Loose Ball links

[chipgibbs]

If I try to move my TRX4 axle side to side, there is slop. It is from the existing looseness of the ball links. I have just replaced them all with new Traxxas links to no benefit.
The 3mm screws also do not fit right in thru the ball. Another slop producer.
Is there a brand of new or method of reducing the slop in ball links?

 

[countrytoker]

Aluminum 3mm spacer. They start at
.5mm thick and go up.

Sent from my XT1650 using Tapatalk

 

[chipgibbs]

Not sure where you want me to put a spacer. The metal ball is loose in the plastic rod end And, the 3mm screw does not fit right thru the metal ball. Both are tolerance problems that are factory made.

 

[mikemcE]

Is this a rerun?

You must have play for the suspension to work, this is not 1:1.

All balls made fit the same sized screws. IF you must, put heat shrink over the screw where it’s loose.


Hang up and Drive

 

[chipgibbs]

Is this a rerun?

You must have play for the suspension to work, this is not 1:1.

All balls made fit the same sized screws. IF you must, put heat shrink over the screw where it’s loose.


Hang up and Drive

So, a vehicle 10 x bigger should have no play in the suspension but, our 10 x smaller vehicles should have a bunch....just so they'll work? Brilliant comment.

 

[mikemcE]

So, a vehicle 10 x bigger should have no play in the suspension but, our 10 x smaller vehicles should have a bunch....just so they'll work? Brilliant comment.

But factual.
Now go drink a Guinness!

 

[nightcrawler48]

Think about this. In order to have movement (flex) in the suspension, something has to be loose enough to move. As I see it, the ball has to be loose on the mounting screw so it can pivot on the screw. Or, if the ball is tightly fixed, the plastic rod end will need to be loose enough to pivot on the metal ball. I believe the last is the most common situation. Eventually the plastic will wear and the metal ball will be loose. Replacing the ball does nothing as it has no wear, the plastic is worn. Replace the whole rod end, they're not that expensive. The RC I use the most will generally need the rod ends replaced once a year, or 2 years at the most. Compare a brand new rod end with one of your sloppy ones. I think you will find the ball on the new one is a tighter fit than the used one.

 

[chipgibbs]

You missed the part where I replaced the links with all NEW Traxxas links.
They seem to have too much slop even when new.

 

[micro racer]

You missed the part where I replaced the links with all NEW Traxxas links.
They seem to have too much slop even when new.

Is the slop on the order of several whole millimeters, or some hundredths of an inch? Because one is indeed a problem and the other is not...

 

[HumboldtEF]

I fully understand what your saying about the 3mm screws being sloppy inside of the ball ends. Tightening this up wont be an issue at all for movement, I think what mikemce assumed was that you want the ball ends to be super tight which could make articulation a bit stiff. so there are two things here guys, the fit of the ball end to the rod end (which cant really be fixed) and theres the fit of the ball end to the m3 screws this could potentially be fixed and tightened up.

I was brainstorming some solutions to the ball ends fit to the m3's a few days ago. I dream of a manufacture making the ball ends threaded, but I imagine thats not very feasible though maybe. The other idea which is do-able is to threadlock the screws into the ball ends though this would prove tricky because of the proximity to plastic (threadlock melts most plastics). Maybe the trick will be to threadlock them while they're off the truck get a build up of threadlock where it meets the rod end (when assembled) though I guess when screwing these in the first hole it passes through will need to be drilled out larger or it will scrape off the threadlock.

For those who need a visual flip a truck over and wiggle/push and pull the axle and look at the lower link at the skid, most will have play. This tends to occur where you aren't able to clamp down the rod end (by tightening the screw), axle link mount tend to be fine since they are usually tighe and when you fasten the screw it can clamp down, with the lower skid link mounts these typically wont allow you to clamp it tight with the screw.

The play seems like .5mm to .75mm

 

[HumboldtEF]

EDIT: Ignore my post below, I just noticed that the tight fit was entirely down to a bur thats left on the bore of the ball from machining. Sorry, I got exited and thought this was something different.



