[MOC][WIP] Steppenwolf

[Didumos69]

UPDATE: Thanks to an amazing effort by Thorsten Spelz full-blown building instructions are now available on Rebrickable!

UPDATE: I updated building directions to reflect some improvements to the front suspension. See entry #30 of this topic.

Hello,

I started a topic on my 'Steppenwolf'-project before, but that post feels a little bit like a false start by now. At that stage I only had digital ideas and there where some correct critiques about the designs I showed, especially about the custom wheel hubs. Since than I thoroughly redesigned the front and rear suspension and about a month ago I started building my 'Steppenwolf'-chassis. Now I have come to a point to show the first 'real life' results and I would like to use this topic to show progress and to elaborate further on specific parts of the concept.

First of all it was a real sensation to start building with real bricks after 25 years of not 'playing' with lego. To show a little bit of where I come from when it comes to Lego Technic: this is my last build from about 25 years ago:

https://bricksafe.co...jpg/800x600.jpg

https://bricksafe.co...jpg/800x600.jpg

With the 'Steppenwolf'-project I aim for an AWD platform that can serve as the base of a push-along car. It is meant to fit 'ordinary' AWD cars rather than Baya truck-like vehicles. The platform combines all-wheel-drive with Ackermann steering, progressive camber angle, caster angle, kingpin inclination, 4 stud suspension travel and 5 stud clearance (with 94.8 x 44 R balloon tire). As suspension and drive characteristics have the main focus in this design, I prefer not to see these characteristics being affected by a too flexible chassis. I want a rigid chassis that does not twist too much while riding on an uneven surface.

All these ideas resulted in a platform that has been built up from three main modules; the front module, the center module and the rear module. These main modules incorporate the complete drive train, including front axles, rear axles and (5+R) gearbox. The gearbox is based on Boratko's 5+R AWD gearbox and has been extended with a center differential lock. The platform has been completed with three secondary modules; a v12 engine, a steering console and finally two car seats that can move and tilt. The engine can be placed at the front or at the back of the chassis. The seats have been inspired by the car seats as can be found in Nathanaël Kuipers' Concept 4x4 and have been extended with the ability to move back and forth.

Both front and rear suspension are independent and based on the double wishbone concept with a longitudinal torsion bar attached to the lower wishbone, see the image below.

This weekend I have been able to actually combine the various modules of my build and I'm quite happy with the results. Here are some pictures and a short preview video.

Ackermann steering:

For the front suspension the shock absorber is directly attached to the lower suspension arm which has been placed up-side-down to avoid it from getting detached from the wheel hub:

At the bottom of this picture you can see how the outer end of the longitudinal torsion bar has been fixed to the chassis:

Once more a front suspension close-up:

The rear suspension is also a double wishbone suspension with longitudinal torsion bars. Instead of using cusps and balls it uses normal axles and liftarms. Each wheel hub is stabalized firmly with two stabilizing links:

Both front and rear wheel hubs are based on a setup that allows the lower suspension liftarm to be placed upside down while leaving enough space for the U-joint attached to the wheel axle (5.5 with end stop) to support 4 stud suspension travel:

5 stud clearance:

More photo's can be found here: https://bricksafe.co...progress-images

And finally here is a short preview video showing the suspension:

I'm very curious what you all think of this. My next step will be to build the body work and I will report on that in this topic. I also plan to post some extra details on the front and rear modules of this design - if there is any interest. I might even share lxf-files containing construction directions for these modules (sofar I didn't plan to make real building instructions, but when the whole thing is finished and when there is enough interest, I might decide to put in the effort).

Thanks so far!

Diederik

EDIT: Building directions for the complete chassis may now be found here: http://bricksafe.com...ding-directions

Edited September 28, 2016 by Didumos69

[Didumos69]

And one more short preview video:

[nicjasno]

This is absolutely brilliant! :)

[emielroumen]

That looks great, a very stable frame with sturdy suspension! I actually might take my 42043 apart to rebuild the suspension! I don't own the large shock, but it can be tweaked with shorter, yellow shocks.

[Didumos69]

This is absolutely brilliant! :)

Thanks! I said it before, your video's on youtube have been of great help!

[emielroumen]

Are you going to make instructions of the 3 building blocks?

