MP LEGO Technic creations Posted July 23 Posted July 23 (edited) Hi everyone! I am back with yet another WIP topic. In search for a rather special classic vehicle about a month ago, I have found this one. What can be more splendid than a one-off coachbuilt Rolls-Royce in a spirit of art deco is? Equipped with its eye-catching circular doors, it is sometimes referred to as the Rolls-Royce Round Door Coupe. More info about this vehicle can be found on the website of Petersen Automotive Museum. As I intend it to be somewhat monumental, the largest wheels and tyres in production are the clear choice for me. I also planned to use a 3D model for reference, yet I have faced some issues when exporting the model as a new part to Stud.io. Therefore, I went with another option - let Studio generate a sculpture (or whatever it is called) form basic parts and use it instead. The whole frame is being designed in modules (differentiated by colour) and bodywork can be easily separated. The current version: approximately 102 cm long weighs about 8,5 kg about 7.000 parts (note that the car is now mostly hollow) I do not have any firm list of wanted features, howewer, I do not want the model be enormous just for the sake of being huge, so some functions can be expected. Steering - now via a medium linear actuator Suspension - the original has leaf springs, I have opted for an imitation with classic shock absorbers Openable doors, hood and trunk Openable individual sunroofs Removable bodywork in one piece - this vehicle will in fact be a 2-in-1 model, as I would like to be able to show the chassis separately - the 'rolling chassis' is everything you would have got from Rolls-Royce in this time period anyway Manual gearbox On the other hand, my main concerns are: Model being too heavy for wheel hubs to handle - this proved to be very true after about first meter of rolling the car along, 3 wheels just came off Bodywork looking too flat and blocky The whole model being large for the sake of being large Too bad that the light bulb does not come in tan And yes, I am aware that the Spirit of Ecstasy should not be an angel, yet the broom is so perfect for this purpose In order to compensate for such a heavy car, I constructed both axles to have a small positive camber angle (though it didn't help that much). And a comparison with my recent (still WIP) Bentley Turbo R LWB. I am pretty sure I would like to write a few more lines, even though I cannot remember, what it should be about Anyway, thanks for reading & suggestions and critique is welcome. Edited July 23 by MP LEGO Technic creations Deleted redundant lines between images Quote
Zerobricks Posted July 23 Posted July 23 Oh wow, what a massive and unique model! Regrding wheels coming off hubs, you can use part 6270135 or 24482 inside the hub pins to reinforce them. Or you could use large turntables! Also, frontpaged! Quote
Thirdwigg Posted July 23 Posted July 23 The size of these MOCs is just incredible. All of my Technic pins are quivering in fear hoping they will not be used in a model so large. Quote
Jundis Posted July 23 Posted July 23 Normally I really don't care about cars, but this is such a giant beast! Even technic are double-stacked and reinforced where I see, just whoa. Will the steering be geared up somehow or did you already try it under weight and decided against? :D Quote
Alex Ilea Posted July 23 Posted July 23 Oh my, what an insane build! You did a good job replicating the body lines, I would say near perfectly. And making a realistic chassis is very doable in this scale and allows for nice details. Honestly, I would 3D a spirit of Ecstasy, just to top of this build, it deserves it. Keep us posted! Quote
MP LEGO Technic creations Posted July 23 Author Posted July 23 (edited) 2 hours ago, Zerobricks said: Oh wow, what a massive and unique model! Regrding wheels coming off hubs, you can use part 6270135 or 24482 inside the hub pins to reinforce them. Or you could use large turntables! Thanks! Initially, I've thought about unicorn horns but the parts you have suggested seem to have a thinner top with smoother surface, therefore suit the purpose better. The question is, will these fit under hubcaps or are they going to stick out more than acceptable? A few screws could also be utilised, otherwise I indeed se no other purist way than using a turntable. 56 minutes ago, Thirdwigg said: All of my Technic pins are quivering in fear hoping they will not be used in a model so large. So far, I feel I have been careful enough with the amount of stress on each part (apart from the wheel hubs, apparently), though Studio shows many pins painted red when checking for stability. However, it even happens in so strange places, that I find hard to believe is accurate. 32 minutes ago, Jundis said: Normally I really don't care about cars, but this is such a giant beast! Even technic are double-stacked and reinforced where I see, just whoa. Will the steering be geared up somehow or did you already try it under weight and decided against? :D Thank you! The only less stable area of the initial digital design turned out to be the A-pillars, which, due to their angle, are not capable of supporting additional weight when put on the roof. I believe I have solved that by adding another support to form a triangle. The first version of the steering was using a planetary wheel hub and a gear rack. Due to the car's weight was the steering influenced rather by any roughness of the floor than by the steering wheel. Therefore, it was clear that I needed another solution. In this situation, a worm gear does not seem to be robust enough, so I opted for a linear actuator. You are absolutely right with the gearing. Previous 20-12 gearing was removed as the steering felt somewhat heavy. Now it takes like 10 rotations to each side to turn the vehicle, yet it is smooth and light enough even when the car is stationary. But let's be honest, a meter long car in itself cannot be considered a very playable and practical toy Edited July 23 by MP LEGO Technic creations Quote
1gor Posted July 23 Posted July 23 1925 model, so this year is his 100th birthday. Unique model, but how to replicate it with Lego (perhaps with english wheel )? Quote
Aurorasaurus Posted July 24 Posted July 24 19 hours ago, MP LEGO Technic creations said: A few screws could also be utilised, otherwise I indeed se no other purist way than using a turntable I have an in-between solution which you may prefer: the tape trick. Place a small square of tape over the 3 pinholes on the wheel you will use, then just push the wheel on like normal. It will take more force but will stay on very well, I used this on rc models jumping and drifting and it never failed me. Cheap semi transparent whiteish tape commonly used for paper and stuff is a little bit stretchy, so I find it works best to use this kind. Plain old clear stuff works okay but not so good. Quote
