Dlux has gone off the deep end

[Erik D_lux]

And that raises the question....

Where do you want your roll center on an RC car and if you provide an answer to that, please provide an explanation as to why.

[Lance Carbuncle]

Originally Posted by Erik D_lux

And that raises the question....

Where do you want your roll center on an RC car and if you provide an answer to that, please provide an explanation as to why.

That IS the million dollar question, and still not detailed enough because we are only looking for an answer to this question in relation to a comp crawler.... not a short course car, trail car... ec. Since rc cars don't always behave like 1:1 cars do..... trial and error like this is really the only way... you build appears to provide an easy way to compare the differences if you can drive this car as a 4 link and as a 3 link with the panhard bar and see how it performs under climb, side hill, and turning at speed and comparing the differences. This would be a really interesting comparison.

Lance

[Erik D_lux]

Yeah, I agree.

Its something that I have messed with on my tri 4 link. I have lowered the roll center by making straight uppers and I hated it instantly. I know some people swear by it though.

Roll center and where it needs to be ideally is one thing I have not really gotten into too much. It would be nice to figure out and have a general idea of where we need to be.

Maybe we should start a list of pros and cons of a high vs low roll center?

[CODYBOY]

Originally Posted by Erik D_lux

And that raises the question....

Where do you want your roll center on an RC car and if you provide an answer to that, please provide an explanation as to why.

All I can say is WOW Erik!!!! Does your brain shut down at night so you can get just a couple hours of sleep???
You build such great parts and are so willing to step out of the box. Well done young Man!!!
Probably a silly question, but do you have an engineering background to go along with that great mind?
Ernie

[Delbert]

Originally Posted by Erik D_lux

G10 is not easy on tools but it sure is not hard, not like CF at all when it comes to cutting. I much prefer to work with G10 over CF.







Yeah, I dont see any reason it wont be at the shootout.



I wish I could just kill FB and come back here.... This is such a more comfortable place to be and all the people who are here are people who enjoy RC. You dont get the random douche who is just talking shit like FB.



I would bash RCcrawler since it does not get views and traffic but this build has way more views now that I would have guessed it would have when it was done. Maybe there is hope?











I know better than to open this can of worms but why do you guys think this is even scale? I dont see how its anymore scale than my MOA other than the body that will have to go on it?







Even back then I was a funny guy! LOL. I dont remember that but sounds like something I would say.









The Panhard is all the way out on the axle. In fact, the front will need to be moved in as it does not clear the wheel at full lock. The rear is correct as seen in the pictures and the front will match that. I could take the rear wider but I want them to be the same front and rear.







I would love if this car just got me in the door to a scale event.

I will hope with you. I am so tired of Facebook.


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[Lance Carbuncle]

One thing that we also need to consider in a side-hilling of road crawler like this, is the same thing you pointed out about offsetting torque twist....... on a side hill, if your chassis mount is on the high side, you are going to be forcing load against the opposite tire, which should in theory , do a good job of planting the wheel on the low side..... but if your chassis mount is on the low side, you are in theory (mine anyways lol) trying to pull the car over... Like with your focus on offsetting toqure twist moving forward, when you give throttle in reverse, its likely not going to be good ;)...... not a problem since you aren't really allowed to use reverse without penalty. Fun stuff to think about.

[Erik D_lux]

Originally Posted by CODYBOY

All I can say is WOW Erik!!!! Does your brain shut down at night so you can get just a couple hours of sleep???
You build such great parts and are so willing to step out of the box. Well done young Man!!!
Probably a silly question, but do you have an engineering background to go along with that great mind?
Ernie

Thanks Ernie! Thats a great compliment coming from a guy like yourself!

I can sleep pretty well every night. Not often do I go to bed and I am not exhausted.

I do have a degree in engineering, its electronic though and pretty sure I forgot 99% of it as I graduated in 2000 and have not had a job that uses the ideas.

Originally Posted by Lance Carbuncle

One thing that we also need to consider in a side-hilling of road crawler like this, is the same thing you pointed out about offsetting torque twist....... on a side hill, if your chassis mount is on the high side, you are going to be forcing load against the opposite tire, which should in theory , do a good job of planting the wheel on the low side..... but if your chassis mount is on the low side, you are in theory (mine anyways lol) trying to pull the car over... Like with your focus on offsetting toqure twist moving forward, when you give throttle in reverse, its likely not going to be good ;)...... not a problem since you aren't really allowed to use reverse without penalty. Fun stuff to think about.

Yeah, huh, I have not thought that far thru it.

Having that panhard on the uphill side does sound interesting. Not only as far as planting to stay level but also the effects of traction and steering up hill...

I guess that could be a problem of the chassis side of the panhard being down hill too. I wonder how much will be offset since the rear would be up and the front would be down hill or vice versa? Might offset it so I dont notice or maybe it would cause a torquing effect?

When in reverse, would you not torque twist the opposite way? If so, the axles would also reduce torque twist in the opposite way and it would be good the same way as going forward?

Lots to think about. Thats the fun part of this hobby! Not until I started building this car did I realize how bored I have gotten with it.

[Erik D_lux]

Branching off that thought of the uphill/downhill panhard...

