Systems tractors and other machinery

[1gor]

After several months of Lego neglecting, today I had some hour time to try something...since LEGO introduced Zetros I had an idea to switch my models to smaller (1:18) scale. First step was Unimog U423 which was fully manual model and presented here. Next on schedule is Fastrac. So far I managed to make drive with two XL motors with total reduction of 12-20 and 12:28.  If someone remember some 2 months ago I have found solution for 87.5mm tractor tire, but now it is 90mm  (probably old 24 x 43 tire stretched a bit since I almost broke my fingers when pulling 81 x 35 tractor tire with 24 x 43 inside on 43.2 x 26 wheel Technic racing small; digital Werner scale or caliper still measured Xerion tire - 107mm). As always main challenge is to fit everything in small space and make it stiff enough. So far it looks like this (wheelbase 22 studs):

As you can see pets blanket is used as background.

Any comment, suggestion, critic are as always welcome.

And this time it will be biggest 8330 instead of 4220 Fastrac.

[Jundis]

Looking forward to this! I was wondering when the first MOC of a tractor with this tire combination would appear :D

Did you use full suspension for you previous tractors also? I'd stick to stiff rear axle, maybe I try to make a suspended cabin in my next one...

[1gor]

1 hour ago, Jundis said:

Looking forward to this! I was wondering when the first MOC of a tractor with this tire combination would appear :D

Did you use full suspension for you previous tractors also? I'd stick to stiff rear axle, maybe I try to make a suspended cabin in my next one...

New chassis is a bit for optimist class (94mm work with it if they would ever be released). That is the reason for transverse position of XL motors (somehow in this configuration I don't have this effect of power oscillation...like when configuration is longitudinal - some people use stronger non-Lego parts due to much higher torque from XL motors in order not to twist axles). Chassis would be fully suspended like on all Fastracs and there will be front steering only. My 4220 has the same type full suspension; both front and rear. Even Syntrac is fully suspended, but a bit to wide and one PF Servo is working from time to time (probably wire issue). Due to last problem, I'm rethinking about using m-motor for steering on Fastrac. This 8000 series will having battery box just over motors, so when kitty will allow me next free hour I'll look what to make from front chassis part and axle; goal is to have as stiff as possible solution with least possible parts... Before planning was really hard for me, but upcoming year 2022 will be the most difficult in my whole life...

Nice to have some support in my projects 

Kind regards

This my old project uses front suspended axle and suspended cab over stiff axle.

https://brickshelf.com/cgi-bin/gallery.cgi?i=6270640

[1gor]

Little update; rear axle is mostly done (need just to implement 3 point hitch) and overall width over rear tires is 18 studs; real machine has overall width from 2550 (with rear 710/70R38 tires) to 2850mm (rear tires 710/60R42 to 900/50R42) for 1:18 scale.

[1gor]

After testing solution posted above is clicking when driving forwards, so I had to make stiffer solution and only possibility was to use new differential from 42109 set in the middle with reduction 12 : 28. Only problem is that I'm missing one (at least) such differential for rear axle.

To have 18 studs chassis width (to make proper width for 1:18 scale; real tractor has 2550 mm wide chassis), I'll use plates at the side of XL motors...

[1gor]

Since I could not (yet) make some narrow enough chassis for 1:18 scale JCB Fastrac 8330 (and can not use 42099 hubs), I have decided to reconstruct Fastrac 4220 in 1:15 scale using 2 XL motor for propulsion. 

As there is a topic for combining motors by @CharlesD I'll use my topic to present current state of this project. From PF XL motors I use 36 to 12 tooth gear upgearing and then 12 to 28 (new differential from 42109 set) as you can see on images below.

at the end there will be planetary reduction hubs from 42099 set

Edited February 25, 2022 by 1gor

[Jundis]

10 hours ago, 1gor said:

From PF XL motors I use 36 to 12 tooth gear upgearing and then 12 to 28 (new differential from 42109 set) as you can see on images below

Could the mounting of the motors onto the black connectors result in some displacement/misalignement by torque and therefor cause friction on the middle axle?

I am not that experienced in electric components, so I could be wrong.

[1gor]

38 minutes ago, Jundis said:

Could the mounting of the motors onto the black connectors result in some displacement/misalignement by torque and therefor cause friction on the middle axle?

I am not that experienced in electric components, so I could be wrong.

Johannes, I have reinforced them with liftarms between black connectors and dark bluish gray ball joint, I have tested this solution on mule, so next step will be making axles. I'm still disappointed because I could not make 1:18 scale models...

[Jurss]

With this gearing this would be really fastrack.

Some 6 years ago I started project building Valtra NX type tractor (with lot of steerign possibilities). And I abondoned that project, as technically it was too hard for me (some 5 steering modes). I thoght about some gearbox at that time, to implement all those steering modes. Now, as there are all those tractor tyres, also powered up hub etc., I thought, that it is time, and I will try to program all those modes. But it seems for me, that in best case I will be able to create just some POC, as I can't just nicely fit some 3 motors (one for drive, two for steering) and that hub in that tractor. OK, if I abondon front swing axle and put hub inside cabin, then maybe.

