[WIP] Maz 535 - 1:15 - RC

[Tamas Juhasz]

Hi all!

I present my newest project, which is among my biggest ones ever. I build the monstrous Maz 535, inspired mainly by real life Maz (537, because there are no working 535 any more, if I know well), and a bit of Spintires. I know about this heavy truck before spintires, too, but when the tech demo released, I could finally "drive" it, simulating a bit the behavior of this truck. It's an awesome and indestructible machine, a real russian cold war truck. So it shouldn't be missing from my mocs.

I build in 1:15 scale, which means the 108 mm tyres. Of course, in this size I'll use again the crawler tyres, RC4WD rock crusher XT's, and maybe later I'll buy a more authentic looking military tyres. I'll make the tractor truck, so there will be no cargo platform in the back.

The real life vehicle:

---> this will be my version

Thanks to spintires, we have some good looking high quality render, so I can make the details properly:

http://www.simulasyonturk.com/wp-content/uploads/2012/10/spin-tires-maz535finihmodel1.jpg

http://2.bp.blogspot.com/-1Lya0MYqf-I/UJXplkmcyuI/AAAAAAAAALQ/aKsF8vN25O8/s1600/maz535_04.jpg

http://4.bp.blogspot.com/-oRD07JncgzY/UJXpgYwP83I/AAAAAAAAALE/A1tpVtJo1Gk/s1600/maz535_03.jpg

https://i.ytimg.com/vi/sRDnX2OQ37I/maxresdefault.jpg

My goals:

- 1:15 scale --> 108 mm custom wheels

- 8x8/4 (first two axles steered)

- Radio controlled with RC buggy system, 1 RC unit, 2 RC motors

- very robust drivetrain and steering

- proportional looking, with model body and details, as close to the original as possible

- 24 studs width at the wheels and body

- full authentic (independent in front and semi-independent in rear) suspension with minimum 2-3 studs of suspension travel

- no portal or planetary hub

- 2 speed gearbox controlled by the RC unit's servo

- working towing cable, with heavy winch and hook (metal)

- working headlights

- dark green color

There will be pictures about the process soon, first I make the front axles and the main placing of components, steering. I collected a pretty large amount of dark green bircks, tiles, etc., so the color shouldn't be a problem. Fortunately, there are curved dark green bricks, to make the curved edges in the top and front.

The gearbox would be a sliding type, and it's movement will be done by the servo of RC unit. To help in this process, and fix the slifing axle in the second gear's position there will be magnets somewhere. By default, the gearbox will be in first gear, when the servo is in 0 position, so it will be reliable under torque. The shifting to second gear this way will be an additional extra, if you want to do.

It's a heavy truck (will be about 3 kg), so even with robust drivetrain I think it won't be capable of doing trial/heavy terrain, but if a medium can be done, that's far enough for me. If a 30° slope and a terrain with 3-4 studs high obstacles is no problem, then I reached my goal with it's off-road capabilities.

Comments and questions, ideas, etc. are appreciated, as always.

[Lego2016Lego]

This will look very good and post pics as soon as you can. I will follow.

[Didumos69]

Very interesting!

I know a little about the Maz 537, especially about the suspension. As far as I know all axles are double wishbone with shocks in the front axles and rigid bogies (no shocks) in the rear. I'm very curious how you are going to realize this. The Maz 537 also has - besides the standard gearbox - portal gearboxes to reduce torque in most of the drive train. Are you going to incorporate these too?

[Tamas Juhasz]

As far as I know all axles are double wishbone with shocks in the front axles and rigid bogies (no shocks) in the rear. I'm very curious how you are going to realize this. The Maz 537 also has - besides the standard gearbox - portal gearboxes to reduce torque in most of the drive train. Are you going to incorporate these too?

You know well, it has simple A-arms / double wishbone system in front and rear. The main differences are in the springs. In the front, there are torsion bars, as can be seen in this model:

.. and shock absorbers for all front wheels.

The rear wheels are linked together, in each side. That big beam is a bit flexible I think, works a little as spring in the back. So the rear suspension:

http://s32.photobuck...ension.jpg.html

It's very easy to build this suspension. Everywhere will be A arms, and in the front I'll put the yellow shocks, with place for additional ones, if needed, and in the rear I'll make simply the bogies to get the wheels linked. The harder part is the drive system, to be enough strong and to fit in the relatively small place (the truck will be only 24 studs wide, and has huge wheels).

