Tekno RC SCT410 2.0 1/10th 4WD Short Course Truck

[nino]

The servo has very little leverage at the ends and any play in the steering rack really gets amplified so the stops really help keep everything noice and toight. Esp since Teknos seem to have a lot of steering (both the .3 and 2.0).

 

[WickedFog]

The servo has very little leverage at the ends and any play in the steering rack really gets amplified so the stops really help keep everything noice and toight. Esp since Teknos seem to have a lot of steering (both the .3 and 2.0).

That's the problem with steering setups in RC cars. The linkage attached to the servo horn travels in an arc, so every degree your horn rotates, the actual steering linkage moves exponentually less. Why this industry hasn't seriously adapted linear actuators for steering servos is beyond me. It would make for a much more accurate way to move the steering linkage.

But I still don't think steering stops are needed, especially with endpoints set correctly. You don't want your servo driving the linkage against a hard stop. If you're hitting full tilt on your steering constantly, you're not driving your RC correctly. Just my opinion.

 

[nino]

Of course it's a given that the endpoints are set correctly. Dunno, it's considered sort of a tuning option, there's been much talk about it on rctech and Tekno forums. I've read stuff from Tekno's Matthew Armeni, Bill DeLong and some other folks that know their stuff and it made sense to me...

 

[RustyUs]

Do you not have your endpoints on your servo set?

Yes, but it's kind of hard to explain. I'm sure there is a video out there on one of Tekno's platforms that shows what happens at that full "locked" point. There is very little to no leverage on the inside spindle/wheel/tire while taking a turn. At that point the inside wheel/tire can have a mind of it's own. Every other Tekno ride I have uses a screw and washers to adjust that last bit of steering throw.

Here is what Tekno RC had to say about the EB48 and SCT410.3 platforms on RCTech:

"teknorc:

I posted this in the EB thread, but it is 100% applicable to the SCT as well:

Yes, we know people like lots of steering. Our pro drivers tell us this all the time . Something to keep in mind though about steering...

The design of the EB/NB line of vehicles has more steering throw than any other vehicle on the market. Probably by a good 5 or more degrees. At first we thought this was a huge advantage. Lately, through constant testing, we have found the cars are faster and waaaaay more consistent with less steering throw.

So if you're not using the built in steering stops, you're doing yourself a huge disservice. We are using 4 steering limiter washers on the EB/NB (SCT410 uses 4 too) and the results have been awesome. Yes, the turning radius is reduced, but lap times and consistency have proven this is a non-factor.

Here's what goes wrong with too much steering throw:
Rear end washes out when landing jumps
Rear end continues to come around exiting corners
Feels like you are struggling for traction at times
Bump handling is unpredictable
Initial steering is extremely twitchy
And other issues to be sure

Here's what's going on. The last 5+ degrees of steering throw happen very quickly and the servo has very very little leverage on the wheels at full throw. This causes the inside wheel to act erratically and get tossed left/right at the whims of the track surface. Without a positive stop there, the inside wheel is going crazy and causing inconsistencies with the handling. The CV's can accommodate this extreme working angle, but there is more chatter which creates further issues.

Even if you just limit your EPA, the inside wheel is still free to move too far when the conditions arise. So install the washers first, then reset your EPA to match.

There are literally dozens of other adjustments that will result in more steering if desired (shocks, springs, ride height, sway bars, diffs, camber links, toe, etc.). By first limiting the throw, you can focus on creating more 'setup steering'. Think of setup steering as being more consistent vs. mechanical steering (i.e. throw).

Additionally, you won't be fighting the car so you will be spending less time tuning something bad out and more time tuning good stuff in.
__________________
Tekno RC
www.teknorc.com "

Picture below is SCT410.3 with steering stop screw:

EB48.3 instructions:

 

[WickedFog]

Yes, but it's kind of hard to explain. I'm sure there is a video out there on one of Tekno's platforms that shows what happens at that full "locked" point. There is very little to no leverage on the inside spindle/wheel/tire while taking a turn. At that point the inside wheel/tire can have a mind of it's own. Every other Tekno ride I have uses a screw and washers to adjust that last bit of steering throw.

Here is what "Mr. Tekno" had to say about the EB48 and SCT410.3 platforms:

That makes sense I guess. Never had a car with that bad of a problem.

 

[9x19]

Nice solution... I noticed mine had room to move after the servo stopped at its end-point... I set my end-point to a shorter throw to adapt, but a hard stop makes sense too.

 

[Lumikko]

Interesting take on the physical steering limit screws. It makes sense, too. Another rc car with a similar problem is the Kyosho Scorpion. The inside wheel at full lock can actually achieve a straight line between the steering link and steering pivot.

