[MOC] Unimog U423and U530 1:20 Scale

[Thirdwigg]

I'm about ready to upload my 100th MOC to Rebrickable, and as I thought about how I wanted to celebrate, it became clear to me that the only appropriate celebration would be another Unimog (is this getting old yet?). Someone on youtube asked me to make one using the tires from the 42122 Wrangler/42139 ATV. I was only too happy to oblige. At the start of 2022, my goal was to upload my 100th MOC to Rebrickable by the end of the year, so that's my deadline. 

Considering all the MOCs made in the scale of the Anthem/Transporter/42128, I wanted to keep it as close to these trucks as I could. The best I can tell, the scale for these trucks is about 1:20 which would put a 3000mm wheelbase with a 2200mm wide U423 at about ~18.5 studs and ~15 studs wide(I'm not doing 14) (check my math @1gor). There was a moment I thought this would fit the scale of all the Thirdwigg Farm vehicles, but that standard seems to be closer to about 1:22.

A chassis draft has been started.

It was helpful to complete the Knunckbook Truck recently, as some of the build techniques apply here (I might use the crane too). Right now I have the following:

• Steering
• RWD with portal axle (sorry @jorgeopesi does the portal axle make up for the lack of four wheel drive this time?)
• Rear suspension
• Engine
• Bed tipper
• Front PTO
• Rear/Top PTO with on/off
• Front/Rear/Bed attachment points

I am not sure about the engine right now. I tend to like the old cylinder parts even if they are a funny scale for most builds. But the 2 cylinder looks tiny here, and a 3 cylinder crankshaft messes with the gearbox and steering. I may still try an axle with stop engine yet, which will also help the reliability of the front PTO.

I'm building with intent to have some attachments, but I want to get the truck done. So we'll see what things I can add and maintain my focus.

More updates soon.....

Edited February 24 by Thirdwigg

[jorgeopesi]

44 minutes ago, Thirdwigg said:

(sorry @jorgeopesi does the portal axle make up for the lack of four wheel drive this time?)

Let me tell you when I had seen more updates but what I am seeing is pretty good so far  .

[1gor]

there are Unimogs U423 with tractor tires up to 2420mm width (wider mudguards), so math is ok. it is very challenging even in 1:18 scale, not to mention 1:20 to make proper Unimog.

looking forward 

Regards

Edited November 17, 2022 by 1gor

[mpj]

49.5mm wheels trucks are more 1:21 scale because real trucks are 2500mm wide and we build the trucks 15 studs wide = 120mm.

If the Unimog is 2200mm wide, should be 13 studs wide to match perfectly with the Mack scale trucks.

Anyway if you are building in 1:20 the scale will be very close 

The start is really promising, can't wait to see the final model! 

[Jundis]

Kyle, you're building to fast for us to comment on all of your models :D

Great start! The flip flop beams are a real blessing considering the possibilities of interconnections.

[Thirdwigg]

15 hours ago, jorgeopesi said:

Let me tell you when I had seen more updates but what I am seeing is pretty good so far  .

I hope I can keep it going in the right direction.

12 hours ago, 1gor said:

there are Unimogs U423 with tractor tires up to 2420mm width (wiser mudguards), math is ok. it is very challenging even in 1:18 scale, not to mention 1:20 to make proper Unimog.

 

7 hours ago, mpj said:

49.5mm wheels trucks are more 1:21 scale because real trucks are 2500mm wide and we build the trucks 15 studs wide = 120mm.

If the Unimog is 2200mm wide, should be 13 studs wide to match perfectly with the Mack scale trucks.

Anyway if you are building in 1:20 the scale will be very close 

Alright, I'm going to keep going as the size is close enough. Yeah it seems depending on tires and fenders, width is from 2200 to 2400 mm, so 15 wide will work for the scale. Plus going down to 13 wide sounds like a mess.

5 hours ago, Jundis said:

Kyle, you're building to fast for us to comment on all of your models :D

Great start! The flip flop beams are a real blessing considering the possibilities of interconnections.

It helps to build small. No need to comment on everything though.  Yeah, with this project, I have to keep pulling the flip flop beams from other builds.

Small update...

I rebuilt the chassis again, and the rear PTO works much better. The front mount is now strong enough, and the front frame is fully braced. The rear still needs some work, but the mechanics are placed and working fine.

