Gramps - TRX-4M Bronco

[Gramps]

When the TRX-4m was announced back in Sept after looking at the specs and watching the Traxxas videos I put one on preorder at my LHS. When it was released on Nov 11th I went up and picked mine up. While driving it around on the living room floor I noticed that at low speed the front wheels were catching when getting close to lock. Upon further investigation I discovered that the tires were rubbing on the steering linkage. So I fired up Freecad and designed some 1.2mm hex shims for the front wheels. Through them on the 3D printer and now my front tires don't rub the steering linkage.

When I took it out on my 1/24 scale rock course it drove pretty well but thought it need some more from weight bias. When I threw it on my balance scales it the bias was 49/51 so it could use some more front weight. When trying to climb one obstacles it would just sit there, giving it throttle and all of a sudden it would take off which made it a little unpredictable. Pretty sure that this is because out of the box it's a trail truck and not a crawler per say. I think the crawler gears will fix this but all the LHS around here are out of them. I heard on YT where putting a bearing kit in it got rid of the low end jerkiness and retained the wheel speed, haven't tried it so I can say for sure but it did look better in the video.



I swapped out the wheels and tires on mine didn't like the black rims on the red body. The wheels are Treal and the tire are Injora Crawl Masters.



I also did the driveshaft fix to help form losing the pin that is held in by an o-ring. I put a piece of clear heat shrink over it.



Not sure if it's going to help or not but I also designed and printed some high clearance links for the back. Seems to me that it exposes the driveshaft to more hangups but I might be wrong about that. On my indoor course it did seem to be better and I really didn't see the driveshaft getting hung up. This might be different outside on the rocks. Need some warm weather to try it.

[DirtMerchant]

Nice update, Gramps. The wheels do look good with the red body. I managed to snag a bearing kit from Fast Eddy, so when it shows up I’ll be anxious to see if it’s much smoother. I have a feeling it will make a difference. Nice job on those rear links.

[B-MOW71]

Nice to see another TRX-4m thread!

Nice info on the shims to fix the steering. I haven't noticed it on mine, but I'm going to take a closer look at it.

Nice choice on the wheel swap! I agree, I don't much like the all black wheel on mine either. I will eventually get alum beadlocks, but until then I'm gonna throw on a coat of paint on the wheels for now.

Looking forward to seeing more!

[tigris99]

Nice work!

I saw where rubbing could be an issue as well. My treal wheels came with 2 different offset hexes so went with the wider ones.

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[OnTheTrail]

I just watched a YT video where he said the bearing kit for the TRX-M made a big difference and even helped the front wheel binding issue as well as smoothed out the low speed control. I'm going to guess the aftermarket will make a steering tie rod out of metal with clearance reliefs for the tire lugs as well.

[Gramps]

RC Review just dropped a video showing that putting bearing in the front will stop the binding. I went a head and ordered the Fast Eddy bearing kit for mine. I don't intend to take mine apart to install the bearings as required.

[Gramps]

Ive seen a lot of reports on YT about the the front wheels clicking at close to full lock and causing the wheels to be jumpy. Mine did this when I purchased it, part of the problem was the tires catching on the front links which was cured with some 1.2mm hex shims I made and 3D printed. I use Purple Extreme which is a synthetic lube mainly used on bike chains. I like it because it dries and does not attract dirt been using it for years to lube the suspension part on my RC's. Also use it on driveshafts and cvds. Put some it the cvds of the TRX-4M a couple of days ago. Today after watching RC Reviews video about the problem I decided to see of mine still did it. To my surprise mine run as smooth at full lock as they do straight ahead. Maybe I wasted money on the bearing kit.

[Gramps]

Been enjoying the heck out of my TRX-4m on my indoor course wish it was warmer so I could play on the rock course. I haven't installed the bearing yet but after lubing the cvd's with Purple Extreme I have no binding when turning from lock. to lock.

From day one I have always thought the TRX-4m should have an interior. So I sat down in front of the computer and drew one up and 3D printed it. Took 6 versions to get it to the point I was happy with it.







Adds 40g of high weight not sure how it crawls yet

The interior is available for download at Cults3D

[DirtMerchant]

Gramps, nice work on the interior. This is the first one I’ve seen.

[B-MOW71]

Interior looks great!

The link to the file doesn't seem to be working.

[Gramps]

Originally Posted by B-MOW71

Interior looks great!

The link to the file doesn't seem to be working.

I took it off line temporarily while I fix it. Discovered that the rear body latch wouldn't catch all the way. It should be back in a day or 2

[B-MOW71]

Originally Posted by Gramps

I took it off line temporarily while I fix it. Discovered that the rear body latch wouldn't catch all the way. It should be back in a day or 2

Oh ok. Wasn't sure if you knew about it. I'll check in a couple days.

[Gramps]

Originally Posted by B-MOW71

Oh ok. Wasn't sure if you knew about it. I'll check in a couple days.

v2 is on the printer now if it works out I'll put it back up with the new files. I'll post up after I upload it.

[Gramps]

Discovered something interesting tonight, the rear wheels on my TRX4m were loose but the wheel nuts were tight. Removed the wheels and put the 1.2mm hex spacers on the back too. Now the wheels will tighten with the wheel nut. The wheels I have are Treal not sure if this pertains to other 1.0" wheels haven't tried any of the others I have.

This are the shims I used. https://www.printables.com/model/317...x4m-wheel-shim

[Gramps]

Originally Posted by B-MOW71

Interior looks great!

The link to the file doesn't seem to be working.

The link should be working again. I just uploaded the revised version

[B-MOW71]

Originally Posted by Gramps

The link should be working again. I just uploaded the revised version

Awesome! Thank you!

This will give my printer something to do during the long weekend!

[Gramps]

Originally Posted by B-MOW71

Awesome! Thank you!

This will give my printer something to do during the long weekend!

Thanks, your printer won't be busy long it about a 3 1/2 hour print.

[Gramps]

I tried 2 different sizes of split rings and some jump rings, basically half a split ring. I could either not get them into the slot or if I did I didn't like the way it fit. So I figured I'd try some hot glue. It works more or less t I'm not sure how well it will hold up on the rocks. I'm almost thinking that shrink wrap that is good an tight would be better. I also have the idea of taking some braided fishing line and wrapping it around till the slot is almost full then securing it with some CA glue.

[Ynad]

Well, that works. Key chain ring in 9mm size fits tightly. Got that on mine. Also paper clip steel wire is comfortable to mod with and comes in various sizes.

Nevermind, just realized you already know that.

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[hnoroian]

Originally Posted by Gramps

I also have the idea of taking some braided fishing line and wrapping it around till the slot is almost full then securing it with some CA glue.

What about safety wire with a twist or two, heat shrink over that to make it a bit more smoother? It could be removed and no damage from the glue.