build problem !!

[johnm21]

Hi
I have created a tuber chassis for my wheely king and now have a problem, when i get to a object to climb over the wheel base shorten and stays crunched up meaning it does not want to go straight ! it keeps crabbing up how can i stop this ?? if i climb a wall it gets so far and then the wheel base shortens to about 8 inches pushing the chassis up and making it fall over backwards !!

I have done something wrong just need ldears how to fix it !!

any suggestions thanks

John

[TONKA TOY]

Got any pics?
Are you running a droop or sprung susp.? I had a similar problem when I first tried to set up a droop style rig. The problem I had was too much travel in the shock, and also not enough weight to drop the shocks back down to normal ride height. I angled my shocks to more of a horizontal position (about 30-45 deg.) Also you can try a limting strap to help limit the travel.

[johnm21]

i will try and get some pic but it will not be until tomorrow now, i using spring system. i already had the springs at about 45 degrees !! I have got so much flex that the top of the shocks break off !!! and need putting back together ! it just does not want to sit back down level after getting crunched up !!!

[johnm21]

i am kind of new to this what are limiting straps and how do they work do you have any pics that would show some being used !!

[JavelinSST390]

We def. need pics of what's going on here... But I'm willing to bet from the sound of it that your link/shock geometry is allllll messed up.

What are S-springs?

Your upper links should be paralell to the ground or slightly higher at the axle end at rest (all four wheels on flat ground.) And the lower links should be fairly close to the opposite of the uppers.

Also, are you still using the stock Wheely king shocks? They are waaaaay too long for a crawler, unless you stand them straight up.

How much total flex do you have? If you can put three tires on the ground and the frouth one on top of a 12oz soda or beer can then you are set. ANy more flex than that and it will only make the rig more un-stable.

Limiting straps are just straps or ropes that go from the chassis to the axles, that keep the axles from dropping down too far. That would be a "band-aid" fix for your situation, it would help, but it's not adressing the REAL cause of your problem.

[rambuller84]

Originally Posted by johnm21

I have got so much flex that the top of the shocks break off !!!

Yeah, that's too much. I'm willing to bet you have too much belly clearance which in turn mangles your link geometry.

[clod & bruiser]

yeah try running a droop setup cause if you got the shocks at 45degrees then you shouldnt have much problems persay. but yeah pics are worth a thousand words man. get 'em up here!!

[breitenbach14]

what about your upper links?

[johnm21]

pictures of my problem !! i think it is the link angles i have got wrong !!

[Patella]

Is it just me or do those front shocks looks really torqued inward? If the chassis is too narrow and the shocks twisted, wouldn't that make them bind up when trying to articulate?

just my 2 cents

Jake

[EHeye]

Never seen a 7 link before.

Those shocks are doing absolutely NOTHING for you. And more than likely this is your problem, the angle is too much, you need them more verticle in my opinion.

[JavelinSST390]

Okay, here is my list of things you need to do:

The chassis is too high off the ground, the shocks are layed down way too far, and the links are too short which is what's causing all the axle steer.

I know you put a lot of work and effort into it, but that chassis is just NOT going to work right without some modifications. It's a good start.
But you are going to have to add some shock mounts that will mount the shocks up higher and more straight up-and-down. Plus they are going to have to m9ount out further away from the chassis.

Also, you should make a custom plate to mount the motor over to the side of the transmission, not above it. Having the motor up that high is terrible for crawling.

Also, make a real four-link setup, the stock plastic Wk upper V-link is JUNK.

you should drill some new holes for the upper link on the chassis about 1/4" higher than they are now. The current set-up has a TON of anti-squat which is what is causing the problem you described.

I think you would be much happier with some shorter shocks. The stock Wk shocks are too long and have too much travel for ANY crawler in ANY configuration. Get some 100mm shocks.

Do all that and it should fix your problem. You've got a good start, but there's a lot more work to be done here.

[Douginala]

This is really helpful. Even though I'm green I've already had steering and link geometry heartburn.

It looks to me like John has a nice start here and even with some changes in order it'll end up just fine and be a great learning tool for all of us.

Javelin, how would you suggest that John redo the upper links to switch to a 4 link setup?

Thanks.

[nfldcrawler]

tanka toy mentioned a limiting strap not a bad idea 4 now i had the exact same prob i mounted my shocks more vertically and cut some small hose to fit in side the shock to limit travel about 1/2 or 5/8 inc long cured the problem.

good luck nice start