some steering issues

[viorel.spinu]

Hi guys,

Guess that due to the fact that the servo is mounted on the chassis, my Vaterra Ascender was always a bit weak on the steering. For example, when going backward at full speed, if I steer half right, the wheels steer right fully. Same issue, different behavior, if I accelerate maximum while the wheels are slipping and I steer a bit, I get some odd lateral movements.

After I switched to 2.2 inch wheels, this issue is more annoying.

Guess it's normal to work this way, there's a lot of play in the steering. Wondering if anyone had the same issues and whether found a fix. Maybe if I upgrade to aluminium parts ? Vaterra Alu Lenkhebel vorne (1 Paar) Ascender , Tamiya Axial Vaterra

You can see this behavior in attached movie below (go to 1:14 if don't want to see the full movie).

[CODYBOY]

What servo are you using? It stands to reason that going to the 2.2 tires would make the problem worse. I'm thinking you may need a stronger servo. Do you have a lot of play in your steering link if you pick up your truck and move one of the front tires with you hand?

[Natedog]

Time for a servo upgrade and a BEC set to proper voltage for that servo.

[Itali83]

The stock servos are weak at best and very prone to output shaft play. My housing actually cracked and I had very sloppy steering. Do yourself a favor and buy a higher torque servo and BEC and you'll be amazed how much better it'll handle.
Ben

[Sammy J.]

Along with a new servo you will want a good servo horn. I installed a Hitec 7954SH servo, and am very pleased with it in the Ascender.
I had trouble finding a servo horn that didn't interfere with the panhard link.
Today I installed a Racers Edge 24t servo horn on the servo and all interference problems are gone.



Sent from my iPad using Tapatalk

[Natedog]

Hudy servo horn will be compact size, very high quality and allow maximum room for panhard, etc. Clamping horns are unnecessary here. Dynamite servo horn is second best and worked very well on both my Ascenders.

[viorel.spinu]

Thanks a lot for your help, guys !

I did some more research today, and it seems to be the steering spindle which flex the most under stress.
Today I'll order aluminium upgrades for the all steering parts.

I'm using a 17 kg cm servo (this one - https://www.pololu.com/product/1057 and a 6 amps external BEC (this one - https://www.pololu.com/product/2865 so I guess should hold.

[KGlock]

So the servo and bec are what you were already using? or did you switch from stock to correct the issue.

[viorel.spinu]

@KGlock

Those are the one I use, I have replaced the stock ones a few weeks after I received the machine.

Now the wobble is fully fixed.

Most of the issues were caused by a flex in the longer plastic end for the rod attached to the steering.

I have replaced all the steering parts with Vaterra aluminium upgrades, and enforced the plastic end rod (see photo, could not find an aluminium upgrade for it).

Now the wobble is gone. Thanks everyone for the ideas

[Asuckaphish]

I recently noticed the same thing with the plastic steering spindles and the links. At first it seemed as if my steering was weak in certain situations then last weekend it got bad enough that when with the wheels full turned and under a little torque the wheel would almost flop over causing it to bind up. Steering servo in my case was is a 7950 with a BEC so plenty of torque. Seems that after enough wear and tear over time that the plastic gets more pliable than it is when it's new. Another buddy with metal steering spindles and chubs also noticed that his steering link was starting to flex under load as well. In my case switching to the metal steering spindles helped a ton I will also be buying a new steering linkage set to replace all the plastic link ends. The plastic parts took alot of abuse before they started this behavior, but does anyone have suggestions for alternative link ends. Or is it just something that you just submit to changing out as part of normal maintenance after so many months of driving?

[pete959]

this is what i used

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