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Showing results for tags 'ackermann steering'.
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I would like to present the result of my Winter-project. A big thank you to everybody who supported me in the corresponding WIP-topic and of course to @DugaldIC for challenging me! Instructions are available on Rebrickable. Features: Turn-table-based wheel-hubs with minimal slack 4WD by means of 4 L-motors powered by two BuWizz 2 units Fully independent suspension Steering with Servo-motor 30 degree steering angle with Ackermann geometry Caster angle Fake V8-engine driven by M-motor Can handle a rough ride Liftable by roof, nose and tail Everything in-system Stats: Parts #: 1844 Weight: 1980gr Length: 54 studs Width: 35 studs Height: 23 studs I hope this will pull @Blakbird back into Technic . Some stills from video-material. And finally a few short videos.
This is a front live axle with kingpin inclination with angle atan(1/4)=14.036... degrees diff lock portal axles with 8/24 gear reduction constant velocity joints Ackermann steering The following picture shows the very high ground clearance and highlighted kingpin axis (in red): A .ldr file can be found on bricksafe. This .ldr file includes building steps. There are 2 black steering links on top and 2 grey links at the bottom. These create a 4-bar linkage. A caster angle can be obtained by angling the whole axle by setting up the 4-bar linkage properly.
Didumos69 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale ModelingUPDATE: 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
Didumos69 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale ModelingWarning: The suggested solution may not be regarded as perfectly 'legal' by some of you. Find out for yourself whether you want to go as far as this when it comes to fine-tuning your build. Everyone who has ever played around with custom steering setups with realstic features such as caster angel and/or camber angle knows the hassle of finding the most optimal tie rod and tooth rack position. Optimal in a sense that effects like toe-in, toe-out and bump steer are avoided as much as possible. And when you have found the optimal placement, there is still so much slack in the ball joints that your build is always left with a certain amount of toe-in or toe-out, When all seems fine when driving forward, there will be some toe-in/toe-out when driving backwards. It may not be the most aesthetic solution but I found a very effective way to reduce the slack in the tie rod / ball joint connections. Simply tie one or more rubber belts around the ball joints, just below the ball part of the joint. In my case the combination of a red rubber belt (24mm) and a white rubber belt (15mm) worked out perfectly, see image below. Note that in a standard steering setup with all ball joints perfectly aligned on a 1-stud grid, this approach will prove hard to apply, as it will pull the pivot points slightly away from their ideal position. It is particularly useful in custom setups that try to obtain non-standard features such as caster angle, camber angle or Ackermann steering.