Traxxas TRX6 to Unimog conversion using Axial UMG10 body

[Cuiken]

It's been done a few times before but there's rarely much method covered in any of the posts I've seen so thought I'd cover it here.

Firstly, why? The TRX6 is great fun but the body is very more 'mall crawler' than 'crawler'. It's just not my thing. Okay, why not buy the actual Axial Unimog 6 wheeled crawler? Two reasons, it's not as good at the TRX6 and it's not nearly as good looking as the 4 wheeled UMG10. Okay, nothing too subjective there then Let's move on.

I bought a used TRX6 last summer. It's good crack but, like I say, I reckon it's pretty ugly. I did a ton of cosmetic mods to mine but I still don't love it. The 'finished' result is shown below, forgive the dust. I've not been out with it for a couple of months:

Summary of mods: Trimmed the mudguards, trimmed/removed the bogging front and rear bumpers before a rock did it for me, added vanquish bumpers front and rear, lowered the body mounts, added sheet aluminium in the rear 'bed', added a cheap interior and stuck on a few bits of scale trim.

It works much better (doesn't get hung up constantly) but I still don't love how it looks.

After a bit of 'youTubing' though I found these and decided a more utilitarian Unimog styled design really appealed to me:

Both of these appear to have been built around the Axial UMG10 body so I gradually accumulated all the parts needed. Getting parts was a challenge, Axial only seem to release one of the four body parts at a time (cab, rear cage, rear sides, interior). I actually haven't been able to get an interior but I'll either use a cheap generic one or just smoke the windows. Either way, I have enough parts to kick off the build.

Basic proof of concept:

Literally balanced the cab on the chassis. Immediately liked how it looks:

Started assembling the cab (I'm planning to use the hidden body mounts) and trimmed off some of the rear cage to get it to fit:

Test mounted the cab, rear and sides onto the chassis:

Finally added the 'visor' from the original Merc shell. This does give it a slightly less 'scale' look but also gives a bit of protection to the front of the cab. I'm 50/50 on it for now but I've drilled the holes so it's already a keeper

I think it will look a bit more 'balanced' once the cab is painted.

It all fits together surprisingly easily. The front body mounts should screw onto the chassis rails with a small amount of modification and I think I should be able to get the rear cage to mount to the chassis mudguards without too much fuss. The front of the cage sits neatly on the chassis so it's all pretty robust.

Updates to follow.

 

[Cuiken]

Okay, bit of an update:

Got the body assembled, disassembled, masked and sprayed.

For the cab I went with Tamiya orange backed with black with the wheel arches and bonnet highlight masked during the orange coats. I then cut and peeled away the overspray film and added a coat of matt lacquer over the black areas on the outside of the shell.

For the rear I went mainly black with the diesel tanks sprayed on the inside with Tamiya red and then backed in black.

As usual I failed to apply enough coats of colour before spraying the black backing. If I'd wanted the orange and red to really 'pop' I should have done a couple more coats (I did 5 think coats) or backed in silver and then black. The result is that the orange and red look darker and murkier than I'd anticipated.

That said though, I think I accidentally got a better result than I was planning for. The slightly dowdy orange colour looks spot on for a Unimog and the darker/shadowed areas serve to pick out the body shell detail and give it a slightly grimy appearance. The fuel tanks look fantastic, almost like they are coated in a film of dirty diesel. So, got lucky basically.

I then cut a sheet of scale checker plate for the rear bed which I think looks properly good.

Here's a few shots:

Obvs the spare wheel is not yet mounted but there's an easy spot to run a bolt so that should be pretty trivial.

