on.
May be change steering knuckle left to right and move steering reducer with cut steering colomn
Your card board model was so helpful, earned a like and subscribe from me!
If you measure the center point at rear axle and put it in front of your vehicle you will have correct Ackerman angle and location in front.for front tie rod locTion
🤔🤷🏻♂️ lol great info thanks for sharing
Sure thing buddy!
What's the point of having a front steer Ackerman if it's just going to be worse than the tires moving at a 1:1 ratio without it?
for example BMW is front of axle steer, on top of that, BMW has very good turning radius, can anyone come up with the geometry for BMW steering?
Anti ackerman. More steering angle on the outer wheel which will have more load on it.
How much degrees angle is at the rear centre of the pivot point at the rear axle?.
Hey, how do you calculate the force on the steering arms, tie rods and the rack while designing?
I don't, I just build what I think would be appropriate. I think if you were going to get that technical it would be best to draw it in software like Solidworks or something similar that can do stress analysis.
just to clarify...'correct' ackerman is possitive & bad one is negative ackerman, right?
Correct, positive means the inside is turning a little tighter in turns.
No entiendo nada, algún día voy a buscar a alguien que me traduzca todos tus videos, y voy a tratar de hacer un juguete para mi, es un reto personal que tengo, gracias por compartir toda tu sabiduría, saludos desde san luis rio colorado sonora, sin llorar..
Lo siento por eso. Si puedo encontrar algo en UA-cam que permita traducciones, lo haré.
¡Me encantaría que pudieras obtener el audio!
Gracias por mirar de todos modos. jajaja
@@DougBugBuilder muchísimas gracias!! Se agradece tu tiempo
I'm a little confused. Inner turn wheel was 29 degrees and outer turn wheel was 31 ? That means that the inner turn wheel turns more compared to the outer turn wheel and thats what you do want, right? -that is, "forward" or "proper" ackerman steering. But shouldnt it be the opposite for your front type steering rack setup ?
The way I was measuring it 0 degrees was straight ahead. So 29 degrees was not as sharp as 31 degrees. So it was a little backwards to what it should have been for proper Ackerman.
THANK YOUUUUUUUUUUUUUUU!!!!!!!!!!!!!!!
You're welcome. ✌
If I can leave a suggestion, I would try to move the steering rack to the back. Your shock looks like it is in the exact middle of the lower arm so it will not interfere, you may just have to get a different rack (that has the shaft coming from above) to help with steering shaft routing/angles. If not an option, while you move the steering arms on the spindles may as well make some new ones that sit as close as possible to the rotor so that the ackerman will be "less worse" 😂 rotors don't flex and your spindles look beefy so I'd say a few mm clearance between them would be enough
Great ideas! I originally was trying to mount the rack back like where you are describing. But the steering shaft was impossible. At least with this rack. So I went with the front steer.
I really like your idea on hugging the rotor though. I'll consider that. Thanks for the idea.
Moving the steering rack rearward should resolve the ackerman issue. 1st and 2nd gen miatas are front wheel steer and the steering rack sits behind the attachement points for the tie rods. Its all about the triangles. Take the triangle that you make with the centerline of the rear axle and the pivot point of the spindle and youll get an angle. Its probably going to be around 20 to 30 degrees depending on track width and wheel base. Thats the angle youre shooting to make between your steering arm and your tie rod connection arm. So lets say you need your tie rod connection arm to be offset at 25° angle for your Ackerman to be right but you have to make it at 20° to keep bumpsteer in check. you can move the steering rack rearwards (in your case) to increase the angle between the steering arm and the tie rod arm by and additional 5° to get your magic number of 25°. Hopefully that makes sense. Unfortunately i cannot upload pictures for you.
scrawnywhiteguy55 this is actually clever, did not think about it but it makes sense. Worth a try at least
@@scrawnywhiteguy55 Thanks for the description. I might draw it out and see if I can get anything that works.
Who knew? very informative!
I know I'm 4 years too late.. but you have ignored the pitman arm in your model. The ackerman adjustments don't have to happen at the spindle. they can be made at the pitman by overlapping the tie rods. Hopefully you've already figured that out.
