8110 - Unimog - MODs and Improvements

[Imanol BB]

Well, after some attempts to make the dropping sides bed, i found that i needed a dumping system to match the real mechanism, but i have concluded that i have no space inside the chassis for any kind of pneumatic cylinder or linear actuator to do that, and because i need just a little bit of space i am going to increase the mog´s length by 10 studs, to match the long wheelbase version of the U500, and this will give me many advantages, i will be able to add a dumping system (hopefully it will be 3-way tilting), i will have much mor space in the sides of the chassis to add any decoration or functional element and with this modification, i maybe could add a rear wheels steering system, which would be good for a better maneuverability and would reduce the turning circle from 1,4m (16.8m in real life) to something about 1.2-1.1m (or at least that is the idea); i also would like to thank Didumos again for his knob wheel drive axle and the mod of the half pins he has made to it, it has reduced a lot the friction of my axle (his axle: http://www.eurobricks.com/forum/index.php?/forums/topic/131333-didumos69s-breadcrumbs/&do=findComment&comment=2669578)

Those are the plans, if you are wondering, this is the goal: https://www.the-blueprints.com/blueprints-depot/trucks/unimog/unimog-u500-lwb-2008.gif, the truck is going to be 31 studs high, 23 studs wide from one mudguard to another (24 wide for the axles with the tires), about 62 studs long (64-65 if you count the attachment points) and the scale will be about 1:12; by the way, has anyone modified the front attachment plate?, because i saw some pictures on the real mog and the lego one is very different, i tried to add a working hitch point, but doesn't look enough good:

So, if you have any suggestion about it, please let me know.

(I have realized that this is my #500 post, I AM A KNIGHT)

Edited October 14, 2016 by ImanolBB

[Imanol BB]

Small update: I think it is no longer a MOD, it is now a MOC (I think):

So far it uses 2 XL-Motors, a 2-speeds gearbox (the same one of Madoca´s tatra t813, thanks for it Madoca), and my knob wheel drive planetary axles (thanks to Efferman and Didumos), good thing about this is that possibl i will be able to add all the electrical components in the chassis, so the cab wont have any motor or receiver, i will keep working on it, wish me luck.

[Didumos69]

13 hours ago, ImanolBB said:

Small update: I think it is no longer a MOD, it is now a MOC (I think):

I agree!

So far I only see LDD-images or renders. I guess you already built a proof of concept for some parts, for instance for the front axles. Do you have pictures, or is it not ready to show?

[Imanol BB]

Yes, that is exactly what i have done, i have made a chassis in real life and here it is (sorry for taking so long, my camera is having troubles to take pictures and connect to the computer):

This is the chassis when it has no load:

An this is it with a payload of 2.5 Kg:

Note that with this load, the chassis is lowered by 1 stud, but 0.5 studs is for the chassis bending and the others 0.5 is for the shock absorbers being compressed, so is not bad

So, i feel satisfied with the result, because for such big chassis (65 studs from the attachment points to the others and 47 studs from the front absorbers to the rear ones), 0.5 or 1 stud of bending is not very bad and there are still more reinforcements to add, and despite being very robust, this chassis is still flexible enough for some torsional bending, just like the real Unimog, i will post more pictures soon (if my camera doesn't die), i hope you like it.

Edited October 5, 2016 by ImanolBB

[Didumos69]

Looking realy cool so far! And indeed I think half a stud bending under 2.5kg load is not bad at all.

About the torsional bending in the chassis. Do you have some background pointers on that? I would like to know more about it.

Edited October 5, 2016 by Didumos69

[Imanol BB]

Yes, i have made some test for that too:

I have put 2 vertical pointers, one in the front and one in the rear, when the chassis is on a flat surface, both pointers are aligned:

Only with the weight of the chassis and even with the axles locked in place (they aren´t moving at all, like if they are fitted to the chassis), the chassis bending is able to get over 2 studs in the front right wheel and 2 studs in the rear left wheel, the total chassis bending is about 5 degrees (maximum without any additional weight,): Note that rear right tire is already taking off from the ground

But if i add only 1Kg of weight, it is able to climb over a maximum of 4 studs on each wheel, and this is only with the bending of the chassis, no axle movement yet, and it has about  20 degrees of bending:

And in case you are wondering which is the maximum movement possible with this chassis and axles, here it is:

In this case, the weight over the chassis is of 1Kg, both axles are unlocked with their anti-roll bars disabled, to do this, you would need to remove the mudguards in the finished version, but it is worth, because it can climb over 9 studs in each wheel, and again the chassis bending is about 20 degrees, so, even when i hadn't the goal to make this chassis so offroad capable, it looks like this could be a very outstanding offroader.

I have more pictures at my bricksafe, every picture has information in their name, they tell you if the axles are unlocked, the load over the chassis, and how many studs it is climbing in each wheel: http://bricksafe.com/pages/imanol/unimog/uni-moc-u500/twisting-of-the-chassis

[Didumos69]

I was actually referring to some internet links (pointers) with background info about torsional bending of the chassis. But these are very nice images and make very clear what you mean with this torsional bending. Thanks!