1gor Posted July 24 Posted July 24 Perhaps this axle (there is also 4 studs long) with Lego nuts could help... https://www.bricklink.com/v2/catalog/catalogitem.page?P=3737b#T=C&C=11 Quote
LEGO Train 12 Volts Posted July 24 Posted July 24 Wow, I don't know what's more impressive: the chassis or the bodywork! Fantastic! Quote
astyanax Posted July 25 Posted July 25 Very impressive and fascinating project! I'll be eagerly following your write-ups. Quote
Michael217 Posted August 1 Posted August 1 Hi! There is a problem with proportions! We need to solve it before it's too late. The door is very small, it is very noticeable + wings need to be made longer or their height reduced, then perhaps the door will look better. Quote
MP LEGO Technic creations Posted August 1 Author Posted August 1 (edited) 53 minutes ago, Michael217 said: Hi! There is a problem with proportions! We need to solve it before it's too late. The door is very small, it is very noticeable + wings need to be made longer or their height reduced, then perhaps the door will look better. Admittedly, I have not checked the size of the doors, as this is their very first version. I indeed agree with you, an increase in size is necessary. Initially, I thought the large curved gear racks would be sufficient, yet that proved to be false. Longitudal size can be increased fairly easily by inserting a few studs to create an oval shape, while the real car seems to have rather elliptic doors. By doing so on each side, I am afraid the door would take a square-ish shape instead, therefore a completely different approach might be needed in case of a complete reshape. On the other hand, I have checked the shape of both front and rear wheel wings (I hope either of us meant those aerodynamic wheel cowlings/mudguards) according to a 3D model I have found online in the very beginning. The visual impression could be caused by some of these factors (or all of them): • Wrong interpretation of the model's curves when creating the 'reference brick sculpture' I have compared it to afterwards. • Insufficient curvature of the wings' edges that makes them look taller. • Too much of ride height or mudguard clearance that gives the model such a tall stance. Of course, I might be completely wrong Edited August 1 by MP LEGO Technic creations Quote
Lipko Posted August 6 Posted August 6 Ambitious project! Though the wheels look a tad too small. Quote
MP LEGO Technic creations Posted August 13 Author Posted August 13 (edited) Since the initial post, I have made the door slightly larger, as suggested by @Michael217. According to my measurements in Sariel's Model Scaler (based on car's aforementioned side profile photo), the door should be 185-190 mm tall and about 210 mm wide to form an ellipse. So far I have achieved a symmetrical round-ish shape by inserting 3L thin liftarms in between each of curved segments. Thus the diameter has been increased to 23 studs (184 mm), which means a difference of 2 studs. Additionally, the brick-built cover of this technic structure has been rebuilt in order to leave no visible curved gear racks behind, therefore, I believe, it is possible to talk about a total size increase of 3 studs. The surrounding black frame has also undergone a few changes in order to accomodate the larger door, the most significant of them being the B-pillar, which has been moved towards the rear by two studs. Unfortunately, I do not think there will be any way to make the door elliptic (rather impossible) or oval, as this would require some significant changes to the whole frame. My further intentions include moving the doors' hinge further forward, as well as replacing the current door with something less crude and colourful looking. Although my Bentley looks quite good next to this RR, here is a size comparison with the only assembled 1:8 vehicle from my collection Edited August 13 by MP LEGO Technic creations Quote
Aleh Posted August 15 Posted August 15 The meaning of "giant MOC" brought new value Oberving this thread Quote
MP LEGO Technic creations Posted Monday at 02:25 PM Author Posted Monday at 02:25 PM (edited) Here is a photo of the current state of the chassis. Somewhat limited playability has been slightly improved by switching the steering gear ratio right before the medium LA from 12-12 to 20-12, since less steering force is required when the steering wheel is fixed in place. Otherwise, I have started with the drive shaft (I was very pleased with how barrel pieces can hide those large CV joints ). More importantly, after almost a month, I have finally figured out (at least partially) solutions to some of the issues. Since reinforcing the connection in between rims and wheel hubs themselves proved to be tricky, I have implemented another recent thought which crossed my mind. Specifically stabilising the wheels against their axle and (potentially) decrease the forces causing the wheels to fall off. Like one would limit the amount of play in any turntable, these wheels are large enough to fit a similar solution. I went with 'round girder', because a circle made of small curved gear racks (though these offer more favourable mounting points) of the same size would presumably tend to split into pieces and as the rim's beams slide directly on the surface of the support, any roughness will likely prevent rotation. The specific distance of the support is achieved by some bars, bushes and 1/2 pins. Additionally, this whole contraption required further reinforcements, therefore a 6L link has been placed under both steered wheels. The rear axle utilises the same solution, the lack of steering allows easier bracing. All in all, after some initial testing the stability seems to be about twice as good (and the wheels still eventually fall off). The yellow support rings will be replaced with DBG ones. And let's not forget that now this ridiculous contraption better resembles the brakes of the original while not introducing that much of friction. Furthermore, positive caster has been increased as well. Apart from that, the A-pillars have been significantly rebuilt and a bit of work has been also done on the doors (now with a working lock and a door handle on a completely wrong spot). Thanks for reading & have a great day. Edited Monday at 02:29 PM by MP LEGO Technic creations Quote
2GodBDGlory Posted Monday at 02:33 PM Posted Monday at 02:33 PM Super fun to watch the progress on this! Quote
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