ZAD2K's First Build Thread - TRX-4 Sport Kit

[Zad2k]

Disclaimer-

I’m just going to give you guys a heads up that I tend to be long winded, it’s just my style and I don’t really intend on altering that for this post, I know not everyone will be into that and that’s ok. This all occurred during the Covid-19 related shutdown so all of my purchasing had to be done online.

Back Story-

After about a 5 year hiatus I’ve recently gotten back into the RC Hobby. Just before I moved houses and my RC stuff went into storage I was getting into scale crawlers and had gotten an Axial Wraith Spawn. I’ve finally gotten back to a point in my life where I felt I had the space and time to break my RC’s out of storage and so out came my Wraith! I started building a modular backyard crawler course and running my Wraith on it, the plastic Idler gear in the transmission finally let go so my truck was down for a week, while waiting for HD metal gears to arrive in the mail…That gave me time to look and discover all the advancements that have been made in the scale crawler world since I’ve been absent the hobby and I ended up being really interested in the 1.9 scene. After much debate and research as to what truck I wanted to go with I decided to go with the Traxxas TRX-4 Sport Kit. I owe a big thanks to several YouTubers whose videos helped me decide from the extensive options out there, especially RC Review’s channel with his numerous shootout/comparison videos. The Budget Build-off series from Harley Designs and Scale Builders Guild inspired me for what route to take with my TRX-4 and so I’m also thankful to them for their content!

Goals with this Truck-

Build something that is tough, performs fairly well and take my first steps into the 1.9 scale building hobby all within a fairly low budget financial situation. Most of my decisions about what I’m currently putting into this truck were based around these guidelines while also falling into a time constraint I’ve put on myself. I’ve got 2.5 weeks scheduled off work coming up and I wanted to have everything I needed to complete the truck arrive by the start of that vacation. It took a lot of time for me to try to research components, best prices and actually find items in stock and was kind of a logistical nightmare for me over the past week trying to make sure I’d covered everything I could need, ahead of actually getting and building the truck. Here’s hoping I got it all covered!

With all that hot air expelled, welcome to my first Build Thread!

Chosen Components-

TRX-4 Sport Kit
I chose this truck because I kept hearing how durable and well-built/engineered the TRX-4 platform is, I saw how capable the stock TRX-4 Sport was in videos, and I love the look of the Sport Body with all those included accessories. The kit was sold out in a lot of places so I ended up going with a U.S. based eBay seller for this one as the kit would arrive in time for my vacation.

Hobbywing Quicrun WP 1080 Brushed ESC
This speed controller is very widely recommended, seems to have great features and is priced extremely reasonably. After watching several videos of people running it and reading reviews, it seemed to be an extremely easy choice to go with this ESC. The hard part was finding one that would arrive on time! The vast majority of online hobby stores were sold out, I found several on eBay shipped from China but was worried they wouldn’t get here quick enough. About 4-5 pages deep on my Google search for online hobby shops I found BeachRC.com who had these puppies in stock for a great price and shipping was totally reasonable. They got it out to Northern California from South Carolina quickly!

Traxxas Titan 21T 550 Motor
This was an area I decided I could save some money, I’ve got a box of electric motors that still have plenty of life left in them sitting in my garage, including a couple Titans from an old E-Maxx, some Kyosho 27T Magnetic Mayhems and various others. I saw Harley Designs pair the Titan with a Hobbywing 1080 in his Budget Build-off and the truck looked like it ran really great to me so I decided to run what I’ve got sitting around until I get more funds and research motors more down the road.

Fan Model FS-20W Steering Servo
I honestly can’t remember why I picked this servo, I know I did a ton of research and came away with no clear winner as to which servo to go after. Maybe I confused it for a Power HD servo or maybe I actually found a convincing recommendation somewhere and just can’t find it to reference back to. What I do know is that it was extremely affordable, supposedly waterproof, had a respectable torque rating for the price and would arrive on time!

FlySky FS-GT3B Radio/Receiver
This radio seems to be very widely recommended as universally the best cheap radio system for ground based RC. It’s been around a long time and is apparently still widely used. This is another item that I had difficulty finding in-stock, priced reasonably and with an ETA that fit my needs. After a tremendous amount of Google searching I found the somewhat sketchy website ArrisHobby.com with a reasonably priced FS-GT3B shipped from their U.S. warehouse, they have a bonus $10 off coupon right now and I got free shipping. Hopefully the thing actually arrives; I’ve got a tracking number so that’s a good sign!

