doug72 Posted November 19, 2017 Posted November 19, 2017 (edited) Perpetual motion GBC ??? Found this on YouTube see video between 1m 26s and 2m10s Does this really work or is there a hidden input behind the white background ? Going to see if I can build a technic version but use glass marbles instead of GBC balls which probably too light to turn the big toothed wheel. Edited December 24, 2017 by Doug72 Quote
ColletArrow Posted November 19, 2017 Posted November 19, 2017 There must be another input, probably hidden in the base, because: a) perpetual motion isn't possible; the energy gained from the ball falling is less than that required to lift it back up, as the height difference is not equal (consider the height required for the balls to roll down the 2 ramps). It's being raised further than it's dropping, so there must be another energy input (I think, based on my understanding of physics). b) the wheel's motion implies it has another power source; it's too smooth and starts/stops to perfectly to be triggered only by the ball. I don't think a wheel powered by the weight of the ball would move that steadily. However something similar would be interesting to build as a GBC, I want to see what you can come up with. Quote
doug72 Posted November 19, 2017 Author Posted November 19, 2017 Just now, ColletArrow said: There must be another input, probably hidden in the base, because: a) perpetual motion isn't possible; the energy gained from the ball falling is less than that required to lift it back up, as the height difference is not equal (consider the height required for the balls to roll down the 2 ramps). It's being raised further than it's dropping, so there must be another energy input (I think, based on my understanding of physics). b) the wheel's motion implies it has another power source; it's too smooth and starts/stops to perfectly to be triggered only by the ball. I don't think a wheel powered by the weight of the ball would move that steadily. However something similar would be interesting to build as a GBC, I want to see what you can come up with. Agree your comments completely. Will have a go at building something to replicate it, using the BWE curved gear racks and white visors for ball buckets Then devise a means of intemittently rotating the wheel in eight steps and connect the ball lift by gears and axles. With a white background to hide the drive system. Makes for a good challenging build which wont take up too much space. Quote
DugaldIC Posted November 19, 2017 Posted November 19, 2017 @Doug72 Question though if it's a "perpetual" motion, how do you plan on integrating it into a line? It's cool on its own but it you try to join it up to other GBCs it'd be cool if you had a secondary step that would pass it on so to speak. It seems like a good contraption to sort of put on hold and go in a loop if things get backed up, do you know what I mean? Cool idea though for sure. Too bad it can't be a motor less build though! Quote
doug72 Posted November 19, 2017 Author Posted November 19, 2017 (edited) 1 hour ago, DugaldIC said: @Doug72 Question though if it's a "perpetual" motion, how do you plan on integrating it into a line? It's cool on its own but it you try to join it up to other GBCs it'd be cool if you had a secondary step that would pass it on so to speak. It seems like a good contraption to sort of put on hold and go in a loop if things get backed up, do you know what I mean? Cool idea though for sure. Too bad it can't be a motor less build though! Bucket wheel now built. I am building it as a stand alone module at the moment, but it could be put into a line if desired. The drive to bucket wheel will rotate it in 8 steps (number of buckets) using an interupter gear (currently WIP), the wheel in turn with rotate the two arm ball lift in sync. before discharging on to next module or return balls back to the bucket wheel. Edited November 19, 2017 by Doug72 Quote
Myers Lego Technic Posted November 19, 2017 Posted November 19, 2017 I have already theorized semi-perpetual motion, but true perpetual motion is only possible with an object nmoving in space. Quote
Technonsense Posted November 19, 2017 Posted November 19, 2017 Watch that guy's hand on the left side. It looks like he's pulling something... Quote
doug72 Posted November 19, 2017 Author Posted November 19, 2017 (edited) Interupter gear now built and I have devised an 8 step Geneva Mechanism using a knob gear !! Edited November 20, 2017 by Doug72 Quote