Drive system:

I won't make portal gearboxes. This model has to contain the big RC unit, two RC buggy motors, 1 LiPo battery, 1 Receiver, at least two M motors, all of these in the front part, above the 4 front wheels. I just want to say with this, the space is very limited. My goal isn't to make it authentically working, but to build it reliable, robust, and proportional. But, of course, there will be large gearing just before the wheels, so, yes, a torque reducing gearbox will be there, but with normal gearing (spur-gears, bevel gears).

And, of course because of RC there will be no fake engine, it's a compromise, we know well.

But, I'll make the cabin, at least the driver's seat, working steering wheel, openable doors.

The roof will be partly openable, to switch the RC unit on-off, and for changing the batteries.

Edited June 3, 2016 by Mbmc

[Didumos69]

...

The rear wheels are linked together, in each side. That big beam is a bit flexible I think, works a little as spring in the back.

...

You know well too. About the flexibility of the big beams (bogies) which make the left and right A-arms in the rear a kind of pendular: I'm quite certain (as in 'I read somewhere on a forum') that the bogies are completely rigid - they can only pendulate - and the reason for that is the enormous load they should be able to carry. The suspension comes from the tyres only, which are enormous too. If I find my source I'll let you know.

Here's another link to many 3D-renders of the Maz 537 but you probably found those already: http://bart300872.re...37/maz-537.html

Good luck! I will follow this topic with great interest.

Edited June 3, 2016 by Didumos69

[agrof]

You raised the bar with Your Unimog 401, soooo I expect something very cool and effective here!

Any chance for WIP pictures?

[Tamas Juhasz]

@Didumos69: thanks for the info, that sounds real, if the beam is rigid, the tyres give enough spring effect. I'll put a studfull or a studless beam there, will be as rigid as Lego.

@ Agrof: Yes, will coming soon, about the front drive, and some LDD renders. I fround a really strong and compact solution with 8880's hubs.

[Didumos69]

@Didumos69: thanks for the info, that sounds real, if the beam is rigid, the tyres give enough spring effect. I'll put a studfull or a studless beam there, will be as rigid as Lego.

@ Agrof: Yes, will coming soon, about the front drive, and some LDD renders. I fround a really strong and compact solution with 8880's hubs.

Found the source: It was said by someone on a Spintires discussion forum: http://steamcommunit...9681598199309/. Maybe not the most trustworthy source, but the guy seems to know what he is talking about. And like you said, it sounds probable.

Edited June 3, 2016 by Didumos69

[Tamas Juhasz]

I make this moc first of all in LDD, and I'M trying out the important working parts.

Here you can see the front axle, in LDD an IRL:

With blue, I marked the moving parts in steering (except the white hubs):

Front drive, marked with green:

As you can see, there are minimal torque in the 12 t bevel gear, and maximal in the 40t gear's axle.

In real life:

Many builders think, 8880's drive is weak. It is, if you use the 3 or 4 L cardans at the other end. But it's strength can be raised extremely, if you use the gearbox gear selector (red in the pictures) and 1L long bush parts, as a semi-homocinetic joints. The 8880's homocinetic joints in the other end can handle surprisingly lot of torque. In the test, at the end the rim rotated around the RC4WD custom 1,9" tyres. So, it will does it's job. This solution has two main advantages: very compact (width in goals can be done), and gives the needed suspension travel. Beside these, has Ackermann geometry in steering, and the pivot point is pretty close to the center of the wheel. To prevent the ball joint's pop out from the 8880's hub, I'll put there small 3 mm D flex hoses. The 6L steering links will be placed inverted way, to get stronger connection.

The front axle unit with outer structure:

Rear axles

These are even more robust in driving than the front axles. I experimented with many brick-built U-joints, homocinetic joints, and this one won, it behaves as a semi-homocinetic joint:

Yellow: swinging parts of the moving parts during the working of suspension.

Green: rotating parts of the moving parts during the working of suspension.

Orange: swingarms and wheel hubs

[Thirdwigg]

I'm interested to see how well the front suspension will work. The rear looks great.

[agrof]

Since we met and chatted, I know You are someone, who really go technical when it comes to MOCing, but the details You show amaze me every time!

I feel like I am participating on an on-line course. :thumbup:

Maybe You can eliminate the wobble in the rear axle if You add half pins on the combi hub, or is it on purpose like that?

