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Almost Finished
Posted: Sun Aug 11, 2024 7:56 am
by SubZero
But seriously....are they ever really finished?
Quick question guys. This is my first clod and 4 wheel steering truck so I'm sorry if this is a dumb question but, the rear axle and tires seem to want to trail off to the driverside of the truck more and it just looks weird when driving a straight line. Is this a servo/alignment issue or a suspension link issue eyc etc? I measured all the links with a digital micrometer and they are all within .5 mm of the same length. This is driving me nuts. Am I overlooking something with it? Working on and tuning this thing feels so much different than all my modern Arrma infraction, Limitless, Mojave and my actual losi and team associated track cars/trucks. Side note, this is only the 2nd monster truck I've owned, first being a traxxas tmaxx pro .15 nitro back in the day. Any help would be appreciated.
Thanks in advance.
Re: Almost Finished
Posted: Sun Aug 11, 2024 9:23 am
by Frankentruck
Very cool Clod! Is your rear issue while driving straight or while turning? Is it how it moves or how it looks (and it still moves as expected)? The front and rear will steer differently from each other, with the front having the steering arms pointing forward and the other pointing behind. Take a 2wd RC and steer going forward, then steer going in reverse. See the difference? Now put that steering all on one RC.
Re: Almost Finished
Posted: Sun Aug 11, 2024 4:18 pm
by Lowgear
Just a guess, but it looks to me like it could very well be that your links are improperly triangulated. That will cause the axles to sway left to right instead of pivoting an a central axis.
The top links should be closer together at the top of the gearbox, and then splay out to the chassis.
The bottom links should be closer together at the chassis, and then splay out to the ends of the axle tubes.
Here's a pic taken from another site that gives you an idea:
Here's a better visual representation of the geometry:
Re: Almost Finished
Posted: Sun Aug 11, 2024 7:42 pm
by Dangeruss
When you say "trailing off to the drivers side"... do you mean dog tracking? Like the rear axle of the truck sits out further on the driver's side than the front axle when you're driving straight?
Might be the drag link from the rear servo to the passenger's rear knuckle is a little too long. Could note the length then adjust it in (shorter) and see if that makes a difference.
It's less important that the links are the same length than it is that the axles/tires are square with the chassis.
Having said that, if adjusting the rear drag link doesn't help... check to make sure the axles are square with the chassis, centered, and the wheelbase/toe is the same on both sides. Misaligned axles are typically the cause of dog tracking.
The double triangulated setup that lowgear showed is best for locating the axles laterally in the chassis while providing the least amount of roll steer but can/will still exhibit dog tracking if the axles aren't square under the truck, same as the single triangulated arrangement you've got which is typically found under 4-link Clods.
Re: Almost Finished
Posted: Sun Aug 11, 2024 8:00 pm
by Lowgear
Upon looking more into this, I forgot that the Clodzillas use a reverse triangulated 4-link setup so they seem to be in the right place on the chassis at least. The angle you have the links that are mounted to the sides of the chassis could possible need greater of an angle though. What you're ultimately looking for are two opposing triangles.
Pick the truck up, and try moving the axles from side to side preferably with the shocks removed. If they sway then it's a link geometry issue. If the axle pivots instead like it's supposed to, then the problem is somewhere else.
You can also try locking out the rear steering. It's common not to run it which is why so many rear lockout kits have been produced over the years.
Re: Almost Finished
Posted: Mon Aug 12, 2024 2:53 am
by Dangeruss
Academically, two opposing triangles is considered optimal, but LMT's, SMT's (even full-size monster trucks) only use a single triangulated arrangement, for a variety of reasons. Clods use the link locations they do because the bars are designed to attach to the factory axle mounting points.
All link mounted axles will have lateral (side-to-side) movement, the important thing is that when the suspension comes to rest, it does so with the axles centered & square. If not, then yep, it's a geometry issue and the links will need to be adjusted to correct it.
Locking out the rear servo while troubleshooting is a good idea though. Reduce the variable on the off chance it's a servo/rear steer related issue.
Not that I'm arguing mind you... suspension dynamics get's me excited... and I just can't hide it.

Re: Almost Finished
Posted: Mon Aug 12, 2024 5:08 am
by Lowgear
I took it as a good deal of pertinent information which is what this is about.

This topic is making me want to build a Clod using one of the Sassy Chassis' I have just to play around with the suspension now.
Slightly unrelated but I've never been a fan of mounting both link ends to the axle tubes like that. Mounting one link to them per side is bad enough. I feel as if the upper links should always be mounted to the top of the gearbox as it's nice and strong, and offers better geometry in my mind.
Re: Almost Finished
Posted: Mon Aug 12, 2024 5:15 am
by RC10th
Nothing beats old school bouncy bouncy

Re: Almost Finished
Posted: Mon Aug 12, 2024 7:01 am
by cas22
That looks amazing, well done.