Lasse D Posted November 20, 2017 Posted November 20, 2017 At 2:06 you can see the motion of the big gear. It seems to be driven by a hidden motor with its speed being almost at full speed immediately (and similarly when it stops) Quote
doug72 Posted November 20, 2017 Author Posted November 20, 2017 (edited) Wheel with 8 buckets now built plus drive system to rotate the wheel in 8 steps. Rotation is indexed using a 4 lobe knob gear. An L motor drives the rotating arm to advance the wheel to release each ball from a bucket and let it pause until next step. I have used white visors as buckets for one ball at a time but could use BWE buckets to increase number of balls carried. Edited November 20, 2017 by Doug72 Changed image for video Quote
Blakbird Posted November 20, 2017 Posted November 20, 2017 On 11/19/2017 at 9:33 AM, Technonsense said: Watch that guy's hand on the left side. It looks like he's pulling something... He's just using the Force. Quote
Myers Lego Technic Posted November 20, 2017 Posted November 20, 2017 1 hour ago, Blakbird said: He's just using the Force. Lol. Quote
BusterHaus Posted November 21, 2017 Posted November 21, 2017 On 19/11/2017 at 11:49 AM, Myers Lego Technic said: I have already theorized semi-perpetual motion, but true perpetual motion is only possible with an object nmoving in space. No, it is not. Perpetual motion is fantasy, and the laws of thermodynamics apply on Earth and in space. Quote
Andy D Posted November 21, 2017 Posted November 21, 2017 (edited) 16 hours ago, Doug72 said: Wheel with 8 buckets now built plus drive system to rotate the wheel in 8 steps. Rotation is indexed using a 4 lobe knob gear. An L motor drives the rotating arm to advance the wheel to release each ball from a bucket and let it pause until next step. I have used white visors as buckets for one ball at a time but could use BWE buckets to increase number of balls carried. It looks like you have a great start replicating the original. Looking forward to what you come up with. I believe you have built something ad a power source similar to what the original must have. Anyway it will be a great GBC! Andy D Edited November 21, 2017 by Andy D Quote
doug72 Posted November 21, 2017 Author Posted November 21, 2017 (edited) 8 hours ago, BusterHaus said: No, it is not. Perpetual motion is fantasy, and the laws of thermodynamics apply on Earth and in space. Correct, I have a book with a whole chapter on perpetual motion with 50+ examples - NONE of which would work. 5 hours ago, Andy D said: It looks like you have a great start replicating the original. Looking forward to what you come up with. I believe you have built something ad a power source similar to what the original must have. Anyway it will be a great GBC! Fairly happy with stepper unit, now working on a gear system to rotate the two arm ball lift to move time with wheel. The stepper unit acts like a Geneva Mechanism, the output from the 4 lobe knob gear is geared down 2:1 to give 8 steps of the bucket wheel. Once proven it works will "hide" the mechanism behind a white background board. Edited November 21, 2017 by Doug72 Quote
Myers Lego Technic Posted November 21, 2017 Posted November 21, 2017 17 hours ago, BusterHaus said: No, it is not. Perpetual motion is fantasy, and the laws of thermodynamics apply on Earth and in space. I suppose you are right if we truly want to abide by the guidelines, as an object moving in space requires some input to begin movement (and there is of course some matter in space) . It is simply the closest we come. Quote
doug72 Posted November 22, 2017 Author Posted November 22, 2017 (edited) Progress & problems ! Re-configured the stepper unit to also drive the two arm ball lift which required a 1:2 step up gear to synchronise the arm with bucket wheel. Steeper unit rotates and holds bucket wheel in 8 steps but occasionally overshoots which in turn effects the two arm ball lift position. The only thing holding the bucket wheel stationary is the weighted arm acting on the knob gear. Getting the two arm ball lift to consistently stop in correct position is also proving difficult due to backlash in gearing. Intend to try to make the steeper unit stop the bucket wheel by means stop pins on the rim of the bucket wheel with a knob gear preventing rotation until steeper unit turns knob gear 1/4t turn to allow stop pin on rim to pass. This means that drive to the wheel will have to slip while the wheel is stationary, using white 24t clutch gears or a linear clutch or would a differential work ? Possibly need another stepper unit for the two arm ball lift. Suggestions & ideas welcome. Edited November 22, 2017 by Doug72 Quote