Another question for the rear arms: is there any constraint to use 4x Technic lever 3M? What about 2x Technic lever 5M?

vs

It would eliminate 4 joints on each suspension unit = stiffer.

Edited June 5, 2016 by agrof

[Didumos69]

The semi-homocinetic joints in the front and in the back are very inventive. You are really exploring the edges of what's possible with Lego.

I agree with Agrof that the A-arms in the back could be done a little more sturdy. The least you could do is adding some overlap between the levers, but that probably boils down to using 5L levers too, just like Agrof suggested. Maybe you want the suspension arms to look like a real A, however, given the original Maz it would also be nice if there was more resemblance between the front and rear A-arms.

Anyway, very interesting designs so far!

Edited June 5, 2016 by Didumos69

[MajklSpajkl]

Many builders think, 8880's drive is weak. It is, if you use the 3 or 4 L cardans at the other end. But it's strength can be raised extremely, if you use the gearbox gear selector (red in the pictures) and 1L long bush parts, as a semi-homocinetic joints.

Interesting solution, indeed it is really strong. I tried it out with two axles without any support ("in the air") and I fear the rotatiton is quite jerky. I wonder how it would work at higher RPM.

[Tamas Juhasz]

Maybe You can eliminate the wobble in the rear axle if You add half pins on the combi hub, or is it on purpose like that?

Another question for the rear arms: is there any constraint to use 4x Technic lever 3M? What about 2x Technic lever 5M?

It would eliminate 4 joints on each suspension unit = stiffer.

Thanks for kind words Peter. That wobble is ok for me, and the reason: if I use the the pins in the driving part, then it's bigger in diamater than 3 studs. Currently, it's also bigger a very bit, that's why I placed also the arms in A shape, to have enough space for it. (In every strong, technic-built U-joint, the problem is, it requires a bit more space in diamater than 3 studs, so you have to give 5 studs, or 4 if it's possible.) I think I answered the liftarm question, too. When I experimented with the rear suspension, I tried the version, which uses only 5L levers and 7 studs width just before the rim, but had some friction between the end of the arms and the rim. Beside that, currently I have a limited amount of these 5L levers, and I want to keep some, if it will be needed elsewhere, as in 90% of my mocs. Another reason for this shape is the A-arm like looking, yes. I'll se how strong it will be, but should be enough, as it's strongly connected in both ends to structural parts.

Interesting solution, indeed it is really strong. I tried it out with two axles without any support ("in the air") and I fear the rotatiton is quite jerky. I wonder how it would work at higher RPM.

Thanks. To avoid misunderstandings, if it works well: I tried out, as can be seen in the IRL pictures, and it worked surprisingly smooth and well. Low torque, high torqe, doesn't matter. Try out with the 8880 hubs, with that angle in the swingarm in the pictures, and then you can see the proper working. The driving ring part isn't offer much angle between input and output, the rest is done by 8880's homocinetic joint. That's why I use them together. (Only the driving ring itself is really strong, as homocinetic joint, but offers a pretty low angle.) I experimented a bit, to adjust the axial spacing of the driving ring (that's why you can see the old 14t gear, as spacer in the pictures), and when it became good, offered the required angle for 2-3 studs of suspension travel with this setup. Even in compressed position, there is no stress in the driving ring or any other drivetrain part.

I was really happy, when I came up with this, finally, the front suspension could be done with these goals:

- independent suspension

- strong (brick built joint)

- narrow (the trucks maximum width is 24 studs)

- no portal or planetary hub

- close pivot point to wheel

- 2-3 studs suspension travel

- hold the rim strongly to avoid it's axial movement

I searched a lot, but there are no other solution in technic which fulfill these requirements. In fact, there are many live axles, but a very few ideas, solutions for heavy duty independent suspension front drives, which are enough narrow and compact to keep the real trucks proportions.

Edited June 5, 2016 by Mbmc

[agrof]

Thanks for explaining, I assumed, that there must be a reason, but couldn't see.

[syclone]

Amazing!

You could try ZBLJ's design of brick-built joints( pulley wheels with three pins and one of those LBG three point axle connectors)

I think he used them in his Coyote( I may be wrong)

EDIT: It is in Jaguar

Edited June 5, 2016 by LXF

[Lego2016Lego]

If you have beamng drive you could download the what you are going to make it is a mod.