 

[RustyUs]

"Mud Guards"

Putting finishing touches on some "mud" guards. I like to call them pebble deflectors, 'cause I rarely run in the mud. Anything that helps keep shock boots/shafts from getting all banged up... I'm all for it. I don't know if they'll be any good, or not, but if you'd see the stuff I run my RCs in, anything is better than nothing. I didn't see any options out there for the SCT410 2.0, so I used my EB48 2.0's guards as a template.

One of these days/weeks the weather will be nice enough to paint a body or two outside.

 

[J’sCrawler]

"Mud Guards"

Putting some finishing touches on some "mud" guards. I like to call them pebble deflectors.
Used my EB48 2.0's guards as template.
View attachment 186009View attachment 186109
One of these days/weeks the weather will be nice enough to paint a body or two outside.

They look good! I like the extra bling of the washers.

 

[RustyUs]

They look good! I like the extra bling of the washers.

They'll be, most likely, all dinged up/defaced after the first outing. Finishing up the 2.0's guards got me in the mood to make some for my ET410 & SCT410SL platforms.

 

[RustyUs]

Shock Pistons​

Had a great first run. Was expecting more debris onboard the chassis.

LOL. She's not a lightweight, that's for sure.
I built/ran the SCT with the pistons swapped... 5x1.1 in the front, and the 5x1.2 in the rear.

I just had to test it out, and get it out of my system. The box stock setup would have you use 700/600cst (front/rear) shock oils. I chose to go with 550cst shock oil front & rear for some rough/rutted action. I don't think I'll be changing my setup anytime soon. The SCT handled great.

 

[RustyUs]

Mud Flaps
One online comment was made about me making/using mud guards, "Don't run them. Too much drag." LOL . I can't wait for the person to comment on my mud flaps . Spare Team Associated SC10 rear bumper just zip-tied onto the existing SCT410 2.0 bumper. They were not meant to be used, long story short, they were just to show someone a possibility, and after surviving first rounds of tumbles/cartwheels... they'll stay on until they tear off. At that point I'll grab some more zit-ties.

Yeah, after looking down at the bumper, the bumper/flaps look narrower than what I remember on a SC10 chassis. If they were any wider there would be body fitment issues I'm sure.

 

[RustyUs]

Interesting take on the physical steering limit screws. It makes sense, too. Another rc car with a similar problem is the Kyosho Scorpion. The inside wheel at full lock can actually achieve a straight line between the steering link and steering pivot.

Yes. If I understand you correctly, that Scorpion steering link is teetering on the leverage/no leverage point of things... same thing with my SCT.

That makes sense I guess. Never had a car with that bad of a problem.

Yes, sorry you never had a too much steering "problem" . I'm sure there are other platforms out there that have an option for steering stops. I can't keep up with all the platforms, but I think is was around 2013 and the Associated "5 series" platforms started to include a molded in spot for steering stop screws.

In any case, my steering stop screws have solved the tire rubbing issue, and I still have the same amount of steering... gobs.

Next up, I'm putting the front anti-sway bar on that I intentionally left in the box.

 

[RustyUs]

Shock Pistons​

I built/ran the SCT with the pistons swapped... 5x1.1 in the front, and the 5x1.2 in the rear.

I just had to test it out, and get it out of my system. The box stock setup would have you use 700/600cst (front/rear) shock oils. I chose to go with 550cst shock oil front & rear for some rough/rutted action. I don't think I'll be changing my setup anytime soon. The SCT handled great.

It seemed like, there for awhile, all you heard about on the SCT410.3 platform was how to get rid of the nosediving. After reading people's posts and their SCT410 2.0 "nosediving" shenanigans, I was like, here we go again. I originally thought the manual had a misprint on the piston/shock build steps. Anyway, after putting another handful of runs through the SCT, the piston swap is staying. The jump takeoff/flight characteristics are right up there with my other SCTs.

 

[RustyUs]

Larger Battery mAh (capacity) Needed

I think it's well known that the SCT410 and SCT410.3 suck the life out of 2S batteries during hard charging racing scenarios. Taking suggestions from others, it's apparent that you need a larger capacity battery to make a 10 minute main if sticking with "rules" . Having been happy with the CNHL LiPo packs used on my SCT410SL for the past year, I thought I'd try out one of their 8200mAh LiHV 120C packs. On the average, I can get 11:20 from the 8200mAh pack (charged 4.2v/cell). That same pack in my 2wd ST will get me 25+ minutes of runtime.

 

[RustyUs]

Shock Caps

There is a pretty huge weight difference between the SCT410SL and the SCT410 2.0 platforms. I'm totally blown away, so far, the composite shock caps have held up seeing as my SCT410SL's one front cap failed on me during the first couple of runs. I do have a spare set of aluminum shocks caps ready to go for fear the SCT410 2.0's caps will follow the same path as the SL.