Rockbrick Posted February 5, 2015 (edited) always called CV joints (found on cars front wheel drive) RZeppa joints...and lego ones universal joints: Named After Alfred Hans Rzeppa, (1885-1965) was an American engineer of Silesian descent working at Ford Motor Company who invented a version of constant-velocity joint in 1926. He proposed an improved design in 1936. Rzeppa's design uses six balls and an inner and outer race to provide almost constant velocity torque transfer regardless of the joint angle. The joint works in a similar manner to a bevel gear with the balls bisecting the joint angle and functioning as the "teeth" to transmit torque. A cardan joint is is more like the lego universal joint; Named after G. Cardano (1501-76), Italian mathematician, its inventor - "a universal joint consisting of a cross like piece, opposite ends of which rotate within the forked end of each of the two shafts connected." Interesting that the design and use of the cardan joint never changed much for 400 years - now Rzeppas are everywhere for driveshafts but still cardan joints are in use - hurray for italian engineering! Edited February 5, 2015 by Rockbrick Share this post Link to post Share on other sites
Milan Posted February 5, 2015 I know the chances of this being all wheel drive are slim but has anyone been able to confirm it? also does anybody know if both rear axles have differentials or will it just be one axle used to drive the fake engine? Only rear wheels driven. speculations are that there are two differentials at the back. Share this post Link to post Share on other sites
XAxles Posted February 5, 2015 Wait. Anyone seen if this model's got a driveshaft? Share this post Link to post Share on other sites
nicjasno Posted February 5, 2015 I think that the length of the shaft is small enough, that torsional oscilation is negligeble. Share this post Link to post Share on other sites
sama Posted February 5, 2015 Wait. Anyone seen if this model's got a driveshaft? It does have a drive shaft. But this drive shaft just connect to the dummy engine to animate it. Wait, so what is the difference between the rear suspension on the Lego Mercedes Benz Arocs, the suspension on the Lego Unimog, and the suspension on Lego 9398? Share this post Link to post Share on other sites
Saberwing40k Posted February 5, 2015 It does have a drive shaft. But this drive shaft just connect to the dummy engine to animate it. Wait, so what is the difference between the rear suspension on the Lego Mercedes Benz Arocs, the suspension on the Lego Unimog, and the suspension on Lego 9398? Well, aside from the scale, obviously, there probably is not that much difference. Both 8110 & 9398 have live axle suspension, using torque tubes instead of links. I'm not quite sure what the Arocs will use, but I think it will be some kind of live axle. Share this post Link to post Share on other sites
nicjasno Posted February 5, 2015 The unimog and 9398 have the same suspension type. The Arocs has trailing arm live axle in the front and in the rear maybe a sort of tandem axle, where the two wheels pivot around a central point and the shock absorbers at each end replace the leaf springs, like in this example (that's how the real life arocs rear suspension is done): Share this post Link to post Share on other sites
DrJB Posted February 5, 2015 (edited) You typed CV instead of U-Joints (or Cardan Joint) to save time? Psst, this was typed from an iPad (not the best keyboard) and was done in bed, late night, and meant as a shortcut. If you and others do not believe that and want to nit-pick, so be it. If you insist on crucifying me for a mistake, how many mistakes have you NOT made in your life. Grow Up, move on! Well, when trying to make a point it helps to use the correct terminology. You referred to 'CV joints' (plural), where CV stands for Constant Velocity, and obviously these are not Constant Velocity joints, but universal joints which are not constant velocity (by themselves). Besides that, your point isn't valid, as Lipko pointed out. The engineers at Mercedes are not idiots! While I fully agree about using proper terminology, I never said/hinted/implied Mercedes engineers were idiots. However, I spent a good part of my life dealing with all sorts of noise and vibration issues, and installing Cardans such as shown in that picture is a no-no Correct! Maybe there is ANOTHER reason Mercedes installed it that way. If that's the case, go ahead and 'enlighten' me. Throwing a blank statement such as: They're Mercedes, they know what they're doing is a self-defeating argument and does not open one up to critical innovation. The picture in nicjasno's post (above, #457) is really how a double cardan needs to be installed. Shall we stop this bickering now and try to understand WHY Mercedes did something different? Edited February 5, 2015 by DrJB Share this post Link to post Share on other sites