[1gor]

@Jurss using planetary reduction hubs from 42099 set will make it slower. Since XL motors spin at 220 rounds and L motor spins 315 rounds, this version will be slower than last; despite I have to save PF servo motors, so I switched back to use only one servo motor in this version 

[Ngoc Nguyen]

Tractors, anyone?

 

 

[1gor]

IMHO Deere is to expensive even as parts pack ...

[whitepen]

14 hours ago, 1gor said:

IMHO Deere is to expensive even as parts pack ...

Unfortunately so.  

[1gor]

On 2/25/2022 at 7:35 AM, Jundis said:

Could the mounting of the motors onto the black connectors result in some displacement/misalignement by torque and therefor cause friction on the middle axle?

I am not that experienced in electric components, so I could be wrong.

I hope you can see the way I "reinforced" chassis part where gears are with liftarm 1 x 5 and this connectors https://www.bricklink.com/v2/catalog/catalogitem.page?P=63869&idColor=11#T=C&C=11

View from above where you can see main structure.

Next step will be rear axle (or main part with steering and m-motor for rear pto and stairs after that. I just hope that I'll be not playing catching my younger cat who steals beams and run with the all over house...

 

 

 

[1gor]

There were some quiet times with my projects, but I can (so far only) post idea how to use portal axles (or other compatible wheel hubs) with futuristic wheels...

@Jim and @Milan I wasn't sure if this is appropriate for General part discussion tread, so I have posted in my tread. If you feel that this solution could be interesting to wider public (than those who peek from time to time into my tread) feel free to copy this post into General part discussion tread.

Edited July 6, 2022 by 1gor

[Jim]

Go ahead and copy it there if you want to.

[1gor]

16 minutes ago, Jim said:

Go ahead and copy it there if you want to.

Ok; I'll make shorter post with link on gallery where those images are hosted.

Thanks buddy

[1gor]

Small progress on 1:18 JCB Fastrac 8330 project; I have switched back to 2 L-motors with reduction 20-28 (using 3 differentials from 42109 set). Overall width over front tires is about 18 studs and rear is about 20 studs (real Trac has from 2750-2900mm width when using 710/60R42 or 900/50R42 tires at the rear).

There is a big chance that I copy solution from 8284 set because even small linear actuator looks to big here

[jorgeopesi]

We have a very good work here, it is a very narrow MOC as the real one is. What do you think about doing it a couple of studs wider?, I do not like too much the idea but sometimes we have to loose a little bit the scale to gain space and have a better MOC, anyway we both know that almost nobody look the machinery width.

[1gor]

@jorgeopesi my goal was to make correct proportions. If I add 2 studs at the front I'll be able to use hub reduction, but it will be way to wide; only way to accomplish it to make somehow appropriate is if  LEGO would make defender wheels in yellow. I could make a bit wider chassis when I finish this model. 2 studs wider will make 20 studs width which would corresponds 2880mm width (for 1:18 scale).

 

[Jack_Moore]

am I the only one that has an extremely difficult time finding those small chain pieces?

[1gor]

32 minutes ago, Jack_Moore said:

am I the only one that has an extremely difficult time finding those small chain pieces?

Small chain pieces? Can you please explain more detail?

[Jundis]

You beat me again with using the zetros tires for front axle on a tractor :D

One question: What is the linear actuator on the rear hitch for? Only as an movable connection point?

[1gor]

Just now, Jundis said:

You beat me again with using the zetros tires for front axle on a tractor :D

One question: What is the linear actuator on the rear hitch for? Only as an movable connection point?

Johannes, don't cause yourself headache anymore; linear actuator was meant for raising/ lowering implements, but I have switched to more compact solution like on 8284 set, but instead 24 tooth I use 8 tooth. Trust me I would be very happy if Lego made just 2 things - yellow Defender wheels and tractor tire 94 x 40 to fit between Zetros tire and Xerion tire, so I wouldn't need to stretch Zetros tire to approximately 88mm to fit standard front tire (540/65R34), and could make harvesters that would fit the scale 1:18.

Prototype for 4 wheel drive using non-modified Zetros tire and Xerion tire I made last autumn but Orion (cat now 12 months old) was very little and I could not do anything more for next half a year. I hope to finish cab soon (from Friday due to rain I'll have some free time for it) and then the bonnet similar to one on 4220; only 13 studs short and more narrow at the cab. And as you can see it is full suspended tractor.

[1gor]

On 7/11/2022 at 6:36 PM, jorgeopesi said:

We have a very good work here, it is a very narrow MOC as the real one is. What do you think about doing it a couple of studs wider?, I do not like too much the idea but sometimes we have to loose a little bit the scale to gain space and have a better MOC, anyway we both know that almost nobody look the machinery width.

This one indeed looks a bit wider overall (both front and rear)