cboggs' 5th D Sucker Punch

[CM9000]

Originally Posted by Erik D_lux

Man, if only somebody figured out how to make the rear under drive even more.... Oh wait... its been done.

im taking it even a step further Erik

its not in the gears either.

[TSK]

Originally Posted by Robbob

Now we are talking. Except still looks like 0 Ackerman knuckles, but compensated with toe out. I still think correct Ackerman, and having zero toe would be the way to go.

On another note, do you think it is too late to ask Axial to release the cutting brake?

And yes, when it comes down to it, Chris is winning again, and that means 5D is kicking everyone's ass.

[Robbob]

Originally Posted by TSK

On another note, do you think it is too late to ask Axial to release the cutting brake?

And yes, when it comes down to it, Chris is winning again, and that means 5D is kicking everyone's ass.

I think that cutting brake is sitting next to an '83 Corvette


And very true .....

[cboggs]

This has turned into a great discussion and making everyone rethink the thoughts on a sporty steering. In my situation, and more than likely everyone else, steering takes importance over front traction in a sporty. I've witnessed it first hand and have been getting my ass handed to me. The over/under drive gearing makes up for the traction loss that would really be more noticeable if both axles were geared the same. When I ran the non 8* and had the push it was super hard to navigate courses, lots of times having to make multiple turn arounds that now I don't need to do. Now a pro rig is going to require another discussion as you have different factors to toss in, dig being the main one, that can really take advantage of a non 8*. I think the way to solve the mystery is to have Erik get back into the sporty class...

[cboggs]

And feel free to post up all the pics you want for examples/tests in here, it don't bother me one bit, its where the discussion is going down.

[CM9000]

Originally Posted by cboggs

I think the way to solve the mystery is to have Erik get back into the sporty class...

what im about to test out after I give a few measurements to him so he can machine some stuffs.. might make him want to get his pinky in it.

1 way bearings with 12mm hex's do exist.

[cboggs]

Just remembered something a lot of us do also, blip throttle induced steering to make even tighter turns. Another thing I noticed between the two is again the non 8* would just hop forward where the 8* hops into the turn...

[TSK]

Originally Posted by CM9000

what im about to test out after I give a few measurements to him so he can machine some stuffs.. might make him want to get his pinky in it.

1 way bearings with 12mm hex's do exist.

That is a great idea. I wonder how long the bearings will last though with the amount of grip, torque and bind modern day comp crawlers experience.

Most of the one way bearing experience I have is with 4wd drifters and 1-10 buggies. neither of which experienced none of those factors. The other being they all still had open limited slip diffs.

Other issue I see will be that the rear axle will have no drag brake or power under reverese throttle.

[Erik D_lux]

Originally Posted by CM9000

im taking it even a step further Erik

its not in the gears either.

I dont think my communication was great or you took it the wrong way. I was teasing my new product that I just sent out for testing. Its possible that this product could eliminate the entire need for this discussion. Sounds like what you have up your sleeve could be cool too.

Originally Posted by cboggs

I think the way to solve the mystery is to have Erik get back into the sporty class...

With this new product I have coming out along with all the products that I stock, I may just have to build another sporty. I dont think I could ever get into them like I do 2.2p or super though. I just dont have the passion for them.

Originally Posted by cboggs

Just remembered something a lot of us do also, blip throttle induced steering to make even tighter turns. Another thing I noticed between the two is again the non 8* would just hop forward where the 8* hops into the turn...

In my head, its almost like I said a couple posts back where you could make an order of how much pressure/traction/whatever you want to call it on the front tires due to the combination of steering combinations. Something like:

Least amount of traction to most amount of traction:
8*, zero scrub, zero caster, toe out
8*, zero scrub, zero caster, neutral toe
8*, zero scrub, zero caster, toe in

8*, minor scrub, zero caster, toe out
8*, minor scrub, zero caster, neutral toe
8*, minor scrub, zero caster, toe in

8*, minor scrub, 10* caster, toe out
8*, minor scrub, 10* caster, neutral toe
8*, minor scrub, 10* caster, toe in

8*, decent scrub, 10* caster, toe out
8*, decent scrub, 10* caster, neutral toe
8*, decent scrub, 10* caster, toe in

8*, decent scrub, 20* caster, toe out
8*, decent scrub, 20* caster, neutral toe
8*, decent scrub, 20* caster, toe in

NON 8*, zero scrub, zero caster, toe out
NON 8*, zero scrub, zero caster, neutral toe
NON 8*, zero scrub, zero caster, toe in

