TinyTrux TRX-4 Sport Kit Build-out
 

So I recently got into the whole RC crawler thing... ordered up an HPI Maverick Scout from Amain for $100. Figured it would be a neat way to get out there for cheap while I tested the waters so to speak. Dang it's fun! Lots of great places to crawl up here in New Hampshire.

Localish RC shop kindly lent me a TRX-4 Sport to run on their indoor/outdoor trails and...WOW I was blown away. Performed incredibly well and seemed solidly built. Decided to jump in with both feet and build one myself with the Unassembled Sport Kit. My shop should be getting it in at the end of the week/beginning of next week.

It'll be a semi budget build to start but I'll document any changes/new parts/mods/etc here. I found all the threads from the likes of Jato, OSRC, Sickpuppy and others to be super helpful and inspiring. Thanks guys!!!

Current Part List:
TRX-4 Sport Unassembled Kit
Traxxas Titan 550 21T Reverse Turn (For $22 it seems like a solid brushed option)
Annimos "20kg" Servo (See how it goes! $18...hard to argue with that)
WP QuicRun 1080 ESC
Yanking the transmitter and receiver from my HPI Mav Scout :razz:
eBay 1.9 Beadlocks (That way I don't have to glue the tires...)

Various things:
Too many Tamiya PS Paints
WERA 1.5, 2.0, 2.5mm Hex Drivers
Masking tapes of various widths
3S Lipo 3000mah 30C

Parts Considering:
Proline 2 stage foams
ScalerFab front and rear bumpers (Casey said they were coming out with TRX-4 Sport specific options this or next week)
Light kit - unsure which Chinese option to nab for cheap

Small parts pile!
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Ran a paint test..looking to get a color close to that of the new Mustang Bullitt and I'll add some graphics halfway down the body to break things up a bit. 2 Coats PS-17, 3 coats PS-22, 3 coats PS-5. My first time ever painting lexan but I think it turned out close to what I want. Will probably do a few more tests...

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Re: TinyTrux TRX-4 Sport Kit Build-out
 

Did some research and seemed like gearing the Sport transmission down to a 45T Spur and 12T Pinion gear would net greater torque and better crawling capability. Since I will be running 3S I think it'll still be plenty fast on the trail...but we'll see! Picked up the spur gear and hardened pinion at the recommendation of a forum member. Also grabbed some marine grease from Dynamite and a pair of metal custom license plates from an eBay seller haha Couldn't resist!

Now just waiting on the kit to arrive this week!

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Re: TinyTrux TRX-4 Sport Kit Build-out
 

Awesome man! Can't wait to see how it turns out!

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Thanks Soze! I'm really debating whether I want to run it with the bed cage or not..have you noticed any tangible performance problems with having it mounted?

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Heh Dynamite repackages marine grease and still keeps the name? That's a new one. You can get it cheaper next time if you go to your local hardware store.

You're going to love this build and the truck.

The cage and accessories add a ton of weight and they do hurt performance.

Re: TinyTrux TRX-4 Sport Kit Build-out
 

^ It does. But it makes it look so good!

Re: TinyTrux TRX-4 Sport Kit Build-out
 

It is so hard to figure out what grease to use! Everyone seems to have their own reasons why one is better than another. Figured that marine grease was a decent place to start. I think the tube was $8 so not terrible.

Hopefully can find a balance between scale and performance. Definitely don't want a capable truck to be hampered...

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Yes, there are so many options in RC that it can be overwhelming as a newbie. And the number of greases out there is just crazy!

Marine grease will be just fine. It has more drag than I personally like, but many people, including myself, have used it without any issues for years.

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Hey man, thanks for creds in the first post, thats awesome!
I'll for sure follow this thread, you're doing it the right way I think.
Looking forward to see pictures of the truck as it grows, so keep the pictures and stories coming, I'll be here reading and commenting for sure :)

BTW: About grease.. If you do the math, if that tube was $8, how much will that cost you broken down to every year? ;) I think I will have my grease tube for the rest of my life since I got my favourite grease who stands both low temperatures and water in two standard size tubes.. :D And the most important thing is that you change the grease every now and then, as long as you do that it would do great with the cheapest grease out there. The biggest issue is if it gets old inside the installation and gets to collect dust and tiny particles of sand in it making it a very effective grinding grit(dont know a better word for it) and it will eat out your bearings and gears in "no time"..