Edited October 6, 2016 by Didumos69

[Imanol BB]

 my bad, here is a picture of a U5000, which is the even most capable off-road version but it is still applied to the u500´s, you can see how the cabin and the rear cargobox move to different sides because of the bending of the chassis, it is done thanks to a flexible connection behind the cabin and in the front of the cargobox, which makes this kind of movement possible:

I have also made some advances in the front end, the mounting plate is fixed better in the chassis, so it wont pop out in case of a hit and it has been made as close as possible to the real mounting plate, i have added a working towing hitch, which can be removed if needed, so, now i need to find out a good system for the steering and once i finish that, i will start to make all the rear part of the chassis, which will be the same as the front part in terms of structure:

 

[Pat-Ard]

Looks good...

Reminds me a little ;)

 

Btw: I made a integrated pneumatic hitch which fits into the chassis... 

 

[Imanol BB]

Thanks for sharing that Pat, i might borrow that idea of the hitch, good thing about the version i am making is that i have like 2 more studs of free space behind the rear axle to incorporate it, it would be under the PTO Motor, by the way, that UHN looks fantastic, the chassis bending is really cool.

[Pat-Ard]

If you need more detailed photos of the hitch just contact me...

Here's a picture of the chassis. Purists be aware, there are some shapeways parts included. But there's an easy way to substitute them...

 

Edited October 12, 2016 by Pat-Ard

[Didumos69]

1 hour ago, Pat-Ard said:

Looks good...

Reminds me a little ;)

@ImanolBB, now I know what you're talking about. Never seen this before. @Pat-Ard this is rediculously cool!!!

[Pat-Ard]

4 minutes ago, Didumos69 said:

this is rediculously cool!!!

Thank you.

[Imanol BB]

Small update, inspiration came and gave me a punch of ideas, and the front steering system should be ready, maybe i will add some minor changes, but i feel good so far with the result, it is pretty robust and with a lot of torque but enough speed:

 

I couldn't attach the 4L axle from the U-joint to the CV one, because LDD limits the CV´s movement to only 17 degrees and i need about 20-22 (which is possible in real life and i have tested it); @Didumos69 Good to know that you know what i was talking about the chassis bending :) .

[Pat-Ard]

What about adding a clutch gear?

[Imanol BB]

Good idea, i have replaced the 24T gear with a clutch one, thanks to the free space i have in the whole steering system, there are many configurations possible for various strengths, for example, you can change the 8/24 gears (which is more for heavy off-road where strength is needed) with 12/20 or 16/16 ones, that would be for flat surfaces where speed is more important that strength:

 

The green axle connector is the main design to add a turning steering wheel, there will be a reduction from the engine to the steering wheel, so it wont spin like a turbine and will be much more realistic; i have also started to make the rear part of the chassis:

[Pat-Ard]

Wow, this is getting good...

[Imanol BB]

the mog is getting in good shape:

The dump bed with the dropping sides is almost finished, and i feel good with the result, it is 37 long and 23 wide, which means it is pretty much bigger than the 8110 bed:

The dumping system, based in Kumbbl 3-side tipping design, but this one uses a V2 large cylinder, real life testings (with a brick built version of the cylinder) have shown that the inclination of the dump bed is about 30 degrees backwards and about 80 to the sides (yes, almost vertical), this happens because there are no multi-stage cylinders which would be the right option here, and the V2 one works different.

So far i only need to finish the rear steering system, place the pneumatic pump, the PF switches and the gearbox shifter (i am thinking to use a micro-motor for this), the red axle connector is for the rear steering, i also think that i have used the weirdest but still efficient way to attach 2 of the IR RC receivers:

I am glad to see that this project is being successfully finished.

 

[Pat-Ard]

BTW: when I overhauled my 8110 I widened the bed to 23 studs, too. So your bed fits perfectly.

What about a double pump?

[Imanol BB]

Good idea, i will try to save as much space as possible, it might be possible, and after i finish all the chassis, i will start with the cabin.

[Pat-Ard]

Do you plan a UHN or do you stay with the U400?

[Imanol BB]

At this point it is supposed to be a U500, but i am also planning that when i finish this version and i get all the pieces and the finished model in real life, i will start to design an UHN version, which wouldn't need to have the PTO´s and the pneumatic pumps, and that could give me enough space to add buggy motors or even 2 Extra XL´s for a total of 4 XL´s, and if the inspiration is enough, maybe i will make it 6x6 like a U2450, i am not sure if i could be able to keep the rear steering in that version, but i will try to.

[Pat-Ard]

That sounds very interesting :)

[Imanol BB]

Hello again, i have an important advice, to avoid filling this topic with only my own MOC, i have decided to continue its designing and building here: http://www.eurobricks.com/forum/index.php?/topic/141812-imanolbb´s-moc´s-and-mod¨s-and-possibly-good-ideas/, however, i will post the highlights of its building process and when it is finished, so you will see it too. 

Edited October 16, 2016 by ImanolBB

[vouthe lego]

how much is there on a caterpillar