This man talks about it a bit as it pertains to a go kart.. same theory though. ua-cam.com/video/WyC2MxgCdE8/v-deo.html
Great video mate very informative 👍keep it up! I have never tackled a steering or suspension build it looks pretty intimidating if im honest. Just wondering if your first bug is actually 5.2 ish degrees out of this acra...thingy 2.6 to get it equal then another 2.6 to get it to zero scrub? Im not being critical or trying to be smart , just seeing if im undstanding the concept correctly. Anyway cheers mate, love your vids and thanks the work you put into sharing with us. 🤙
Keep in mind I'm going a little OCD with this. Building a front end doesn't have to be this neurotic.
If I could remove the 2.6 degrees then I'd be at neutral steering. I don't know how much it would need to be true Ackerman. I'd need to lay it out like I did on the board. But it would probably be a couple degrees. But pretty much what you described.
@@DougBugBuilder thanks mate, I think it's all above my pay grade but I might give it a go one day. I agree physical models are the way to go with things like this. Rock on brother 🤙
Your cardboard demo is for a single point of attachment. The buggy has two points of attachment. Cross the attachments and you will be fine. Passenger side steering rod to drivers side bolt hole (rear). Drivers side rod to passenger side bolt hole (front). This is still Ackerman's theory. If two attachment points they need to cross.
I can't argue with you. But the point of the cardboard was really just to visualize for people how the Ackerman works.
Pretend this buggy is solid axle. 😂
Would you provide a link to your next video that explains your outcome of your changes to the Ackerman angles. I cannot find it in your list of videos. Thanks
I never did a second video on the Ackerman. But I can tell you with the changes the steering is pretty good. Straight line running no issues obviously, tight turns you can hear it scrub some on asphalt, but it's not bad. And this vehicle is really only used at dirt tracks and trails, so really a non issue here. I hope that helps.
@@DougBugBuilder Thanks for the reply. This video was very helpful because I had a major anti-ackerman on my 1991 Dodge XPlorer motor home. With that much weight it didn't take long to eat my tire treads. I moved my steering center link closer to the axle and it worked. I guess it is the same as if you moved your steering rack closer to the front axle.
A great explanation and job 🙋👏👍
Thanks!
Off Road cars arent designed around the ackerman principle. Your steering box location is very bad.
who in the heck is Ackerman ? haha! :] ]
He's a pain in my ass! That's who he is. ;-)
@@DougBugBuilder hahaha... thats funny!
im actually watching a bunch of your videos right now, getting caught up on them.
and contemplating on buying a bug,
im wanting to start where i left-off 35yrs ago, oh, i had a baja buggy and i loved it very muchly, but one day it was gone, someone stole it from me,
i hope i can come up with the money for this one ive been looking at, before someone else gets it,
ha its ever the same color i painted mine and with the same kit too... yay! :D
my videos suck but i just might make a few if and when i get my lil buggy back home!
I think you may have made a mistake when you were measuring the steering angle on the car, at least as shown. You are supposed to measure the angle away from straight/neutral (whatever you like to call it), so either choose parallel or perpendicular lines. 10:20 shows that you were measuring the angle between the line that is perpendicular to when steering is centre, and the line that is parallel to the wheel. If this meathod is used, then the inside wheel should have a lower number.
Although I'm not English speaker I got what you have said. Genius explanation
Thanks!
I want to know where you found those brake calipers n rotors!
Those calipers and rotors came in the Combo kit from Jamar.
www.kartek.com/parts/jamar-performance-combo-link-front-disc-brake-kit-with-2-piston-calipers-and-10-rotors.html
Can’t you simply add more of a cantilever device where the tie rods come together. So when turning to the left, the left tie rod would travel further distance than the right tie rod utilizing the angle of the pitmann arm thus adjusting you ackerman angle to a more favorable ackerman? In your schematic, you use a straight tie rod from one spindle to the other, but in reality, the tie rod on the left and right could have a different rate when turning left vs right? Couldn’t it?
Dude, you're making my brain hurt first thing in the morning.😉 You can do that if the center steering is rotating on an axis. Like a Pitman arm setup. But mine is a rack, and that moves linear back and forth. So I don't have that option with this setup. But your logic is sound for sure. 👍
Don't forget that each front tire has a different slip angle going through the turn... You have more slip angle on the laden wheel(outside) than you do on the inside. Thus, the path that your outside tire is taking is actually less severe than the angle that your outside hub/ wheel is taking... thus minimizing the anti ackerman that you have... check out the anti ackerman on an F1 car, might be shocking...
Thank you🙏🙏❤️❤️
Thank you for explaining something in plain language that is easy to follow instead of techno babble.
Glad it was helpful!
Thanks for the comment.