I threw some body and attachments drafts just to see if the chassis hard points will work. Whenever I do these system builds, it helps to keep various components close just to make sure every tweak works with the whole package. You can see a gritter, crane, and plow mount here so far. 

[GerritvdG]

 Looks really promising. And, wow, your 100th MOC to Rebrickable  , it's both the quantity and the quality of these MOCs and most of them are free, really impressive and inspiring.

Edited November 17, 2022 by GerritvdG

[Thirdwigg]

3 hours ago, GerritvdG said:

 Looks really promising. And, wow, your 100th MOC to Rebrickable  , it's both the quantity and the quality of these MOCs and most of them are free, really impressive and inspiring.

Yeah, I guess I'm turning into a little bit of an old-timer. Glad you like the quality too. I try to keep as many Rebrickable MOC free as I can. I've received a lot from other builders, so this is my little way to give back.

I hope this project turns out well enough.

[Jurss]

I was thinking, why there won't be front axle driven, and just later realised, that this is on those smallest tractor tires.

[Thirdwigg]

On 11/18/2022 at 1:35 AM, Jurss said:

I was thinking, why there won't be front axle driven, and just later realised, that this is on those smallest tractor tires.

Yeah, I seem to making things harder for myself then I should.

OK, another update. I have all the stuff in where I want it. The transmission works well, and I added the HOG for the bed tilt in the place of the radiator. A simple fuel tank and steps are added.

We got hammered with snow yesterday, so I was inspired to work on the gritter and the plow.

I'll work on the cab tonight as I need to think about something other than the chassis, which is causing me some headaches. I tend to put in as many mechanics as I can, and the functions I have are causing some trouble with this chassis. Frame stiffness is not where it needs to be. Particularly the center of the frame and the front mount. Basically no frame rail goes from the front to the rear, and there are only one vertical braces from the top and bottom frame rail.

Second, the front mount is not helping. I have done four drafts of the front mount, and none of them are great. Also, so many gears and axles are getting in the way of the frame parts. It's a mess right now. So I headed into Studio to see if I could make any sense of the frame without the headache of rebuilding everything over and over.

I'll set this part aside for a little bit, and come back to it when I have a little more clarity.

 

Edited November 19, 2022 by Thirdwigg

[Jurss]

This scale is really challenging. But there always some solution - compromise :)

[Thirdwigg]

OK, I spent some time away from the chassis for a couple of days, and I'm glad I did. I built a front which, a rear bed, draft 1 of the the knucklebone crane, and draft 2 of both the plow and the gritter. The project is progressing nicely.

Today, I was ready to get back into the chassis, so I first continued the work in Studio. This helped, as I could play with some big parts and move all the major structural parts around the mechanical parts until I could get something to work with. I now have two upper and lower frame rails that connect to the front mount, and two side to side braces that are locked.

I then went back to the parts, built it thinking of instruction sequencing, and added all the mechanicals in. I'll need to next rebuild it in Studio, placing steps as I go.

I kept the 2 cylinder engine, which seems a little puny, but I still like these better.

It's busy here, but everything is in and braced well. The frame is not perfectly stiff, but it's about 90% of what I expect. Also, now the front mount is ridged and strong, and there is no bowing in the frame.

I did a couple of drafts for the hood, and like this one the best (which is almost the same as the larger 430). Also, I can't believe after all these orange builds, I need more parts, but here we are .... I'll do an order in the coming weeks, when the rest of the accessories are complete, and I know if other parts are needed.

OK, American Thanksgiving is tomorrow, so I'll set this aside for a couple of days, and I'll get back to it soon enough.

[1gor]

shape is coming along nicely, i wonder about front bullbar solution in this scale...

[mpj]

Very good looking model, and full of functions. I especially like the snowplow + saltspreader version.

[Thirdwigg]

On 11/24/2022 at 6:34 AM, mpj said:

Very good looking model, and full of functions. I especially like the snowplow + saltspreader version.

I agree. I have a couple more edits that I need to make for those, and then they’ll be done too. 
 

 

On 11/23/2022 at 10:24 PM, 1gor said:

shape is coming along nicely, i wonder about front bullbar solution in this scale...

Thanks, I never feel like the bull bars on my MOGs are any good. Axles always seem too big, and bars always look a little clunky. Flex tubes would be fine, but they are hard to get and replicate for other builders. Maybe someday better options will be available. 