doug72 Posted November 24, 2017 Author Posted November 24, 2017 (edited) Finally got a reliable a stepper unit that stops the wheel precisely, without over shoot in 8 steps per revolution using a compact gear box to drive wheel & trip unit plus an output for the two arm ball lift, (yet to be buil). Achieved using a 24/16 differential driven by an L motor and worm gear on the differential 24T gear. Took quite some time to figure out the trip mechanism to stop the wheel and then release it but got there in the end. Better photos later plus a video. Edited November 24, 2017 by Doug72 Quote
aeh5040 Posted November 24, 2017 Posted November 24, 2017 (edited) Definitely looking forward to seeing video of that latest "stepper" - it looks very intriguing! Keep up the good work... Edited November 24, 2017 by aeh5040 Quote
doug72 Posted November 25, 2017 Author Posted November 25, 2017 (edited) 14 hours ago, aeh5040 said: Definitely looking forward to seeing video of that latest "stepper" - it looks very intriguing! Keep up the good work... Steeper Unit Ver 2: Fine tuned the unit and added Yellow & red beams to highlight how it works. The red beam has two 12T gears on friction free pins and the 20T gear is on a friction pin. The 20T gear engages with the 24T gear on the output from the differential that drives the rotating arm that actuates the trip lever system via the yellow link beams. The retardation ensure that when bucket wheel (BW) is released it rotates as more drive goes the BW which has less resistance than the drive for the trip system. A counterweight ensure the trip system returns to stop position to hold the bucket wheel at the next step. Edited November 25, 2017 by Doug72 Quote
RohanBeckett Posted November 26, 2017 Posted November 26, 2017 interesting... curious as why it skips twice sometimes? Quote
doug72 Posted November 26, 2017 Author Posted November 26, 2017 (edited) 6 hours ago, RohanBeckett said: interesting... curious as why it skips twice sometimes? So am I, still trying to figure how to stop it happening. Think the bucket wheel has too much force and pushes the trip lever enough to allow it to skip if counterweight hasn't return lever to the hold position. Every time I add next stage the dynamics of the system changes !!! Might need a radical re-think with possibly two motors one to drive the bucket wheel the other to drive the trip system. Edited November 26, 2017 by Doug72 Quote
RohanBeckett Posted November 26, 2017 Posted November 26, 2017 I need to get some of those scoops! :) they seem to be perfectly suited to GBC! Quote
doug72 Posted November 26, 2017 Author Posted November 26, 2017 (edited) 29 minutes ago, RohanBeckett said: I need to get some of those scoops! :) they seem to be perfectly suited to GBC! https://www.brickowl.com/catalog/lego-visor-2007-57702 also comes in transluscent blue Edited November 26, 2017 by Doug72 Quote
doug72 Posted November 27, 2017 Author Posted November 27, 2017 (edited) Stepper Unit Mk 3 Having had many failed attempts to get a stepper unit to function consistently using only one motor and a differential I have concluded it not workable. So have now devised a two motor system to precisely step the bucket wheel (BW) which has an added bonus that the speed and step timings are adjustable for BW rotation & the dwell time for each step. No longer skips steps. The “L” motor still drives the BW via a differential but the other differential output goes to a gear train which has two 24T gears on friction pins, this allows L motor to run while BW is stationary. When BW is released the friction gears stop turning until the next step. The “M” motor drives via a 24:1 reduction a knob gear which holds & release the BW. No longer need cranks and lift arms to actuate the trip as knob gear slowly rotate 1/4 turn it release the BW and catch the next stop pin on BW rim. Now to start building the other part of this module. M motor and reduction gearing now placed within the main support frame legs Edited November 27, 2017 by Doug72 Quote
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