Kraton M6s EXB and K6s EXB steering slop fixes ???

[332_RC]

I found these McMaster Carr 95630A438 PTFE shims for my K6. They are 1mm thick each & really slick. These are RPM arms. I put 1 at back 3 in front & it's perfect. No slop & super smooth, no bind w the shocks off. The rear mount is the screw type & stock upper pins.

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The only movement that is there is very slight & it's in the arm pin hole & the pin. Very little. No forward or backwards movement w the shims.

Yeah, that'll definitely get rid of the fore and aft movement of the arm, unfortunately, it won't do anything for how sloppy the arms are on the hinge pins. Which is what the real problem is for me.. my brand new K8S is downright disgusting how much slop there is at the front upper arms.. no shims will help, it's the poor fitment between the pins and arms. Have a look at this RR hinge pin/plate fitment..this is a brand new rig with maybe 2 packs through it. I'm referring to the gap between the aluminum D block and hinge pins..this is poor quality IMO.

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Dang dude, that does stink!

 

[KnowAir]

The grind marks on the red plate are from me grinding the pins flush after I had removed and cut them shorter so I could adapt the stock front v1 rtr bumper to the rear. Basically used the plastic A block front cover over the rear D block plate so I could add a rear bumper to the rig.

 

[ActionJackson]

Sounds like opened up Pandora’s box

Thanks for all the great input and explanation of what an Ackerman plate is

 

[SrC]

I just learned to live with the slop.. I feel that Arrma could do better, but aside from replacing arms, hubs, bushings and end links on a routine basis..not much we as end users can do about it.
I will give TRX some credit, IDK if it's the plastics they use or what, but seem to stay tighter for longer than my Arrma's. At least in bigger scale (1/8 and 1/6) rigs, the 1/10 not so much.

Trax stuff is made in Taiwan, Trx spends more $$ on their plastics. Better quality THB.

 

[KnowAir]

Trax stuff is made in Taiwan, Trx spends more $$ on their plastics. Better quality THB.

Makes sense. BTW, I'm not knocking Arrma, for the bashers they are, easily the best bang for the buck. Just really surprised by some of what I find considering. All my Arrma's with the exception of the K8S need some TLC. My K6 rear suspension is really bad..loose at every hinge..then again, knowing what I'm going to do to it, eh, I'll just rebuild after something let's go. LOL.

 

[slick2500]

So the BQ CF Ackerman is way better & removed some or all of slop? I bent the stock one on my K6 & flattened it back out but it needs replacing. I have a EXB on my Notorious & it's ok, some slop there. Seems CF is the move?

Idk about the the Basherqueen one but the cheapo CF ones are terrible. Try the bearings in the ackerman fix first https://www.arrmaforum.com/threads/bearings-for-the-6s-ackerman-bar.52621/ The EXB ackerman is crap just like the rtr one imho. Hell the one on my EXB bent faster than the one on my rtr Outcast did.

 

[332_RC]

Idk about the the Basherqueen one but the cheapo CF ones are terrible. Try the bearings in the ackerman fix first https://www.arrmaforum.com/threads/bearings-for-the-6s-ackerman-bar.52621/ The EXB ackerman is crap just like the rtr one imho. Hell the one on my EXB bent faster than the one on my rtr Outcast did.

The BQ-CF is cheaper than the EXB by a long shot & I can tell the BQ one is not twill CF but the plain type, which is a little stronger than twill. I bent the regular aluminum ackerman bar back straight by hand...

 

[SrC]

(9) 6s's later, and learned to find and pick my battles carefully. At their price point, absolutely great bashers.
Coming from a my Tekno 410 before them, I tried to build them up like a Tekno. Diffs and all.
Don't even bother. Will never even be close. Just a waste of time money and fun.
Arrma 6s diffs can be tweaked way more durable out the box. Most important of all IMHO.
With my first Arrma, a 6s OC, I was flabergasted about diffs mostly. After about 90-100 diff rebuilds I finally git down where they are quite durable. WHat matters most to me.
Will never be a Tekno diff of course.