Traxxas 8080 TRX-4 Narrow Inner Fender Kit
The inner fenders are something I really like about the TRX-4 platform and also the other brand’s contenders, I had a hard time figuring out which fenders would be the best for the TRX-4 sport body but I knew that these would fit underneath without having to modify anything. I will throw this kit on the truck and run it until I find an option that seals up the chassis better, if you’ve got any info on which set works the best with the Sport body let me know!

That’s it for now, I’ll be updating this post and thread with further impressions and photos when stuff comes in, the truck itself should be waiting for me when I get home from work today!

 

[JatoTheRipper]

Welcome back to this awesome hobby!

The TRX-4 is a great kit. It's so fun to build - one of the best in any genre of RC. The truck is also great. I think you'll be very happy.

Everything else looks good except maybe that servo. It looks like a rebrand or clone of a PowerHD. You may or may not have good luck with it.

The Arris Hobby website looks like a Chinese reseller.

 

[Zad2k]

So my Kit and servo arrived in the mail yesterday and I was able to begin working on it. This kit is fantastic so far and I've only managed to slightly strip one screw in the transmission case! (Usually I end up stripping all sorts of screws when they go into plastic, it just never really got tight enough for me to realize it was good, and I was tightening by hand) I'll probably go back and throw some threadlocker in that stripped screw hole unless there's a better way to remedy this?

Here's what I got done last night, transmission and rear end completed!

I also opened up my servo to see what came in the box, all sorts of bits and bobs that I don't think I'll ever use.

One tip I have for anyone new or having trouble with insertion of the Transmission Shift Plug; use a tiny drop of Windex on the tip of that plug, just the tip mind you, :mrgreen: and your rubber plug should be all lubed up for easy insertion!

So far everything is going pretty darn smooth, I do recommend some sort of powered driver with hex bits to get the screws most of the way in as most of these screws are going into untapped plastic, be sure to stop just before the screw gets tight and finish by hand (that's what she said) or you will run a higher risk of stripping the plastic holes with the powered driver.

 

[OSRC]

Put some CA on a tooth pick and swirl it around the hole. Let it dry. It'll give the screw something to bite into again, just don't crank down on it when tightening - snug it up and call it good. Works like a charm, I do it on all my old Tamiya rebuilds.

 

[Zad2k]

Put some CA on a tooth pick and swirl it around the hole. Let it dry. It'll give the screw something to bite into again, just don't crank down on it when tightening - snug it up and call it good. Works like a charm, I do it on all my old Tamiya rebuilds.

Thanks for the tip!

 

[mass-hole]

I bought fenders, but never installed them on my sport kit. At least in my environment, i really havent found that much crap gets up inside/under the the body.

The fenders also have the shock towers integrated into them, and I wanted to run extended towers. I would have to notch out the fenders to to fit my towers and not sure how secure they would be at that point.

 

[ChrisSandstorm]

Looking forward to your build. I just did the same build and almost wrapped up over the weekend. I am waiting for my Hobbywing ESC to arrive from Escondido, CA and paint from Amazon.

I also bought my son a Tan TRX4 Sport and we just had to replace the Servo arm, it was such an easy repair after building my own.

 

[Zad2k]

Looking forward to your build. I just did the same build and almost wrapped up over the weekend. I am waiting for my Hobbywing ESC to arrive from Escondido, CA and paint from Amazon.

I also bought my son a Tan TRX4 Sport and we just had to replace the Servo arm, it was such an easy repair after building my own.

That's at least the second mention I've heard of having to replace the stock servo horn on the TRX4, was it the same as the aluminum one that comes with the kit?

Just trying to be somewhat ahead of broken parts so I don't have overly extended downtime while we have such nice weather. In another month or so it's going to start getting hot here in Nor Cal and I'm not going to want to be outside as much.

 

[ChrisSandstorm]

That's at least the second mention I've heard of having to replace the stock servo horn on the TRX4, was it the same as the aluminum one that comes with the kit?

Just trying to be somewhat ahead of broken parts so I don't have overly extended downtime while we have such nice weather. In another month or so it's going to start getting hot here in Nor Cal and I'm not going to want to be outside as much.