sama Posted February 5, 2015 The unimog and 9398 have the same suspension type. The Arocs has trailing arm live axle in the front and in the rear maybe a sort of tandem axle, where the two wheels pivot around a central point and the shock absorbers at each end replace the leaf springs, like in this example (that's how the real life arocs rear suspension is done): Oh, I see. So both axles are essentially just floating there, other than two bars on each axle connecting to the frame, and ofcourse the springs/leaf springs? It also looks like that means it isn't independent suspension then. But nonetheless, it is very technical, and a nice challenge for Lego to put this much complexity in a smaller scale set. Share this post Link to post Share on other sites
DrJB Posted February 5, 2015 Interesting that the design and use of the cardan joint never changed much for 400 years - now Rzeppas are everywhere for driveshafts but still cardan joints are in use - hurray for italian engineering! From a technical/innovation point of view, you're absolutely right. But the reason many automakers pick one design over another is often (if not always) driven by cost. So, YES the CV is better than Cardan for uniform speed, but other performances, such as cost and max torque, I'm not so sure. Real Engineering (and they only touch upon that in school) is about balancing multiple performances that often are conflicting in nature. There is a multitude of examples out there, of course. Share this post Link to post Share on other sites
DrJB Posted February 5, 2015 (edited) I know we're straying way off topic, but this is a beautiful piece of engineering. Have you noticed the complexity and 'rich' (many) features? I see 3 differentials, brakes, leaf springs (Efferman's parts could be used here), wheel hubs with final/planetary reduction, and many more. Anyone brave enough to replicate this in Lego? Edited February 5, 2015 by DrJB Share this post Link to post Share on other sites
H3NRIK Posted February 5, 2015 Yea its quite heavy (I've got about $600 - $800 worth for the set and parts I've put on the Twins), it's pretty good because its free shipping, bought my first one at a Lego Store in NJ second one was on eBay, and its in pristine condition, I try to keep my twin Unimogs for myself until I get settled down and introduce them to my future kids (girl or boy), these are the gems of my collection, don't get me wrong I like the Arocs but I was expecting another Unimog set (UHN-series U5023, the last one was a UGN-series U400), I may just get one but I'm still open to getting another one if the Arocs turns out well worthy of a successor for the 8110. Some of my pics are on my IG account www.instagram.com/mrpauloabesamis I say get a boy AND a girl, give them a 8110 each ! (I have a boy&girl) :) will check out your IG later ;) I know we're straying way off topic, but this is a beautiful piece of engineering. Have you noticed the complexity and 'rich' (many) features? I see 3 differentials, brakes, leaf springs (Efferman's parts could be used here), wheel hubs with final/planetary reduction, and many more. Anyone brave enough to replicate this in Lego? Certainly not me :) Soo looking forward to see how they replicated this setup! Am I the only one itching to put a XL motor on it, putting torque through that driveline?? :) indeed this set seems to be working out to be the finest ever... I remember back in '94 when 8880 was all groundbreaking... could this be the same quantumleap in lego?? :) Share this post Link to post Share on other sites
Lipko Posted February 5, 2015 (edited) While I fully agree about using proper terminology, I never said/hinted/implied Mercedes engineers were idiots. However, I spent a good part of my life dealing with all sorts of noise and vibration issues, and installing Cardans such as shown in that picture is a no-no. Maybe there is ANOTHER reason Mercedes installed it that way. If that's the case, go ahead and 'enlighten' me. Throwing a blank statement such as: They're Mercedes, they know what they're doing is a self-defeating argument and does not open one up to critical innovation. The picture in nicjasno's post (above, #457) is really how a double cardan needs to be installed. Shall we stop this bickering now and try to understand WHY Mercedes did something different? Do you read the posts? If you install the cardans the other way then you not only have an oscillating middle shaft, but an oscillating like crazy end shaft (you basically want to double the oscillation?). Stating that you are an engineer won't make you right. I'm an engineer too, so what? I tried to make an explanation, we linked the wikipedia page, all the installations you can find are the same as the Mercedes'. If you look again closely, Post #457 shows exactly the same setup. EDIT: for some whatever reason, the picture I posted is broken. So again: Image source: http://www.jeepforum.com/forum/f12/drive-shaft-geometry-593045/ Edited February 5, 2015 by Lipko Share this post Link to post Share on other sites
