Projects My '23 Roadster project

No...its the picture. I noticed that also. I no longer have that camera.

 

Get some flat steering arms and bolt them to the top back plate bolts and PLEASE put the tie rod behind the axle. You should do a search on Ackermans Principle and understand how it works. The rest is looking cool. JW

 

Its already been fixed - long ago. This is an older thread, those pictures are a few months old now. I just haven't taken any new pictures lately.

 

Glad to here, now its totally cool. JW

 

I've been reading this thread with interest since I want to build my own project. I hope you dont think this is a hi-jack.

If anyone with experience can help..I dont understand with the front end mech58 is doing, which is like alot of other cars I've seen being made, when the ch***is rolls (as in when taking a curve) in relation to the front axle, the way I see it, the radius arms are trying to twist the axle? Wont this rip the bracket welds/bend something?

Or is it a kind of "anti-roll" effect? Dont you need parallel bars with a joint on rear end of each bar?

Thanks for advice on this.

Tom.

 

Tom, on the first page of this thread there is a pretty good explanation of the Ackerman principle. It's post 15.

 

Mech58, Ackerman principle is steering, my question was about front suspension geometry.

 

Ok...this type of setup is very rigid Tom and it does result in sort of an anti-roll effect. The whole idea is simplicity.

 

Got started on my fuel tank today....

Should hold somewhere between 20 and 21 gallons. I couldn't find one to meet my spec for a reasonable price so I decided to build one myself. I think its going to work out good.

 

Been awhile since I took these pictures, figured I'd post em up though - my Ackerman Angle, corrected....





The 'tie rod' there is just a piece of conduit I was using for the mock-up.

 

Worked on this all day today - dis***embled it and finished welding out the ch***is, then cleaned everything up and started painting.

Ready for paint...





Front end parts...



I fully intended to take pics of it in primer...but I forgot. lol

 

Tidy. JW

 

Thanks...I run a tight ship. lol

 

Nice job, really glad you got the Ackerman issue out of the way. Nothing holds up a project like a stretched out "discussion". One thing that has been buggin' me is the build of the Tribute T project in Rod & Custom magazine. At first I thought it was just a quick ***embly and would be corrected, however they left it like it was started. I'm talking about the same thing you just went through........ the steering arms are in the front on their build, which puts the steering geometry way out in left field. I wanted to contact them, but figured a 70 year 'ol fart wouldn't be listened to anyway. A few years ago I was at a local cruise in, when I heard a car pull in with a howling of tires. Later when I was looking at this car (T-Bucket), I mentioned to the owner of the issue he had. He told me I didn't know what I was talking about and that noise was his tight posi rear end. Before the night was over he had looked me up and apologized, saying that about a dozen other people had told him the same thing. Sometimes people on this site might come on as know it alls, but in reality are usually right. Some are blunt, some try to slide in quietly, and some can be outright confrontational, but in the long run have your best interest at heart. I think you're doin' a fine job, and I'm glad you changed your arms. Good luck on the build.

 

Thanks Coop - the main reason I participate in these forums is so I can learn from others. I also have a lot of knowledge to share - however before I posted this thread I didn't know one iota about the Ackerman principle. I am very glad it was pointed out to me because I am the type of person that likes to do **** the right way, especially from an engineering standpoint. I'm going to a lot of trouble to build this car and I want it to be right. Consequently, I went to a great deal of trouble to correct this error. Anyway, its odd that you mentioned the guy's tale about his problem being caused by a tight posi unit - I am really worried that I may actually have that problem also. The 9" axle that's in my car has a very tight trac-loc diff in it and I am wondering if it might cause me some problems. I hope not.

 

Another 'issue' I am starting to suspect that I might have is with my rear spring - I am afraid it's not going to be stout enough. I am using a Speedway medium arch spring - it seems to be pretty soft. I basically designed this whole ch***is around THAT spring. I really hope I don't end up having to have a spring custom made. The way my luck runs I figure I probably will. :|

 

I just finished a T last fall, built out of a whole bunch of "extra parts". I used the speedway bracket that welds to the axle to create a "spring behind" system. In my infinite wisdom I used the front spring of a '48 ford. I re-arched the leaves to fit the template that I had made. Only removed a couple of leaves to attain the height that I wanted. My first trip out of town, I was followed by a friend that informed me that my tires were bouncing a lot. Come to find out the whole car was leaving the ground on a bump 'cause the spring was too stiff. It was rigid enough to bend the speedway bracket on the axle , even with the gusset that comes with it. So before you change the rate of your spring, try it out first, you can always remove or add leaves to get the ride you want. Just a tip here, 'cause I ain't no expert. Just know that this is experience talkin'.

 

The keys to a good driving and riding T bucket are a working suspension, comfortable to use controls, and a comfortable seat.
The working suspension part is often the worst done on many Ts. I expect a T to bounce a couple of times when the frame corners are pushed down and released. Too many have harsh or non-working and shocks.
Ergonomics of controls means simply making sure you can easily and quickly reach and operate steering, pedals, switches.
Comfortable seat is easiest using a seat cushion of coil springs. Stock ones are available from Car Line Mfg. in Beaumont TX at 1-409-833-9757.
For the seat backrest you can use a stock coil ***embly OR a nice one-piece upholstery insert with foam cushioning.

