Aeromax AWD flat bed.

[Snochaser]

I like the versatility Travis. Really good idea for someone who can't have several trucks, leaves the options open for several different functions. Thumbs up.

Ben

[Lil Giants]

http://www.beam-wiki.org/wiki/Steeri...erman_Steering



The pic above, say up is forward. Notice how the left tire (inside wheel of the turn) is so much sharper than the right? Then picture down is forward & you'll notice the opposite has happened.


I got this lil red dump trk that Freddy built, 1st load on it I peeled the tamiya floats off the rims (WTF?!). Thinking the floats didn't have enough sidewall strength, I changed them out to the Tamiya standard tire & the same thing happened.... turn the trk over for a look see & yep! tie rod infront! Something else that I took note of was this shorter wheelbase dump couldn't make turn before the entry level to the wooden ramp by the water heater. My KH which is a 6x4 too & the w/b 3.25 inches longer does make the turn without backing up.

I built some hay wagons from semi truck frames, I turned the front axles around so the tie rod is in front, made it easy to cut the tie rod tube, weld in another ball joint & bolt each side directly to the hitch tongue for easy control of the steering... what a mistake!!! you should see this thing rip up the ground while turning sharp loaded, the two tires fighting each... ofcourse the wagons still make a reasonably sharp b/c the tractor pulling them ultimately decides that, but the outside tire of the turn really rolls up the dirt b/c it's way too sharp!

Heck, even my combine with rear steering has the tie rod behind the axle. Combine cuts pretty sharp going forward, much wider turn in reverse, it will not follow the same track.

Try putting your tie rod behind the axle Steve, I'll put money on it that it turns shorter & smoother.

[ihbuilder]

I'm about to make new knuckles for it doo to the weight I'm twisting the steer arm that you put the extension on for the drag link . on the FDM's and most real axles you have steer arms on the top and bottom of the axle . I'd like to doo the same to eliminate the extension . With a full load of logs , I might be taxing out the plastic axle . I just might put a pair of these on it . Would've been nice if the ratio was the same . But maybe these rears will werk better with my hendrixson walking beam

[Espeefan]

Cool first hand experience Joe. If I'm not mistaken, most 1:1 trucks with solid front axles have the tie rods in front of the axle, but they can still achieve the proper ackerman geometry. I think a lot of solid axle 4x4s are like this.

[mtloperator]

Depends on the application Nate . If the truck it's on is going to be in a severe inviroment where it could get bent easily they'll put it in the rear .

[fhhhstix]

Here is a pic of the Tamiya TLT axle directly from the Tamiya web site. It is designed to have the tie rod in the front. Any body who has worked with them much knows the TLT does not have much turning ability any way due to the built in stops. If you modify the stops it will turn a little sharper but it starts to bind the axles since Tamiya did not put the pivot point of the shafts in line with the king pins either. But the Integy axles have the pivot in line with the king pins and it has twice as much or more turning capability.



Travis

[Lil Giants]

So is the hilift axle, but they're both wrong with their steering geometry.

I use the tlt's in two of my GL's.



Try doing it with the tie rod behind once and measure the difference in radius of the turn. It's a hassle to raise the tie rod with spacers to clear the bell on the diff & make a wishbone to pivot off the top of the steering knuckle for the steering servo to remain in the stock position.

[doodlebug]

Hey Joe, have you seen this style of tie rod? see the link for the Sisu steer axle, http://www.marmon-herrington.com/p/b...su/FSDP10S.pdf See page 2.
Cheer's, Neil.

Originally Posted by Lil Giants

So is the hilift axle, but they're both wrong with their steering geometry.

I use the tlt's in two of my GL's.



Try doing it with the tie rod behind once and measure the difference in radius of the turn. It's a hassle to raise the tie rod with spacers to clear the bell on the diff & make a wishbone to pivot off the top of the steering knuckle for the steering servo to remain in the stock position.

[ptebbe]

Lil Giants: this looks like the right setup for correct Ackerman geometry to me. There are 2 challenges here as you mentioned: having the rear steering arm clear the driveshaft and the other is setting up a steering linkage from the original location of the servo (in front of the axle.)

Here a YouTube example of another ingenious solution: using steering arm extenders for a steering linkage in front of the axles. This moves the lever arm outward past the kingpins and into the inside of the wheels for correct geometry. When I look at my truck models the clearance inside the wheels looks very, very tight to do such a setup.

http://www.youtube.com/watch?v=F9JsMhTA48Q

Originally Posted by Lil Giants

So is the hilift axle, but they're both wrong with their steering geometry.

I use the tlt's in two of my GL's.



Try doing it with the tie rod behind once and measure the difference in radius of the turn. It's a hassle to raise the tie rod with spacers to clear the bell on the diff & make a wishbone to pivot off the top of the steering knuckle for the steering servo to remain in the stock position.

[fhhhstix]

Like I said I am good with it its not that big of a deal.

Travis

[Lil Giants]

What's that saying "lead a horse to water..."

But now it's becoming "beat a dead horse..", I know, won't mention again

[egronvold]

Nice setup. Does the new axles seems as though/ durable as the Tamiya axles?

[ptebbe]

In this application of small, lightweight, "low mileage" vehilcles where tire-life and turning perfomance are not life-and-death issues, the steering geometry is felt to be "good enough." One tire or the other scrubs a bit and the turn is not as precise as it could be but it's not a big deal.

In order to get the correct Ackerman Geometry with the steering linkage in front of the axle the tie-rod ends must extend out past the king-pin (pivot point.) Thus with the linkage behind the axle you can have angled-in steering arms but in front of the axle they just be toed-out. This puts them actually inside the wheels themselves, which is even more problematic in setting up the steering in our models. So we generally make due with "good enough."

[ptebbe]

Here's the best diagram I could find that shows why the steering arms in front vs in the rear of the axle are angled the way they are. I found this helpful.

[grumpygrady]

morning folks ,
I know that when I had my IHC pick-up aligned they had to put wedges between the axle and the springs to get the caster and camber right ,
lets see caster is tilt of kingpin forwards and backwards and camber is tilt of kingpin inside and outside
this has a bunch to due with setting up the right angles for the Ackerman design
I can find out more and post it on the site if anyone cares
thanks
grumpygrady

[Lil Giants]

That's a great find on both the sketch & the video ptebe, both explain very clearly how to make a tie rod infront work correctly. Thank you for the edumacation.

[ptebbe]

I hate to beat a dead horse, but this steering geometry issue has intrigued me.

I found this product from Gear Doctor (Germany) which should make it easy to set up correct steering and keep the typical servo location. #20399. This is one of the upgrades to the Tamiya axle that they offer (along with lockable diffs.)

Looks like a good product.

Paul

[fhhhstix]

Here is a small update of the truck with a little paint on it.







Thanks for looking.
Travis

[Tamiya Cowboy]

looking good Travis

[fhhhstix]

Originally Posted by Tamiya Cowboy

looking good Travis

Thanks, I need to work on my picture taking skills though. The truck look so much better in person.

Travis