Let's see those crawlers and trail runners!

[Shadows]

Received all the parts I needed to get the TRX4 up and running today!

Definitely a more serious rig than the trail one I did. Awesome articulation. Quite a section you built.

 

[Arise0185]

Definitely a more serious rig than the trail one I did. Awesome articulation. Quite a section you built.

To be quite honest, I can't take any credit for this "build." It came mostly RTR but I had to fix a few things. That being said, I'm not sure what components are allowing this to have more articulation than a stock TRX-4. As far as I can tell it has stock shocks, shock mounts, and axles. The links are aftermarket Incision stainless but I don't think those factor in too much.

Maybe it's just a trick of the camera

 

[Shadows]

To be quite honest, I can't take any credit for this "build." It came mostly RTR but I had to fix a few things. That being said, I'm not sure what components are allowing this to have more articulation than a stock TRX-4. As far as I can tell it has stock shocks, shock mounts, and axles. The links are aftermarket Incision stainless but I don't think those factor in too much.

Maybe it's just a trick of the camera

Ah, okay. Probably the body giving it that more crawl serious look, then.

 

[blaster27]

Beautiful scenery. Unreal to me.

Well, it's not my first choice by a wide margin, but with a bit of fooling around, it will pull lines that would surprise you. We are working on a piece for the website called The Tale of Two Ryfts. One built as a rock racer, the other a rock crawler. Both are progressing well towards their goals, but the rock crawler is really starting to shine.

Glad you like the photos.

sView attachment 360384

What's your favorite crawler?

 

[Steve B in Vegas]

What's your favorite crawler?

Hmmm,

Out of our fleet, that's hard to say. I enjoy the SCX-6 quite a bit, and the Vanquish VRD is also a real pleasure to drive. Much of it comes down to the type of rock I'm crawling that day, and if I'm in the mood to just cruise around to explore or if I'm attacking difficult lines. The 2.2" Capras we built are also fun to creep along chunky, rocky terrain.

We are about to start building a pair of titanium caged moon buggies, so this should be interesting.

s

 

[Steve B in Vegas]

 

[Arise0185]

View attachment 361212

SCX6 is so sick! I would love to have one except I would have nowhere to run it 1/10 scale is just about perfect around here, whether it's bashing or crawling.

In other news, my Zuul arrived. I ran it with stock wheels/tires for about 10 minutes, but immediately decided they were too small. Swapped wheels/tires with the TRX-4 (Injora 4.7" super swampers) and performance was greatly improved. The stock Zuul tires on the TRX-4 don't work half-bad, and makes the car look a little more "scale" as well, though that certainly isn't the goal.

With the tires swapped, the Zuul and TRX-4 are about equal in performance, but the TRX-4 is pretty far from stock. I just discovered last night that the TRX-4 already has overdrive gears installed, which is a nice bonus.

The stock Zuul servo is very weak and I definitely noticed it stalling out, so I will be swapping in the rs800v2 that came with the TRX-4. I already installed my 40kg AGFRC servo into the TRX-4, which seems to perform just fine (not noticeably worse than the rs800v2). The brushed drivetrain on the Zuul is also pretty touchy, so I may try swapping in a HW 1080 brushed ESC I have on my Spec Slash to see how big of an improvement that is. Or might just spring for another Fusion Pro or SE, since the Pro that's currently on the TRX-4 is so freaking amazing!

The sway bar arrangement on the rear is interesting as well. Seems like it would help for side hilling (preventing roll), but it's very obviously limiting articulation of the rear axle. Will have to do some back-to-back testing with and without the sway bar. Currently the TRX-4 has way better articulation than the Zuul.

 

[Shadows]

Wanna see a poor attempt at a trail/crawler? Something laughable. I took one of the most breakable RC's well known to the hobby and attempted to mimic a Summit in capability.

 

[Steve B in Vegas]

Looks great! I removed the sway bar from our crawler Ecto, but remember; more range of travel in suspension is not always better. On level, chunky terrain, it is beneficial, but on steep terrain, it is detrimental.

In this photo, the Antero crawler has very limited suspension travel, allowing it to remain close to the rock. With more travel, it will want to "peel back" from the rock as the torque through the axle makes it want to lift away. As the tire rotates forward, it wants to lift the front end ( think dragster ). This is one of the reasons we calculate anti-squat values when building crawlers. Ignoring this math just makes things take longer to sort out.

Sway bars are not really ideal for any slow-moving crawler in the RC world, but they are a cool scale detail that some love.

 

[Arise0185]

Looks great! I removed the sway bar from our crawler Ecto, but remember; more range of travel in suspension is not always better. On level, chunky terrain, it is beneficial, but on steep terrain, it is detrimental.

In this photo, the Antero crawler has very limited suspension travel, allowing it to remain close to the rock. With more travel, it will want to "peel back" from the rock as the torque through the axle makes it want to lift away. As the tire rotates forward, it wants to lift the front end ( think dragster ). This is one of the reasons we calculate anti-squat values when building crawlers. Ignoring this math just makes things take longer to sort out.

Sway bars are not really ideal for any slow-moving crawler in the RC world, but they are a cool scale detail that some love.



View attachment 361433

Awesome, that rig looks very low to the ground.

Anti-squat is something I commonly read/think about in regards to MTB and motorcycles, but haven't really thought about it for crawlers yet. The term "anti-squat" in MTB refers to how much the rear suspension design resists compression during an acceleration. So on flat ground, if you start pedaling to accelerate, a 100% anti-squat value would mean that your rear suspension does not compress at all. A >100% value would indicate your rear suspension actually extends, and a <100% value means your rear suspension compresses.