 

Yeah, I'm not planning to change anything yet - not until I can test it out thoroughly. The main reason i am concerned about the rear spring is because as I add to the car I keep watching it compress...and compress, etc. By the time I get it finished and fill the gas tank up I am worried there won't be much travel left. I did actually exchange the first spring I got - it was a reversed eye medium arch spring - I exchanged it for a standard eye medium arch spring. That gave me about 2 more inches out back that I needed.

As far as ergonomics are concerned I think I got that covered. I have spent a great deal of time on the layout of the ****pit of this car. I am planning to build my own seat. I mocked up several different seats before I settled on how I want it to be, once I got that part figured out I started laying out my steering column and box mount. It should be very comfortable to drive for me. I'm 5'11" and 205lbs. If you'll notice in the pics of my frame above you can see two pieces of 2" angle welded to the top of frame rails in the ****pit area - those are going to support my floor. So the floor of the car will actually be 5" from the bottom edge of the body.

 

Here's a quick picture of the rear spring I was talking about. As soon as I can dig my way thru the 26" of snow to get to my barn I'm gonna pull a couple of leaves out of it. This rig has no shocks right now, but I'm gonna put some on before I hit the road again. Like you, I don't wanna set any lower cause I'm about as low as I can get. In fact when I remove the leaves, I'm going to replace the same amount of steel as a spacer to at least maintain the height I have.

 

I was originally going to use a Model A rear crossmember but decided not to. The only reason I decided not to was because I already had that medium arch spring and they just will not work with an arched crossmember. In retrospect - what I shoulda done was stuck with that crossmember and got a different spring. This is my first traditional ch***is build, so I'm learning as I go here.

 

Not sure if I have this pic posted in this thread or not...taken a few months ago.

 

I need some ideas for some windshield posts. This body didn't come with any - I don't want a double-stacked, folding windshield, just something short and sleek. I don't want a 'frame' running across the top of the gl*** either.

 

Hi, I am sorry to be late to the party, but just to offer some information on Ackerman that I don't think has been posted:

1 - It is indeed important to properly set the Ackerman as that improves handling, reduces tire wear and most importantly provides self-centering after a turn, itself an inspection requirement for custom vehicles in many states.

2 - You can have correct Ackerman with the tie rod in front!

Just find the steering arm angle as if the arms were facing backwards. Then duplicate that angle and length with the arms facing forwards. Done.

Think about it - you could have a parallel tie rod with dual sets of steering arms, facing backwards and forward. One tie rod ahead, another behind. There would be no interference movement if the steering arm angles and lengths were exactly the same.

That's why you have have proper Ackerman with a forward-mounted tie rod.

BTW I am really liking the design and the way you laid out and locked in the sheelbase.

 

Yep - I do realize that you can have a 'correct' Ackerman with a front-mounted tie rod - however that geometry doesn't usually jive well with most wheels and tires. Usually with that type of setup, the knuckle and tie rod end are situated very close to the edge of the rim, or interfering with it all together - requiring a wheel spacer or a different offset wheel.

Since this concept was pointed out to me several months ago I have checked out dozens of other peoples' rods with front-mounted tie-rods and so far every single one I have seen has been done incorrectly. I think most folks are truly just unaware of the concept. I was - I do remember reading about it many years ago when I was just young, but since I have never really designed and built a car from scratch before I never got a chance to apply the knowledge and it just got covered up with years and years worth of other ********. lol

 

I'm having trouble understanding how the rim knows whether the tie rod is up front or out back.

Are you saying that it is difficult to set up proper Ackerman? Or that the clearance differs front to rear, making a front setup more difficult to dial in?

 

^^^^ Study the diagram in post 15 and focus on the two lines from the rear end that p*** over the king pin centres, you should be able to work it out. JW

 

That diagram shows how to set up Ackerman. Duh.

It does not explain, nor have you, how rim interference would be different if the tie rod was mounted in front or behind.

Perhaps you should reread my post, a few above, to understand how you can have correct Ackerman with the tie rod in front.

The OP stated that with the tie rod in front, it would interfere with the rim. If there is interference with the rim, then that interference would be the same front or back. Right?

 

this is a great thread with great info!! to answer a couple questions with my .02....generally it's best to have 4bars with a tube axle as a tube axle doesn't flex like an I-beam will.

also ,it's difficult to obtain zero bumpsteer with the tierod in front as you've found out Mech58.To get the outer tierod end to lay on where your string line would p*** would most likely need the rim moved further outward from the hub...no such problem as you've done it.

Plym49 ...yes the rim clearance is different with the tierod end in front or behind.In the photo in post #41 ,if the stringline ran straight instead of hooking round that grease ****** ,it'd most likely run into the rim not an imaginary point where the centre of the tierod end would need to be. Study the diagram in post #15.

 

Correct ackerman is achieved with the tie rod in front by having the steering arms angled out. If you p*** a line through the centre of the tie rod end (with wheels at straight ahead) and the centre of the kingpin and then carry on to the centre of the rear axle and this line is straight this will give you CORRECT ACKERMAN. Because the steering arms are angled out this is why the tie rod end will most likely interfere with the wheel rim or brake drum. Ackerman is to achieve toe out on turns as both front wheels travel in different arcs. That is as simple as I can make it, I hope that helps. JW

ps; sorry 58 to go over this in your thread.