[WIP] John Deere 8RT 410 tractor

[MP LEGO Technic creations]

Today I started to build a tractor in quite a large scale.

I haven't made a lot of progress yet but I hope some will be made soon.

Features on my wishlist:

Drive by 4 C+ XL motors

Subtractor - steering connected to the steering wheel

Pneumatic pump - 1 C+ L/XL motor

PTO - 1 C+ XL motor

Total: 2 C+ hubs - 8 motors

Some photos of the original:

And progress made so far:

Front wheels use these old round bricks:

Thank you for visiting. & Comments are welcome.

Edited March 24, 2021 by MP LEGO Technic creations

[Jundis]

Initial thought: "Uh, this will definitely be a nice application for the bigger and smaller sprocket wheel .... WHAAAAAAT!"

[MP LEGO Technic creations]

1 minute ago, Jundis said:

Initial thought: "Uh, this will definitely be a nice application for the bigger and smaller sprocket wheel .... WHAAAAAAT!"

Not a bad idea, but there wouldn't be enough space for a subtractor and so on 

[MP LEGO Technic creations]

These wheels could fit nicely...

 

[Void_S]

Is it going to be a 1:1 scale? 

[1gor]

This would be a huge scale, but looking forward to see how it will end up. I went the opposite direction - smaller scale (less parts and usually much stiffer).

Looking forward

[sm1995]

I’m getting nightmares just thinking about building those tracks 

Good luck!

[MP LEGO Technic creations]

1 hour ago, sm1995 said:

I’m getting nightmares just thinking about building those tracks 

Me either.

1 hour ago, I_Igor said:

This would be a huge scale, but looking forward to see how it will end up. I went the opposite direction - smaller scale (less parts and usually much stiffer).

Looking forward

Yes, it'll be quite huge.

Total parts number is now 1947...

 

Edited March 24, 2021 by MP LEGO Technic creations

[MP LEGO Technic creations]

30 minutes ago, Void_S said:

Is it going to be a 1:1 scale? 

Unfortunately, it isn't going to be 1:1. 

Edited March 24, 2021 by MP LEGO Technic creations

[Andman]

I'm really looking forward to see it in real life. Nearly 90 studs long! Good luck! :-D

[Bartybum]

Well that's...uh...big

[MP LEGO Technic creations]

8 hours ago, Andman said:

I'm really looking forward to see it in real life. Nearly 90 studs long! Good luck! :-D

Yes, it's going to be very large.

 

5 hours ago, Bartybum said:

Well that's...uh...big

I hope 4 C+ XL motors will have enough power to move the tractor around.

Edited March 25, 2021 by MP LEGO Technic creations

[Jundis]

14 hours ago, I_Igor said:

I went the opposite direction - smaller scale (less parts and usually much stiffer).

Are you working in this machine? I also have it on my "to-moc"-list :D

42 minutes ago, MP LEGO Technic creations said:

Yes, it's going to be very large.

As I just ordered some technic liftarms in green I just wanna warn you: The price will be astronomical for such a thing to build in technic pieces.

[MP LEGO Technic creations]

1 minute ago, Jundis said:

As I just ordered some technic liftarms in green I just wanna warn you: The price will be astronomical for such a thing to build in technic pieces.

So thank you! I plan to build it first in colours that i already have in order to minimalize use of not-so-important green parts.

[1gor]

3 hours ago, Jundis said:

Are you working in this machine? I also have it on my "to-moc"-list :D

Actually I hope to see what I can do (not Scooby doo) with new Zetros tire and decide if I'll switch to 1:18 models instead of 1:15; smaller scale is better for my Unimog U423 (cab should be 15 studs wide which makes me easier), classic US trucks could have 17 studs wide chassis with 62.4 tires, and I can perhaps make Fastrac 8330 together with smaller 4220 (based on new Zetros tire perhaps). Currently I still work on telehandler, but it is a bit of standstill because I have come to solution which is very similar to one @eric trax made on his Scorpion telehandler, but I want to have some my ideas, and it is tempting for me to try to make small telehandler with Jeep tires (I have bought one set and tires are gorgeous  )... so basically I spend more time on forum that building specially waiting for time to get confirmation on Zetros tire dimensions. As for Deere, I had few years ago made 7R model, but I'm rethinking on making this if yellow sprockets will fit the 1:18 scale...you could say it is on my to-do mocs list, but have fould that in 1:18 scale Liebherr sprockets will perfectly fit terratrac Claas Jaguar or Lexion... with new Zetros tire on rear...