Only bit that required any thought was how to mount the body. Here's a couple of photos to help explain:

The Axial UMG10 uses these downward pointing body mounts that fit through a couple of mounts screwed to the rails at the front of the truck:

Unfortunately, the rails sit a fraction lower on the TRX chassis so I needed to figure out a DIY mount. Ultimately, dead simple, just an aluminium plate bolted to the front bumper with a couple of holes drilled to accept the body posts:

So, the body posts (shown below with clips inserted) just pop through those holes and the front is sorted:

The rear was a little fiddlier as the UMG10 body actually hinges off the back of the chassis. This is not possible on the TRX. So, instead, I trimmed the cag down (as shown previously) and added a pair of downward pointing body posts (these are the incredibly useful Traxxas 3727A mounts).

These body mounts then pass through a couple of holes that I drilled in the TRX chassis' built in mudguards and clip from below:

Not a lot to it frankly but a bit fiddly getting everything lined up.

Looking again at the photo below I think the rear bumper is too wide and sits to far back. As a general comment, even with most of the TRX6 shell's bumper trimmed off and the original chassis bumper replaced with the Vanquish one, it still got hung up all the time.

So, I'm going to remove about 1.5cm of the chassis rails at the back and pull the bumper further in. I'll then trim the width down to better suit the Unimog design (I think the UMG10 actually tapers to a very narrow bumper).


Not sure what is next with it after that. Possible ideas:

1. Mount the rear wheel. Do I want a matching wheel to the rest of the truck or is it better having a mismatched spare? I'm undecided.

2. Throw a bit of scale luggage at it.

3. Add a longer rear bed over the back of the chassis? Again, I'm not sure. the exposed chassis looks pretty good already.

4. Do I want to add a sound box to emulate engine noise? I have always thought they are pretty cheesy but I think it might work on this rig.


Any thoughts/ideas welcomed.

 

[smc-93]

I'm one of the oddballs that likes the G63 body. However, these UMG/TRX 6x6s I keep seeing look awesome, yours included.

The main thing hold me back from doing something similar is, like you said, parts availability (and several other projects I need to finish). I can never seam to find everything at once and never end up buying them one at a time.

Sent from my LM-V600 using Tapatalk

 

[Cuiken]

Thanks!

Yes, the parts availability is a huge pain. I think the UMG10 may have been discontinued now too (why would they do that?) so it's unlikely to improve.

Like I said, I ended up buying the parts piecemeal over a few months whenever I saw them in stock. Spread the cost a bit too

I'd have to concede that, with some fairly dramatic trimming, the G63 can look pretty good too. I just prefer the agricultural look for a 6x6. Here's a shot of my G63 'in the wild'. Sort of Jurasic Park style

 

[xagoras]

You don't have to cut the rails, to move the bumper. If you trim the plastic mount, you can turn it around to face inwards and move the bumper closer to the chassis. I've done something similar in my G500




Improves departure angle a lot. This Defender style bumper also helps, because it has different mounting positions to adjust height. Mine was limited by the opening of the truck bed's rear door, but in your rig, it could sit even higher.

 

[Cuiken]

Totally, you can do a lot without trimming the rails.

If you look below though you can see that I'd already pulled the bumper in (by modding the mount) as far as I could. Basically, the rails were pushed up against the lip of the bumper.

I tried flipping the mount but then the bumper sat really high and fouled against the inner fenders.

In the end, I trimmed ~2cm off the end of the rails and reduced the width of the bumper.

The end result looks really good to me and gives me a really nice departure angle too:

As you can see from the last shot, I've got almost no chassis rail/bumper overhang at the back at all now.

This doesn't work with the G63 shell but it looks spot on for the 'Mog.

 

[xagoras]

Nice. Looks much better now. You could even fabricate a straight bumper coming out of the rails and it would still look right at home.

 

[Cuiken]

Thanks. The photos don't quite show it (wrong angle) but the way I managed to cut the bumper gives a really nice 'taper' that follows the lines of the inner fenders.

Looks quite authentic.

I also got a matched spare on it last night too. I'll post a couple of pics when I have time.

Only remaining jobs:

1. Lights.

2. Actually drive it

 

[Cuiken]

Couple more shots showing the finished bumper in context.