DrJB Posted February 5, 2015 (edited) Do you read the posts? It is not about NOT reading the posts, it's about the pictures. Now I realize what has happened. It was late at night and I was looking at a different page (which was wrong) and somehow did not look closely at the Mercedes double axle. I realize where my (honest) mistake is now. Yes, the Mercedes installation IS correct. Besides the 'heated' debate, hopefully no harm done. Time to go back and correct the posts - Done! Edited February 5, 2015 by DrJB Share this post Link to post Share on other sites
MrPaulo23 Posted February 5, 2015 I say get a boy AND a girl, give them a 8110 each ! (I have a boy&girl) :) will check out your IG later ;) Certainly not me :) Soo looking forward to see how they replicated this setup! Am I the only one itching to put a XL motor on it, putting torque through that driveline?? :) indeed this set seems to be working out to be the finest ever... I remember back in '94 when 8880 was all groundbreaking... could this be the same quantumleap in lego?? :) That strayed a little I'm just too attached to my unimog twins, but after inspecting set 42043 through the only existing video and close-up stills, this set proves to be very promising, with a working suspension system on all axles, I'll have to get existing specs from Mercedes-Benz to advance the details on this set, still it's going to be a big let down if our speculations of a Straight-6 turns down if LBG made it a Straight-4, but hey the 8258 which is its closest predecessor had a V8 on it, save for this set which has 2 working differentials at the back and dually setup last seen in 8285 so I'm still hoping its a Straight-6. If it has enough space to where they installed the L-Motor, I might ditch it and place an XL-Motor :D Share this post Link to post Share on other sites
Milan Posted February 5, 2015 You typed CV instead of U-Joints (or Cardan Joint) to save time? If you insist on crucifying me for a mistake, how many mistakes have you NOT made in your life. Grow Up, move on! I don't want to crucify you, neither I understand why you are so offensive. I did not know if you are joking with equalizing CV and Ujoints, so I was just ask the question. And please don't tell me what to do with my life, this topic is for Mercedes stuffs.. Share this post Link to post Share on other sites
jantjeuh Posted February 5, 2015 I've noticed this before, that DrJB tends to take arguments too personally, too quickly. Try to relax a bit more man Sorry for moderating. Share this post Link to post Share on other sites
aol000xw Posted February 5, 2015 So that's all? I was about to get my pitchfork and join the mob Care someone to explain what are the negative effects besides vibrations of incorrectly setting he UJoints if any? I guess it is not relevant at Lego scale, but to be honest never cared of UJoints alignment so at least this argument was useful to me. Share this post Link to post Share on other sites
Lipko Posted February 5, 2015 (edited) So that's all? I was about to get my pitchfork and join the mob Care someone to explain what are the negative effects besides vibrations of incorrectly setting he UJoints if any? I guess it is not relevant at Lego scale, but to be honest never cared of UJoints alignment so at least this argument was useful to me. Jerky movement is a negative effect and it's noticeable in Lego. Especially when angles are big (say, 20 degrees). One example is steering, but maybe in case of driving too. It's just my experience and I may remember wrong, but the jerkiness is similar to a stressed knob-wheel - knob-wheel drive. I even noticed the jerkiness in my current MOC where I only drive a V8 fake engine with the double cardan shaft. Edited February 5, 2015 by Lipko Share this post Link to post Share on other sites
Milan Posted February 5, 2015 And just to note, negative effects only happens when angle of the Ujoints is different than zero, otherwise it does not matter how you will position them. Share this post Link to post Share on other sites
