20vmki's TRX-4 Sport Buildup!

[20vmki]

Delivery today...

I fell in love with the Samix front shock towers so I had to get the rear ones as well For the Sport wheel base I had to install them backwards, I hope that's normal?

SSD Portal Covers, love the look, and weight:

And finally, under driving the rear diff:

Kinda a bummer the underdrive gear doesn't have the notches like the stock gear, all the strain is on the screws now

Pardon the fan and music

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[Benp]

Excellent!!

Boy I’m not sure on the rears. I went to sammix direct website and looked at them. They say suitable for mounting on defender and these are some of the pictures.

I’m not really sure what’s going on. Those pictures are definitely not of a sport.

Maybe one of the longer wheelbase models?

I’d say if mounts are sturdy, shocks are straight up and down or slightly towards front just let it buck.

I’ve been really pleased with all sammix parts I’ve bought. But there is always the chance of Friday/Monday build items like anything else.

I really like the SSD portal brass as well.

When I did the front overdrive, I too wondered about the non notched parts. I guess time will tell. I most likely will install the underDrive in the rear here shortly and just be done with it.

I believe you are going to be very very pleased with the new set up and the course may need a makeover now to reflect the trucks new capabilities. [emoji106][emoji106][emoji106][emoji106]

And definitely more tiger traps. [emoji16]

 

[mr_alister]

The photo looks like you have the left's and right's mixed up to me. Switch sides with those shock mounts and it should be ok.?

 

[20vmki]

The photo looks like you have the left's and right's mixed up to me. Switch sides with those shock mounts and it should be ok.?

If I flip them then they don't like up with the Sport's shorter wheelbase.

 

[Benp]

Like I mentioned. If it’s sturdy and shocks are mounted well, I’d just run it. [emoji106]

 

[Omega-Tron]

Looks like you installed the shock mounts correctly. The 4 different wheelbase options are obtained by moving the shock mounts forward or back and swapping them left to right.

Defender wheelbase:

Sport wheelbase:

 

[20vmki]

I took a stab at 3d printing with ABS, instead of PLA. My problem has been, on my LCG battery tray, the rear shock mount screw threads into the tray and I've been too successful at splitting the tray by tightening the screw too tight (I want the shock tower secure). So I printed ABS but it split while tapping the hole...no dice. So I just used a longer screw and put a nut on the back, problem solved for now! Also, while swapping trays around I weighed them all:

Stock Tray:

Old PLA tray:

New ABS Tray:

Installed (along with the 3d ESC mount, and custom sliders):

And, why not weigh the whole truck:

 

[20vmki]

While riding our bikes today my kid and I found some work being done at our local park which resulted in a big pile of dirt...hmmm, what 11 year old boy would pass up the chance to play in the dirt? So we came back with our R/C cars...

You made it through all the pictures, so here's a short video
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[Benp]

That’s pretty good!

Nice change of pace for you.

I started yelling “no no no” at the end of the very first video run. [emoji1787][emoji106]

Looks like you guys had fun!

 

[20vmki]

Just a few pictures from running the backyard course today.

 

[Benp]

Great pictures!!!!

That’s a sharp looking rig!

 

[20vmki]

My slow motion video highlighted a behavior of the front wheels, jerking when turned, so I tried it on the bench:

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I assume this is normal and a limitation of the CV joints? (I hope?)

Oh, and another tree had to be trimmed in the neighborhood so, more course updates coming soon!

 

[Benp]

That’s interesting.

I’ve got nothing for that one.

Mine does it on the ground like that because of the overdrive in front.

Servo making any odd noises?

Maybe need an endpoint adjustment?

 

[20vmki]

That’s interesting.

I’ve got nothing for that one.

Mine does it on the ground like that because of the overdrive in front.

Servo making any odd noises?

Maybe need an endpoint adjustment?

Pretty sure it's not a servo issue, as the problem only comes with speed. Endpoints are adjusted using the Link module, so there is no rubbing.


Found this after finding the right keywords to Google:


https://forums.traxxas.com/showthread.php?9085159-Sport-Shudders-on-Turns


and explained here (I watched this same video when working on my 1:1 truck!):
https://www.youtube.com/watch?v=Idk3BVDVHq4

 

[20vmki]

Found yet another cut up tree in the neighborhood!

 

[mr_alister]

Looking forward to seeing what you do with all that wood!

 

[20vmki]

First up, another package came in the mail! SSD 1.9 Beadlocks! The two front tires are also getting the brass inner ring.

After watching a few Youtube videos I ended up baking my wheels at 350 degrees, 15 mins a side, or until a toothpick comes out clean.

It wasn't until after I put two together that I found out they weren't vented. I know there are two schools of thought, vent the wheel or vent the tire. I went with vent the wheel and drilled two small holes in the back collar and inner ring.

There is some sliiiight rubbing on the front tires, but it doesn't seem to bad, the offset seems to be about the same as the stock wheels.

Not sure if it's the new wheel, or the baking process, the tires seem a bit squishier. The tires seemed to bubble out a bit more that I remember, you can kind of see it here in the rear tire.

The reason for the new wheels? To look more like big brother of course!

 

[mr_alister]

Yeah they look great! Good choice. I run my wheels unvented coz I like to drive through every creek and puddle I see. I dunno why, I just can't help myself lol.

 

[HumboldtEF]

My slow motion video highlighted a behavior of the front wheels, jerking when turned, so I tried it on the bench:
I assume this is normal and a limitation of the CV joints? (I hope?)

Yes this is normal with the TRX-4, the axles can only turn so far before they start to bind. You can back off the travel, live with it or clearance the axles though that may make them weaker. I just live with it and I think they may have broken in a tiny bit. Anyway Just avoid full throttle and full lock at the same time if you push the limits of steering.


Instead of ASB which off gasses toxic fumes I'd recommend PETG I found its a great easy to print filament that holds a thread very well and can handle heat better than PLA.

Regarding prints splitting when threading in screws, what size hole do you use for a m3 for example? (I use 2.6mm)
And how much material do you leave around it?

 

[20vmki]

A few shots on the initial layout of the new section of the back yard course