Does the same hold true in the world of crawlers? Or is it more just a matter of location of CG in relation to axle height, etc. Of course that all comes into play too in MTB, but I guess what I'm asking is how important is the design of the rear suspension linkage. I may not be asking that question in an intelligible manner...

 

[Steve B in Vegas]

Awesome, that rig looks very low to the ground.

Anti-squat is something I commonly read/think about in regards to MTB and motorcycles, but haven't really thought about it for crawlers yet. The term "anti-squat" in MTB refers to how much the rear suspension design resists compression during an acceleration. So on flat ground, if you start pedaling to accelerate, a 100% anti-squat value would mean that your rear suspension does not compress at all. A >100% value would indicate your rear suspension actually extends, and a <100% value means your rear suspension compresses.

Does the same hold true in the world of crawlers? Or is it more just a matter of location of CG in relation to axle height, etc. Of course that all comes into play too in MTB, but I guess what I'm asking is how important is the design of the rear suspension linkage. I may not be asking that question in an intelligible manner...

So yes in MTB it's a thing, but really quite different. Really, it's an apples to potatoes in comparison terms.

Anti-squat in off-roading is a tremendously important thing to sort out. That's why all those holes exist on frames as well as link risers; they allow you to adjust anti-squat. MTB suspension is very basic in comparison and not really a good analog; there are just too many variables. It's best to set aside the MTB analogy and start fresh.

This video will set you straight:

It's detailed enough and to the point that you'll see the physics of what's taking place.

This link is to our page where you can see the SCX-6 calculations: https://www.mojavevalleyrcadventures.com/axial-scx-6.html

 

[Steve B in Vegas]

There is a lot of information in this video, and while it's not 100% useful in crawler world, you sorta need to understand this if, and only if, you are changing the link setup from the factory. They've already done this math for the intended use of the crawler they designed. Companies like Vanquish with their new VRD did a very good job with this math.

That said, while everything is a compromise, it can be done better. Here are some images from this build, and after watching the video, you'll understand why the numbers are coming out this way. In reality, it's just a hair below center line in that our calcs are with a 5" tire, but you get the idea.

Here is the end result of this setup

Ok, so with those charts, there is a very important bit of data that most won't catch, and it's one of the main reasons our Antero walks up walls: CG.

The calculated CG is 2.39" The Rupture is nominally 4.92" in diameter, and half that is 2.46". This places the CG of the Antero below the center-line of the axle. It was a real trick to do that with a chassis-mounted servo.

 

[King blitz]

Wanna see a poor attempt at a trail/crawler? Something laughable. I took one of the most breakable RC's well known to the hobby and attempted to mimic a Summit in capability.

View attachment 361422View attachment 361423View attachment 361424View attachment 361425View attachment 361426View attachment 361427View attachment 361428

Yo that's badd ass . Pretty darn sweet bro

 

[Arise0185]

So yes in MTB it's a thing, but really quite different. Really, it's an apples to potatoes in comparison terms.

Anti-squat in off-roading is a tremendously important thing to sort out. That's why all those holes exist on frames as well as link risers; they allow you to adjust anti-squat. MTB suspension is very basic in comparison and not really a good analog; there are just too many variables. It's best to set aside the MTB analogy and start fresh.

This video will set you straight:

It's detailed enough and to the point that you'll see the physics of what's taking place.

This link is to our page where you can see the SCX-6 calculations: https://www.mojavevalleyrcadventures.com/axial-scx-6.html

There is a lot of information in this video, and while it's not 100% useful in crawler world, you sorta need to understand this if, and only if, you are changing the link setup from the factory. They've already done this math for the intended use of the crawler they designed. Companies like Vanquish with their new VRD did a very good job with this math.

That said, while everything is a compromise, it can be done better. Here are some images from this build, and after watching the video, you'll understand why the numbers are coming out this way. In reality, it's just a hair below center line in that our calcs are with a 5" tire, but you get the idea.

View attachment 361457View attachment 361458

View attachment 361459

Here is the end result of this setup

Ok, so with those charts, there is a very important bit of data that most won't catch, and it's one of the main reasons our Antero walks up walls: CG.

The calculated CG is 2.39" The Rupture is nominally 4.92" in diameter, and half that is 2.46". This places the CG of the Antero below the center-line of the axle. It was a real trick to do that with a chassis-mounted servo.

View attachment 361461

This is a lot of info to digest, but very interesting stuff! Appreciate the detailed info.

 

[blaster27]

Wanna see a poor attempt at a trail/crawler? Something laughable. I took one of the most breakable RC's well known to the hobby and attempted to mimic a Summit in capability.

View attachment 361422View attachment 361423View attachment 361424View attachment 361425View attachment 361426View attachment 361427View attachment 361428

That's sweet.

 

[Arise0185]

Dropped in the Fusion Pro and rs800v2 servo from the TRX-4. Also bumped up the overdrive to 12% using the included gears. Man what a different truck!

 

[Steve B in Vegas]

 

[Retrowomble]

Element ecto .ftx paso ,scx24 and fms magnum

 

[Arise0185]

Tried running the Zuul without the sway bar for a few runs. So far it hasn't proved as a major advantage or disadvantage on my backyard course. It allows for more articulation, but the truck didn't necessarily NEED that extra articulation.

 

[lipo-joe]

tooling around on some rocks …