barman Posted February 5, 2015 Hello everyone, It been a while since I've posted something on EB. To crawler crane and Mercedes Acros are wonderful sets. For me blue is a interesting color so I got very excited when I saw the crawler crane. The 42043 is a beast. The biggest Technic set every (in parts) and very interesting new parts. Like Efferman I design me own parts, so it was a nice think to try and work out the new parts bases on what I could see in the video's and fill in the gapes with me parts designer experience. This is what I got so far. New Technic parts 2015H2 by Barman76, on Flickr The turntable is coming soon. In 2D it is pretty much done. Hopefully in the weekend I can make the 3D model. It has 60 teeth. Just throwing this out there. I haven't read the entire tread yet. The bucket is proving a bit difficult, but with the last video I have a good idea about the inside and the connection points. New Technic parts 2015H2 sliding beam by Barman76, on Flickr Here is the new sliding beam and gear-rack. The gear-rack is 14studs long which is a bit unusual for Studless Technic. It has many connections and a big groove just under the teeth, which I think is for connecting with the sliding beam. The sliding beam is 15 studs long and 2 wide. Not everything was good to see in the pictures (stills) I made from the available video's. Based of my experience I think there is a hole next to the 3 pin holes. It this was solid I would have used more material and that is what TLC doesn't want. So this could be a solution? The gear rack can extend 8 studs. Because the function in the 42043 is done with pneumatic it only goes 7.5 studs, see picture Pneumatics V2. In order to hold the gear rack there needs to be a pin or something to grip in the groove of the gear rack, see the detail picture (profile). This could very well be just a small bulb like in the city crane boom part http://www.bricklink.com/catalogItem.asp?P=57779 New Technic parts 2015H2 Pneumatic V2 by Barman76, on Flickr Here are the pneumatic parts. In this picture I like to show you how I calculatied the extentions. Both cylinders are 11 studs long. the narrow one extends 7.5 studs and the wide one 6. The circles in the picture show that there is a small difference in the length, but extentions are always in full or halve studs. This is my point of view on the new parts. Let me know what you think. Share this post Link to post Share on other sites
jantjeuh Posted February 5, 2015 (edited) Nevermind Edited February 5, 2015 by jantjeuh Share this post Link to post Share on other sites
Dafgek81 Posted February 5, 2015 Can't wait to get these long pneumatics, still collecting parts for my old school Actros 4150K side tipping dumptruck with crane. Want to use the skinny one for extending the 3rd cranesection and the thick ones for moverent on the 2nd and 3rd cranesection Share this post Link to post Share on other sites
Blakbird Posted February 5, 2015 Trucks don't have independent rear suspension. That would be grossly too expensive and too complicated and serve no real puprose. Tatra's do! Share this post Link to post Share on other sites
Sheepo Posted February 5, 2015 Anyone brave enough to replicate this in Lego? Me ;) Two years ago a Mercedes Trucks Dealership asked me about built a Arocs for them in big scale. When I had the chassis finished they decide don't buy me the truck, so I stopped the development, but I kept the chassis assembled. This is what I built (the chassis has tons of dust... but after two years on a shelf is normal ;) ) Rear axles. They have the same design as the axles posted by nicjasno. The axles have 3-link suspension. Common leaf springs, drum brakes and 3 differentials. One differential for each axle and a third one to control the axles together, the last one is placed inside the first rear axle(third axle of the truck), again like the nicjasno's picture. Front axles. They are like the real Arocs again, solid axles with leaf springs, disc brakes(yes, the real Arcos can has disc brakes), complete ackerman steering with linkage mechanism and 3 differentials working like the rear axles 6L engine. Now the truck has some parts missing, but after 2 years I have needed some of them to other proyects. The complete assembly, including the central differential with lock. I am publishing this because probably I will never finish this truck, and now with so many people talking about the MB Arocs I think it is a good moment to show it. ;) Share this post Link to post Share on other sites