The prebuilt Sport's come with a plastic Servo arm and it just didn't holdup. I had bought an aluminum one for my build, as I did not realize there was a steel/aluminum (?) one in the box. So I was able to use the aluminum one for my son's. I used the one from the kit in my build, it was a little heavier. One thing I wished I had done and passed on was brass Portal covers for the front. The front is kind of light and they were not expensive.

 

[Zad2k]

The prebuilt Sport's come with a plastic Servo arm and it just didn't holdup. I had bought an aluminum one for my build, as I did not realize there was a steel/aluminum (?) one in the box. So I was able to use the aluminum one for my son's. I used the one from the kit in my build, it was a little heavier. One thing I wished I had done and passed on was brass Portal covers for the front. The front is kind of light and they were not expensive.

Thanks, for the info, I'll keep the weighted front end parts in mind!

 

[Zad2k]

Day two of my TRX-4 build has arrived and with it a few more things in the mail, I received my ESC, a pack of 3.5mm bullet connectors I plan to use for the motor and my Traxxas 8080 Narrow Inner Fender Kit. Looks like I've got everything I need for an evening of 1/10th wrenching!

Here are a few more shots of what's included in the Hobbywing Quicrun WP 1080 Brushed ESC:

Included is a programming card and the appropriate connector cable.

A couple small zip-ties, some double sided foam tape and a couple short pieces of heat-shrink tubing.

The ESC and programer feel like quality items in hand and further impressions/reflections about this product will be posted later in this thread as I have more experience with them.

I'd also like to note that I came away from my experience with BeachRC.com impressed by their prompt shipping and extra customer service touch! Along with my ESC they sent a store logo sticker sheet, a couple pieces of bubble gum and a handwritten thank you on the receipt. It's touches like these that will bring me back as a return customer.

As far as I know, bullet connectors are bullet connectors, so I just grabbed these off of eBay because they were fast and cheap. I haven't soldered these type of connectors specifically but my soldering skills are solidly mediocre so I think I'm up for the task! 8)

Build day two went well, I feel like I made a lot of progress and am really enjoying this kit! I managed to strip a screw in the front red diff cover and another in the receiver box even though I've been trying to be super careful. I finished the front end and got the chassis mostly completed.

I have to say the axles and chassis all feel very stout! Unfortunately I did come up missing one 10mm screw from the Chassis hardware, I might have an extra in my spare hardware but for now it's no big deal as I left it out of the rear bumper mount and it's not affecting much. It would have been nice if Traxxas had thrown in a few spare screws of each size though, it wouldn't have cost them much and would have been greatly appreciated by me and many others I presume.

I also came away from the front end build being impressed by how silky smooth the steering and gear mesh is. This kit has such a high degree of precision to it, it's miles away from the Traxxas Stampede Kit I built years ago!

Well that's it for day two, looking forward to more tonight!

 

[mass-hole]

Day two of my TRX-4 build has arrived and with it a few more things in the mail, I received my ESC, a pack of 3.5mm bullet connectors I plan to use for the motor and my Traxxas 8080 Narrow Inner Fender Kit. Looks like I've got everything I need for an evening of 1/10th wrenching!

Here are a few more shots of what's included in the Hobbywing Quicrun WP 1080 Brushed ESC:

Included is a programming card and the appropriate connector cable.

A couple small zip-ties, some double sided foam tape and a couple short pieces of heat-shrink tubing.

The ESC and programer feel like quality items in hand and further impressions/reflections about this product will be posted later in this thread as I have more experience with them.

I'd also like to note that I came away from my experience with BeachRC.com impressed by their prompt shipping and extra customer service touch! Along with my ESC they sent a store logo sticker sheet, a couple pieces of bubble gum and a handwritten thank you on the receipt. It's touches like these that will bring me back as a return customer.

As far as I know, bullet connectors are bullet connectors, so I just grabbed these off of eBay because they were fast and cheap. I haven't soldered these type of connectors specifically but my soldering skills are solidly mediocre so I think I'm up for the task! 8)

Build day two went well, I feel like I made a lot of progress and am really enjoying this kit! I managed to strip a screw in the front red diff cover and another in the receiver box even though I've been trying to be super careful. I finished the front end and got the chassis mostly completed.

I have to say the axles and chassis all feel very stout! Unfortunately I did come up missing one 10mm screw from the Chassis hardware, I might have an extra in my spare hardware but for now it's no big deal as I left it out of the rear bumper mount and it's not affecting much. It would have been nice if Traxxas had thrown in a few spare screws of each size though, it wouldn't have cost them much and would have been greatly appreciated by me and many others I presume.

