TRX4/Climb like a spider. Climb up STEEP things. Budget, free & cheap mods for Traxxas TRX-4

[@FoxRacingGaming]

How did you attach the suspension and manage to get the inner fender off? I was going to do this on a new body, but it appeared as if the lift kit I put in it a long time ago, attaches the shock straight to the fender. Did you cut it or?

[@hilltoprccrawlers1979]

I performed your suggested mods to my RCR Gen-8 with UGRC Labs Predator chassis. WOW! What a difference.Great video. Thanks for sharing. :)

[@North49RC]

The science behind this makes sense and is the first time I have seen anyone use the physics of geometry for traction on these crawlers. If you havent yet it would be cool to see you have a 3D printed belly pan/link mount as a more permanent fixture, something others could easily fit to their own rigs. Great work, and i will be looking at my axial to see if there are any pssibilities there in the future. Thank you

[@JustScalin]

Thanks! I've got some skids (and some prototype ones not yet released) on my thingverse, but they are for the NWSD Scattergun v2 frame. I will look into link risers for a TRX4 as it shouldn't be too hard to sort out. For the Axials search Shapeways or eBay for a "RULR" or Rear Upper Link Riser. They are pretty common and help do a similar thing. Really appreciate the feedback, let me know how you get on!

[@North49RC]

@@JustScalin I have yet to get my Axial, i did order a rear cantilever suspension kit for it, this RULR unit you speak of is intriguing. I will look for it. Thanks again

[@Lokithefeline]

@@JustScalin i would be interested in this too. tho i dont have a 3D printer, if you produce them how much would u charge? when u do i will want one.

[@mossy4050]

Great video with easy to follow steps! Thanks for the info 😀

[@JustScalin]

You're welcome, glad it was useful!

[@dunerinaz]

Your entire method in the rear is completely opposite of how anti squat works. Using a 1:1 drag car with a 4 link rear end as an example, raising the rear of the upper links and/or lowering the front of the upper rear links creates anti squat and will actually lift the rear under acceleration. This is what drives the front axle down. Our crawlers are no different.

[@HollerRC]

You’re right. I’m surprised it took 3 years for someone to comment who knew better. I learned about anti squat from watching videos on 1:1 vehicle geometry which inspired me to design and sell rear link risers for the scx24 and CR18P that mount to the rear axle. I’m going to try one on my trx4, but I’m skeptical that petg is durable enough.

[@Tuidkskiwjdhdbd]

Just found your channel love my trx4 as well it's the only traxxis I love lol but I did just get a capra kit I'm excited to tinker with that but I want to put brushless in it but I can't afford a 200 system what the best budget option on if you don't mind or should I just save for a castle or sum

[@JustScalin]

I'm not sure if it would fit, but the Hobbywing Fusion is probably the best budget brushless and one of the best brushless crawling systems you can get. If not then the HW Axe in a 540 would be a safe bet. Castle combos are fantastic but can get pricey quickly. Also if you're not dunking it in water I'd probably go for a brushed Hobbywing 1080 with a HH sport motor

[@Lokithefeline]

haha thats a well loved body. looks like my red one haha. love it

[@JustScalin]

Yeah I run them until they fall apart

[@roblockhart8287]

Great well put together video and some intelligently thought out mods. Looking forward to seeing it in action. What's the best way to find the centre of gravity of your rig? I assume that if another vehicle had a different centre of gravity then the link positions would need to be different or you would need a similar cog to yours to do the same positions and mods as yours?

[@JustScalin]

So one way is to hang the vehicle by the bumper mounts and take a photo of each way. Then draw a line straight down vertically and where these lines intersect (vehicle up & vehicle down) would be your CoG. To make this work you need to zip-tie your axles at "ride height" to stop them from fully extending. Another way is to just weigh all your parts that are "sprung" and all those that are "unsprung" and work out the ratio, then find the point on the car (from the ground) that's that ratio from the floor. E.g. if your sprung weight is 1kg and unsprung weight is 2kg then measure from the ground to the top of the shell and pick a point that's 1/3rd the way up. Even if you don't measure, you can use the same mount positions I did and you'll get a similar, but maybe not as strong effect. This is because the instant centre (where the links join) should be in the anti-squat and anti-dive zones on any rig that has 50% of its weight below the highest point of the motor on a TRX4. In that case, you won't need as much pre-load on the suspension but the car will push into the front wheels when accelerating. This is why the "non-permanent" way is to get a link mount and remove the upper rear link where it goes into the chassis, then put the bolt back in, and then the two screws in the link mount go either side and you attach it using another piece of plastic. I used one of the mounts from a slider which I just cut off my side trays, but any piece of plastic or maybe a big washer and a nut would do.

[@ConditionZero76]

sky rc scale

[@Lokithefeline]

how does this setup affect descending?

[@JustScalin]

Increased anti-squat doesn’t really hurt descents as long as you take it slow and carefully

[@richardmarsden6516]

Thats interesting thanks for sharing you tried this on anything other than a trx?

[@JustScalin]

Not yet, but the theory is taken from the 1:1 world and I’ve use a LOT of anti-squat on the scattergun build

[@richardmarsden6516]

Never seen or heard of this before I learn loads off your videos makes me want to try it out

[@taylorstarcevic1015]

That was a smooth intro

[@JustScalin]

Haha thanks! The it’s one of my first videos but thinking how I can get back to a similar style

[@logiqalone8249]

Very nice. You could design a crawler from scratch.

[@JustScalin]

I’ve thought about it! Maybe over winter where I have time and space to do it

[@0000oooopppp]

Where is the clip where it climbs like a spider?

[@JustScalin]

In other videos maybe, this is about the theory and was one of my earliest videos

[@cyclorando3559]

very very interesting, but the problem is the camera is blurred and unfortunately, it is the case for most of the videos ont this channel.

[@JustScalin]

That might be your internet connection, no-one else has noticed it being blurry

[@DJSpannamanUK]

Top bodger!

[@ka4172]

Aluminium skids doesent slide well.

[@JustScalin]

Yeah, they all got pulled off shortly after. They were actually stainless, but that's soft too

[@MikeRCWorld]

interesting.. :)

[@JustScalin]

Thanks! I might reshoot it later in the year now I’ve had a bit more KZbin practice and just focus on the geometry bits

[@jasonlund4750]

U do realize that putting a link riser on the rear axle of a portal axle don't work rite??? The portal gearing makes it work opposite direction. Now link riser on a strate none portal works for your anti dive yes but a portal axle spins in the opposite direction at the portal it's not the same

[@JustScalin]

The wheels still spin in the same direction though so the twisting forces put on the the axle are the same direction so it doesn’t matter if it’s straights or portals the effect is the same.

[@jazzbass321]

That’s not a trx4

[@FoxRacingGaming]

It is, he's literally stripped everything off it, including the floor and the fenders making look like a diff truck. but its a trx4.