MB Trac - German tractor

[Balrog]

Hi everyone.

Today I want to present my latest build. It is a Mercedes Benz Tractor. The famous MB Trac. The design is not by me. It was made by arhthra08/ vttdirty08. He also provided instructions in his brickshelf folder.

I was in search for a tractor that had 4 wheels of the same size. Now if you go searching for a vehice like this, you will most likely find the Claas Xerion and the MB Trac. But nothing much else. Also I looked around to find some probably ready instructions. Now I found the MB Trac including instructions from arhthra08. I looked through the instructions. I knew, I wouldn't build it in yellow (since I have not many yellow pieces yet), but I could build it in red. So I did that. And since I couldn't find any evidence, that it has already been presented here, I thought I'd share my own version.

The tractor features the following:

- all-wheel drive

- 4-cylinder inline engine

- suspended and steed front axle

- steering via HOG

- openable hood and doors

- rear PTO

- rear PPTO

- trailer hitch

- pneumatic drawbar for attachments.

First, I made a digital model in LDD. Not visible in the pic are most pneumatic parts. I just skipped them (except for the big cylinder). That showed me the progress of the build and later enabled me to make an approximately correct parts list. Here is a render:

So far so good. When I had the digital model finished, I could create the parts list. Easy. I just had to upload the .lxf to Rebrickable and include the rest of the parts I missed out. But since a large portion of my parts was occupied, with my version of Crowkillers DS2, I had to disassemble that first. But last weekend I pulled through. On Saturday I pre-counted the pieced and began the building, finishing on Sunday afternoon. I was so eager to go on, that I even built a trailer. So here are some pictures.

I know the roof is orange. You are allowed to laugh. But I yet have the panel only in orange or grey. And I wanted to keep the grey for the trailer. Also, please forgive me the ill-coloring on some spaces. But, once my BL orders are here, I will finish this properly.

On the next pic, you can see the trailer attached to the hitch, completely with PPTO attachment and drawbar.

And finally a pic of the trailer.

I know the trailer is nothing fancy, But I like it. It was build spontaneously and I managed to make a sturdy frame and even a pneumatic linkage that works. It is operated from the back of the tractor, since only one hose is attached. Though, I am not yet satisfied with the angle that the bed can reach. I will need to turn the pneumatic and linkage around to make it better.

So this is it for now. I am very happy with the result for now. There are more pictures available in my Brickshelf folder (once moderated).

I am not finished yet with this. I am currently highly motivated due to this build. To be frank, I planned to build Crowkillers Porsche next. But, this came inbetween and I will stick to it for now. I made some Bricklink orders to mainly supplement my inventory for the Porsche, as well as a re-build of the DS2 and the Vampire GT later. But I also purchased some parts for the MB Trac. As you can probably see on the bigger pictures, it is lacking the front logo. It also lacks some smaller parts.

So what am I going to do to this MOC? Plainly I want to rebuild it entirely (once I have all parts). I already fixed the loose gear rack of the steering. Also I put a handle on the small pump and changed the hose layout, so I only have a single PPTO. I found a fault when steering to the maximum where the inner wheel won't turn anymore and want to fix that. I also want to widen the center chassis and incorporate a more complex gearbox and include power functions to have the PTO motorized and a motorized compressor. From my estimates, there should be enough room for this with the given dimensions. And I want to build some more attachments and tools.

Todo:

- fix error in steering where inner wheel won't turn when steered to the max.

- fix colors

- include motorized PTO

- include motorized pump

I will update this thread when I have made notable achievements.

Also, I want to give 'making instructions' a try. But that will not happen after I finished the Todo list.

I hope you all like the model so far. Thanks again to arhthra08 for making the original instructions and building it. If you have hints or ideas I could use, please let me know. Also, I welcome all comments and criticism (as long as it is not about the colors).

Update #1

Update #2

Update #3

Edited May 11, 2013 by Balrog

[AndyCW]

I like it. It is important to me to always have a list of improvements to make to our creations. I do the same thing and it allows me to continually push forward with concrete objectives.