Idk about the the Basherqueen one but the cheapo CF ones are terrible. Try the bearings in the ackerman fix first https://www.arrmaforum.com/threads/bearings-for-the-6s-ackerman-bar.52621/ The EXB ackerman is crap just like the rtr one imho. Hell the one on my EXB bent faster than the one on my rtr Outcast did.

I tell everyone ... the TLRT ackerman is best way to go, short of an M2c one. Never tried M2C however. Bent every single stocker ackerman, every 6s rig over and over.
TLRT not Bent one time. Many front wheel hits and I keep checking that TLRT Ackerman, always straight as an arrow. Must be a true 7075 alloy. Unlike the EXB ackerman.
Slop can be another story, with those "stepped bushings" however.

 

[slick2500]

Been there also. Additional Caster shimming won't address the Arm and Hinge pin's poor fit inside within arm. The arms hinge pin "shaft" is just poorly molded. Oversized. That's where the main Slop issue comes from. Fore and Aft caster movement can be shimmed with some success, but not the perfect one solution. And Over shimming in this area to compensate, will just Bind up the upper arm. Been there. I have considered using something to lightly fill, coating the Arms inner shaft, a glue, epoxy or similar. Let cure, then ream it out with a Reamer tool, to match the O.D. of that upper hinge pin. I wont get that crazy with it however. I'm sure it can be done. And probably been done by someone already.
The Fr lower Arms and Rears also have this same slop. Not just the front Upper arms. And with an On road 6s platform with speed running for instance, I feel the rear arm's fit is more critical. This affects the Rear Toe, getting all sloppy. Affecting directional stability more so at high speeds. Getting all Squirelly under load. How I see it.

I know it doesn't that is why I said I just live with it and shim out as much of the for and aft play as possible without binding. That is literally the only option we have imho.

The front lower and rear arms are not near as bad as the front uppers on any of my Arrmas. The second worst spot is the rear hubs.

This is just ridiculous. Would you believe that the one on the right has older hubs in it! The hubs on the Outcast are like 5 years old, the ones on the F2500 are the ones that came on Kraton EXB 2 years ago.

 

[SrC]

What I did with a few of mine is I drilled out in 2 places on the hub and screwed in 2 grub screws. Grinding flats on the hub hinge Pins. Now the hubs don't rock back and forth on the arms. The hubs hinge pin is captured now....Then doing that, it revealed remaining slop at the BB's so I shimmed the outer BB at the hub using Diff shims. Outer BB's being the same size as the diff BB's., My Lim. Things got nice and tight. I tried just one hole and grub. Works, but 2 is better. M3 or M4 short grub screw will work. Drilled out to size accordingly. Want a very tight Grub fit. Bigger grub is better. It will never be 100% perfect. So don't go crazy overthinking all that slop. Double check and adjust your wheel alignment after you do this. These are just toys in the end.
Tekno uses grubs at the hubs/uprights as well. What gave me the idea.

 

[slick2500]

What I did with a few of mine is I drilled out in 2 places on the hub and screwed in 2 grub screws. Grinding flats on the hub hinge Pins. Now the hubs don't rock back and forth on the arms. The hubs hinge pin is captured now....Then doing that, it revealed remaining slop at the BB's so I shimmed the outer BB at the hub using Diff shims. Outer BB's being the same size as the diff BB's., My Lim. Things got nice and tight. I tried just one hole and grub. Works, but 2 is better. M3 or M4 short grub screw will work. Drilled out to size accordingly. Want a very tight Grub fit. Bigger grub is better. It will never be 100% perfect. So don't go crazy overthinking all that slop. Double check and adjust your wheel alignment after you do this. These are just toys in the end.
Tekno uses grubs at the hubs/uprights as well. What gave me the idea.

I notice quite a few of the race kits do that, the upgrade hubs for my D8T use grub screws in them.