Okay I just found something useful last night while assembling some Dlux Fab knuckles. He uses a unique ball end that fits an M3 screw like a glove, you actually need to thread or force it in.

The rub is they are expensive ($10 for 4) and they are 4.9mm long compared to a more typical length like 7.6mm or 7.5mm and they are 5.98mm (or 6mm) diameter ball. So while you can eliminate the slop in the screw to ball fit you end up will side to side play and you need to find a rod end that uses a ball close to this size. You can stuff some washers in with the ball ends to fill the extra 2.6mm or so of side to side play. I found SSD rod end were a decent fit for the balls, SSD balls are 5.8mm so its tight but moves and should free up a bit over time I would think.

Here are the ball ends (they are the knuckle balls) https://dluxfab.ecwid.com/#!/Knuckle-Parts/p/32773612/category=6232191

 

[MAGNUMB]

o-rings help me shore up loose links. Also helps prevent dirt from entering

 

[Natedog]

@OP, I've seen the very loose Traxxas ball ends. Axial and Vaterra end links fit snugly on the steel balls as they should, I've run both of them and they take months more like years to get the slop that you're experiencing. As HumboldtEF mentioned DLux makes very high quality parts too.

 

[89Industries]

I'm going to revive this dead thread rather than start a new one.

The looseness of the rod ends drives me nuts so I've figured out a way to get rid of it that seems to last reasonably well.

I first wrapped the ball with teflon tape and then installed it in the rod end like mentioned in an earlier post in this thread. Did ok, didn't last super long and definitely needed to be redone anytime you took the ball of the rod end.

So my current solution is to use waxed dental floss. Loop it through the hole in rod end 2 or 3 times and tie it on the outside, then install the ball. Slop goes away, can use more or less loops depending on how loose the ball is and the wax acts as a lubricant (good enough for Tour d'France bike chains).

Doesn't look awesome but can be pretty easily hidden.

I've found the newer style of floss that is more like a very thin piece of non-adhesive tape works best but even the old school waxed thread-like stuff works and lasts. Can totally take the ball out and put it back in without having to redo the floss.

Can find some of each kind of floss at the dollar store as well so pretty cheap fix.

I plan to try this on the fit of the ball to the chassis mounts as well instead of trying to jam tiny 3mm shims in there which only takes up the side to side play but not the radial play of the ball to the screw so with the shim it can still knock a bit.

Not designing the mounts where the balls fit into the skid plate to have a way to pinch the ball is just lazy in my opinion and while this is for little toys, would be totally unacceptable in almost any other application. Even my SSD knuckles for some reason came with just a m3 threaded holes on both sides of the clevis holding the tie rod and drag link for some reason which didn't let it tighten down on the pivot ball. So I clearanced the first side so it could actually pinch the ball and keep it from knocking and moving. Pivot ball shouldn't be rotating on the bolt.

Any other ideas since this thread was last updated in 2019?

In the bike world we call this "klunk-klunk". Because you can feel the bike go klunk klunk every time you hit a bump.

 

[oldnick]

Brilliant thinking regards the floss tape

The steering links on my Buffalo are really sloppy, although the suspension seems ok.

I love a cheap fix

 

[89Industries]

Only my Capra kit had all sufficiently tight rod ends on suspension and shocks. And those shocks leaked oil terribly so they didn't stay.

All other trucks (of 7) had at least 2 or 3 loose rod ends somewhere if not more. the 2 Element trucks seem to have the most slop even with all metal balls replacing the plastic ones they come with.

The top cap on Element shocks are not even close. Not sure what ball is supposed to fit into those. They're so big they fall off the ball. Those i had to use the floss and o-rings on either side. But they don't leak much.

 

[MAGNUMB]

As long as the links are not falling off im good

 

[89Industries]

Magnumb, I'm curious if you tune your shocks?

I do, and enjoy "fixing" all these little things but some don't and just like to drive the things.