Are you going to remote control the whole assembly? Autovalves would help in this.

v/r

Andy

[Balrog]

Are you going to remote control the whole assembly? Autovalves would help in this.

Since I do not have any PF parts for remote control yet - no, I simply can't.

[Zerobricks]

Its a relly good and detailed model-something Lego could do!

Can you share the LDD file?

[Balrog]

The .lxf can be downloaded here!

Please note, that the round 1x1 trans-clear plates should originally be 1x2 trans-clear plates. The position for the pump and the switches can be easily reviewed in the original instructions.

[Someonenamedjon]

Great job! I like how you did the trailer hitch!

[Balrog]

Thanks for the replies and compliments.

In the meantime, I received the most of my Bricklink orders and I was able to update the tractor a fair bit for details.

Mainly I properly replaced parts on the roof and the rear fenders. Now it is properly colored there. I guess the rest will be made properly, when I rebuild it.

Again, please go to my Brickshelf folder for more pictures after they are moderated. I really like these outdoor shots. Hopefully I'll get ahead with equipment, so I can put the tractor to labor

I also worked on the trailer. But I have no new pictures yet. It works better now, but I still have to improve the mechanism a bit.

Edited April 26, 2013 by Balrog

[Technic Gearhead]

It looks fantastic color corrected so to speak.

Very nice tractor indeed - good work!

[Someonenamedjon]

It looks fantastic color corrected so to speak.

Very nice tractor indeed - good work!

Agreed!

[Balrog]

I just played around with a LDD. I can fit the battery box. I can fit the motor. Only thing to solve is the pneumatic pump. But I have an idea already. This is gonna be so cool if I manage to work all that out. Well, I have to re-work the whole center, but that is worth it.

Stay tuned.

[Balrog]

I have some pictures of my progress for you guys.

On Sunday, I tried to build a replica of the center structure and including the motor, gearing and the mounting point for the pump. I had prepared it in LDD and wasn't really satisfied, but the idea was good already.

The geartrain worked as expected. And I could also mount the first half of the pump well (the two 2L thin liftarms).

But the whole thing wasn't very stable, since I had to leave out some of the main structural liftarms. So I discarded the idea.

Again I looked at my finished model, these pictues and my digital model, until I realized, that I could mount the motor higher. This time I took LDD and tried to do it properly there. For now I haven't had the chance to build it, but I want to share the results I got.

Here you can see the motor being mounted. It is well hidden behind the steps for the driver. You can also see some of the gears. The motor is not only attached to a liftarm I have placed additionally, but also through some technic bricks below.

In this next picture, you can see the "pump" and it's mounting. Again I used the 2L blue thin liftarms for the driven side. The other side is sitting loose on the axle that drives the motor through a Liftarm 1 x 2 Thick with Pin Hole and Axle Hole. I had to lengthen the motor axle, but that was no problem. I additionally reinforced it's other end, so it won't experience to much bending. At least I hope that.

And finally, how I want to mount the battery box. Please note, this is just preliminary. I will propably change how it is mounted. But it will most likely be somehow like this.

I didn't change the gearbox directly. Currently you have to use the pump by hand and the gearbox is driven when the tractor is driving. If you raise the lever to enable the function, the rear PTO will move as you drive around.

I disengaged the rear PTO from the drivetrain. The PTO is now always running, when you switch on the battery box. And the gearbox works in reverse. So the axle with the driving ring stand still. When the driving ring engages the gear, the axle starts moving. And now when you rise the lever, the pneumatic pump will be driven. Perhaps I should make a video or two to explain all this.

So that's it for now. It turns out to be serious engineering what I am doing here. But it is so much fun.

Please stay tuned for more updates.

[Balrog]

Long time no update. Well, I was pretty busy. In the meantime I have built my motorized version of the MB Trac. But before I show it off, I want to show you guys a video of the unmotorized version.