 

[SrC]

D8T does . I never knew that.
My Milennium Era TC3 also has grubs on the hubs.

 

[slick2500]

D8T does . I never knew that.
My Milennium Era TC3 also has grubs on the hubs.

Not the stock hubs, the upgraded ones from HPI.

 

[KnowAir]

What I did with a few of mine is I drilled out in 2 places on the hub and screwed in 2 grub screws. Grinding flats on the hub hinge Pins. Now the hubs don't rock back and forth on the arms. The hubs hinge pin is captured now....Then doing that, it revealed remaining slop at the BB's so I shimmed the outer BB at the hub using Diff shims. Outer BB's being the same size as the diff BB's., My Lim. Things got nice and tight. I tried just one hole and grub. Works, but 2 is better. M3 or M4 short grub screw will work. Drilled out to size accordingly. Want a very tight Grub fit. Bigger grub is better. It will never be 100% perfect. So don't go crazy overthinking all that slop. Double check and adjust your wheel alignment after you do this. These are just toys in the end.
Tekno uses grubs at the hubs/uprights as well. What gave me the idea.

Good idea. Once I buy new hubs/arms, I'll give it a try. Wonder if it would help my K8S front upper arms? They're tight between the A/B blocks, just sloppy on the pins..

 

[Dan B.]

Looks like good advice...

So many places to start. The Ackerman is a great place to start, steering bearing over bushing. I also found the stock Ackerman bar (bar in the middle that joins each side) lots of slop when replaced with a basher queen carbon fiber far better. From there, slop in the upper arms using shims to tighten it.

I concur in spades. The BQ is the best setup I’ve used to date. Comes with flanged steering bearings. Huge difference.

So the BQ CF Ackerman is way better & removed some or all of slop? I bent the stock one on my K6 & flattened it back out but it needs replacing. I have a EXB on my Notorious & it's ok, some slop there. Seems CF is the move?

Not just CF. Any material, but precisely machined units that replace the steering bushings with flanged bearings. If you also add a quality aluminum bell crank (I would ONLY recommend Scorched or Vitavon, personally) then you have just eliminated virtually all of the slop from the servo to the toe links. If you then properly shim the hub bearings and properly tension and set the pivot balls it’s outstanding. I would never do all of this for any of my bashers, but for the street rigs you just jumped from KIA quality to Formula 1.
Also, thanks to @SrC for the tip of putting Teflon tape on the ball ends of the links. I’m loving that idea, and most definitely will try it. I ordered GPM links for an upcoming build but I really don’t like them. There is definitely far less play than the stick ones, but they’re twice the weight and quite “clunky” looking. It’s been a pet peeve of mine for quite some time that people make beautifully machined Titanium turnbuckle rods but nobody makes a better rod end! Makes no sense. Why, for the love of god, can’t we get some tiny, NASA quality heim joints for those blasted things?!?!

Sounds like opened up Pandora’s box

Thanks for all the great input and explanation of what an Ackerman plate is

That’s what we’re here for. Two primary reasons that work hand in hand.
1. To offer so many opinions that whereas you were initially asking intelligent questions, you’ve now transitioned into the realm of being hopelessly confused, and,
2. To subsequently drain your bank account as you explore which of the many options work the best for you.
We aim to please.

 

[Jluther@becoinc]

Both my rigs have a lot of slop in the steering and I’d like to know how to tighten up their steering.

Seems to occur somewhere between the servo and steering links-to-hub attachments. I can wiggle the wheels side to side ~10-15 degrees although the servo is sitting still and not moving at all.

Any recommendations?

Thanks and Merry Christmas!

I bought these links and they really help. I had to adjust them to the right length then pull them apart one end at a time so I could keep the same adjustment and put a good amount of blue lock tote on them. After that I let them dry for a couple days . They got rid of the slop. So far they have held up great! They’re cheap and I can usually get them next day . I have them on several rigs.