Building and HEMTT TRX-8

[Ekarius]

Hello together,
my name is Peter and I’m from Germany. So I apologize for my bad english already.
I’m pretty sure you are wondering what a german guy wants in an US forum.
Well, I’m on of the last german diploma mechanical engineers and I designed something that I want to show the world wide TRX fans. Not only the german ones.

What will this be here. This is going to be a building report with detailed informations what I did.
The TRX-8 is driving already so be excited.
To raise your appetite check out my youtube channel:
https://youtu.be/YGYHzZTwWdU

[Gula]

Das erste video sieht aus, als man das mit einem taschenrechner aufgenommen hat.

Post ein paar bilder hier auch, vielleicht ein build thread?

[OnTheTrail]

That's amazing Ekarius! I always wonder about a TRX-6 converted to an 8x8. Love to see the details on how you did the pass through on the front axles. Great job. Hope to see more.

[Ekarius]

Yeah the videos are made with my phone, not the best.
Think my acount was not activated yet. I can't post pictures or I don't find the button

[Ekarius]

Till I find out how this works you can watch the TRX-8 delivering a parcel
TRX-8 parcel service

[xagoras]

MonsterHopups? Nice touch. I had a lot of things for my TRX-4 from these guys. Good prices and speedy service.

Nice project you have there. Keep it up

[Ekarius]

Hello together,
Thank you for your responses and interest. Amazing!
I was busy in real life, so it took me some days to really start here.
How all begun.
Middle of last year I separated from my girlfriend and together with the hard corona measures here in Germany this was a pretty hard time. I was looking for something to occupy my mind. On day I visited my best friend. And he showed me his new RC car. An TRX-4 with Bronco body. I never saw this kind of RC cars before. I was very excited, especially about the off-road qualities with the lockable differentials. Fascinated about this small piece of great engineering work it took only two more weeks till I bought myself a TRX-4 with the Landover body. I also have a kind of private crawler park 2 minutes next to my flat. Perfect conditions for that hobby! This is where I recorded my videos and made most of the pictures.



Of course I started customizing my baby, improved it’s off-road capabilities and did some scale stuff on the body and some lights.
Then one day I was sitting on my couch and truck trial reached my mind. I started watching some videos on youtube about 8x8 and like always I wished I could have an 8x8 as an RC car. The idea was born. I started investigating the Trx-6 more closer, the explosion drawings where very helpful. And in then a plan formed in my head how it could be possible.

Chapter one – A Plan how to do it
Like I said I first did an intensive study of the explosion drawings of the Trx-6
Main Questions that I had to clarify:
How does the output shaft on the midle axle work and could that be used for the frontaxle?

• It is solved with an special diferential gearbox cover, it can be ordered separetly

• Rotating direction oft he output shaft fort he additional frontaxle would be opposite then if I use the original one as the second frontaxle. The original one can’t be used. The Trx-6 back axle has a mirrored differential, compared to the middle axle. That’s how both axles rotate in the same direction

• To use the back axle as a second front axle is also not possible because of the wrong connection points for the suspension.

Solution was to design the second front axle on my own with mirrored, or in my case rotated diff gearbox housing. The goal was to do it plug & and play, using only my axle. All other parts should be original and without any modifications to make it work well.
But how to get these parts then? For that I bought a 3D printer. As I work with CAD every day at work, I would say I have very deep knowledge in that, but on the other side in 3D printing this is all completely new to me.
I also needed to get this new axle mounted to the Trx-6 that I used as a basis. For this I designed a kind of connector part for the Trx-6 frame to another Trx-4 frame. This connector contains all needed mounting points for the second axle, as well as a servo holder to shift the differential of the second axle. It has full functionality. With using another Trx-4 frame I also could use all original suspension parts, also the mounting of the steering servo is completely original.
Here is a picture of this axle in CAD and from an 3D printing company.






This is the complete module with an axle printed on my own


I’m going to go into more detail on the axle….
Greetings Ekarius aka Omnius Allgeist


almost forgot my new video
https://www.youtube.com/watch?v=_bmdmEtqLGM&t=12s

[Rav3n]

Hi Ekarius

Fantastic effort! i wish i could see more! But your youtube video/channel is private? :(