More pictures and a video of the motorized version will be available soon. Hopefully we have good weather tomorrow.

Edited May 11, 2013 by Balrog

[Traktor]

Great tractor, I could recognize it right away. I have one comment on the drawbar, I you want to keep it realistic it should not be flexible, since the hitch on a real tractor actually carries 1/3 of the trailer weight. The get the right angel you should rather have a flexible bogie on the trailer.

Edited May 11, 2013 by Traktor

[Balrog]

Great tractor, I could recognize it right away. I have one comment on the drawbar, I you want to keep it realistic it should not be flexible, since the hitch on a real tractor actually carries 1/3 of the trailer weight. The get the right angel you should rather have a flexible bogie on the trailer.

You are right. Now that I have thought about it, that totally makes sense. I chose to make it flexible, because of when you drive over angled surfaces, so the wheels stay on the ground. I will change that anyway. The trailer was just a quick build and since I finished the tractor, I can now concentrate on the attachments. When I fix it, the angle of the hitch should be ok so the trailer stays straight. I wasn't satisfied anyway, because the hitch was always pushed down because of the pneumatic hose. So thanks for pointing that out.

[N-4K0]

This MOC is awesome, I've just started building my own version

[Junpei]

Thanks for bumping this topic, I somehow missed it. Great job on the tractor, the linkage in the back looks very complicated! Will you post a video of the motorized version?

[Balrog]

Oh I already forgot to post the video :D Still have to compile some of the files.

Beware, the front axle is not very optimal. If you find a proper solution, please let me know.

[jantjeuh]

I missed this one as well, looks pretty cool! Wouldn't mind some instructions (or loads of pictures) when you finish it ;-)

[Balrog]

I missed this one as well, looks pretty cool! Wouldn't mind some instructions (or loads of pictures) when you finish it ;-)

There are some LDD files for the different versions in my Brickshelf folder: Balrog's Brickshelf

And there is a step-by-step picture guide in arthra08's Brickshelf (though only for the manual version): instructions

[N-4K0]

It's been going slowly with me lately. I built mine in maybe 3 days, but had to do a BL-order for the parts I didn't have.

Today I put the finishing touch on it. I've made some modifications from the original MOC given in the first post, but otherwise it's the same.

I've put mirrors in front of the doors, added some pieces to make a lock for the hood when it's down, and otherwise some minor adjustments like placing the air filter on the left side in the position where the exhaust pipe is on the right side, and replaced the connectors making the diagonal edges of the cabin with axles.

I've put 1 half-bush on the inside of the wheel rims to get the tires a bit further out, as I experienced that the tires touched the frame of the tractor when fully turned.

[Balrog]

It's been going slowly with me lately. I built mine in maybe 3 days, but had to do a BL-order for the parts I didn't have.

Today I put the finishing touch on it. I've made some modifications from the original MOC given in the first post, but otherwise it's the same.

I've put mirrors in front of the doors, added some pieces to make a lock for the hood when it's down, and otherwise some minor adjustments like placing the air filter on the left side in the position where the exhaust pipe is on the right side, and replaced the connectors making the diagonal edges of the cabin with axles.

I've put 1 half-bush on the inside of the wheel rims to get the tires a bit further out, as I experienced that the tires touched the frame of the tractor when fully turned.

Do you have some pictures of your changes? That would be nice.

I know about the issue with the wheels touching the chassis. More concerning would be, if your front axles do bend as mine did. Or if you found a solution to that apart from increasing the width of the axle.

[N-4K0]

Moving the tires further out with a half-bushing is the only thing I've done with the front axle.

If I take some pics, will I have to upload them to BrickShelf or any other website before I can post them here? I've done pretty much nothing such before. It would probably be a disaster

[Balrog]

If you use Bricksafe, you can deeplink automatic resized pictures here easily.

[N-4K0]

Do I need an account on BrickSafe to upload pics there? I doubt I'll be doing such very often, so I dunno if I should bother with it

[Balrog]

Yes you need an account.