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Thanks sickpuppy!! Appreciate the kind words and support. Makes total sense about changing the grease out. Same as a bicycle "thumbsup"

Got off work a bit early to drive down to the LHS and pickup my kit!! Started building last night and then a bit more this morning before work. It's really satisfying using up every single part that came in the bag for a given component.

So far just the trans, rear axle, and part of the front axle finished. Will do some more over lunch and then tonight. Hoping to have it finished (unpainted) by Saturday afternoon!

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Re: TinyTrux TRX-4 Sport Kit Build-out
 

Got her all built! Took about 6 hours or so all told. Felt pretty good overall for my first time ever putting together anything RC. Didn't have time to paint the body plus the weather has been not good so figured a little extra coverage on the exterior wouldn't hurt! haha :mrgreen:

Getting to run back to back Sports was interesting. Seeing the difference in how mine was geared down (45/12) and the 20KG servo, along with the Hobbywing ESC. Felt like I had great control of the car for climbing and descents. Still fast enough with 3S and the gearing. The servo was sweet, seemed to me faster and stronger than the stock 2075X.

Paint might happen Monday. Along with rest of the body install, mirrors, light buckets, etc etc. Still debating on the cage.

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Re: TinyTrux TRX-4 Sport Kit Build-out
 

HA! I love the "paintless"-job. :lmao: Nice choices on parts so far, I think you'll like it all. The TRX seems to be such a well designed rig that it "notices" every little change you make to it. Depending where and how you drive, some things make more difference than others. Try what you like, it'll change back if you don't like it. :D Keep us updated.


8) jim

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Hey Jim!! Thanks for the kind words and encouragement! :) Definitely agree that the platform seems so well built that any tweak has a tangible effect. I was impressed with the precision of the components during the build. If a link was 67.18mm long they meant it!

So with these Chinese headlocks the offset was different. Or the hubs didn’t ride as deeply in the hole. Either way it pushed the wheels out wider and caused a good bit of rub on the flairs and front bumper corners. Marked those areas out and trimmed them neatly with the xacto. Still looks fairly stock and no more rub! May start painting tomorrow if the weather holds.

Cheers!

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Nice build so far! The one addition I would recommend is a set of SSD portal weights.

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Can you give more detail on the license plates? Like who sells them on eBay?
Thinking I could use NH plates as well... :)

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Nice work building this in a few hours! I would've used three days I guess, plus I would've broken a lot of parts so I'd have to wait for replacement parts as well.. :D There is a saying here in Norway, "He's born with 12 thumbs", meaning the person isn't very practical..
Well, I dont have 12 of them, but I guess I'm around 6 or 7.. haha :D

I liked the masked off body, and I'm looking forward to see it painted!
Keep up the good work, buddy. :)

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Getting a kick out of the masking paint job. Looks effective too.

Looking forward to seeing it painted as well, that mustang Green looks like a good color choice.

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Thanks! I'd love to get some more weight down low for sure!

Ordered the plates from Yeti RC and they were super fast Here's the item https://www.ebay.com/itm/173740130719

That's a lot of thumbs! lol I did find yesterday that I didn't get a couple of set screws tight enough. Little locktite fixed the problem though.

Yah it was pretty funny seeing it on the trail like that. Going to mask some stripes over lunch and hopefully start laying down the first coats after work today! Cheers!

Re: TinyTrux TRX-4 Sport Kit Build-out
 

Paint paint paint paint paint paint haha But first I spent like two hours furiously taping some stripes and the back 1/3rd of the bed. I had even more elaborate design ideas in mind but ditched them because I was tired of masking lol Maybe next time...

Laid down the first dark metallic green. The stripes and back half will be gunmetal gray backed with silver. Bed and flares will be painted on top with black Rustoleum bed liner. Only had *I think* a couple areas where my masking lifted and there may be some green bleed into the gray areas. Definitely won't rush it next time, but we have had like 2 days in 10 be sunny and warm enough to paint outside so I didn't want to miss the window.

Laid down two lightish coats of Metallic green, followed by about 4-5 coats of racing green, then a ton of black backer.

Just starting the racing green:
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All coated in black:
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Little peeks of what the color should look like:
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Re: TinyTrux TRX-4 Sport Kit Build-out
 

So I ripped off the masking for the stripes and only a few small marks of bleed from the green. Overall fairly straight looking lines! (blue is where interior masking was and gray will be) The bed is getting Rustoleum bed liner coated from the outside so don't worry about that part ;) Went ahead and did about 4 coats of gunmetal gray to the back half of the truck, backed it with silver to brighten it up just a tad. Itching to peel the overspray protection off but I need to do the bed and flares first UGH

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