Doug, do you have to do anything special, to the rotors or calipers, for off road use when you expect a lot of sand and dirt to kick up in there?
Not really, although I do try to set them up so they are at least 1/2" away from the inside of the wheels. This allows dirt and rocks to pass between the calipers and wheels if possible.
You made this really easy for me to understand, thanks for taking the time to do this! Really well done!
Glad it helped!
Hello from my understanding for your vehicle you actually should have steering in front of axel. This is called anti ackerman and the reason is because you have soft suspension. With soft suspension when you turn the load/weight easily shifts to the outer tire. Due to physics this means the outer tire needs more angle than the inner tire in order to turn that extra load. This is why your other vehicle also has anti ackerman
how about your scrub radius?
stupid noob question but could you swap hubs so your left forward steer becomes a right rear steer ?
Making it rear steer would solve the Ackerman issue for sure. But the reason this is front steer is because there isn't room with the A Arm suspension to have the rack and pinion mounted that far back. So for clearance the rack has to go forward and makes it need to be front steer.
3:36 wait why is it exaggerated? your tierod pivots on the lines you talk about at 2:54
It might good idea to move, the main pivot of tire , inboard, to improve the pivot-set alignment. Instead of move the secondary one. thanks for attention, enjoy.
That how poor ackerman is on a stock axial first generation scx10 rc crawler.
I was just getting out of RC when the Axial was getting popular. So I'll take your word for it. ;-)
Thanks sir to make such helpful video it really helpful
Glad it helped, and thanks for the comment.
I'm getting severe anti akerman lolol not sure how to sort it my brake rotor is in the way also does steering rack angle effect akerman?
My rotor ends up being in the way too.
The rack position will affect it, but honestly it has to be pretty far forward or back to actually have any negative effects.
Great video! I emailed you some pics of my build, it was all simulated in CAD before I built it. I downloaded your files that you shared for the spindle layout, and also discovered the issue with the backwards Ackerman! The setup I have now is not perfect, but it's pretty close.
I just saw this comment, can you send a photo of the spindles with your steering arms on it so I can see what you did?
dougbugbuilder@gmail.com
@@DougBugBuilder I will email some pics later today
why not install the steering gear behind the front wheels and swap the spindles from one side to the other?
Usually that's a good way to go. However on the build of this Baja the rack needs to be in front for clearance of the steering shaft.
Designing a go-kart and realizing I meant to use Ackerman, but I accidentally made it forward steer... oh well :P I guess it doesn't matter that much, though. Anyway, thanks for the video! Nice looking machines, btw
It's possible to get proper Ackerman with Forward steer. But usually it's not practical.
Good luck with the build.
@@DougBugBuilder Thanks!
Best akerman video I've seen yet. Good explanation bud. The little model really helps. 👍👍
Thanks 👍
Thanks for the very well explained video!
Who knew? very informative!
Thanks!
Cool ! If only a dependable Davis mechanism could be devised and built it'd suit your baja just right, both because of its mathematically perfect differential steering (compared to an Ackerman type) as well as its standard assembly being already ahead of the spindles...
thanks for this. Im old and feeble and limited to 1/10 scale rc cars. however, next time I put additional rear drive axles on a home built rc car or build a half track truck, Ill smoke a joint or 6 so I can work out the correct ackerman easily. A great explanation.
I've toyed with RC cars my whole life. I'm sure when I run out of money or energy I'll go back to those.
I was just hoping you would have a model and then bam, model comes out. The model made all the difference I had experience with the topic but you your explanation was very good. Good video.
Thanks, I'm the same way. Really need to see it for my brain to wrap around it.
My understanding is that Ackerman is for perfect conditions, but with slippage and loss of friction as off-roaders will often encounter, having a toe-in on the wheels helps with stability in most conditions so I wonder if the pro-ackerman linkage was chosen to enhance stability on variable terrain.
Personally I think the design was more "this is what fits". But you're right, Ackerman isn't that important for offroad. But I'll still do what I can to get it as close as possible.
Excellent explanation, thank you. I’m also getting the same question a lot on my build, you’ve helped me massively.
Awesome!
Glad it helped and thanks for the comment.
Ive been rackin my brain on my drag car I changed my rear steer to front steer. U just solved my problem! Thanks 👍👍🙏🙏
Glad it helped, thanks for the comment.
Thank you for taking the time to build that cool model and explaining how different situations affect the steering. Awesome video!
No problem 👍 Thanks for the comment.