I also came away from the front end build being impressed by how silky smooth the steering and gear mesh is. This kit has such a high degree of precision to it, it's miles away from the Traxxas Stampede Kit I built years ago!

Well that's it for day two, looking forward to more tonight!

I also had one missing screw in my sport kit. I feel it was one of the button head screws that pass horizontally through the chassis rails in the back.

 

[Sausage gut]

Nice,I just started my build also. I can’t wait to see this thing finished


Sent from my iPhone using Tapatalk

 

[ChrisSandstorm]

"thumbsup"

 

[Zad2k]

Well I'm back with a BIG leap forward in build progress!!! I spent pretty much all day yesterday working on the TRX-4 and got it completed. I'm still waiting on a few things to come in, like body paint and my TX/RX. I was too impatient and had to try the truck out so I robbed the TX/RX from my Stampede and got the electronics temporarily mounted so I could give her a go!

The only build note I really have for the rest of the truck was for the front top tube of the Expedition Rack. I would suggest using a powered driver to pre-thread the holes before you mount the tube to the rack. Then when you mount it maybe just put the screws in by hand tool rather than the powered driver. The reason for this suggestion is because there are a couple tiny tabs on that tube intended to hold it in the proper angle on the rack. Maybe it should have been obvious to me but those tiny tabs do NOT hold up to the torque of a powered driver!

Well here's how she looks at the moment!

I decided to run some super cheap plastic beadlock wheels so I didn't have to glue the tires. I think they look pretty good actually.

I got the build done yesterday afternoon and decided to do some detail painting on the truck, I feel like these details added a lot to the look! I just used Gundam paint markers for the details.

Front grill badge.

Snorkel grill.

TRX badge on the snorkel.

Some of the studs on the traction boards. I found some pictures of real ones where just the first few rows of studs were stainless steel and the rest were orange so I was relieved not to have to paint them all!

Fire extinguisher. I was particularly happy with how this piece turned out!

High lift jack.

Axe and shovel.

Gas can caps.

Tailgate badge and handle.

And finally my temporary electronics mounted up!

I took her out for her maiden voyage on my backyard rock wall obstacle, she's already got a few battle scars but I was pretty darn happy with the stock performance!! Crawling is very controllable and the stock tires seem very grippy.

One thing I noticed is how hot the motor and ESC got with just the few minutes of slow crawling I was doing. I do know that the 22 turn Kyosho Magnetic Mayhem motor I have in it is NOT reverse rotation so I have the motor wires switched. Would this cause the Hobbywing 1080 ESC to get pretty hot?

I was running stock Sport Kit pinion and spur gearing on a 2S Lipo. The drivetrain seems smooth to me but pretty low geared feeling. I checked that everything was smooth every step of the way. I greased everything with Marine Grease rather than the Traxxas kit grease but I didn't pack a ton in each area, just enough to coat gear teeth.

I'm looking at going ahead and buying a cheap new motor since none of the ones I have are reverse rotation. Looking at the Traxxas Titan 550 21t or the Holmes Hobby Trailmaster 550 21t. They're both roughly the same price with the Traxxas being a couple dollars cheaper and will get here quicker. I'm assuming most would go for the HH?

 

[MaX-D]

HH FTW!

Sent from my LM-G710VM using Tapatalk

 

[CriMiN4L]

I dont know if this will help you with the over heating but it may, if you haven't configured it yet.


https://www.youtube.com/watch?v=BMjtsGJlYVM

 

[Zad2k]

I think my heat issue was being caused by the recommended gear mesh position being too tight for the motor mount and from using that specific motor. As per new2rocks' guide I went one mounting position further than the manual suggests and switched to a Titan 550 and now it seems better.

 

[Zad2k]

I got my paint done today! I went with silver and black on the inside with green and black on the outside. I know traditionally RC paint is done on the inside to protect it but I wanted to try an idea I heard about where when the paint gets scratched off it will show silver through the scratches. I thought ultimately this would give the truck more character and be more similar to 1:1 where the truck will receive the occasional "battle scars". I'm pretty happy with how it turned out, this was my second real attempt at painting an RC body and it turned out much better than the first time.

I was doing a little crawling on my rock wall this evening and the Traxxas Titan motor started smoking a little. My Holmes Hobby motor should be here in a few more days, I don't imagine this Titan motor will last much longer!

 

[ChrisSandstorm]

Looks awesome!