[Didumos69]

That looks great, a very stable frame with sturdy suspension! I actually might take my 42043 apart to rebuild the suspension! I don't own the large shock, but it can be tweaked with shorter, yellow shocks.

I don't know if this suspension setup will fit the smaller scaled 42043. But if you would want to use the tilted wheel hubs shown above than you should know that the position of the pivot points probably requires a tooth rack that is an even number of studs long. In my build I had to place an 8 stud tooth rack between the track rods. It looks like this:

Once I have updated my LDD-files with the real life build I will place some images that show the complete suspension setup while leaving the rest of the design out.

Edited March 21, 2016 by Didumos69

[emielroumen]

Thanks for the detailed response. I meant taking the 42043 apart (and the Backhoe V2) to rebuild your chassis :), not to modify the Merc. After the GMK6400 ai might get addicted to car MOCs.

I don't know if this suspension setup will fit the smaller scaled 42043. But if you would want to use the tilted wheel hubs shown above than you should know that the position of the pivot points probably requires a tooth rack that is an even number of studs long. In my build I had to place an 8 stud tooth rack between the track rods. It looks like this:

Once I have updated my LDD-files with the real life build I will place some images that show the complete suspension setup while leaving the rest of the design out.

[ifilin]

Impressive work.

[Didumos69]

Are you going to make instructions of the 3 building blocks?

I'm planning to share buillding directions in terms of groups in an lxf-file for the front and rear modules. I will have to finish those first though. For the center module probably not because it includes Boratko's 5+R AWD gearbox and he is selling instructions for that gearbox himself. But maybe I could leave the gears out.

[Didumos69]

Once I have updated my LDD-files with the real life build I will place some images that show the complete suspension setup while leaving the rest of the design out.

Here are some cut-outs showing the basic setup of the front and rear suspensions:

And finally the wheel hubs. Note the yellow half bush that helps tighten the tilted setup:

Edited March 29, 2016 by Didumos69

[JJ2]

Absolutely brilliant suspension! is there any chance of releasing the LDD file?

How much slack is in where the wheels connect to the hubs using the 5.5L axle?

I really want to build this or base something off of this

[Didumos69]

Absolutely brilliant suspension! is there any chance of releasing the LDD file?

How much slack is in where the wheels connect to the hubs using the 5.5L axle?

I really want to build this or base something off of this

Yes, I will release the LDD-files, at least for the front and rear modules. However, they still need some rework. As soon as they are ready I will post download directions here.

The slack is slightly better than a nomal axle through a single 1 stud hole due to the end-stop on the 5.5L axle. Front suspension and rear suspension both have a positive camber (with an angle )of about 4 degrees) when the suspension is fully expanded. This makes the wheels stand up perfectly straight under the cars own weight, regardless of the present slack.

Slack also depends on how tight the wheel is attached to the axle. I use a little trick - although others are convinced that two extra half bushes on the same axle will perform equally well - with a rubber connector, see image links below. My experience is that this works especially well with the 6-pin-hole rims. I'm even afraid to break parts when I try to slide this over the axle by hand. That's why I postponed installing this trick untill the build is completely finished. I'd say you have to try to know if this will be useful.

http://bricksafe.com...jpg/800x600.jpg

http://bricksafe.com...jpg/800x600.jpg

http://bricksafe.com...jpg/800x600.jpg

http://bricksafe.com...jpg/800x600.jpg

Alternatively you could replace the double cross block that holds the axle with LPEPower's turntable wheel hubs: http://www.lpepower....table-wheel-hub. For a video see:

. My guess is that the LT cardan ball will fit in the wheel hubs just like the U-joints do. However, it would bring the wheel one more stud away from the virtual kingpin, which does not improve the steering characteristics. Edited March 15, 2016 by Didumos69

[JJ2]

Yes, I will release the LDD-files, at least for the front and rear modules. However, they still need some rework. As soon as they are ready I will post download directions here.

Awesome cant wait.

The slack is slightly better than a nomal axle through a single 1 stud hole due to the end-stop on the 5.5L axle. Slack is also slightly reduced by the weight of the car, which makes the axle want to center in the hole of the double cross block its running through, but that effect is useless on uneven surface.