[1gor]

6 hours ago, Thirdwigg said:

Flex tubes would be fine, but they are hard to get and replicate for other builders. Maybe someday better options will be available. 

i spent few weeks intil i got acceptable shape on my Unimog (but my solution is not stiff)

[Thirdwigg]

OK, I'm back. I finalized the built, so I was able to finish the Studio file. Everything works well in the real build, now I just need all the parts in the right colors. The steps are all set in the file as well, so instructions should move pretty quickly.

The mirrors are not perfect, but they'll work. I decided on the panel rather than brick build doors, and I'm still not sold on the rear bed arch. Also, I think I may change the bed corners from DBG to Black.

The Snow Package is done now too, but I'll need a couple more parts for this as well.

Finally, the little crane will need a little more work. I'm not sure I'll be able to get to it this weekend, but we'll see. I also have in my mind a little roadside mower as well, but maybe I'm trying to do too much. 

I'll be done soon....

[gyenesvi]

It's coming together nicely, looks pretty cool! Only thing that looks weird for me are those headrests for the seats. It looks too bulky with those backwards protruding mounts. Maybe something like the Zetros has could work here as well?

[MangaNOID]

Handsome build  

[Thirdwigg]

6 hours ago, gyenesvi said:

It's coming together nicely, looks pretty cool! Only thing that looks weird for me are those headrests for the seats. It looks too bulky with those backwards protruding mounts. Maybe something like the Zetros has could work here as well?

Let me try an another option. I'll still have a backward protruding mount because I hate when those seat panels can move, but maybe I can hide it a little through some color changes.

10 minutes ago, MangaNOID said:

Handsome build  

Thanks!

[proran]

I agree, there is no better way to celebrate the 100th MOC for you than a Unimog. BTW, I cannot wrap my head around that number. Mine is 5 overall and zero on Rebrickable in 8 years.

I am especially fascinated by this build, since I did the old U406 with the same-ish wheels. Comparing it to your build is a study in compromising. Looks aside and comparing chasis and functions, its two completely different approaches to roughly the same subject. I've focused on appearance of the functions so to say and have tried to squeeze all of it in. As a result most of them barely work. There is a ton of backlash, no sufficient torque from the wheels to drive the PTOs and the fake engine, and steering is reversed. You instead prioritized the robustness of the functions and sacrificed 4WD and front suspension. Fascinating!

Cannot to see this fully completed!

 

[GerritvdG]

15 hours ago, Thirdwigg said:

I'll be done soon....

Looking forward to the final presentation! I am curious about the gear 36 on the side, does it maybe dial something?

[Thirdwigg]

22 hours ago, proran said:

I agree, there is no better way to celebrate the 100th MOC for you than a Unimog. BTW, I cannot wrap my head around that number. Mine is 5 overall and zero on Rebrickable in 8 years.

I am especially fascinated by this build, since I did the old U406 with the same-ish wheels. Comparing it to your build is a study in compromising. Looks aside and comparing chasis and functions, its two completely different approaches to roughly the same subject. I've focused on appearance of the functions so to say and have tried to squeeze all of it in. As a result most of them barely work. There is a ton of backlash, no sufficient torque from the wheels to drive the PTOs and the fake engine, and steering is reversed. You instead prioritized the robustness of the functions and sacrificed 4WD and front suspension. Fascinating!

Cannot to see this fully completed!

 

Don't beat yourself up too much about this. There is no doubt my priorities are too tilted towards LEGO sometimes, so don't use me as your role model. Either way, yeah for the 100th, it had to be a 'Mog.

I had my kids break one too many of my MOCs that I started to prioritize sturdiness. I try to get as many functions in, and make it looks as best as I can, but if it falls apart, no go. Functions are no exception. If they can work over and over; redesign. I'm glad that even though some of the functions are out, you still like it.

If it makes you feel any better, I do really like your 406, and used it as inspiration for a couple of the parts of this build. I hope to see more like it.

18 hours ago, GerritvdG said:

Looking forward to the final presentation! I am curious about the gear 36 on the side, does it maybe dial something?

Should be ready soon.

The 36 gear on the side is the HOG for the bed lift. I'm trying to reduce the number of 12 tooth gears I use to move functions, and rather hide the levers/knobs into parts of the bodywork. This 36 gear is supposed to look like the radiator. 

[Thirdwigg]

It's a little hard to see, but are the headrests any better @gyenesvi? I can do the 1x2 think liftarms too.

 

Edited December 10, 2022 by Thirdwigg

[1gor]

it's looking nice and simple