Ivan_M Posted May 14, 2017 Posted May 14, 2017 Hi everyone, I would like to present my latest excavator (I guess I'm obssed with them). This time it is rope shovel excavator loosely based on Menck type Mc (1,6m3 volume of bucket). Such excavators were common till the hydraulic excavators started to rule in 60-70'. The larger types were mostly used in mines (and they are today used as well), but smaller types were used in all sort of works in constructions. My model is equipped with one L motor and gearbox with 6 motorized functions: 1 - boon elevation with rope 2 - arm elevation with rope 3 - arm extension with shaft drive 4 - rotation 5 - left tracks 6 - right tracks Emptying the shovel is done manually. I wanted to build the machanical aspect of the machine as closely to real machine as possible, however the arm extension was not possible to recreate. On most excavators the extension worked with third rope drum and the rope for extension and elevation was shared. This system worked in lego only for substraction and not extension as this was usually done by the weight of the shovel. Some excavators (mainly steam and electric) used another motor directly on arm for forced extension/substraction. However I wanted to stick with one motor only as it was my intention to see how complex gearbox is possible to make. As you can see from the video the L motor has no problem to drive 2-3 functions at once. The movement of tracks is very poor, but that is given by usage of small wheels that are not really suitable to serve as the only wheels driving the tracks. The smaller tracks would be better, but I don't have them. This time I really didn't bother much with aestethics so it is just bunch of panells, my main focus was on function. IMGP4995 by Ivan Moc, on Flickr IMGP4993 by Ivan Moc, on Flickr IMGP4992 by Ivan Moc, on Flickr IMGP4991 by Ivan Moc, on Flickr Quote
Leonardo da Bricki Posted May 14, 2017 Posted May 14, 2017 Dang! Please take the panels off and give us some pics! I would kill to see the distribution gearbox you have made! Great model! Quote
BrickbyBrickTechnic Posted May 14, 2017 Posted May 14, 2017 I 21 minutes ago, Leonardo da Bricki said: Dang! Please take the panels off and give us some pics! I would kill to see the distribution gearbox you have made! Great model! I second that. Quote
Ivan_M Posted May 15, 2017 Author Posted May 15, 2017 Thank you everyone for kind words. I have taken pictures to show you internal gearing 20170515_181940 by Ivan Moc, on Flickr This is the most simple reversal distribution gears, the motor is mounted in front of the gearbox traversally with 12t and 20t bewel gears reduction. Since almost all functions of the excavator requires worm gear I wanted to keep gearbox spinning at higher rpm. It has only one flaw, there is no clutch gear to protect the motor. 20170515_182010 by Ivan Moc, on Flickr In picture above you can see 1st shaft from gearbox running worm gear with matching 24t gear, 16t with 20t gear and 20t bewel gear mated with turntable. The second gearbox output is also visible there, it is also spinning worm gear and 24t connected to winch that elevates boon. 20170515_182029 by Ivan Moc, on Flickr Looking at the other side you can see pair of 16t gears followed with worm gear and 24t gear. There is another 24t gear on same shaft that mates with 20t bewel gear on pivot point of the boon. 20t bewel gear mates with 12t bewel and the shaft runs to the middle of the boon where pair of 20t bewel gears are. This drives the arm extension. Only this function is problematic due to three reasons - gearing up, high load on pivot axle and slight bend of the boon. It creates quite a lot of friction. The second output from gearbox is going to worm gear and 8t gear for arm elevation, I have choosen 8t as I wanted some speed and it is powerfull enough. 20170515_182436 by Ivan Moc, on Flickr Two middle outputs from the gearbox are for drive. There is an old differential for turntable passthrough, so the setup from gearbox is: pair of bewel gears for 90° turn and then 12t bewel mating with 24t gear or 24t side of differential. 20170515_182156 by Ivan Moc, on Flickr Undercarrige is self explanatiory, there are three pair of 12/20t gears. It is quite tight fit everywhere. I hope you like it! Quote
Ivan_M Posted May 21, 2017 Author Posted May 21, 2017 I have finished .io file and put it on Rebrickable, you can check it here: https://rebrickable.com/mocs/MOC-8225/Ivan_M/rope-shovel-excavator/ rope excavator by Ivan Moc, on Flickr Quote
suffocation Posted May 22, 2017 Posted May 22, 2017 Love how nice and compact it is - great job! Quote
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