NON 8*, minor scrub, zero caster, toe out
NON 8*, minor scrub, zero caster, neutral toe
NON 8*, minor scrub, zero caster, toe in

NON 8*, minor scrub, 10* caster, toe out
NON 8*, minor scrub, 10* caster, neutral toe
NON 8*, minor scrub, 10* caster, toe in

NON 8*, decent scrub, 10* caster, toe out
NON 8*, decent scrub, 10* caster, neutral toe
NON 8*, decent scrub, 10* caster, toe in

NON 8*, decent scrub, 20* caster, toe out
NON 8*, decent scrub, 20* caster, neutral toe
NON 8*, decent scrub, 20* caster, toe in

I am just shooting from the hip on those thoughts, might be right on, may be way off. Either way, it would be cool to figure out and then you could take it a step at a time until you found the spot where its a good compromise between steering and ability. I would be super curious to see if the least amount of push "NON 8*, zero scrub, zero caster, toe out" from a non 8* would be too much still. Seems if you went off the assumptions that I have charted above, what you have now would just be one step below "non 8*, zero scrub, 0 caster, toe out".

[TSK]

Originally Posted by Erik D_lux

Least amount of traction to most amount of traction:
8*, zero scrub, zero caster, toe out
8*, zero scrub, zero caster, neutral toe
8*, zero scrub, zero caster, toe in

8*, minor scrub, zero caster, toe out
8*, minor scrub, zero caster, neutral toe
8*, minor scrub, zero caster, toe in

8*, minor scrub, 10* caster, toe out
8*, minor scrub, 10* caster, neutral toe
8*, minor scrub, 10* caster, toe in

8*, decent scrub, 10* caster, toe out
8*, decent scrub, 10* caster, neutral toe
8*, decent scrub, 10* caster, toe in

8*, decent scrub, 20* caster, toe out
8*, decent scrub, 20* caster, neutral toe
8*, decent scrub, 20* caster, toe in

NON 8*, zero scrub, zero caster, toe out
NON 8*, zero scrub, zero caster, neutral toe
NON 8*, zero scrub, zero caster, toe in

NON 8*, minor scrub, zero caster, toe out
NON 8*, minor scrub, zero caster, neutral toe
NON 8*, minor scrub, zero caster, toe in

NON 8*, minor scrub, 10* caster, toe out
NON 8*, minor scrub, 10* caster, neutral toe
NON 8*, minor scrub, 10* caster, toe in

NON 8*, decent scrub, 10* caster, toe out
NON 8*, decent scrub, 10* caster, neutral toe
NON 8*, decent scrub, 10* caster, toe in

NON 8*, decent scrub, 20* caster, toe out
NON 8*, decent scrub, 20* caster, neutral toe
NON 8*, decent scrub, 20* caster, toe in

I am just shooting from the hip on those thoughts, might be right on, may be way off. Either way, it would be cool to figure out and then you could take it a step at a time until you found the spot where its a good compromise between steering and ability. I would be super curious to see if the least amount of push "NON 8*, zero scrub, zero caster, toe out" from a non 8* would be too much still. Seems if you went off the assumptions that I have charted above, what you have now would just be one step below "non 8*, zero scrub, 0 caster, toe out".

Phew. that is some typing!

I think we should also remember that the non 8* knuckle setup loads the front outside tire once your turn, whereas the 8* setup keeps the axle relatively level to the ground.

[Erik D_lux]

Originally Posted by TSK

Phew. that is some typing!

I think we should also remember that the non 8* knuckle setup loads the front outside tire once your turn, whereas the 8* setup keeps the axle relatively level to the ground.

A lot of copy/paste. LOL. I forgot all the types of ackerman too!

Non 8* can load the outside tire, but so can 8* depending on scrub and caster. Thats what makes me laugh the most when somebody says they prefer 8* but then run a monster load of scrub and caster. I have seen 8* get just as bad as non 8* for those reasons. Really all 8* does is reduce that scrub, if you want to call it that. Maybe I should say it keeps the tire flatter.

[Robbob]

Originally Posted by TSK

Phew. that is some typing!

I think we should also remember that the non 8* knuckle setup loads the front outside tire once your turn, whereas the 8* setup keeps the axle relatively level to the ground.

Unless Im reading wrong I think what you might be seeing as 'level to the ground' is actually the caster effecting it.