4 hours ago, MP LEGO Technic creations said:

So thank you! I plan to build it first in colours that i already have in order to minimalize use of not-so-important green parts.

"Internals" could be based on frames and to cover it with green panels and liftarms

[trekman]

As you will most likely be driving the large gear racks at the rear of the machine, your loading on the motors might not be as bad as you fear.  They will have a natural reduction at the circumference, compared to driving a gear which is rotated at the centre.  However if you try to build a centre into those wheels, then it will be a different challenge.
I admire you for doing it.  My bravery is normally limited to the parts which i have.

[MP LEGO Technic creations]

10 hours ago, trekman said:

As you will most likely be driving the large gear racks at the rear of the machine, your loading on the motors might not be as bad as you fear.  They will have a natural reduction at the circumference, compared to driving a gear which is rotated at the centre.  However if you try to build a centre into those wheels, then it will be a different challenge.
I admire you for doing it.  My bravery is normally limited to the parts which i have.

My intention was to power the central axle, but I'm not very satisfied with this wheel centre.

 

[Milan]

4 hours ago, MP LEGO Technic creations said:

My intention was to power the central axle, but I'm not very satisfied with this wheel centre.

I would strongly suggest to power the outer ring piece, as Trekman suggested. Free reduction and smooth power delivery.
Powering the central axle will twist it, and the vehicle's movement will be jerky.

[Void_S]

1 hour ago, Milan said:

I would strongly suggest to power the outer ring piece, as Trekman suggested. Free reduction and smooth power delivery.
Powering the central axle will twist it, and the vehicle's movement will be jerky.

Plus to that, if the inner part rotates (powered) when outer still stopped, the tension force will easily disassemble the "spikes" made of red axles and yellow #1 connector.
I would use the liftarms (solid pinhole-to-pinhole structure), which can handle the tension forces.

Besides that, I wouldn't loose in mind the rule of squares and cubes - making the model x2 bigger in all dimensions, you will get it up to x8 heavier. It makes a huge sense for plastic parts!

Edited March 26, 2021 by Void_S

[MP LEGO Technic creations]

1 hour ago, Milan said:

I would strongly suggest to power the outer ring piece, as Trekman suggested. Free reduction and smooth power delivery.

Thank you for suggestion. This will probably be the only solution that could move a vehicle like this smoothly.

 

1 hour ago, Milan said:

Powering the central axle will twist it, and the vehicle's movement will be jerky.

That's what I was afraid of.

[MinusAndy]

You could use a pair of 57585 connectors in opposition on a central axle to give you a stronger hub connection, then drive it through the rim?

[MP LEGO Technic creations]

28 minutes ago, MinusAndy said:

You could use a pair of 57585 connectors in opposition on a central axle to give you a stronger hub connection, then drive it through the rim?

I haven't decided the way to build the wheel yet. 

But I'll remember your suggestion and test it on the wheel prototype 

[Milan]

I would also suggest to make a custom hub to hold the wheel/sprocket firmly.
For this 142mm wheel, i made, for example, a heavy duty hub, made out of two turntable pieces (one studless, one studful), to withstand the forces. It also served as hub reduction, as it was driven by 2 of the 8t gears.

 

[MP LEGO Technic creations]

2 minutes ago, Milan said:

I would also suggest to make a custom hub to hold the wheel/sprocket firmly.
For this 142mm wheel, i made, for example, a heavy duty hub, made out of two turntable pieces (one studless, one studful), to withstand the forces. It also served as hub reduction, as it was driven by 2 of the 8t gears.

Looks interesting!

[Milan]

You can attach the big turntable to the Ferris Wheel and get a really strong connection to the chassis.