Does it not matter where the chassis side of the panhard is? Meaning, what if my shocks are extended or what if they are collapsed? It seems it would have drastically different effects depending on that.

[Lance Carbuncle]

Originally Posted by Erik D_lux

Branching off that thought of the uphill/downhill panhard...

Does it not matter where the chassis side of the panhard is? Meaning, what if my shocks are extended or what if they are collapsed? It seems it would have drastically different effects depending on that.

The roll center is going to be a point in the middle of the bar, so as the suspension travels, this point moves up and down as the panhard arc's. To reduce the uphill/downhill differences, you want to lower the mount as far down as you can, and make the bar as long as possible. Equivalent bump on one side of the car vs. the other would likely have two different roll center heights because of the length of the bar and side its mounting on, causing very different behavior when side hilling as we talked about before...

I will discredit myself and say that I am not a suspension designer or engineer. I have designed and studied real race car suspensions but am not an expert.

If you really want to play around, I recommend the awesome suspension designer software Susprog3D

and the Suspension "Bible" Race Car Vehicle Dynamics

Then at the end of the day, you will have learned a Lot of stuff that you will be able to use as a knowledge base when you say **** it and go back to trial and error!

[CM9000]

I don't think this rig will have a problem sidehilling at all. not unless it gets to be in a hard situation with gate placement... but I doubt even then it will have a hard time.

with the skid being more on the low slung side.. "belly dragger" I think... if I could imagine controlling it myself it might need to be driven like a u4 rig on the flatter ground. it might want to jump gaps or hop up walls.

a lot of suspension setup has to also do with your driving style.

[War Pig]

I can’t wait to see this rig out on course and see what it’ll do! You’ve almost got me ready to build a sporty with all this panhard goodness....

[TSK]

Erik, I’m truly just teasing. It has panhard bars for Christ’s sake. Lol!

I really love the idea and def want to see video of this on course. The truck is trick!

[JDcustomfab]

Erik, Thanks for posting this build here, I don't like Facebook. It's cool to see innovative engineering in progress. I think that's the part of RC I like the most, the engineering. Also, thanks for the great parts and service.

[Erik D_lux]

I figured out a super simple and effective battery mount. Not only does this hold the battery but it also firms up the servo mount. Its up higher than the servo and can move so I doubt it will ever be a problem.

Any interest in these? If so, I can put them on my site. They would only be $3 so they are cheap and they can be used on any of the AR60 setups also.

[Erik D_lux]

Originally Posted by TSK

Erik, I’m truly just teasing. It has panhard bars for Christ’s sake. Lol!

I really love the idea and def want to see video of this on course. The truck is trick!

Oh! So now youre teasing me too! Damn man!

Its just funny to me when something is scale and something is not and both are 100% real. Let me say that again.... both... are... 100%... real.... LOL. In fact, would say tri 4 link would be more common so I would place it as more scale?

Originally Posted by JDcustomfab

Erik, Thanks for posting this build here, I don't like Facebook. It's cool to see innovative engineering in progress. I think that's the part of RC I like the most, the engineering. Also, thanks for the great parts and service.

Thanks man! Sure is nice to have all the good words.

[Erik D_lux]

Driveshafts...

I really, really, really wanted to use a dog bone style shaft for this build. I used one on my Losi Comp crawler and I loved it. Small, light weight and strong.

These style of driveshafts are horrible to setup and on this build, its just not going to work due to the angles. Too bad. Maybe in hindsight I would have moved the diffs to the passenger and run a centered axle.... nah! LOL

Anyway, I decided to make my life easy and I got Fac'd instead.

If anybody else wants these, I actually ordered a bunch of parts to make these happen. They sure would be a sweet setup if you had better angles to work with.

[Robbob]

DCJ's ....... youve come this far you cant just do a normal driveshaft

[winnerone23]

Long time thread follower, first time poster..

Erik, you have been doing some killer work on this rig!!!
It's good to see you in sporty class and will be interesting to see your progress, on the rocks, with this truck!

These driveshafts definitely peak my interest!
No tiny a$$ pins to fall out or break!

Are these going to be a "builder" setup?
IE: cut to length, at home? (I hope so!)

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[Erik D_lux]

DCJ's? What is that?

I am fine with the driveshafts for now. I will run them and probably come back to revisit with something else.

I did learn a lot on my last build and doing my own driveshafts. They turned out super cool but I went for tight tolerances which was a mistake. I like my driveshafts super sloppy so they dont restrict the travel at all. JunFac shafts provide perfect slop. LOL

[Erik D_lux]

Originally Posted by winnerone23

Long time thread follower, first time poster..

Erik, you have been doing some killer work on this rig!!!
It's good to see you in sporty class and will be interesting to see your progress, on the rocks, with this truck!

These driveshafts definitely peak my interest!
No tiny a$$ pins to fall out or break!

Are these going to be a "builder" setup?
IE: cut to length, at home? (I hope so!)

Hi Troy,

Thanks for being brave and posting for your first time. I hope you feel comfortable here. Consider this a safe space for you.

I wonder how much progress there will be with this car.... I sure am having fun building it but not sure how much I will drive it therefore not sure how good I will do at comps with it. We will see.

Yep, builder shafts for sure. Cut to length, put a flat on it and done. Pretty cheap too. Under $20 I am pretty sure.