8* KPI actually causes the tire to rotate on an arch .... think of it as a frown. 8* when turned lifts and lowers the wheels. I learned this with my SK racing last year, too much caster caused me to jack the left front weight up and gave me a push off corners. Different speeds but same dynamics in my mind.

Non 8* actually lets the contact patch stay more consistent/flatter through its radius. I havent had non 8 since the LCC days but I think thats why we see it work better on the Mod trucks.

Interesting video here
https://www.youtube.com/watch?v=IZLiP_37Oso

But also interesting one here and he says what I think you may be seeing ..... we can balance out the negative effect of kpi by using caster.
https://www.youtube.com/watch?v=mh_BUOguZQk


I think if I rolled my caster up on my sporty you would see the inside tire lay flatter and the outside rolled to the outside more. The frown effect of 8* in my head.
You also see the axle level out more too, not have the inside area lifted up off center so much. We transfer weight onto the outside tire more I think with our caster and 8* with out realizing it but we dont see it that way because to some it feels like it steers more? If that makes sense. ?


Could also be a reason why mis tuned 8* trucks tend to lift inside tires because its making that corner lighter? Probably another reason why non 8* works better in Mod class? Great theories and ideas in here though.

[TSK]

I know the 8*KPI rotates on an arch. But if you are to zero out the caster on both setups, and turn to full lock, the non 8* KPI will load the outside tire as the axle will lean towards the outside.

In your photo, that 8*KPI's arch is what causes the inside tire to lean over more than the outside, as the outside tire will lose caster and the insdie tire will gain caster. I'm not sure caster gain/loss is the proper terminology to descrige it, but it is the best way I can describe it.

On an 8* KPI, with 0 caster, when you turn full ock, the axle remains pretty much level.

Running 20-30* caster on a 8* KPI setup witll cause the same side loading but to a lesser degree

I can't find the pic of my old Berg that would show the significant difference in axle level while turning

[cboggs]

Here's 10* castor, zero toe and 8* wraith on my current set up.

[WHITE-TRASH]

Looks like you gave vp 0* ackerman arms on there with the tie rod under the arms. That sets you at 50* before the tie rod end hits the housing.

There is enough meat on the dlux arms to drill them for the same geometry as the arms you run now. I have a double arm I drilled for the drag link to be on the back of the knuckle to mimic my bouncer but with the tie rod on effectively longer arms the leverage wasn't there. On the bouncer it works great though.

Now that I think of it you could drill the dlux arms for the same geometry then run the tie rod and drag link above the arms with the drag link in the original outward hole spaced up your clear the tie rod. That would have good leverage and 70* ability.

[TotoRax]

Hi,

I appreciate this discussion, become too rare…

Here some 3D diagrams, to illustrate the effects of the various adjustments of the front axle. The wheels are steering with 70°.

NON 8*, decent scrub, 0* caster, neutral toe


NON 8*, decent scrub, 20* caster, neutral toe


8*, decent scrub, 0* caster, neutral toe


8*, decent scrub, 20* caster, neutral toe

[TSK]

Originally Posted by TotoRax

Hi,

I appreciate this discussion, become too rare…

Here some 3D diagrams, to illustrate the effects of the various adjustments of the front axle. The wheels are steering with 70°.

NON 8*, decent scrub, 0* caster, neutral toe


NON 8*, decent scrub, 20* caster, neutral toe


8*, decent scrub, 0* caster, neutral toe


8*, decent scrub, 20* caster, neutral toe

Thanks for sharing those images. It really makes it easier to see what is going on, especially with the 8* KPI. You can clearly see how the onside tire almost wants to turn over itself while the inside tire stretches away.

[CM9000]

Originally Posted by TSK

That is a great idea. I wonder how long the bearings will last though with the amount of grip, torque and bind modern day comp crawlers experience.

Most of the one way bearing experience I have is with 4wd drifters and 1-10 buggies. neither of which experienced none of those factors. The other being they all still had open limited slip diffs.

Other issue I see will be that the rear axle will have no drag brake or power under reverese throttle.

no drag brake on a decent. and no reverse. but.. who needs reverse anyway? still got it with the front axle

I would like to see a steering battle. how do we set up our front axles the right way?????

[WHITE-TRASH]

Originally Posted by CM9000

I would like to see a steering battle. how do we set up our front axles the right way?????

I'm on it this weekend. I have all the popular parts on hand except rcbros steering arms but if some provides the dimensions I'll build a set to test.

[cboggs]

Took another first place today, 55 points separated 1st and 2nd. Rig is definitely ready for the championships!