Slack also depends on how tight the wheel is attached to the axle. I use a little trick - although others are convinced that two extra half bushes on the same axle will perform equally well - with a rubber connector, see image links below. My experience is that this works especially well with the 6-pin-hole rims. I'm even afraid to break parts when I try to slide this over the axle by hand. That's why I postponed installing this trick untill the build is completely finished. I'd say you have to try to know if this will be useful.

http://bricksafe.com...jpg/800x600.jpg

http://bricksafe.com...jpg/800x600.jpg

http://bricksafe.com...jpg/800x600.jpg

http://bricksafe.com...jpg/800x600.jpg

Alternatively you could replace the double cross block that holds the axle with LPEPower's turntable wheel hubs: http://www.lpepower....table-wheel-hub. For a video see:

. My guess is that the LT cardan ball will fit in the wheel hub just like the U-joint does. However, it would bring the wheel one more stud away from the virtual kingpin, which does not improve the steering characteristics.

Exactly what I was thinking to do! I really want to get some or make some myself because they look awesome.

[Didumos69]

Okay, here we go. LDD-files with building directions for the front and rear modules are now online. Please follow the instructions on this page: http://bricksafe.com/pages/Didumos/steppenwolf/building-directions.

I also submitted the modules as MOC with parts list on Rebrickable, but I'm still awaiting approval.

Cheers!

Edited March 23, 2016 by Didumos69

[Didumos69]

Moving the engine from front to rear module:

The parts needed to connect the engine:

Edited March 19, 2016 by Didumos69

[probey]

Thanks for sharing. This platform looks promising! I will try to see if I can fit an automatic gear box like this http://www.eurobricks.com/forum/index.php?showtopic=38999 in the frame to save my self some motors.

Just ordered some parts, can't build it til next week

[z3_2drive]

Really amazing work,very clever arrangement of parts to create those hubs, I might build this and test it out too. Thanks!

[Didumos69]

I got clearance from both mister Paul Boratko and mister Nathanaël Kuipers for making available LDD-files of the center module and the car seats module.

The 5+R gearbox incorporated in the center module is based on Paul's AWD transmission and the car seats are based on the car seats in Nathanaël's Concept 4x4.

Building directions for the complete platform may now be found here: http://bricksafe.com...ding-directions

Thanks again, Paul and Nathanaël!

Thanks for sharing. This platform looks promising! I will try to see if I can fit an automatic gear box like this http://www.eurobrick...showtopic=38999 in the frame to save my self some motors. Just ordered some parts, can't build it til next week

That's an interesting gearbox. If you plan to motorize this platform, please read these directions first: http://bricksafe.com...ding-directions

Really amazing work,very clever arrangement of parts to create those hubs, I might build this and test it out too. Thanks!

Thanks! If you build this, please let me know about the result.

Edited March 23, 2016 by Didumos69

[Rockbrick]

Great Chassis, has a nice 'stance' to it

[Didumos69]

Great Chassis, has a nice 'stance' to it

Thanks! I've been searching to put a bit of character to it.

[ifilin]

Didumos69, thank You very much for this high level creation.

I think, this MOC with bodycover should be present in the form of an instruction. :) And I will be ready to buy it. :)

[Didumos69]

Didumos69, thank You very much for this high level creation.

I think, this MOC with bodycover should be present in the form of an instruction. :) And I will be ready to buy it. :)

You're welcome! For now I only have building directions available for the chassis in terms of LDD-files, see: http://bricksafe.com/pages/Didumos/steppenwolf/building-directions

When all is finished, including bodywork, and there is enough interest, I might put in the effort of creating real building instructions.

[Didumos69]

Over the last few weeks I experienced the following issue: When too much torque is applied to front and/or rear differential, the attached CV joints may be pulled out of the differential. As far as I understand the shaft of the joint is designed to allow the inserted axle to slide in and out slightly while rotating. Both front and rear module rely on this property. However, when too much torque is applied, the inserted axle clasps itself to the shaft and may pull the joint out of the differential. I solved this issue with an extra half bush on the cardan cusp axle and a modified differential casing (see images).

I updated the LDD-files, which may be found here: https://bricksafe.com/pages/Didumos/steppenwolf/building-directions

Edited April 1, 2016 by Didumos69

[dpkong]

Just to let you know I'm following this project and trying to build with LDD. It's possible but not easy. I love this vehicle. Many thanks for making LXF files available.