[Rockbrick]

genius with the cardan joints.....

[Tamas Juhasz]

You could try ZBLJ's design of brick-built joints( pulley wheels with three pins and one of those LBG three point axle connectors)

Those are great joints, but I already solved the rear axle drive with similar solution, which worked well in the tests. In the front, both version would be too large, there are a bit less space between the two A arm in the front, than 3 studs in height, because of the angled position.

If you have beamng drive you could download the what you are going to make it is a mod.

It's a great simulator, but as I wrote, I drove it in Spintires, that's a pretty good off roading game, too. (although, I was dissapointed about the final release, became too boring, the demo was better)

genius with the cardan joints.....

Thanks, without these, I think the whole truck would contain more compromises.

And.. the building process with the whole chassis, suspension, drivetrain, and the most of the steering parts:

full size image: http://bricksafe.com...5---wip/033.png

I marked the drivetrain with light green, the gearbox's sliding axle with orange and the magnets which help in keeping second gear's position, with blue.

The normal green axle is the input axle, there come the two RC buggy motors. The red 3L axle connects the sliding axle with the RC units servo, as shifting mechanism.

full size image (4k): http://bricksafe.com...5---wip/034.png

(I just tried out Bluerender, and it's an awesome rendering program, with it's simplicity, speed and results --> highly recommended to use, as alternative for Pov-Ray)

I also added a 2x1x2 panel in the edges of front bumper, to look more authentically:

More LDD screenshots:

Edited June 7, 2016 by Mbmc

[Beck]

This is one of the best technic MOCs in quite some time. I cannot wait to see this finished! You're going to need some weight over the rear axles for (some type of trailer) for your leafsprings to work.

[Lego2016Lego]

You put (there come the two RC buggy motors) how do you get buggy motors? Bricklink? I ask because I need them cheap.

And it looks very nice!

Edited June 8, 2016 by Lego2016Lego

[Technic Jim]

You put (there come the two RC buggy motors) how do you get buggy motors? Bricklink? I ask because I need them cheap.

And it looks very nice!

I bought mine off bricklink for £25 each and the unit for £45 and the controller for £30. They were the cheapest I could find all from one store at that time so as you can see they don't really come in a 'cheap' version!

[Lego2016Lego]

I bought mine off bricklink for £25 each and the unit for £45 and the controller for £30. They were the cheapest I could find all from one store at that time so as you can see they don't really come in a 'cheap' version!

can you use them with a new receiver and remote?

[Saberwing40k]

Yes and no. Technically speaking, RC buggy motors have the old 9v connector, so you will need a PF adapter cable as a go between. But, the motors draw a lot of current, so much so that the V1 PF receivers will shut down due to their thermal regulators. I don't know if this happens to battery boxes to, but it might. So, you can use them with PF equipment, just not at full power.

I actually have four motors and two receivers, but I got them in the sets they came in. I ran the numbers, and I determined that it was only a little bit more expensive for me to find the sets than to buy the parts individually. Also, try Ebay, as sometimes the sets will appear for less than the average price on Bricklink.

[Tamas Juhasz]

This is one of the best technic MOCs in quite some time. I cannot wait to see this finished! You're going to need some weight over the rear axles for (some type of trailer) for your leafsprings to work.

Thanks. The rear axles have no springs, they are connected with solid pivot beams, and the air in the huge tyres functions as "spring". The rear suspension will work without any trailer or additional weight to the rear. Currently, I don't plan to make a trailer, too, but maybe in the future I'll build.

You put (there come the two RC buggy motors) how do you get buggy motors? Bricklink? I ask because I need them cheap.

And it looks very nice!

As others wrote, the easiest and cheapest way to get them, is Ebay, from whole sets (8366, 8475). I have 4 RC motors and 2 RC units with this method.

Using RC motors with PF receivers and battery:

You can see also here many examples about that, v2 receiver is recommended, but that will shut down due to their thermal regulation, too, but goes further in current, than v1. The power, you can get, is MUCH more if you use v2. The LiPo battery has current limitation too, about 1,5 A. Except these and the converter cable, everything is the same, as with PF motors.

The gearbox in this moc will provide 1:25 and 1:9 ratios, so a high torque and a fast mode will be available. In default, the gearbox will be in first gear.

Edited June 9, 2016 by Mbmc